Pulp & Paper Canada May/June 2009

May/June 2009

www.pulpandpapercanada.com

Unlocking the potential [ ] of biomass

Employee-owned model works for Harmac Tips for managing a shrinking industry Point of view: HSPP’s Mac Palmiere Journal of Record, pulp and paper technical association of canada LANG: Effect of the Dryer Fabric on Energy Consumption

p 01 Cover.indd 1

11/06/09 12:34 PM

The Chemistry of Paper and Water You can’t make paper without water and at Kemira, we know both. Built on our expertise in water and fiber chemistry management, we offer a complete product portfolio designed to provide value for our customers. Our solutions not only help enhance your paper processes, but also help you make better use of scarce resources like water, energy, and fibers.

Ready to create chemistry? Just add Kemira.

1380 Country Road #2, P.O. Box 615 Maitland, Ontario KOE 1PO www.kemira.com

p 02 Kemira ad.indd 2

11/06/09 12:35 PM

February 2009

www.pulpandpapercanada.com

MAY/JUNE 2009 Vol. 110, No. 5/6 A Business Information Group Publication ISSN 0316-4004

FEATURES

10 13 17 62

BIOMASS POTENTIAL

13

HARMAC

17

GREEN LIQUOR SPLITTER

51

Managing a Shrinking Industry Four industry experts say forest products must stop clinging to the past and develop products geared to the future.

Unlocking the Potential of Biomass What was once roadside waste can now be transformed into biofuels, syngas, electricity, or chemicals. Which will it be for Canadian forests?

Harmac: The Little Mill that Could The worker-owned mill has defies its critics and boosts productivity by empowering employees.

Tough decisions for tough times Howe Sound Pulp & Paper CEO Mac Palmiere talks about the culture change occurring at this West Coast pulp and newsprint mill.

TECHNICAL PAPERS

19 Partnerships for Successful Enterprise Transformation of Forest Industry Companies Implementing the Forest Biorefinery The recommended approach is to identify added-value biorefinery products for the longer-term and choose quality partners.

By V. Chambost (École Polytehnique), J. McNutt (Georgia Institute of Technology), and P.R. Stuart (École Polytehnique)

25 Integrating Bioethanol Production into an Integrated Kraft Pulp

and Paper Mill: Techno-Economic Assessment In this case study, several integrated forest biorefinery design alternatives have been evaluated for an integrated kraft pulp and paper mill.

By E. Hytönen (École Polytehnique) and P.R. Stuart (École Polytehnique)

33 Effect of the Dryer Fabric on Energy Consumption in the Drying

Section Higher heat transfer coefficients and improved mass transfer allow the dryer section to operate at lower steam pressure.

By I. Lang continued on page 4

MISSION STATEMENT:

To promote the pulp and paper industry in Canada by publishing news of the people and their innovations in research, technology, management and financing, as well as forecasts of future trends.

Authorized to publish papers of the Pulp and Paper Technical Association of Canada, which are identified by the symbol

IN EVERY ISSUE

4 6 9 57 58 60 60

Editorial Industry News On the Move Events Technology News Classified Ads Advertiser Index

Serving the industry since 1903.

pulpandpapercanada.com

p 03-4 table of contents.indd 3

Pulp & Paper Canada MAY/JUNE 2009

3

11/06/09 12:38 PM

editorial Variations on a theme

I must be brief this month. First, I extend my best wishes to Pulp & Paper Canada’s publisher Eileen MacDonell. Yes, MacDonell. Eileen Walters was married in May and has taken the name MacDonell.

Her email address is now eileen@pulpandpapercanada.com.

Speaking of names, the many variations of Macdonald always amuse me. Look for David McDonald in the forestry story, and John MacDonald in the bioenergy article.

Table of contents continued from page 3

38 A Perspective on Expanded Use of Secondary Species in

Mechanical Pulping Strategies for using aspen, birch, and larch, in mechanical pulping.

By K. Law (Université de Québec à Trois-Rivières) and R. Lanouette (Université de Québec à Trois-Rivières)

44 Towards Overcoming the Brightness Ceiling of Mechanical Pulps

Prepared from Blue-Stained Lodgepole Pine Chips Promising results from sodium borohydride , and a high bleaching end pH in peroxide bleaching.

By T. Q. Hu (FPInnovations – Paprican), T. Williams (FPInnovations – Paprican), S. Yazdi (FPInnovations – Paprican), P. Watson (Canfor Pulp Limited Partnership, R&D)

51 Demonstration of the Green Liquor Splitter (GLS) System at Millar Cindy Macdonald Editor news releases: media@pulpandpapercanada.com letters to the editor: cindy@pulpandpapercanada.com

Editorial Editor CINDY MACDONALD 416-510-6755 cindy@pulpandpapercanada.com Contributing Editors HEATHER LYNCH Advisory Board Richard Foucault Greg Hay Dr. Richard Kerekes Barbara van Lierop Dr. David McDonald Dennis McNinch Dr. Yonghao Ni Bryant Prosser Dr. Paul Stuart Ross Williams Administration Publisher EILEEN MACDONELL eileen@pulpandpapercanada.com President, Business Information Group BRUCE CREIGHTON Vice President, Publishing ALEX PAPANOU Editorial And Sales Offices: 12 Concorde Place, Suite 800 Toronto, ON M3C 4J2 Phone: 416-442-5600.

Toll Free: c da 800-268-7742; usa 800-387-0273

4

Production Art Directors RON TAYLOR rtaylor@bizinfogroup.ca VALERIE PERROTT vperrott@bizinfogroup.ca Circulation Manager CINDI HOLDER cholder@bizinfogroup.ca

Scandinavia and Finland: Jyri Virmalainen, Exomedia Oy, Latokartanontie 7A, 4 krs, 00700, Helsinki, Finland; Phone: +3589-61500100; Telex 121394 tltx sf (Att: Exomedia); Fax 358-9-61500106.

E-mail: jyri.virmalainen@exomedia.fi

Market Production Manager KIMBERLY COLLINS kcollins@bizinfogroup.ca Print Production Manager PHYLLIS WRIGHT pwright@bizinfogroup.ca Reprint requests: Marisa Sementilli 416-510-6829 News and Press Releases media@pulpandpapercanada.com Sales Representation North America: Eileen MacDonell, Publisher, Phone: 514-630-5955, Fax: 514-630-5980, eileen@pulpandpapercanada.com Inside Sales and Classified Ads: Jim Bussiere, Senior Account Manager, Phone: 514-630-5955, Fax: 514-630-5980, jim@pulpandpapercanada.com We acknowledge the financial support of the Government of Canada through the Publications Assistance Program towards our mailing costs.

April 2009 Pulp & Paper Canada

p 03-4 table of contents.indd 4

Western’s Meadow Lake Closed-Cycle BCTMP Mill The green liquor splitter system removes sodium hydrosulphide and allows the sodium carbonate/hydroxide to be used in the bleach plant.

By N. Jemaa (FPInnovations-Paprican), M. Paleologou (FPInnovationsPaprican), A. Thibault (FPInnovations-Paprican), J. Fleck (Millar Western Pulp Ltd.), K. Miller (Husky Energy), M. Sheedy (Eco Tec), and C. Brown (Chemionex)

Sustaining member, Pulp and Paper Technical Association of Canada; Member, Canadian Business Press and Audit Bureau of Circulation.

Indexed by: Canadian Business Periodicals Index; Abstract Bulletin, The Institute of Paper Science and Technology; Materials Science Citation Index PULP & PAPER CANADA (ISSN 03164004) is published by a division of Business Information Group Magazines, Limited Partnership, 12 Concorde Place, Suite 800, Toronto, ON, M3C 4J2.

Subscription rates: Canada – $90Cdn/1 year; $133Cdn/2 yrs.

U.S. – $95US/1 year.

All other countries – $200US/1 year. Single copies $19.50. Air Mail: $96 extra (Cdn $ in Canada; US $ other)/1 year; Single copies: $8 (by airmail) per issue extra (As above). (All subscription prices exclusive of taxes.)

The editors have made every reasonable effort to provide accurate and authoritative information but they assume no liability for the accuracy or completeness of the text or its fitness for any particular purpose.

All rights reserved. The contents of this publication may not be reproduced in part or in full without the consent of the copyright owner.

From time to time, we make our subscription list available to select companies and organizations whose product or service may interest you. If you do not wish your contact information to be made available, please contact us via one of the following methods.

Phone: 1-800-668-2374; fax: 416-442-2191; e-mail: privacyofficer@businessinformationgroup.ca; mail to: Privacy Officer, Business Information Group, 800-12 Concorde Place, Toronto, ON, M3C 4J2 Canada Postmaster: Please forward 29B and 67B to 6600 Trans Canada Highwary, Suite 209 Pointe Claire, QC H9R 4S2. Legal deposit Quebec National Library. Canada Post Publications Product Agreement No. 40069240. Publications Mail Registration No. 09777. USPS 751-630. US office of publication: 2424 Niagara Falls Blvd., Niagara Falls, NY 14304-5709. Periodicals Postage paid at Niagara Falls, NY. US postmaster: Send address changes to Pulp & Paper Canada, 2424 Niagara Falls Blvd., Niagara Falls, NY 14304. Printed in Canada. Return undeliverable Canadian addresses to Circulation Dept. – Pulp & Paper Canada, 800-12 Concorde Place, Toronto, ON, M3C 4J2.

Canada Post Canadian Publications Mail Agreement #40069240 PAP Reg. No. 09777 A Business Information Group Publication ISSN 0316-4004

pulpandpapercanada.com

11/06/09 12:38 PM

1 4 ZELLCHEMING th

ANNUAL GENERAL MEETING AND EXPO J U N E 2 3 T O J U N E 2 5, 2 0 0 9 , W I E S B A D E N , G E R M A N Y

Take your chance to create new business relationships, meet colleagues from industry and research, and be inspired by a state-of-the-art symposium which bridges the gap between research and industry in a newly structured and adjusted way: From June 23 to June 25 each and everyone of distinction in the international pulp and paper research and industry will meet in the Rhein-Main-Hallen Wiesbaden.

Starting March 2009 EXPO visitors may download program and registration form at www.zellcheming.com or send an e-mail to zellcheming@zellcheming.de EXPO exhibitors register at www.hanseatic-congress.de or send an e-mail to hanseatic-congress@t-online.de We look forward to seeing you at the number one annual event of our industry!

eastofmain

OFFENBACH

COME TO WHERE THE BUSINESS IS!

ZELLCHEMING, BRIDGING THE GAP BETWEEN RESEARCH AND INDUSTRY

p 05 Zellchming ad.indd 5

11/06/09 12:39 PM

industry news BLACK LIQUOR

Canadian government considering response to black liquor tax credit

VANCOUVER — A loophole in a U.S. tax credit for use of alternative fuels is playing havoc with the global pulp sector. With international outcry building, the credit could be short-lived, but it has already paid big dividends to eligible producers.

The U.S. program allows pulp producers to add a small amount of diesel to the black liquor they burn, and have that material considered an alternate fuel, eligible for a tax credit.

“The fact that an alternative fuel subsidy is being tweaked so that adding diesel renders this incredible subsidy is staggering,” Natural Resources Minister Lisa Raitt said at the recent PricewaterhouseCoopers forest products conference.

“I’ve written [U.S. Department of Energy] Secretary Steven Chu indicating that it is completely distorting the market.”

Raitt says the federal government is considering its options, and is “very much aware of the dangers of the situation.”

According to Raitt, the Obama administration intends to have the loophole closed by Oct. 1 of this year.

Meanwhile, the Canadian government

The alternative fuel tax credit available to U.S. pulp mills leaves Canadian kraft pulp producers, at a competitive disadvantage. Above: Howe Sound Pulp & Paper.

CANADIAN FOREST INDUSTRY vs. CANADIAN AUTO INDUSTRY FOREST INDUSTRY

AUTO INDUSTRY

Total revenue $94 billion $84 billion Total exports $80 billion $42 billion % of Canada’s GCP 3% 3% 12% % of Canada’s manufacturing GDP 12.4% 135,000 300,000 Direct jobs 863,900 440,000 Direct and indirect jobs Sources: Forest Products Association of Canada, Statistics Canada, Ward’s Automotive, CAW research, Centre for Automotive Research is “working to determine if we have a program pulp and paper companies can take advantage of, but we have to be mindful that we are signatories to the SLA,” she explains.

“We have consulted the industry, and companies are seeing the effect [of this subsidy] now, so we have to act quickly.”

Raitt is not promising that a Canadian program will be similar to that in the U.S., nor that it will match the U.S. program for funding.

However, the awkward truth is that some pulp and paper companies which operate in both Canada and the U.S. are benefitting from this credit.

Domtar, in its first quarter results, reported a $46-million tax credit for use of alternative fuels. The company estimates that this is only 40% of the eligible alternative fuel tax credits available to it each quarter.

Mike Richmond, an analyst with Salman Partners, reports that the black liquor tax credit has dramatically altered cost profiles for pulp producers in the short-term and that it could also have a longer-term impact through the improved liquidity on weak balance sheets.

Donna Harman, CEO of the Ameri-

can Forest & Paper Association, argues that the tax credit is not a subsidy. “We have an extensive legal brief saying it is not a subsidy under WTO rules. It’s not focused on the pulp and paper industry.”

“Our position is that our industry should get credit for the renewable energy it consumes and provides,” she continues.

“Existing facilities should have access to the same financial credits as newcomers to the renewable energy sector.”

PROTEST

Thousands of forest workers tell Ottawa to ‘wake up’

OTTAWA — About 2,500 forest industry supporters marched in Ottawa June 2 to raise awareness of the impact of the forestry crisis on families and communities across Canada. Laid-off forestry workers, worried pensioners, mayors and officials from mill towns, and hundreds of forest-industry supporters joined the workers in a noisy march through the streets of Ottawa from Natural Resources Minister Lisa Raitt’s office to Prime Minister Stephen Harper’s office at the Langevin block.

The event was organized by the Communications, Energy and Paperworkers

Visit www.pulpandpapercanada.com for details: New Manitoba regulations protect forest from insects and disease…Paper sect s s s

6

May/June 2009 Pulp & Paper Canada

p 06-9 news.indd 6

pulpandpapercanada.com

11/06/09 12:40 PM

industry news

Forest industry workers and supporters made their concerns known to the federal government with a rally in early June.

Union. “Our main demand has always been for the federal government to backstop loans so that viable companies can keep operating, saving jobs and communities,” says CEP president Dave Coles.

“We are not asking for a bailout.”

In addition, the union wants the federal government level the playing field by

PAPERCLIPS

matching U.S. tax credits for the use of alternative fuel.

In May, forestry workers occupied the offices of four Conservative Cabinet Ministers and three MPs to drive home their demand for action on Canada’s forest crisis.

The CEP claims 55,000 jobs have been lost in the forest products industry in the last two years.

NDP Leader Jack Layton and Bloc Quebecois Leader Gilles Duceppe also addressed the rally. Liberal Leader Michael Ignatieff was invited but declined.

BANKRUPTCY

AbitibiBowater restructuring sends ripples through the industry

MONTREAL — AbitibiBowater moved quickly to secure financing and terminate prior agreements in the days following its April filing for creditor protection. The newsprint maker plans to use this process to “deal decisively” with its debt burden.

The company has a tremendous foot-

print in Canada: it employs 10,000, has 14 pulp and paper mills, and operates 28 forest products plants.

AbitibiBowater announced that debtor-in-possession (DIP) financing and continuation of existing receivables securitization programs will allow it to meet its current operating needs and continue day-to-day functioning during restructuring.

A financing arrangement has been made with Fairfax Financial Holdings Limited and Avenue Management LLC, plus the Quebec court has authorized Abitibi to enter into a loan agreement with Bank of Montreal for debtor-inpossession financing which will be guaranteed by Investissement Quebec. The Abitibi Quebec agreement will provide up to $100 million.

Pensions immediately came up for discussion as part of the restructuring plan. The Quebec Superior Court gave approval for AbitibiBowater to suspend pension payments towards its unfunded liabilities for workers, but ruled that the company must abide by its collective continued on page 8

Pulp chair is durable and waterproof Södra has developed a children’s chair made from pulp that is said to be both durable and waterproof, despite having the look and feel of ordinary paper. The chair has been named Parupu after the Japanese word for pulp. It is recyclable, environmentally-friendly, stackable, and colourful.

The chair was designed in collaboration with design and architect firm Claesson Koivisto Rune, and made its world premiere at the Milan Furniture Fair in 2008.

The team’s objective was to make something that felt like paper but had the durability normally associated with materials such as steel, wood, or hard plastic. Working with Södra and research company STFI Packforsk, Claesson Koivisto Rune experimented and tested the suitability of the material for use in a tough and practical chair for children.

The material is a specialty pulp from Södra Cell combined with PLA, a biodegradable plastic made from maize starch and cane sugar.

The chair’s base material, which can be moulded and could potentially replace plastic in a number of applications, has been named DuraPulp. A piece of DuraPulp only a couple of millimetres in thickness is enough to support the weight of a person. It can be left outdoors for several

years without degrading.

“DuraPulp is also suitable for producing quality packaging and labels, and can be run perfectly well in a normal paper machine. Our hope is that the chair will create interest and ideas amongst our existing customers as well as leading to discussions with new customer groups and new markets,” she says.

For more info, visit www.sodrapulplabs.com.

e…Paper sector losses in 2008… Amazon’s Kindle reading device replaces textbooks in come classrooms…Alberta forest oversight s s s pulpandpapercanada.com

p 06-9 news.indd 7

Pulp & Paper Canada May/June 2009

7

11/06/09 12:40 PM

industry news labour agreement and apply changes to its pension program that were to take effect on May 1.

Prior to seeking bankruptcy protection, AbitibiBowater unilaterally rescinded pension benefit improvements that had been negotiated in an earlier collective agreement and were to take effect on May 1. According to the Globe and Mail, lawyers for Abitibi told the court the company could not cover the cost of about $68 million to pension fund payouts to allow for early retirement at 57 instead of 58 for some workers.

Highlighting Abitibi’s reach in Quebec, the judge overseeing the company’s restructuring had to excuse himself from this pension motion because his father is among the company’s pensioners.

SFK Pulp felt the effects of AbitibiBowater’s restructuring immediately, as the insolvent company terminated fibre and bark supply agreements for SFK’s mill in St. Félicien, Que. Under these agreements, Abitibi supplied about 80% of the fibre requirements of that mill.

“We intend to continue our discus-

sions with Abitibi to establish a fair price for black spruce and jack pine wood chips.

During ongoing negotiations between the parties, Abitibi offered a minimum of 500,000 metric tonnes/year of wood chips and an adequate volume of bark to SFK Pulp. We are also firming up our business opportunities with other wood chip suppliers that are not already under contract with Abitibi,” reports Pierre Gabriel Côté, president and CEO of SFK Pulp.

AbitibiBowater produces a wide range of newsprint, commercial printing papers, market pulp, and wood products.

PULP MARKET

Producers raise pulp prices for Europe

LOS ANGELES — Mercer International Inc., Canfor Pulp LP, and Finland’s Oy Metsä-Botnia Ab have separately announced that their June 1 list prices in Europe for northern bleached softwood kraft (NBSK) pulp will be US$630 per tonne.

This price is up $30/tonne from the May 1 list price.

Screening & Processing Size Reduction Material Handling

Their moves follow the $630/tonne announcement yesterday by Sweden’s Södra Cell AB, which was the first from a European producer and provided support for previous announcements by Canadian NBSK producers Domtar Corp. and West Fraser Timber Co. -- provided by ForestWeb ENFORCEMENT

Eurocan pulp mill fined $130,000 for effluent spill

KITIMAT, B.C. — West Fraser Mills Ltd. received a penalty totaling $130,000 after pleading guilty in provincial court to one count of depositing a deleterious substance into water frequented by fish, contrary to subsection 36(3) of the federal Fisheries Act. Crown and defence counsels jointly filed an agreed statement of facts with the court.

West Fraser’s Eurocan Pulp & Paper Co. mill in Kitimat produces unbleached linerboard and sack kraft. The investigation of the spill on June 21, 2007, revealed that West Fraser had not been duly diligent in the maintenance of the effluent

Storage & Reclaim Pneumatics Truck Dumpers

If you’re looking for Truck Dumpers, Chip Thickness Screening, Fines Screening, Boiler Feeding Systems, Storage and Reclaim Equipment, Pneumatic Systems or Size Reduction Equipment, call Jeffrey Rader Corporation. We have been supplying and supporting the Pulp and Paper industry for over 50 years. Jeffrey Rader Corporation is now your one-stop shop for your boiler house, chip mill and wood yard processing equipment. Please give us a call and let our team of experts work with you on matching the perfect equipment for a given application.

CRUSH. FEED. PROCESS. CONVEY. STORE. www.jeffreyrader.com/ppc Jeffrey Rader Corporation s 398 Willis Road s Woodruff, South Carolina 29388 s 1.800.615.9296 s info@jeffreyrader.com Montreal, Quebec s 2350 Place Trans-Canadienne s Dorval, Quebec H9P 2X5 Canada s 514.822.2660 Vancouver, BC s Unit 2, 62 Fawcett Road s Coquitlam, BC V3K 6V5 Canada s 604.299.0241 8

May/June 2009 Pulp & Paper Canada

p 06-9 news.indd 8

pulpandpapercanada.com

11/06/09 12:41 PM

industry news treatment systems, specifically the main effluent line.

ECONOMIC CRISIS

Federal government provides $80 million for forest product innovation

As part of a $170-million aid package for the forest products sector, $80 million will be directed toward emerging technologies through the Transformative Technologies program administered by FPInnovations.

“This investment is another solid step forward in helping the communities and workers who depend on the forest sector weather the current economic storm,” says Minister of State (Agriculture) JeanPierre Blackburn. “By targeting the marketing and innovation side of our forest industries, our government is not only helping this sector during these current challenges, but we are also giving this sector a stronger foundation for the future.”

The forestry component of the Conservatives’ economic action plan also provides $40 million to programs that help forestry companies market innovative products internationally, $10 million to support demonstrations of Canadian wood in construction, and $40 million for pilot-scale demonstrations of new products.

Quebec’s forest industry association expressed disappointment with the Harper government’s efforts. Guy Chevrette, CEO of the Quebec Forest Industry Council (CIFQ) told a Quebec newspaper, Le Soleil, “It’s not money for marketing and research that we need in the short term. We need something that will save our businesses.”

PROCESS TECHNOLOGY

TAPPI honours Dr. Ian Journeaux

NORCROSS, GA. — In recognition of his outstanding contributions, TAPPI’s Process Control Division has honored Dr. Ian Journeaux with its 2009 Leadership & Service Award.

A 20-year industry veteran, Journeaux is now manager of process technology at NewPage Corporation in Wisconsin Rapids, Wi. A native of Quebec, Journeaux holds a B.S. in Chemical Engineering from the University of Waterloo (1980), as well as an M.S. from The pulpandpapercanada.com

p 06-9 news.indd 9

Institute of Paper Chemistry (1982) and a Ph.D. from McGill University’s Chemical Engineering Department (1990).

ENVIRONMENT

EPA finds carbon dioxide is a pollutant

The U.S. Environmental Protection Agency has issued a proposed finding that greenhouse gases contribute to air pollution that may endanger public health or welfare. This finding is the first step in regulating carbon dioxide and other pollutants linked to climate change.

The proposed finding, which now moves to a public comment period, iden-

STARTS, STOPS, CHANGES

Catalyst Paper has announced further staffing reductions. Approximately 100 staff positions will be affected.

Permanent reductions will occur mainly at the Richmond and Nanaimo offices while the indefinite layoff of 55 salaried staff will take place at the Elk Falls mill and Crofton pulp mill. Both mills were curtailed indefinitely at the end of February.

“The steps we are taking today will continue to bring costs down as we strive to put in place the lean manufacturing structure necessary for what could be a smaller paper market going forward,” said Richard Garneau, president and chief executive officer.

The unprecedented layoffs reflect the severity of recent demand declines and the likelihood that curtailed production will not restart in the short term.

St. Marys Paper in Sault Ste. Marie, Ont., idled two of its three paper machines for inventory-related downtime and temporarily laid off about 60 workers, according to a report in the Sault Star. The production curtailment is expected to last one month.

The mill produces supercalendered paper for use in catalogs, magazines, and advertising inserts.

Mill production will be handled by paper machine #5, which can produce about 60% of the mill’s 240,000-tonne annual output, according to the Sault Star.

tified six greenhouse gases that pose a potential threat. “This finding confirms that greenhouse gas pollution is a serious problem now and for future generations.

Fortunately, it follows President Obama’s call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation,” says EPA administrator Lisa P. Jackson.

ON THE MOVE

Domtar Corp. has changed the composition and structure of its management committee. All members of the management committee will report directly to the president and CEO, John D. Williams. Michael Edwards will continue in his present role as senior vice-president, pulp and paper manufacturing, and Jean-Francois Merette remains as senior vice-president, forest products.

Sales and marketing functions will be consolidated under Richard Thomas as senior vice-president sales and marketing.

A new senior vice-president, distribution will be recruited. Jim Lenhoff has agreed to continue his current responsibilities and take retirement once a successor is appointed.

Similarly, Michel Dagenais will continue his current responsibilities and take retirement once a new senior vice-president, human resources is appointed.

Continuing in their present position are: Daniel Buron, senior vicepresident and chief financial officer; Zygmunt Jablonski, senior vice-president and general counsel; Patrick Loulou, senior vice-president, corporate development.

Nexterra Energy Corp. has added three executives to its North American sales force, strengthening the company’s strategic focus on regional biomass energy opportunities. Joining Nexterra’s sales organization are Jim McNamara, covering the Northeastern U.S., Jo-Ann Yantzis for Eastern Canada and the Great Lakes Region, and Jonathan Harris, who will be responsible for new business development.

Pulp & Paper Canada May/June 2009

9

11/06/09 12:41 PM

forestry outlook

Managing a shrinking industry Four industry experts say forest products companies must stop clinging to the past and develop products geared to the future. This crisis is an opportunity to reinvent, to challenge, and above all, to

By Heather Lynch take stock of what isn’t working and focus on what is.

“T

he Canadian industry has moved from the frying pan into the fire,” Kevin Mason says simply. The managing director of forest products for Equity Research predicts more mills will be added to the list of dozens that have already closed before the ‘rut’ is over. “Most major paper grades have entered secular decline and the issue going forward is managing a shrinking industry – and as we’ve seen in newsprint, this is incredibly difficult.”

Relying too heavily on its small cornerstones of success and not addressing the bigger picture has contributed to the industry’s downfall, says Antony Marcil, president and CEO of the Forest Stewardship Council (FSC). “The new housing starts in the U.S. are, and will remain, the dominant factor in the health of the Canadian forest industry. Our greatest strength in regard to that is the high quality of Canadian SPF. Our greatest weakness is our dependence on that market. Our second greatest weakness is lack of investment in our production facilities over the last many decades. That lack of investment has meant lost opportunities in terms of productivity gains not realized and diversification into added-value products not undertaken.”

David McDonald, vice president of research and education for FPInnovations, agrees, noting that Canada’s main strengths lie in its diverse and high quality fibre supply, and other abundant natural resources such as water, minerals, and relatively low-cost energy. “We have extensive infrastructure to collect and process forest biomass and a trained workforce,” he says.

“But these attributes are also our weakness. We have focused on optimizing traditional product lines to defend against shrinking markets and international competitors. However, the changes in the past few years have been too great to be offset by incremental improvements.”

What is the best use of this forest resource?

That’s up for debate as the industry moves from traditional products to more value-added products.

10

May/June 2009 Pulp & Paper Canada

p 10-12 forestry.indd 10

Cautious optimism for biomass

Biomass is often touted as a potential area for capitalization, growth, and rejuvenation for Canada’s forest sector, but here too, industry experts caution against undue optimism. FSC’s Antony Marcil sees opportunity in biomass, but is concerned about stressing the forests. “That competition may mean enhanced economic returns for some but the forests may suffer pulpandpapercanada.com

12/06/09 7:26 AM

forestry outlook if too much biomass is removed,” he in many cases. There could definitely It is tough to shrink says. Mason of Equity Research worbe competition between biomass and your way to prosperity. ries the inherent costs associated with pulp/paper markets for fibre and the biomass may render any economic development of provincial policies Kevin Mason, Equity Research incentive virtually useless. “Getting around these issues will be key.” previously unused biomass delivered to facilities in a cost-effecIn addition to strategic policy, FPInnovations’ David Mactive manner is a huge hurdle to overcome,” he notes. “Even if the Donald is calling on industry to challenge its own ways of biomass is free, the transportation costs cripple the economics doing business by building partnerships with other industries.

He foresees a future industry that produces not only traditional products, but higher value offerings such as lightweight composite materials, bioplastics, biofuels, and biochemicals. “To be successful, the companies in the forest sector will have to partner P&PC asked Antony Marcil of FSC, Avrim Lazar of FPAC, with those in other industrial sectors: aerospace, automobile, Kevin Mason of Equity Research, and David McDonald of chemical, and pharmaceutical,” he says. “These partnerships will FPInnovations what keeps them up at night with regard to the be necessary to understand the market and performance characcurrent state of the forestry industry: teristics of these new products and jointly develop processes to make them.”

Antony Marcil: From my perspective, global climate change and its side effects are the number one threat to our forests Public policy: support and a safety net and thus to the forestry and woodlands sector. The continuAs the forestry sector tries to ward off currency, competition, ing closures of mills due to the lack of U.S. demand and and resource challenges, industries and institutions alike are the competition from cheaper fibre from far away also rank turning to governments for answers. Few would contest that quite high on my concerns list. The other side of that coin public policy plays a critical role in fostering an environment is the lack of progress in developing added-value products to conducive to healthy competition and a level playing field for enhance Canadian offerings. And by added-value I mean not forestry. At a very basic level, job and income protection for just more sophisticated products but also marketing terms, forestry workers is critical, according to the Forest Products time, place, function, and scale utilities.

Association of Canada (FPAC). “With our jobs and well-being

What worries you?

Kevin Mason: What keeps me up at night is whether or not there will be an industry left for me to analyze! Will we ever get back to the glory days? I fear not. It is tough to shrink your way to prosperity. We are debating issues from the last decade, not thinking ahead to what the future may hold. We need to encourage and reward entrepreneurs in this industry, and we aren’t great at doing that. We need to move beyond our commodity focus and the attendant volatility that implies and move up the value chain. Some companies have tried, but they have had little help.

Avrim Lazar: If governments wait too long to improve business conditions, many more thousands of jobs will be needlessly lost.

David McDonald: There are two nagging questions: When the economy begins to rebound, what will be left of the Canadian forest industry? And will we be able to introduce new, higher value products in time?

Marcil pulpandpapercanada.com

p 10-12 forestry.indd 11

Mason

Lazar Pulp & Paper Canada May/June 2009

11

11/06/09 12:42 PM

forestry outlook

Getting previously unused biomass to a processing facility will be a hurdle for industries using it as a feedstock.

at stake, the answers are relatively straightforward,” declares Avrim Lazar, president and CEO of FPAC. “Governments can provide a safety net that lessens the pain for displaced workers and prepares them for new jobs. They can also assist community adjustment. This is a role they are embracing and playing well.”

12

May/June 2009 Pulp & Paper Canada

p 10-12 forestry.indd 12

While softening the blow for workers who have lost their forestry sector jobs is one area for governments to address, the development of policy to assist the current industry is equally vital. Here, however, the lines become somewhat blurred. As Lazar emphasizes, the current economic climate has made navigating policy even more difficult. “Governments can also stimulate the economy through spending and macroeconomic policies. While some think more is necessary, the truth is that in these uncharted economic times there are no clear prescriptions.”

While policy in this context is not one-size-fits-all, a definitive area for emphasis includes improving what FPAC considers “hosting” conditions for business. Lazar notes the only viable safeguard against job loss is competitive businesses. “Canada is an exporting nation selling into the global marketplace. If we are competitive, we maintain our standard of living. If we are not, we lose our jobs. There is not enough money in the government’s collective treasuries or policy power in the Ministry of Finance to protect us from the need to be competitive.”

Mason concurs with this view, noting the need for changes to competition rules. “Our industry is shrinking and if the governments think of forest products as a sunset industry, then perception will become reality. Companies and associations need to be vigilant in keeping the pressure on government to consider the state of the industry – it is still a huge employer in Canada, especially in the rural areas. We have to expand our regional focus and think globally.”

Uncertainty about the wider economy translates to Canada’s forestry industry. What the sector will look like in the near future remains unclear, and definitive approaches on goals, directions, and achievable outcomes are equally elusive. However, there is widespread accordance on a need for flexibility, both by industry and governments, to respond to shifting challenges and priorities, in order to position Canada’s forest sector at the forefront ppc of future industry, in whichever form it takes. pulpandpapercanada.com

11/06/09 12:42 PM

bioenergy

Unlocking the potential

of biomass

There are more questions than answers in the bioenergy field, with naysayers unconvinced of the economics of getting biomass from the forest to the plant, even as commercial-scale gasification projects for heat and power move ahead in B.C.

By Cindy Macdonald, editor

W

e live in a power-hungry world. In fact, technology visionary John MacDonald argues that readily-available energy is the basis of our modern lifestyle. And he’s concerned that our hunger for energy will exceed our conventional supply within this century. His pessimistic scenario proposes that world demand could exceed the capacity of our conventional power sources as early as 2012 to 2015.

What’s going to fill the gap? In his view, more nuclear power, and the development of renewable energy –

pulpandpapercanada.com

p 13-16 Biorefining story.indd 13

solar, wind, hydro, biomass, geothermal.

MacDonald was co-founder of MacDonald Dettwiler and Associates (MDA), Canada’s principal space company, and is now chairman and CEO of Day4 Energy Inc., a solar energy company.

His conclusion is that, despite the hurdles, there’s a real need for more energy supplies.

Into this potent stew of possibilities for green energy comes a growing Canadian bioenergy industry.

“The use of wood for bioenergy is

growing, driven by incentive policies, rising energy prices, and more efficient use of raw materials,” says Petri Lehtonen, deputy managing director of Finnish consulting firm Indufor Oy. Lehtonen was a speaker at the PricewaterhouseCoopers Global Forest and Paper Industry Conference in May. He envisions a global market for biomass, driven by wood-poor nations trying to meet renewable energy targets.

Others agree that the industry is headed for a breakthrough.

“The way we use energy across North America is going to change.

Pulp & Paper Canada May/June 2009

13

11/06/09 12:43 PM

bioenergy

Economics of Power Generation from Different Fuels

B.C. is on the leading edge of this,” says Harvie Campbell. Campbell is a founder of Pristine Power Inc., an independent power producer based in British ­Columbia.

As support for bioenergy evolves, it becomes clear that there are many paths by which forest biomass can be exploited.

Already, there is a market for wood pellets, composed of sawdust, for residential and industrial heating, particularly in Europe.

There’s a market for biomass gasification technologies that convert wood residue to syngas, which is then used for residential and industrial heat and power.

This market is just entering the commercial stage, with numerous Canadian players.

There are also several projects underway to convert cellulose to ethanol, which is also in the early stages of commercialization.

Wood does not easily beget energy

If the economics of different power sources are considered, hydro power is the most competitive, then nuclear, says Petri Väisänen of Pöyry Energy. But carbon taxes change the situation; wind power becomes more competitive.

Source: Petri Väisänen of Pöyry Energy

The forest resource: traditional and emerging uses Small dimension logs (pulpwood) – Traditional users of pulpwood logs are pulp mills and the wood-based panel sector. However energy companies have a high wood-paying capability and are competing directly with these industries for raw material.

Harvesting residues – Tree tops and branches left behind in the forest after harvesting. This remains a largely unutilized resource in most countries and has low competition from the traditional wood consuming industries.

Bark – Has relatively low calorific value and high ash content and is therefore not favoured by the bioenergy industry. It is a major by-product of the softwood sawmilling industry, and often burned at sawmills to provide heat (for drying kilns) and energy.

Chips/Sawdust – A major by-product from the sawmilling industry, and important raw material for the pulp and paper and wood-based panels sector. Now also in strong demand by wood pellet producers and energy companies. Recovery of waste wood from communities and construction/demolition is also growing in importance for the bioenergy sector.

Wood pellets – Generally made from compacted sawdust. Wood pellets are extremely dense and have a low water content, which offers logistic advantages.

They are mainly used in domestic heating and co-firing plants due to their homogeneity and their high quality as wood fuel.

Source: Petri Väisänen of Pöyry Energy 14

May/June 2009 Pulp & Paper Canada

p 13-16 Biorefining story.indd 14

One stumbling block for many of these technologies is that woody biomass is not a particularly energy-dense fuel source when compared with fossil fuels. However, acting in its favour as a raw material to produce electricity is the fact that it can be a steady, not intermittent, fuel source.

Because it becomes inefficient to transport woody biomass too far in its original state – as logs, limbs, tops, and stumps – bioenergy from wood is likely to be a local enterprise. Fossil fuels have high energy density; they’ve been cooked in the earth for hundreds of years, explains Michael Burnside, president and CEO of Catchlight Energy LLC. Petroleum is energy dense, and can be moved as a liquid or gas. “Moving solids is a different proposition,” he notes dryly.

For biofuel production, Burnside envisions a network of small plants, rather than the large refineries typical of fossil fuel transformation, because of the challenge of collecting and transporting biomass. “You need a large network of plants, because you can only move biomass so far economically.”

“We will need a large, distributed network vs. the petroleum industry today, which has a few large regional centres.”

Burnside has a unique perspective on pulpandpapercanada.com

11/06/09 12:43 PM

bioenergy this – Catchlight is a joint venture in biofuels development between Chevron and Weyerhaeuser.

Based on European experience, Lehtonen says a reasonable distance to transport tops and limbs is 30 to 50 miles.

Closer to home, in B.C., Campbell estimates that 50 miles is the upper limit for transporting standing bug kill material. At those distances, however, it makes the electricity expensive, he comments.

“Power is the bottom feeder of the wood industry,” he adds.

“We take anything – roots, stumps, limbs.”

Picture biomass as a global commodity

As the industry develops, the scale of individual biomass investments is increasing, requiring larger volumes of biomass, according to Petri Väisänen, a biomass expert with Pöyry Energy Oy. “The biomass market will become more and more international. Biomass consumption for heat and fuel will more or less double by 2015,” he predicts. Biomass is expected to deliver most of the renewable energy for the European Union to meet its so-called 20-20-20 target (which includes a goal to have 20% of total energy production from renewable sources by 2020).

“It will change the traditional operating environment of the forest industry,” says Väisänen. “We already see pulpwood going to power boilers.”

Väisänen believes havesting residues are an underused resource that will become an important source of biomass in the future. The main biomass resource now is small dimension logs and wood chips.

Further, he notes, there are currently not many market players who could provide international biomass sourcing on a large scale.

To make a bioenergy investment successful, Väisänen suggests that a company’s highest priority should be to secure a sustainable biomass supply.

wood users and those who use biomass for energy. “Depending on the conversion efficiency, bioenergy could pay a lot more for pulpwood than the pulp and paper industry.”

Magnus Hall agrees. Hall is CEO of the Holmen Group, an integrated forest products company based in Sweden. He foresees competition between pulp mills and biofuel producers.

“I think we might find a fibre shortage and price pressure.”

There are some in the forest products industry who believe that bioenergy can’t stand on its own two feet when it comes to fibre supply.

“In my opinion, I think [bioenergy] is based on creative economics,” says Jim Shepard, CEO of Canfor. “I can’t see the economics of sending logging trucks into the woods to bring in wood to be burned in a boiler. I can see it if the wood [destined for energy] gets a free ride.”

Richard Garneau of Catalyst Paper contributes: “When you have a capital intensive facility, you need a low-cost raw material. We don’t have that on the B.C. Coast right now.”

In the current economic model, we assume green energy has to be priced higher than other power, he states. But governments should be wary of the effect any policy decisions could have on the pulp and paper industry.

On the other hand, supporters of bioenergy caution against protectionism toward traditional forest products.

Ross MacLachlan, president and CEO of Lignol Innovations, a biofuel producer: “If we’re going to grow this bioenergy industry, we need tenure reform and a robust suite of different

More hands in the fibre basket

The current low cost of forest biomass is due to synergy with the forest industry, says Neil Barnard, CEO of Ceres BioVentures Ltd. In his view, competition between is looming between pulp-

UNBC will use biomass gasification to heat Prince George campus VANCOUVER – Nexterra Energy Corp. has been selected by the University of Northern British Columbia to supply and install a turnkey biomass gasification system to heat UNBC’s Prince George campus and anchor its new Northern Bioenergy Innovation Centre.

The Nexterra gasification system will convert locallysourced wood residue into clean-burning “syngas” that will displace up to 85% of the natural gas currently used to heat the campus.

By using wood residue to displace natural gas, UNBC will reduce its fossil fuel consumption by 80,000 GJ/year, the equivalent of natural gas required to heat over 700 homes in B.C. The new system will also reduce the university’s carbon footprint by approximately 3500 tonnes annually. pulpandpapercanada.com

p 13-16 Biorefining story.indd 15

Pulp & Paper Canada May/June 2009

15

11/06/09 12:44 PM

bioenergy applications for the fibre resource.”

Also representing the bioenergy side, Nexterra’s Jonathan Rhone notes that there’s a transformation happening in the world of energy as the industry considers the value chain for forest biomass. “We’ve got to get our act together up here. We can’t have the idea that one industry has a protectionist policy. Our interests are more aligned than not.”

“We won’t know how much we can draw out of the resource until we try,” says Catchlight’s Burnside. “Eventually it’s got to be an open market for fibre.”

High-level decisions determine direction

Decisions that will shape the bioenergy industry are being made now. An important early step is the policy framework for renewable and clean energy.

“The industry’s transformation is just starting. How thoughtful are we going to be about it?” asks forest products analyst Don Roberts of CIBC World Markets Inc. In B.C., “the policy framework is right,” says the Council of Forest Industries’ John Allan. “We just need an implementation strategy.”

In Quebec, the provincial government announced this spring a policy for the allocation and harvesting of forest biomass. The biomass action plan will also promote the use of forest biomass as a substitute for fossil fuels. In addition, Hydro-Québec is seeking proposals for electricity from biomass.

Federal lawmakers in the United States are at the point of defining types of energy that will considered “alternative” and “renewable”. Catchlight’s Burnside explains that the definition of qualifying biomass and conversion methods in the U.S. national fuel standards is very important to this nascent industry.

West Coast powerhouse

In B.C., the use of forest biomass for heat and power is proceeding well.

Nexterra president and CEO Jonathan Rhone says the province is fertile ground for bioenergy.

“B.C. has advantages in bioenergy: we have a bioenergy industry already; we have world class equipment suppliers; we have a history of converting biomass to energy; we have a culture of innovation; and we have good government policies.”

Harvie Campbell of Pristine Power estimates that B.C. biomass has the potential to produce as much as 2500 MW of power, which could be sold for as much as $30 per MW/h.

Many states now have renewable energy standards. California, for example, requires its electricity companies to increase procurement of renewable energy to 20% by 2010. It is expected to require 13400 MW of renewable energy by 2016.

“We believe fundamentally in bioenergy,” says Campbell.

For independent power producers, he says, the paramount concern is the risk of fuel supply interruptions. To encourage the development of this sector, the risk

Gasoline and diesel produced from lignocellulose biomass VANCOUVER – Dynamotive Energy Systems Corporation reports the successful production of “significant amounts” of renewable gasoline and diesel from biomass at its research facility in Waterloo, Ont., through a novel two-stage upgrading process of BioOil. The process developed by Dr. Desmond Radlein and his research team involves pyrolysis of lignocellulosic biomass to produce a primary liquid fuel, BioOil, which is then hydro-reformed to a Stage 1 gas-oil equivalent liquid fuel. This liquid fuel can either be directly utilized in blends with hydrocarbon fuels for industrial stationary power and heating applications or be further upgraded to transportation grade liquid hydrocarbon fuels (gasoline/diesel) in a Stage 2 hydrotreating process.

The major by-product from lignocellulosic biomass pyrolysis is Biochar which has emerging value for soil productivity enhancement and carbon sequestration.

Based on initial test and analysis, the company currently estimates that it can deliver advanced (second generation) fuels from biomass at a cost of less than $2 per gallon of ethanol-equivalent fuel in facilities processing about 70,000 tonnes of biomass per annum.

16

May/June 2009 Pulp & Paper Canada

p 13-16 Biorefining story.indd 16

of sawmill closures needs to mitigated, and First Nations’ involvement needs to be respected. Other risk factors identified

by Campbell are fuel cost as it relates to the transportation of roadside slash, and potential for changes to stumpage rules and rates.

Campbell’s risk assessment underscores a fundamental fact about the economics of bioenergy. Many in the field believe that bioenergy needs the forest products industry to share the cost of getting the resource from the woods to a plant where it can be transformed to energy.

Learning to live together

Be prepared for turmoil when the interests of forestry and energy collide, because all indications are that “green” energy is here to stay.

Converting biomass to energy is not yet competitive with other forms of electricity generation. It still needs subsidies, because the investment needs for power infrastructure are substantial.

Fibre supply is also an issue. While the infrastructure to access fibre is in place, “now it is a logistics issue,” says Lignol’s MacLachlan. “The cost of getting fibre to the gate in many cases makes the technology not viable.”

And there is some inertia to overcome.

As Rhone states: “The value chains we are displacing – conventional energy – have been in place for a long time.” Not to mention the history of the forest products industry in this country.

But with global demand for electricity rising, and our culture’s strong dependence on fossil fuel, conventional energy sources are not in danger of being displaced. “My thinking is that world demand for energy keeps going up. All forms of energy will need to be delivered.

Biofuels will supplement, not displace, oil. Every drop will be needed,” says Burnside.

“In the next few years, the challenge is how to get over that mountain of uncerPPC tainty.”

Much of the foregoing material was presented at the PricewaterhouseCoopers Forest Products Conference 2009, and the BC Bioenergy Conference, both held in Vancouver in May. pulpandpapercanada.com

11/06/09 12:44 PM

success story

The little that

mill could

Worker-owned mill defies the critics and boosts productivity by empowering employees.

pulpandpapercanada.com

p 17-18 success story.indd 17

estimated $50-million in clean-up costs in the event of a permanent closure.

Yet in less than four months — lightning speed for receivership proceedings — the employee group managed to convince the courts its proposal was the best available option for both Pope & Talbot’s

creditors and the community.

In October, just as the U.S. economy began to implode, Harmac Pacific reopened with 230 workers churning out between 700 and 800 tonnes of ready-toship pulp per day from one of the plant’s three production lines.

Harmac president Levi Sampson (seated) and company director Bob Smiley say the recently reborn worker-owned mill is strong enough to survive the current market slump.

Photo: Brennan Clarke

I

n his 32 years at the Harmac pulp and paper mill outside Nanaimo, B.C., Doug Narver has seen a procession of owners come and go — from MacMillanBloedel in the 1980s to re-structured Mac-Blo entity Harmac Pacific in the 1990s to the decade-long tenure of Pope & Talbot that ended in bankruptcy last spring.

But he’s never felt better about coming to work than he does under the current ownership group. Of course that’s a somewhat biased opinion, since he’s one of the shareholders.

“This is the fourth owner I’ve been through and it’s definitely the best one so far,” Narver says. “The whole concept of employee ownership is something I bought into figuratively and literally.”

Narver, Harmac’s No. 3 machine operator, is one of more than 200 longtime employees who invested $25,000 apiece in the operation as part of a bid to save the mill after it went into receivership last May. In a move that raised eyebrows across the industry, the displaced workers secured backing from three B.C.-based investment partners and purchased the failed operation last summer for $13.2 million.

Under the name Nanaimo Forest Products, former employees pledged 25% of the purchase price, with matching investments from Pioneer Log Homes of Williams Lake, Totzauer Holdings, a Fraser Valley construction firm, and the Sampson Group, a large Calgary-based oil and gas firm.

Analysts scoffed at the proposal, suggesting the aging pulp factory needed $100 million in upgrades and predicting the province would get stuck with an

By Brennan Clarke

Pulp & Paper Canada May/June 2009

17

11/06/09 12:45 PM

success story

Six months into the worst economic crisis in living memory, the workerowned mill continues to defy the skeptics.

“I didn’t think they’d make it, but it’s not just me. Everybody’s surprised,” says Paul Quinn, a forestry analyst with RBC Capital Markets in Vancouver.

“People are astounded that the guys who are running it now can run it successfully in these conditions.”

Long-term contracts sealed the deal

Former union treasurer Bob Smiley, now a director on the Harmac board, says the proposal contained two key elements — a five-year fibre supply agreement with Western Forest Products and a long-term marketing deal under which Coastal Pulp and Paper is obligated to buy 100% of Harmac’s product.

B.C. Supreme Court Justice Donald Brenner, who approved the sale in August, was swayed by the group’s intimate knowledge of the facility, sound business plan, and commitment to saving local jobs.

“The receiver actually didn’t support our bid but Justice Brenner could see the logic of what we were proposing. We knew the mill, we knew the age of the assets, we knew that Pope & Talbot had invested about $300 million in upgrades,” says Smiley.

“We made sure the WFP fibre supply was part of any agreement with the receiver.”

On-site ownership provides flexibility

The driving force behind the new operation is Levi Sampson, son of Ed Sampson, founder Niko Resources, a Calgarybased oil and gas firm with $1.3 billion in assets.

At age 28, Sampson is barely half Smiley’s age and has no prior experience in the forest industry. On the other hand, he brings a fresh approach with no sense of allegiance to past practices, and a determination to do things differently in the future.

“There’s no way we would have gotten involved in this if there wasn’t change,” Sampson says.

18

“Our attitude is more entrepreneurial. We want to use the assets from this mill in a way that makes sense in this market.”

Future plans include a wood-chipping facility that will save on the cost of paying outside companies to chip Harmac’s waste wood for re-use. With only 300 of Harmac’s 1,200 acres occupied by the mill, the company is planning to lease some of its excess industrial land to other companies. There are also discussions underway with the City of Nanaimo about using Harmac’s waste treatment systems to treat municipal sewage.

Sitting in the company’s modest thirdfloor boardroom, Smiley and Sampson reel off a list of advantages that have allowed the re-born mill to compete.

Harmac has no outside debt to burden it during the credit crunch.

It has a guarantee from its workerowners that there will be no lockouts or strikes for 11 years.

Since reopening in October, the company has reduced its production costs by about $100 a tonne.

With North American pulp prices down from about $885 a tonne last August to $650 a tonne at the end of March, Sampson declines to reveal Harmac’s current production cost, but insists that company’s new efficiencies are paying off.

“We’re tremendously more competitive now,” he says. “It’s going to be the companies that make it through the downturn that prosper in the end. We’re at an advantage because we’ve been hurting far less than everyone else.”

Smiley says the scaled-down size of the company, coupled with on-site ownership, allows Harmac a flexibility it never had under larger corporate structures.

“Pope & Talbot’s office was in Portland, Ore., and I think they lost touch with what could be done and should be done,” Smiley says. “Now all of the decisions are made right here in this mill, in the best interests of Harmac.”

Worker-owners now have a direct line of communication with management and a vested interest in contributing costsaving ideas, he adds “The guys in the shop have an ability

May/June 2009 Pulp & Paper Canada

p 17-18 success story.indd 18

to affect results on a daily basis and that really adds a lot,” Smiley says.

Machine operator Doug Narver says the new contract promotes efficiency by allowing workers to perform any job for which they are qualified.

“Now when a machine goes down there are guys down here right away helping out,” Narver says. “They know they can’t afford a shutdown.”

Even more important, he adds, there’s been a fundamental change in attitude.

“There used to be a lot of negative energy in this place. The guys who chose not to come back were constantly telling us we’d never survive,” Narver said. “It’s probably good they didn’t come back.

Everybody that’s here now was willing to pay to be here.”

Good business model will weather the downturn

Still, as the industry casualties continue to pile up, the long-term survival of Harmac’s worker-owned mill is far from ensured.

In December, Harmac’s main competitor, Catalyst, announced temporary shutdowns at its four West Coast mills.

By the end of February, Catalyst had eliminated more than half of the 300 jobs at its Powell River plant on the mainland, laid off two-thirds of the 750 workers at its Crofton Mill on Vancouver Island, and shut down its Elk Falls mill in Campbell River, eliminating about 350 jobs.

Despite some of the worst industry conditions he’s ever seen, Quinn admits Harmac’s low overhead, flexible management structure, and motivated work force may allow it to survive the downturn.

“If you can get everyone moving in the same direction, it’s a pretty powerful thing and that’s what I think Harmac has going for it right now,” he says.

There’s already talk of bringing back another 40 workers to start up Harmac’s second production line and Sampson maintains that Harmac is well-positioned to capitalize when the markets begin to improve.

“We’ve got a great model here,” he says. “It’s just that the real world hasn’t co-operated with us yet. But it will.”

PPC

pulpandpapercanada.com

11/06/09 12:45 PM

biorefining

T52

Partnerships for Successful Enterprise Transformation of Forest Industry Companies Implementing the Forest Biorefinery

By V. Chambost, J. McNutt, and P.R. Stuart Abstract: Increasingly, forest product companies are seeking to diversify their revenues, and improve their profitability via implementation of the forest biorefinery. This paper considers the overall approach that forestry companies might consider for the implementation of the forest biorefinery, the enterprise transformations implicated, and, most importantly, the partnerships that must be created in order to mitigate risk and enhance the potential for success of biorefinery implementation. Forestry companies that limit their consideration of the biorefinery as an investment in projects that yield interesting returns in the short term, such as pellet mills or biofuels, may or may not be successful at transforming the business models of their companies in the longer term. The recommended approach is to identify new added-value biorefinery products to be manufactured over the longer term, the new supply chain mechanisms needed for their efficient delivery, and importantly, the quality partners needed to be successful in this objective.

T

he forest biorefinery (fbr) is increasingly being considered by forest products companies as a viable business option to diversify and grow revenues – while at the same time potentially resulting in significant reductions of greenhouse gas emissions. In practice there are many possible biorefinery routes, i.e. product and process combinations that might be feasible for a company, but only a few options will bring sustainable competitive advantages. The forestry industry, at the same time struggling with its economic stalemate situation [1], must capture the intrinsic value of its existing activities while identifying these viable new product/process opportunities. Critically, the company’s enhanced product portfolio after biorefinery implementation, i.e. traditional pulp and paper products plus new biorefinery products, must be systematically identified in order to maximize the likelihood for successful transformation. At the same time as assessing the enhanced product portfolio, the technical, techno-economic, and commercial risks associated with each strategy must be identified and mitigated.

The development and the integration of a slate of new products into an existing product portfolio requires the selection of viable biorefinery processes permitting the manufacture of the products at a competitive price (key to the technology strategy), and the identification of promising products for the market including their penetration via efficient delivery systems (key to the business strategy). The forest industry, vested in a commodity and manufacturing-centric core business, must be prepared to transform in order pulpandpapercanada.com

p 19-24 Chambost TP.indd 19

to compete in new competitive markets such as the biofuels and added-value biochemicals markets. In this context, forestry companies must recognize their competitive weaknesses and maximize their existing competitive strengths in order to establish successful biorefinery strategies.

One of the immediate priorities of forestry companies is thus establishing ‘quality’ biorefinery strategic alliances with other companies that enable risk mitigation/sharing, and value creation via assets sharing. One type of strategic alliance referred to in this paper is that of the value-chain partnership, which can be defined as “companies in different industries with different but complementary skills which link their capabilities to create value for ultimate users.” [2] There are several partner and partnership model scenarios that potentially offer competitive advantages over the longer term. The strategic compatibility of business models and visions, the long-term capital investments required, and the potential revenue diversification are critical elements in partnership creation. However, how to identify the best partner and partnership model enabling the creation of sustainable competitive advantages is not obvious.

One strategy is to implement the biorefinery via a phased approach that supports a targeted new product portfolio [3]. According to this strategy, forest companies gradually implement the biorefinery by lowering manufacturing costs, diversifying the product slate, and finally optimizing existing delivery systems and supply chains. Most importantly, these phases must be supported by the selection of appropriate partners and partner-

V. Chambost, NSERC Environmental Design Engineering Chair in Process Integration, Department of Chemical Engineering, École Polytechnique, Montréal

J. McNutt, Center for Paper Business and Industry Studies (CPBIS), Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA

P.R. Stuart, NSERC Environmental Design Engineering Chair in Process Integration, Department of Chemical Engineering, École Polytechnique, Montréal

Pulp & Paper Canada May/June 2009

19

12/06/09 7:29 AM

T53

biorefining

Fig. 1: Examples of strategic partnerships for biofuels/bioproducts development

ship models. Depending on the business model targeted by a forestry company, different technological, commercial, and financial partnership strategies could be considered [4].

The phased implementation of the biorefinery implies Enterprise Transformation (ET). ET is a core strategy of leading companies for enhancing organizational performance to stimulate attractive profits that are sustainable over the longer term. In this manner, ET should become the recognized target for forestry companies embarking on the FBR. The value capture subsequent to FBR implementation is expressed through ET and should significantly help the forest sector focus on achieving a new competitive position in the market by becoming marginscentric, for example. The overall benefit of the FBR must not be limited to revenue increase or product diversification in the short-term, but rather should target an improved business strategy over the intermediate term [2].

In implementing the FBR, forest product companies must understand the linkage of markets/products/processes and partnership selection with business models and ET in order to create and secure value over the long term.

OBJECTIVE

In order for forestry companies to successfully implement the FBR, it is critical that competitive disadvantages such as access to capital and other factors be addressed through strategic partnerships and partnership models. The objective of this paper is to demonstrate the importance of developing a long term, sustainable biorefinery vision, as opposed to considering only short-term cash flow objectives, and the 20

linkage of this with partnership selection.

SOME PARTNERSHIP EXAMPLES FOR FOREST BIOREFINERY DEVELOPMENT

As market interest increases for carbonneutral alternatives to petrochemical products, including biofuels and added-value biochemicals, strategic R&D partnerships for technology development and/or market access are being announced, mainly in the chemical and petrochemical industries (Fig. 1). The strategy of building such non-traditional partnerships is gaining the interest of forestry companies that are considering FBR implementation and company transformation.

Working on the extension of its product portfolio, UPM-Kymmene has developed a strategic partnership with Andritz-Carbona in order to cooperate on the development of a technology for biomass gasification and biodiesel production. Biodiesel has been recognized by UPM-Kymmene as a “natural extension for companies whose core business is now newly defined as adding value to wood raw material.” [5] In North America, the forestry company Weyerhaeuser, in collaboration with Chevron, has created a joint-venture called Catchlight Energy LLC. Each company contributes to the JV, whose goal is to develop economical, low-carbon biofuels while maximizing each company’s competitive advantages. Catchlight Energy LLC offers a strategic, low-risk diversification opportunity to both participating companies. Other partnerships with universities, laboratories, and technologybased companies support the development of second generation biofuels.

Another interesting example is that

May/June 2009 Pulp & Paper Canada

p 19-24 Chambost TP.indd 20

Fig. 2: Examples of potential biorefinery partners for a forest company considering the implementation of the forest biorefinery

of StoraEnso,which signed an agreement with Neste Oil to develop technology for the production of biofuels, e.g. biodiesel from wood residues [6]. In this case, each company defined its contribution to the joint venture, such as biomass supply in the case of StoraEnso, and refining and marketing of the end-product in the case of Neste Oil. More recently, StoraEnso has announced that they are seeking to manufacture beyond biofuels production, and develop for added-value chemicals production.

These forestry companies have embarked on partnership development with specific implications to the supply chain, and may partner with other stakeholders who offer complementary skills across the supply chain to maximize the partnership outcomes [7]. Different kinds of partnership models can be established, depending on the company’s business model, and vision and mission for the company over the longer term. As per the above examples, efforts must identify the right partner and partnership model in order to implement the biorefinery successfully using less-risky approaches.

PARTNERSHIPS FOR THE FOREST BIOREFINERY

If the FBR is considered by forestry companies as another capital spending project seeking an interesting internal rate of return (IRR) in the short term, then the likelihood of company failure may well increase in the longer term [8]. The FBR represents a unique opportunity to gradually diversify revenues and transform the core business of forestry companies. The FBR thus implies the determination of an evolving product portfolio including traditional pulp and paper products as well pulpandpapercanada.com

12/06/09 7:30 AM

biorefining

Fig. 3: Strategic phased implementation of the FBR

as new biorefinery products [2]. Then a suitable technology strategy should be developed that serves the business strategy associated with the new product portfolio, as well as the modes of product delivery and associated enterprise transformation.

Successful large product diversification for a company is a strong function of its strategic alliances [9]. Partnerships can facilitate critical issues such as accessing complementary assets and know-how, reducing time to market, mitigating risks, sharing investment costs; hence partnerships can increase the probability of capturing (and sustaining) first-mover advantages [10]. This is especially true for the financially distressed forest industry which must gather the capital required for FBR transformation.

Partnerships for the FBR are critical in order to (1) meet profitability targets by milestone dates, (2) reduce transformation risks associated with the manufacture of new products intended for new markets, (3) ensure rapid and efficient business development of the biorefinery ahead of potential competitors, (4) secure competitive advantages in the short term, (5) enter an existing value chain to mitigate market risk, and (6) efficiently set up new and ideally unique supply chains.

Partner selection Benefits of partnering may well decrease as the number of partners increases [5], if a strategic approach is not well-defined.

In fact, not all strategic alliances bring a competitive advantage nor will they necessarily ensure a sustainable business model over the long term. The selection of the “best” partner(s) is thus necessary, but not obvious.

Many possible partnerships can be identified from a forestry company perpulpandpapercanada.com

p 19-24 Chambost TP.indd 21

T54

Fig. 4: Example of evolved product portfolio for a forestry company implementing the biorefinery

spective for enhancing the potential for successful FBR implementation (Fig. 2).

At the operational level, feedstock partners could increase feedstock supply and lower overall feedstock costs secured for the long-term. Commercial partners, for example chemical companies and/or logistics partners, could better enable product development and its efficient delivery to the market. Outside the operational level, technology partners could bring a shortterm competitive advantage providing the opportunity to be first-to-market for targeted green biorefinery products. Finally, financial partners, such as equity partners, can help address the complex issues associated with the required large project investment, which must be invested over the long term in order to transform the company.

Opportunistic or strategic partner selection should be made in order to identify “quality” partners [11]. Among the possible selection criteria, some are essential, such as (a) the perspective of each potential stakeholder(s) and (b) the identification of key drivers for partnering. The partnership should enable the creation of unique competitive advantages via, for example, (a) the development of a slate of products that will be part of the new product portfolio of the forestry company, and (b) the delivery of products to the market via the exploitation of existing value chains coupled with the design of a unique and efficient new supply chain.

Through a panel discussion that included (1) a major chemicals company, (2) a major forestry company, and (3) a leading biorefinery technology provider, the following elements were identified as among the most critical for establishing the long term business alliances essential for the success of the FBR [3].

The existing strategic business model of each company must embrace the biorefinery concept.

The executives of partnering companies must have an expressed company strategy that embraces the biorefinery in order to justify the long-term commitment needed for its implementation. Equally important, the partnering companies must come to agreement regarding partnership control and management in order to enhance business success [12]. Thereafter, biorefinery partnerships should bring value to stakeholders relative to the risk taken by each of the partners. For example, the partial and/ or complete integration of a corporation’s core business into the partnership business model should be determined in order to best serve the long-term returns sought by the partnership, while preserving interim cash flow and other requirements. For the case of forestry companies that may have difficulty obtaining the necessary capital to invest over the longer-term, this may, for example, involve sacrificing some of their best assets to the partnership.

The biorefinery product portfolio vision should be well-defined, but flexible in its definition for the longer term.

The value offered by an expanded product portfolio resulting from biorefinery implementation should be recognized by the partners. For example, the potential to mitigate the risk due to uncontrollable factors, such as price volatility, via the development of an appropriate product portfolio will greatly enhance the long-term viability of a partnership. In the case of forest product companies, for example, it is critical that existing assets be considered for incorporation into the partnership so that a unique supply chain can be exploited. In contrast, the model Pulp & Paper Canada May/June 2009

21

12/06/09 7:30 AM

T55

biorefining where forestry companies supply biomass to a joint venture that processes this into primary chemicals for sale to a chemical or energy company may not result in a company transformation to a profitable business model in the longer term.

Biorefinery process technologies are emerging and future market conditions are difficult to predict due to ever-lower oil reserves and emerging carbon policy.

The partnership model should thus allow for flexibility in the terms and conditions needed to change and thus sustain the partnership under changing market conditions.

Financial risk mitigation for each partner: “One project, one site at a time.”

Financial risk identification and mitigation is a critical concern for any partnership, and is perhaps particularly complex in the case of the biorefinery where substantial outlays of capital are required over a period of years. Further, in the context of a company-to-company partnership, financial risk is difficult to recognize in the partnership model. A careful product portfolio expansion is required where, for example, targeted added-value bioproducts are to be made and a market segment dominated by the new joint venture company. This should be implemented in a number of implementation phases, each of which must be financially attractive. The approach of creating a long-term partnership vision, implemented one project, one site at a time, and incorporating contractual flexibility is crucial to mitigating financial risk associated with the partnership.

FOREST BIOREFINERY IMPLEMENTATION STRATEGY

As forest companies pursue different FBR strategies, various approaches will emerge, including (a) deferring an investment in biorefinery processes until they are wellproven and relatively risk-free, (b) focusing on cost reduction strategies related to FBR opportunities and implementing projects to replace fossil fuel use or produce commodity biofuels, (c) moving beyond cost enhancement to produce new added-value bioproducts resulting in revenue growth and some improvement in business model profitability, and (d) moving to a new business model where the ultimate goal is sustainable margin enhancement for the long term [2].

22

For companies seeking to transform their business into profitable enterprises, the final option is undoubtedly the vision to be embraced. To achieve this, companies must implement a series of technologies and produce a portfolio of new products.

The successful implementation of the FBR at an existing pulp and paper mill might be achieved using a strategic phased approach, taking into account short, midand long-term goals expressed in Fig. 3.

Biorefinery Phase I – Lowering operating costs Lowering mill operating costs by replacing fossil fuel use at the mill via the production of biofuels represents an interesting alternative to address in part the current economic stalemate situation of forestry companies. This first biorefinery product could be consumed by the mill itself to replace fossil fuels in the short term, or could entail the manufacture of biofuels for the market. It should be considered as a “building block” process for the production of added-value chemicals at a later point in the biorefinery development. The viability of these projects is based in the emergence of policy and regulations related to global warming, as well as the volatile and increasing price of petroleum. This preliminary phase of the biorefinery should also ensure a long-term viable price of a large volume of biomass for the forestry company core business at the same time.

Alone, this biorefinery implementation phase will assist to lower costs, but does not result in company transformation nor render the forestry operations competitive for the longer term.

Biorefinery Phase II – Value creation The goal of this biorefinery implementation phase is to increase revenues through the production of added-value biochemicals and diversification of the existing product portfolio. The new revenue streams may be from the development of a biorefinery product family based on the chemical “building block” produced in Phase I, or companies may wish to invest directly in process technology for bioproducts that diversify revenues. At this stage, strategic definitions of process/product combinations, product delivery to the market, competitive position of product on the market, and flexibility of the product family are

May/June 2009 Pulp & Paper Canada

p 19-24 Chambost TP.indd 22

essential in order to successfully determine the evolving business model. The modified product portfolio might be implemented gradually one project at a time, at several mills, and support the creation of value over the long term. Partnerships are thus essential in order to minimize technical, commercial, economic, and financial risks.

Biorefinery Phase III – Value maximization The goal of this phase is to maximize the operating margins from the transformed company, and improve bottom line results through the re-engineering of supply chains, systems that exploit manufacturing flexibility, new delivery mechanisms, etc.

Partnerships are critical also at this stage in order to optimize the results of the new delivery systems [13].

Linkages of Strategy with Enterprise Transformation Enterprise transformation is a core strategy of some leading companies to increase profits sustainably over the longer term.

In the case of so-called “inside-out enterprise transformation”, the current mission/vision of the company is maintained, but the company is made-over from bottom to top in terms of their processes.

On the other hand, “outside-in transformation” is when the core vision/mission changes. In this case, the targeted service or product is changed for a company as well as the way it is delivered. Naturally, this must be done in a manner synergistic with the core business and competency of the pre-transformed company, e.g. UPS has become “Big Brown” and focuses on delivering supply chain services in and around their basic courier service.

The forest industry transformation to the biorefinery requires achieving both of these transformations.

In addressing Phase II of this transformation, the company must see itself as ultimately committing to the manufacture of new biorefinery products in the context of a change in the core business, and not simply as a revenue increase. If the context of the biorefinery investment is in a separate JV, then the forestry company will have achieved inside-out transformation but not outside-in transformation. The manifestation of both transformations is complete only after the execution of Phase III, where the new product portfolio is delivered using new business processes. pulpandpapercanada.com

12/06/09 7:31 AM

biorefining BUILDING STRATEGIC AND SUSTAINBLE PARTNERSHIPS

Employing the phased approach described above will lead forestry companies towards the identification and formation of partnerships during the early stages of FBR implementation. This is because whereas a systematic product and market analysis may lead to a number of potentially successful business plans, there will be a smaller number of “quality” partners available to forestry companies for the biorefinery, and it will be essential to negotiate and partner with these before other companies who are potentially competing in bioproduct markets.

Financial partners could be considered at each phase of the strategy in order to bring sufficient financial capacity to the FBR project. The financial partners could be limited to the role of investment, or could at the same time be the operating partner for the enhanced product portfolio.

Below, some examples are presented in order to illustrate partnership opportunity during this phased approach. Issues of interest for partnerships are presented in the context of a forest company’s overall vision, i.e. the approach to partnership will change depending on the perceived endpoint. In many cases today, a company’s endpoint might well be Phase I, i.e. lowering operating cost.

Biorefinery Strategy End-Point: Lowering Operating Costs During the implementation of Phase I, a mill’s product portfolio is extended via the production of bioenergy products and/or a chemical building block, such as bioethanol or biodiesel. Several outcomes could emerge from this strategy as an end-point, including the following for examples: • Lowering of delivered biomass costs due to the implementation of new and efficient biomass harvesting technologies that transport increased quantities of biomass to mill site; • Reduction of the carbon footprint of forestry companies due to the elimination of fossil fuels, and benefits from trading the carbon credits; • Reduction of mill operating costs via the replacement of fossil fuel at the mill, or marginal increase of revenues via the sale of commodity bioethanol into a fuel blend tank. However, except in unusual cases, pulpandpapercanada.com

p 19-24 Chambost TP.indd 23

finite bioethanol volumes will be produced (limited by biomass availability) at a given site and will be sold at commodity prices.

Associated with this as an end-point biorefinery strategy, two kinds of partners might be considered: Feedstock partner – enabling economies of scale Securing low-cost, sustainable access to additional quality biomass, i.e. forest and other biomass such as agricultural biomass, residues, and energy crops, could secure low costs for secure production of both pulp and paper as well as biorefining products.

Technology partner – enabling a short-term competitive advantage Identifying partners whose technology would enable the cost-competitive manufacture of biofuels and at the same time would be prepared to commit to a single forestry company for a period of time, is not obvious. The technology partner, whose general goal is to accelerate the commercialization of the biorefinery technology, should be able to provide a competitive position to the forestry company in terms of low product manufacturing costs. Nevertheless, the speed of competing technology development on the market will likely only provide a short-term cost competitive advantage.

Biorefinery Strategy End-Point: Increase revenues Figure 4 illustrates an example of product portfolio development, which begins with the introduction of a product family based on the Phase I production of bioethanol followed by the implementation of ethylene and polyethylene in Phase II. Manufacturing flexibility enables stable revenue diversification by mitigating the effect of product price volatility [14]. Reducing product volumes along the biorefinery process chain is accompanied by increased process and market complexity, nevertheless, even accounting for yield loses from ethanol to polyethylene, overall revenues should increase [15].

The outcomes that could emerge from this strategy as an end-point include the following: • Increased opportunity for process integration between the biorefinery and existing mill operations, resulting in lower

T56

unit production costs for pulp and paper products (depending on the site-specific processes and conditions) due to shared facilities and overheads; • Increased opportunity for sales revenue from new products; • Increased potential for synergies in product delivery logistics.

In addition to the partners associated with the biorefinery end-point strategy targeting cost reduction, partners could be considered for revenue diversification through new products delivery, based on enabling the efficient delivery and sale of products. The competitive advantage resides in the definition of an efficient and competitive supply chain via the selection of the right delivery product partner.

For example, this step might involve a commercial partnership between a forestry company and a large multi-national chemicals producer, who seeks access to lignocellulosic biomass needed to produce green products that replace or substitute existing fossil-based products. A robust business model, implying an outside-in transformation, is required in order to maximize the value of creating a new product portfolio, and in the case of the example shown in Fig. 4, the potential for selling flexible quantities of ethanol, ethylene and/or polyethylene depending on market conditions.

Biorefinery Strategy End-Point: Improve profit margins Phase III is about value maximization via the optimization of product delivery systems, and other transformative changes that might take place such as outsourcing or off-shoring. The company should evolve the supply chain policy from being manufacturing-centric to margins-centric in order to deliver the new product portfolio [7]. Whereas the business model was essentially defined in Phase II of the biorefinery strategy, it is only with the Phase III end-point that significantly improved margins will be achieved via implementation of the biorefinery. In Phase II, the company would have identified the partners and products providing an interesting market. In Phase III, systems would be implemented to deliver the product portfolio including wood, pulp, paper, energy, and bioproducts in a supply chain that is unique to the newly-formed biorefinery company.

Pulp & Paper Canada May/June 2009

23

12/06/09 7:31 AM

T57

biorefining In addition to the partners described above, logistics partners such as value chain partners, might be considered in order to strengthen a company’s competitive position over the long term. At this stage, the company is made-over via an outside-in transformation [2].

The importance of partnering in order to implement the FBR shouldn’t bring additional complexity to the business model, but rather it should enable a better focus on core competencies, and allow biorefinery companies to optimize existing assets.

DISCUSSION AND CONCLUSIONS

Different forestry companies have their own vision regarding the forest biorefinery.

Certainly, there will be forestry companies who will not implement the biorefinery.

There will be those who will employ a poorly-conceived strategy for its implementation and those who will proactively and strategically make decisions suitable for transforming their company into a unique new biomass-processing company making profits sustainable into the longterm.

The phased approach proposed here recommends the incremental implementation of the FBR over the long term, through (a) the identification of a longterm business model, and (b) the proactive creation of quality partnerships in the short term. Phase III of the overall strategy implies the definition of clear and achievable targets, as well as changing the mission and vision of the company over the long term. In this context, partnerships are essential for consolidating and securing value creation, as well as enabling the company’s transformation by addressing the company’s competitive disadvantages.

There are a number of key partnership issues that must still be addressed once the strategic approach has been fixed.

For example, how can forestry companies

24

quantitatively identify and recognize the benefits of implementing the FBR in terms of value creation, enterprise transformation, and associated risk identification and mitigation? What are the appropriate partnership models in order to best ensure the development of a viable product portfolio that is flexible with market conditions over the long term?

In implementing the FBR, forest product companies must therefore understand the linkage of markets, products, and processes with partnerships and business models. Different biorefinery strategies will lead to different levels of FBR implementation, different partnership strategies, and different degrees of enterprise transformation.

ACKNOWLEDGEMENTS

This work was supported by the Natural Sciences Engineering Research Council of Canada (NSERC) Environmental Design Engineering Chair at École Polytechnique in Montreal.

REFERENCES

1 STUART, P. R. The forest biorefinery: survival strategy for Canada’s P&P sector? Pulp & Paper Canada 107(6): 13-16 (2006).

2 KANTER, R. M. Collaborative advantage: the art of alliances. Harvard Business Review 72:96-96 (1994).

Résumé: Les entreprises de produits forestières cherchent de plus en plus à diversifier leurs revenus et à améliorer leur rentabilité en implantant des activités de bioraffinage forestier. Ce papier considère les stratégies que ces entreprises pourraient adopter en matière de bioraffinage forestier, sur les transformations à apporter, et aussi sur les partenariats qui devraient être établis afin de réduire les risques et d’accroître le potentiel de réussite des bioraffineries. Les entreprises forestières qui considèrent le bioraffinage seulement comme un investissement classique dans des projets offrant des rendements intéressants à court terme, comme la fabrication de billes de bois (wood pellets) ou de biocombustibles, pourraient ne pas réussir à transformer leurs modèles d’entreprises à plus long terme. L’approche présentée souligne la nécessité de déterminer quels sont les nouveaux produits de bioraffinage à valeur ajoutée à fabriquer à plus long terme, les nouveaux mécanismes de la chaîne d’approvisionnement nécessaires afin de pouvoir les livrer plus efficacement, et plus important les partenaires stratégiques requis pour attiendre ces objectifs.

Reference: Chambost, V., McNutt, J., and Stuart, P.R. Partnerships for successful enterprise

transformation of forest industry companies implementing the forest biorefinery. Pulp & Paper Canada May/June 2009 T52-T58. Paper presented at the 95th PAPTAC Annual Meeting in Montreal, February 2009. Not be reproduced without permission of PAPTAC. Manuscript received Sep. 1, 2008. Revised manuscript approved for publication by the reviewing panel on March 13, 2009.

Keywords: FOREST BIOREFINERY, ENTERPRISE TRANSFORMATION, PARTNERSHIP, PRODUCT PORTFOLIO.

May/June 2009 Pulp & Paper Canada

p 19-24 Chambost TP.indd 24

3 CHAMBOST, V., McNUTT, J., and STUART, P.R. Guided Tour: Implementing the Forest Biorefinery at an existing Pulp and Paper Mill. Pulp & Paper Canada 109(7/8):19-27 (2008).

4 JANSSEN, M., CHAMBOST, V., and STUART, P.R. Successful partnership for the forest biorefinery, Industrial Biotechnology 4(4): 352-362 (2008).

5 UPM Kymmene web site, Capital Market Day 2008 presentations.

6 StoraEnso. http://www.storaenso.com (Sept. 1, 2008).

7 CORBETT C.J., BLACKBURN J.D., and VAN WASSENHOVE L.N. Partnerships to improve supply chains. Sloan Management Review 40(4):71–82 (1999).

8 BROWN D. Risk perception and financing options for biorefineries, TAPPI International Bioenergy & Bioproducts Conference, Portland, OR (27-29 August 2008).

9 DEEDS, D. L. and HILL, C. W. L. Strategic alliances and the rate of new product development: An empirical study of entrepreneurial biotechnology firms.

Journal of Business Venturing 11(1):41-55 (1996).

10 MOHR J., and SPEKMAN, R.E. Characteristics of partnership success: partnership attributes, communication behaviour, and conflict resolution techniques.

Strategic Management Journal 15(2):135–152 (1994).

11 DOHERTY, A. M. Market and partner selection processes in international retail franchising. Journal of Business Research In Press, Corrected Proof (2008).

12 LYNCH, R. P. Business alliances guide. J. Wiley New York (1993).

13 MANSOORNEJAD, B., CHAMBOST, V., and STUART, P.R. Integrating product portfolio design and supply chain design for the forest biorefinery.

Accepted, Proceedings – Foundations of ComputerAided Process Design (FOCAPD) Conference – June 2008.

14 CHAMBOST, V. and STUART, P.R. Selecting the most appropriate products for the forest biorefinery, Industrial Biotechnology 3(2):112-119 (2007).

15 CHAMBOST, V., MARTIN, G., and STUART, P.R. “Identifying the Forest Biorefinery Product Portfolio”, Keynote at the 18th International Congress of Chemical and Process Engineering, Prague, CZ (2008).

pulpandpapercanada.com

12/06/09 7:31 AM

biorefining

T58

Integrating Bioethanol Production into an Integrated Kraft Pulp and Paper Mill: Techno-Economic Assessment

By E. Hytönen and P.R. Stuart Abstract: Both thermochemical and sugar process technologies can convert lignocellulosic raw materials into ethanol. To identify economically feasible solutions using these technologies, while the final decision should be based on a more extensive set of criteria, simple after-tax Internal Rate of Return (IRR) can be used as a selection criterion. In this paper, several integrated forest biorefinery design alternatives have been evaluated for an integrated kraft pulp and paper mill.

Based on prices and raw material availability, as well as published information about biorefinery processes, it was clear in this particular case study that corn ethanol is the most feasible option. It provides an IRR of over 20% at larger plant capacities. Following the corn ethanol option, thermochemical mixed alcohol synthesis routes also have interesting economics.

A

lthough fossil-based transportation fuel prices have plunged quickly after having skyrocketed during 2008, the environmental awareness and goals for fossil fuel use and emissions reduction have not been forgotten. Also, other aspects, such as energy security and the opportunity to increase revenues by manufacturing products based on biomass in general, continue to provide strong motivation.

Forestry companies are seeking improved profits from the implementation of new and sustainable business models, and one serious strategy exploits the concept of biorefining.

Bioethanol production as a biorefinery objective is very popular. It is volume-wise the most produced bio-product in the world after pulp and paper products, and its demand is rising due in good part to government legislation and policies.

The food-fuel dispute has led to increasing interest in lignocellulosic biorefineries, but in order to fulfil the demand using these feedstocks, new and existing technologies need to be further developed and integrated with existing ones.

One promising option is the integrated forest biorefinery (IFBR). The forest industry has access to the most abundant biomass resource. The IFBR can provide the forest industry both product portfolio diversification, and at the same time, reduced pulp and paper product production costs, to help companies survive the current difficult markets, and possibly even prosper into the future.

Bioethanol, and other bioalcohols and biofuels, can subsequently be used as raw material for the production of value-added derivative bioproducts.

This could be the next step for forest industry companies to further diversify their product portfolio and generate additional revenues. pulpandpapercanada.com

p 25-32 Hytonen TP.indd 25

This study focuses on assessing the profitability of bioethanol production using different process technologies. This enables the selection of promising ethanol production options, but does not consider the relative economic attractiveness of producing other biofuels and bioproducts.

To assess the production and capital investment costs of ethanol biorefineries, as well as the impacts on environment and the supply chain, process systems engineering (PSE) tools can be used. Tools such as process simulation cost modelling, life cycle assessment (LCA), and supply chain management (SCM) all have their place in the analysis of biorefinery implementation strategies.

Since the economic aspects are in many cases the dominating final decision making criteria, systematic methods are needed to evaluate and compare different IFBR options to demonstrate to the forest industry and policy makers the profitability of biofuel production.

Literature review

Raw material availability and cost plays a key role in high volume biofuel production. It varies significantly on a national and even on a regional level, and therefore biorefinery solutions are location-dependent. Perhaps the best known example of comprehensive raw material assessment is the “billion-ton vision” from the U.S. Department of Energy [1]. The data and other information used in this assessment are public and have been used in several state-level assessments that are useful for mill-level decision making in the U.S. [2, 3].

It has been recognized that raw material cost is an important factor in biorefining. “Process improvement invariably makes the cost of raw material the dominant factor in overall refinery economics” is

E. Hytönen NSERC Environmental Design Engineering Chair, École Polytechnique, Montreal

P.R. Stuart NSERC Environmental Design Engineering Chair, École Polytechnique, Montreal

Pulp & Paper Canada May/June 2009

25

12/06/09 7:34 AM

T59

biorefining table i. Raw material definition.

Code Raw material B Woody biomass: energy wood, bark, logging slash, undesirable trees, thinnings and forest debris P Pulpwood (hardwood) H Hemicelluloses extracted from pulpwood L Lignin separated from pulpwood C Corn CS Corn stover FW Food processing waste: brewer grains and whey from the dairy industry

one of the main conclusions of a study looking at well-established oil and wet corn-based refining industries [4]. The same study concludes that biofuels will be the main end product of companies investing in the biorefinery.

Several technologies are currently under development to produce biofuels from lignocellulosic biomass. Some references list available technologies and their current development stage based on publicly available information [5, 6]. It can be concluded that none of these technologies is yet operating at a commercial scale.

One of the reasons is that they are not competitive with current bioethanol production processes that use corn and sugar cane as raw material. However, targeted process efficiencies should render these processes competitive in the near future. This is shown in many published process assessments that use targeted efficiencies instead of current conditions for both the biorefinery and pulp and paper industry: enzymes are assumed to be available at a very low cost in biochemical process assessments [7], separation processes are assumed to be well established [8], and pulp and paper mills are considered to be modern [9].

Thorp et al. [10, 11] divided the production routes for biofuels into two groups based on their operating principles: • Thermochemical biorefinery processes: raw material is thermally degraded into carbon oxides and hydrogen, which are then synthesized into the targeted end product, and; • Sugar platform biorefinery processes: polysaccharides are first converted into sugars, which are then further fermented to produce the targeted end product.

One of the promising sugar platform routes to produce biofuels has been termed Value Prior to Pulping (VPP), where hemicelluloses are extracted from wood chips before pulping for ethanol and chemical production. The cellulose continues to be used for pulp and paper production [8, 12, 13]. The first demonstration scale bioethanol IFBRs are currently under construction in the U.S., and one of those is the integration of the VPP process into a kraft pulp mill in Old Town, Maine.

A promising thermochemical process concept is black liquor gasification, where the dissolved organics from the pulping process are converted into synthesis gas and further to energy, fuels, or chemicals. The most comprehensive study on this process was done by Larson et al. [9].

Few systematic comparisons of IFBR raw material and process options for biofuel production have been published to date.

Biorefinery techno-economic studies have generally considered one process at a time, and because the assumptions are not the same in each study, comparisons are difficult. U.S. DOEfunded research reports are one exception. They use same general 26

May/June 2009 Pulp & Paper Canada

p 25-32 Hytonen TP.indd 26

table iI. Thermochemical ethanol production routes.

T1 T2 T3 T4

Gasification, MA synthesis, ethanol separation Gasification, syngas fermentation, ethanol purification Steam reforming, MA synthesis, ethanol separation Steam reforming, syngas fermentation, ethanol purification

Table III. General sugar platform ethanol production routes.

S1 Acid hydrolysis, fermentation, ethanol purification S2 Pre-treatment, enzymatic hydrolysis, fermentation, ethanol purification

approach and basis for techno-economic assessments; however, they have been done for stand-alone facilities [7, 14, 15].

Selecting the most profitable or most suitable process or process combination to be integrated into a pulp and paper mill from the many possible options (raw material-technology combinations) is a complex task. One method proposed for the selection of a biorefinery process uses a superstructure of biorefinery options, PSE tools, and optimization [16], which targets process selection based on generic design methodologies. Another method, used in a pulp and paper mill retrofit case study [17], is called Large Block Analysis (LBA), and holds significant promise. However, this method has not yet been applied in the biorefinery context.

The economies of scale for biorefining have been addressed in certain cases [18-20]: the bigger the production capacity is, the lower the production costs and capital investment costs are on a per tonne of product basis. However, a small IFBR might be economically viable when it is integrated into a pulp mill. This aspect is very important in strategic decision making, especially for the production of bulk products such as bioethanol.

There is an important need for evaluating different technologies on as similar a basis as possible using a systematic methodology, even given the risks implicated due to different design bases from different sources of information.

Objective

This paper focuses on the integration of bioethanol production processes into a pulp and paper mill. The objective is to compare the techno-economics of different bioethanol IFBR design options in order to be able to screen out non-profitable options.

This approach takes into account the impacts of IFBR integration (integration into the pulp and paper mill and integration of several bio-processes). A North American hardwood kraft pulp mill is the case study context.

Methodology

A conventional techno-economic assessment is used in order to calculate the profitability of IFBR for the case study. First the raw material inventory and assessment for the mill location was completed. Then existing and emerging technologies for bioethanol production were examined to define IFBR cases. Different mill configurations (current scenario and modernized mill scenario) were examined to account for different integration possibilities if mill were to be modernized concurrently with biorefinery implementation. Mass and energy balances and production and capital investment costs were calculated based on reference information for both scenarios. Last, the profitability of each case was estimated by calculating the after-tax Internal Rate of Return (IRR). pulpandpapercanada.com

12/06/09 7:35 AM

biorefining

T60

TABLE IV. Reference descriptions of biorefinery processes.

Technology

Description of available information

High temperature gasification [9] Medium temperature gasification [15] Mixed alcohol synthesis and ethanol separation [15] Syngas fermentation [25, 26, 28] Acidic hydrolysis [29] Enzymatic hydrolysis [7, 14, 30] Corn ethanol [14, 31, 32] Hemicellulose extraction [8, 13]

Forest biomass gasification; mixed alcohol production balances of reference are not used in this study Detailed balances and cost definitions for medium temperature gasification of forest biomass Detailed balances and cost definitions for MA synthesis and alcohol separation processes Only estimates of production costs available, no mass and energy analysis available Mixed hardwood to ethanol process balances and cost analysis Detailed balances and costing for corn stover-ethanol process Detailed balances and costs for dry milling corn ethanol plant Balances and costs of extraction of VPP options

Technology assessment The processes to produce ethanol were divided based on the definition given by Thorp et al. [10, 11]. In the following sections, the generic routes to produce ethanol and the IFBR design cases (raw material – route combinations) are defined.

(syngas), 3) gas cleaning by removing inorganic components and adjusting the H2:CO molar ratio via the water-gas shift reaction, and 4) gas compression and synthesis either with biological catalysts (enzymes) to ethanol or with chemical catalysts to mixed alcohols (MA).

Feedstock handling and drying before gasification, and product gas cleaning and conditioning are well developed process steps. Thermal degradation can be done with several gasification technologies. The two proven technology groups are high temperature (~1000°C) and medium temperature (~600°C) gasification. In high temperature gasification, part of the feedstock is combusted in the gasifier with addition of oxygen to generate the required heat for the endothermic gasification reactions. Lower temperatures are sufficient in indirectly heated gasifiers (steam reformers); they typically use external combustion of product gas or char to provide the energy for the process. The heat is transferred to the feedstock by indirect heating and solid “sand” circulation [15, 23].

The main processing step, alcohol synthesis, has not reached the commercial stage. However, there are several studies considering alcohol synthesis with chemical and biochemical catalysts [26, 28]. In chemical synthesis, the end product is a mixture of alcohols – methanol, ethanol and higher-molecular weight alcohols – from which the targeted component(s) can be separated.

In biosynthesis, syngas is fermented to ethanol. The advantage of biosynthesis over chemical synthesis is that the syngas can be converted largely to ethanol instead of several alcohols, and therefore the ethanol yield is higher. On the other hand, biosynthesis is constrained because of poor solubility of CO in ethanol.

Therefore, converting syngas to ethanol can take up to 25 days in contrast to 1-2 days with MA (mixed alcohol) synthesis. Also, by adjusting the H2:CO molar ratio, MA synthesis can be optimized to achieve a higher ethanol yield. [9, 15, 24-26] By combining these different process steps to produce ethanol, four thermochemical routes were established (Table II).

Thermochemical processes Thermochemical conversion routes are suitable for all raw material types. However, generally sugar-containing and starchy raw materials are more easily converted to ethanol through sugar platform processes.

Bioethanol production through thermochemical routes is not yet considered to be commercial. However, parts of the process employ well-known technologies. Thermochemical bioethanol production consists of four main steps, 1) feedstock preparation and drying, 2) thermal degradation of biomass into synthesis gas

Sugar platform processes The sugar platform is suited for most types of raw materials.

However, it is not yet possible to convert lignin and some other components of the feedstock such as proteins and fats into sugars, and subsequently to ethanol with biochemical processes. Sugar platform ethanol processes can be divided into four main processing steps: 1) during pre-treatment, the feedstock is fractionated mechanically, thermally, and/or chemically, 2) during saccharification, polysaccharides are converted to sugars, 3) during fermentation, the sugar(s) are converted to ethanol and 4) during

TABLE V. IFBR cases considered (raw material-process combinations, see Tables II and III for processes).

T1

T2

T3

T4

S1

S2

Biomass ✓ ✓ ✓ ✓ ✓ Pulp wood ✓ ✓ ✓ ✓ ✓ Hemicelluloses ✓ Lignin ✓ ✓ ✓ ✓ Corn Corn stover ✓ ✓ ✓ ✓ ✓ Food processing waste

✓ ✓ ✓ ✓ ✓ ✓

The calculations were done using Microsoft Excel. The methodology and assumptions are described in the following sections.

Raw material assessment The availability of raw material in the region around the mill was defined for raw materials (Table I).

Raw material costs at the mill gate as a function of plant capacity were defined using a published method [21] and mill region-specific information [2]. The raw material yield was assumed to be constant in the area where the mill is located, and was based on availability in a 50-mile radius. The hemicelluloses of pulpwood processed at the mill (10% of pulpwood) and lignin (35% of pulpwood) are assumed to be available at energy price (coal price), larger amounts are available at pulpwood price. Agrobased raw material base costs were taken from the literature [3, 22], and forest-based raw material base costs are calculated using actual prices.

pulpandpapercanada.com

p 25-32 Hytonen TP.indd 27

Pulp & Paper Canada May/June 2009

27

12/06/09 7:35 AM

T61

biorefining TABLE VI. Economic assessment variables.

Pulping line WWT

WT

Heat & power

Pulp mill

P

Pulp

B C CS

Legend: H

L

Commodity/waste Raw material/product Raw material By-prod.

End product Process Abbreviations: P = pulpwood B = biomass C = corn CS = corn stover FW = food processing waste H = hemicelluloses L = lignin WWT = waste water treatment WT = water treatment E:OH

Biorefinery

FW Process Process Process Process

FIG. 1. Case mill IFBR context.

purification, ethanol is separated from the fermentation broth.

Typically, technologies are characterized based on their saccharification process step: acid or enzymatic hydrolysis. The acid hydrolysis route uses either dilute or concentrated acid (mainly sulphuric acid) to break cellulose and hemicellulose into sugars. In the enzymatic hydrolysis route, the conversion is done with a mixture of cellulase enzymes. Enzymes are capable of breaking down polysaccharides to sugars, whereas acids will further degrade sugars to smaller molecules. Although enzymatic hydrolysis is thus selective, it is generally slower than acid hydrolysis. The second critical difference between hydrolysis processes resides in the preparation for fermentation. Because of the pH requirements for fermentation, the acid hydrolysis route needs neutralization and/or acid recycling before the fermentation step. The enzymatic hydrolysis route works in the same pH range as fermentation and thus does not need significant pH adjustments.

Another dimension to the sugar platform processes is the pre-treatment step. Perhaps the most comprehensive comparison between pre-treatment processes was conducted by CAFI (Consortium for Applied Fundamentals and Innovation). They compared five pre-treatment technologies for corn stover based on individual projects that characterized and optimized the technologies [27]. The biomass pre-treatment considered for each option was that considered in the referenced studies.

Some sugar platform processes also produce ethanol as coproduct. An example is acetone-butanol-ethanol (ABE) process.

These processes are not considered in this study.

Based on the above considerations, two generic routes for the sugar platform were defined for this study (Table III).

Case study design basis Several technology providers exist for the process routes described above, each of them having different process configurations and therefore also different economic performance. However, technology-specific mass and energy balance information for systematic and reliable comparison is not publicly available.

28

May/June 2009 Pulp & Paper Canada

p 25-32 Hytonen TP.indd 28

Tax 30% (when income positive) Depreciation MACRS (Modified Accelerated Cost Recovery System) with 200% declining balance depreciation method and 7-year recovery period Investment 100% paid in 2011 Working capital 5% Plant life 20 years Inflation factor 3% Start up 2012 (75% production), 2013 — 2032 (100% production) Selling price of ethanol 2$/gal Selling price of mixed alcohols (other than ethanol) 1.15$/gal Price of Distillers Dry Grind with Soluble (DDGS) (a by-product of the corn ethanol process) 100$/bdt

Therefore, mainly governmentally funded, published research reports that include comparable mass and energy balances have been used to describe these technologies (Table IV). Furthermore, the references are assumed to represent the routes for all possible raw materials, even though the reports consider specific processes/technologies for specific raw materials. Also, references are assumed to be valid for a range of plant capacities.

Case definitions The raw material-process combinations considered in this study are shown in Table V. These combinations describe the processing of one type of raw material (Table I) with one of the identified process routes (Tables II and III). These IFBR cases can be further combined to form hybrid IFBR cases (several raw materials-one process route).

Ethanol yields for different processing routes were taken from references (Table IV): • Thermochemical route alcohol yield is 90% of the theoretical maximum yield [15] • 85% of the mixed alcohols yield is ethanol [15] • Woody raw materials (B, P, L) have the same yields in thermochemical cases, but corn stover (CS) has lower yield due to its ash content (10% ash assumed) • Ethanol yields are 65% and 75% of theoretical maximum for the acid and enzymatic hydrolysis cases [7, 14, 29] • The ethanol yield from food processing waste is assumed to be 50% of corn ethanol yield.

Scenario definition Mill scenarios The case study mill IFBR is summarized in Fig 1.

All cases were integrated into the host kraft pulping process keeping pulp production unchanged, except for the case of pulp wood-to-ethanol, where no pulp is produced. The biorefinery processes use existing steam and power generation, water treatment, and waste water treatment systems until their excess capacity is fully utilized.

The case study mill wished to consider mill modernization. pulpandpapercanada.com

12/06/09 7:35 AM

biorefining 35%

Hemicelluloses

180

Cost ($/bdt)

140

Lignin

120

Hardwood

Biomass

Biomass

Corn stover

Pulpwood

Lignin

25%

Softwood

160

100

After-tax IRR

200

T62

80

20 %

15% 5% 0%

-5%

60

Corn

40 20

Food proc. waste

0 0

-15%

Corn stover

0.5 1 Biomass capacity (MM bdt/year)

0

50 T1

1.5

100 T2

150 T3

200 T4

Plant capacity (MMGPY EtOH)

FIG. 3. After-tax IRR of single line thermochemical cases as function of plant capacity

FIG. 2. Raw material supply curves.

After-tax IRR

The current and modernized mill configu- ity), purified water, and waste water were (TPI) is then: rations were considered to account for the considered. The demand of these aspects TPI = TIC * (1 + ind + cont) (2) 1 case was study data for biomass feeds at the time of the study were used, different interfaces with the biorefinery defined whether the caseSpecific mill capacity unusually lowor at processes. The main objectives of the mill sufficient to provide these demands, Here ind is the indirect project costs modernization were production capac- which ethanol plant capacity new systems (engineering, field expenses, etc.) and cont ity increase, energy and chemical recovery are needed. the contingency costs as percentage of total system updates, and water cleaning system installed equipment cost.

35% capacity increase.

The main changes with Capital Lignin investment costs Biomass Corn stover Pulpwood 8 the modernized mill were the increase in The capital investment cost should be cal- Manufacturing costs 25% hemicellulose and lignin availability for culated at the 20departmental level in order Bioethanol manufacturing costs with % the IFBR, and the boiler update enabled to account for cost decreases due to the capacity M, CM, consist of variable costs 15% the burning of solid residues from the integration. This information can be found (raw material, chemicals and utilities) and biochemical cases. in the literature, and therefore this level fixed costs (insurance, maintenance sup5% Both mill scenarios were assumed to of detail was used.

The equation for total plies): 0% start -5% at the same point in time, hence, investment costs (TIC) is: mill modernization and biorefinery impleCM = j pj mj + ins * TPI + maint * TIC (3) -15% mentation would be concurrent. Since the ai 0 50 100 M starting point is T1fixed, the impact of timeT3 150 TIC = iT4 200 ——— Ceq,i (1) where j represents streams of the proT2 Mref on economic variablesPlant such as prices, on cess, pj is the unit price of stream j, mj is capacity (MMGPY EtOH) raw material availability and on technolthe mass flow of stream j, TIC is total ogy development was the same for both where i represents the departments of installed equipment costs, TPI is total scenarios. the biorefinery plant including integrated project investment cost, ins and maint are departments, M represents the production insurance and maintenance supplies costs Economic scenarios capacity of the plant and Mref the produc- as a percentage of TPI and TIC. It was 1 Several must feeds be tion plant, ai isat the there additional labour Specificeconomic case studyparameters data for biomass at thecapacity time ofofthereference study were used, whichassumed point thethat price of are cornnowas defined order to have comparable scaling factor for department i, Ceq,i is the costs for the biorefinery, i.e. operators and unusuallyinlow results. The economic assumptions used installed equipment cost of department i in other personnel at the pulp mill would also in the literature (Table IV) were applied in the installation year. be qualified to manage and control the this study, e.g. the departmental capacity The three integration departments new biorefinery process. scaling factors, indirect investment costs, (energy, purified water and waste water 8 and contingencies. In Table VI the vari- systems) are subtracted if the mill’s existing Profitability estimation ables for after-tax Internal Rate of Return capacities were sufficient for both the pulp After-tax Internal Rate of Return (IRR) calculation are given. mill and biorefinery. In addition to this was used to measure the profitability of each integration aspect, in hybrid biorefinery scenario. IRR is calculated from net profit Mass and energy balances & cost calcula- cases the departments that can be com- and the TPI (equation 2) assuming the ecotion bined (such as distillation or fermentation nomic variables given in Table VI. IRR was in the sugar platform cases) were calculated calculated according to the following: Mass and energy balances Based on the literature (Table IV) and by scaling the department of one of the the mill scenarios, mass and energy bal- single production lines to total capacity of 20 incomet ———— = 0 (4) ances were calculated. This defines the the combined case. This way full integra- NPV = t=0 (1+IRR)t possible level of integration. As integra- tion benefits would be exploited.

From TIC the total project investment tion aspects, energy (heat and electric-

[(

) ]



pulpandpapercanada.com

p 25-32 Hytonen TP.indd 29

Pulp & Paper Canada May/June 2009

29

12/06/09 7:36 AM

biorefining

T63

where NPV is the net present value, and t is the plant life used in this study. The income is annual after-tax: incomet = | (IEtOH + Iby–prod – Cm) (1+inf)t – deprt |(1 – tax) -

(5)

where IEtOH is the income from ethanol, Iby-prod the income from by-products (such as mixed alcohols, DDGS, or excess electricity), CM is the manufacturing cost (these three variables are zero in the year t=0, which is the construction year), inf is the inflation factor, depr is the depreciation of the plant based on the depreciation system, and tax is the national income tax (applied only when income is positive).

RESULTS AND DISCUSSION

In Fig. 2 the raw material assessment results and supply curves of raw materials are summarized.

The unit price of raw material at the mill gate decreased as a function of hauling distance, which has also been found in other studies [20, 21]. When some critical capacity is reached, for example the amount of hemicelluloses at the mill, then the cost curve increases suddenly. Energy wood and corn stover raw materials have the lowest unit price except at small biomass capacities where hemicellulose and food processing waste have a lower cost.

Pulpwood has the highest unit price1.

The profitability of the single line IFBR cases are shown in Figures 3 and 4, and profitability of each case with 25 and 75 MMGPY ethanol production capacities are summarized in Table VII. The steam reforming options (T3 and T4) have higher IRR than the high temperature gasification cases (T1 and T2), which have higher investment costs and therefore lower IRR values. The mixed alcohol synthesis option (T3) has better economics than the syngas fermentation options (T4). This is due to higher investment costs for the fermentation route. In high temperature gasification cases syngas fermentation (T2) and mixed alcohol synthesis (T1) are comparable. Low cost raw materials, such as biomass and corn stover, are most profitable when comparing raw Specific case study data for biomass feeds at the time of the study were used, at which point the price of corn was unusually low 1

30

TABLE VII. After-tax IRR of single line cases with 25 and 75 MMGPY ethanol production capacities Process option

Feedstock

High temp. gasification + mixed alcohol synthesis (T1)

High temp. gasification + syngas fermentation (T2)

Steam reforming + mixed alcohol synthesis (T3)

Steam reforming + syngas fermentation (T4)

Acid hydrolysis + fermentation (S1)

Pre-treatment + Enzymatic hydrolysis + fermentation (S2)

Biomass Pulpwood Lignin Corn stover Biomass Pulpwood Lignin Corn stover Biomass Pulpwood Lignin Corn stover Biomass Pulpwood Lignin Corn stover Biomass Pulpwood Hemicelluloses Corn stover Biomass Pulpwood Hemicelluloses Corn stover Corn Food proc. waste

material options for each processing route.

Of the sugar platform cases, the corn ethanol process was found to have the highest IRR. The food processing waste case is comparable, but only at small capacity. The corn stover and pulpwood cases have the second highest IRR values, primarily because these processes have lower yields compared to the corn ethanol case.

All other cases have lower IRRs and are not shown in the figure. The acid hydrolysis process had higher IRR value than the enzymatic hydrolysis process with all raw material options.

Validation of these results is difficult.

However, it can be said that differences in prices, especially in chemical prices, result in lower profitability values in this study compared to the case studies published in the literature [7, 8, 33].

The results of single line cases with two ethanol production capacities, 25 and 75 MMGPY are presented in Table VII. Some examples of thermochemical hybrid cases are shown in Figure 5, and sugar platform hybrid cases in Figure 6. All shown cases are combinations of two raw materials using the same processing route.

Only the results for one raw material share proportion, 1:1, are shown in

May/June 2009 Pulp & Paper Canada

p 25-32 Hytonen TP.indd 30

25 MMGPY

75 MMGPY

–2 % – – –6 % 5 % 1 % –3 % 4 % 20 % 12 % 8 % 16 % 7 % 1 % –3 % 5 % 5 % 11 % – 22 % –3 % – – 8 % 26 % –

–1 % – – –4 % 7% 3% – 7% 25 % 17 % 3% 22 % 9% 3% – 8% – 15 % – 30 % – – – 13 % 37 % –

the thermochemical hybrid figure (Fig. 5). As can be estimated from the single line cases (Fig. 3), the hybrid case will have a high IRR value, if the single-line cases have high IRR values. For example steam reforming and mixed alcohol synthesis of biomass and corn stover has high IRR value. However, combinations of low single-line IRR values might have higher IRR values when combined, because of the lower capital investment costs (syngas cleaning and alcohol synthesis steps of the two cases could possibly be done with the same equipment).

Similar results were found for the sugar platform hybrid cases (Figure 6). Combining corn with other raw materials increases substantially the profitability of the other raw material. However, the total profitability will be lower than for the corn feedstock (only) case. For example, corn (95% of ethanol process feedstock) and hemicelluloses as hybrid case feedstock would have very high IRR value, although only the ethanol purification process could be integrated for these raw materials.

It was found that the modernized mill scenario impacted only the sugar platform cases. The impact of mill modernization can be seen by comparing Figures 4 and pulpandpapercanada.com

12/06/09 7:36 AM

Steam reforming + mixed alcohol synthesis (T3)

40%

Steam reforming + syngas fermentation (T4) High temp gasification + syngas fermentation (T2)

After-tax IRR

30%

biorefining

High temp gasification + mixed alcohol synthesis (T1) 20 %

20% 10% 60%

Food proc. waste Corn

50%

Pulpwood

Corn stover

Biomass

Hemicelluloses

0%

Steam reforming + syngas fermentation (T4)

0%

High temp gasification + syngas fermentation (T2)

30% 0

50

100

20%

150

200 20 %

Total plant capacity (MMGPY)

10%

After-tax IRR

After-tax IRR

Steam reforming + mixed alcohol synthesis (T3)

40%

40%

-10% 30%

T64

0%

0% -10%

High temp gasification + mixed alcohol synthesis (T1) 20 %

20% 10%

0%

0%

Enzymatic hydrolysis (S2)

Acidic hydrolysis (S1)

-10%

-20% 0

20

40

60

80

100

120

140

160

180

0

200

50

100

150

200

Total plant capacity (MMGPY)

Plant capacity (MMGPY EtOH)

FIG. 4. After-tax IRR of single line sugar platform cases as function of plant capacity.

FIG. 5. After-tax IRR of hybrid thermochemical cases (biomass (50%) + corn stover (50%)) as function of plant capacity.

60%

30%

Food proc. waste Corn

50%

Pulpwood

Corn stover

Biomass

Hemicelluloses

20 %

15%

Biomass (50%) + Pulpwood (50%)

After-tax IRR

After-tax IRR

40%

Biomass (50%) + Corn stover (50%)

Corn (50%) + Corn stover (50%)

-10%

100

Acidic hydrolysis (S1)

150

200

Enzymatic hydrolysis (S2)

Total plant capacity (MMGPY)

20 %

10%

30% 0%

After-tax IRR

50

20%

Corn (95%) + Hemicelluloses (5%)

0% 0

30%

0% Enzymatic hydrolysis (S2)

Acidic hydrolysis (S1)

-20% 0

20

40

60

80

100

120

140

160

180

20 %

200

Plant capacity (MMGPY EtOH) Biomass (50%) + Pulpwood (50%)

15%

Biomass (50%) + Corn stover (50%)

FIG. 6. After-tax IRR of combined sugar platform cases as function of plant capacity.

10

Corn (95%) + Hemicelluloses (5%) FIG. 7. Modernized mill scenario, sugar platform after-tax Corn (50%) + Corn stover (50%) IRR.

0%

0

50

7. Surprising differences were observed Biomass 5 % CONCLUSIONS 7% High temp. for the corn stover case: after modernizatechno-economic Pulpwood 1 % An order-of-magnitude 3% gasification + tion, it has an even higher IRR value than assessment was completed for a wide range syngas Lignin -3 % the corn ethanol case for small capacities. of biorefinery technologies suitable for fermentation (T2) Corn stover 4% 7% Also, all other cases except the corn to the production of ethanol, considering 20 %the specific 25 % conditions for a case study Steam ethanol case have a Biomass ~10% higher IRR. Pulpwood 12 % 17 % reforming + mixed This is mainly due to the capacity of pulp and paper mill. Of the single-line alcohol synthesis 8 % thermochemical 3% the modernized mill Lignin to handle the solid ethanol production cases, (T3) residue from the sugar processes Corn stover in the 16 %only corn 22stover % and pulpwood based promodernized energy and chemical recovery duction were Steam Biomass 7% 9 % found to be profitable at a systems. The of this scenario are large scale reforming + results Pulpwood 1% 3 %due to raw material availability comparable to published results for hemi- and prices. However, biomass-based thersyngas Lignin -3 % pulpwood-based ethanol mochemical ethanol (MA synthesis) seems fcellulose-i and (T4) [8, 33]. to be profitable for smaller capacities.

Screening out non-profitable options For the set of assumptions in this parbased on the methodology employed ticular analysis, 9 single-line sugar-platform appears to be feasible. However, without forest-based routes were less economically knowing the sensitivity of the IRR values attractive when compared to thermochemon the made assumptions, a large set of ical-based processes, without combining potentially acceptable options has to be them with corn ethanol production. For kept in order to, for example, account for instance, the hemicellulose extraction case possible future price changes. No ranking integrated into a corn ethanol plant (5% of the considered options was therefore of ethanol from hemicelluloses) is ecoreported. nomically interesting. Especially if there pulpandpapercanada.com

p 25-32 Hytonen TP.indd 31

100

Acidic hydrolysis (S1)

150

200

Enzymatic hydrolysis (S2)

isTotal a need to expand pulp production, this plant capacity (MMGPY) option could be considered as a way to keep the organic load of a recovery boiler constant.

Modernizing the mill only has a posi10 tive impact on the sugar platform cases, because modernized boilers would be designed to be capable of burning the solid residues of the bioethanol production process. It increases the IRR of all cases until the capacity of the boilers has been reached.

In general, the techno-economic approach used in this study can be used to compare the order-of-magnitude profitability of different biorefinery cases. The results of this study are based on published estimates of biorefinery mass and energy balances, as well as capital and operating costs. This approach incorporates uncertainty, because inconsistent design and techno-economic analysis methods have been used in different published studies.

For example, in the case of high tempera-

11 31 Pulp & Paper Canada  May/June 2009 

12/06/09 7:36 AM

T65

biorefining ture gasification [9] the investment cost estimates are made by an engineering consulting company, whereas in the low temperature gasification case [15] the research group estimated installed equipment costs by combining literature, vendor quotes, and software calculations. Inadequate data are available to validate how realistic or comparable the cost estimates are in each case. Process and price assumptions (raw material yield/area, ethanol yield/raw material/route, etc.) should be validated on a case-by-case basis to obtain comparable results. Finally, technical uncertainties should be considered as well as possible subsidy scenarios using sensitivity analysis techniques.

In conclusion, several parameters were found to have a significant impact on the economic viability of sugar platform ethanol production which may increase its attractiveness compared to thermochemical ethanol production in an IFBR.

ACKNOWLEDGEMENTS

This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Environmental Design Engineering Chair at École Polytechnique de Montréal, and by a research project in the BioRefine Technology Programme of the Finnish Funding Agency for Technology and Innovation (TEKES).

7. ADEN, A., et al. Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stover. 2002. p. 154.

8. MAO, H., et al. Technical Economic Evaluation of a Hardwood Biorefinery Using the “Near-Neutral” Hemicellulose Pre-Extraction Process. Journal of Biobased Materials and Bioenergy 2008 2(2): p. 9.

9. LARSON, E.D., et al. A Cost-Benefit Assessment of Gasification-Based Biorefining in the Kraft Pulp and Paper Industry, Vol. 1: Main Report. 2006, U.S. Department of Energy. p. 365.

10. THORP, B. The Verdict Is In: Biofuels Boom. 2007, U.S. Forest Products Laboratory: Society of American Foresters Annual Meeting Oregon Convention Center, Portland , Oregon p. 44.

11. THORP, B.A., B.A.T. IV, and MURDOCK-THORP, L.D. A Compelling Case for Integrated Biorefineries (Part II), Paper360° April 2008. p. 20-22.

12. VAN HEININGEN, A. Converting a kraft pulp mill into an integrated forest biorefinery. Pulp & Paper Canada 107 (6),. 2006. p. 6.

13. FREDERICK, W.J., Jr., et al. Co-production of ethanol and cellulose fiber from Southern Pine: A technical and economic assessment. Biomass and bioenergy, 32 (12):10 2008: p. 10.

14. MCALOON, A., et al. Determining the Cost of Producing Ethanol from Corn Starch and Lignocellulosic Feedstocks. 2000, NREL National Renewable Energy Laboratory. p. 43.

15. PHILLIPS, S., et al. Thermochemical Ethanol via Indirect Gasification and Mixed Alcohol Synthesis of Lignocellulosic Biomass. 2007, NREL National Renewable Energy Laboratory. p. 132.

16. SAMMONS Jr., N.E., et al. Optimal biorefinery product allocation by combining process and economic modeling. Chemical Engineering Research and Design, 2008. article in press: p. 9.

17. JANSSEN, M., et al. Techno-economic considerations for dip production increase and implementation of cogeneration at an integrated newsprint mill. in 91st Annual Meeting of the Pulp and Paper Technical Association of Canada. 2005. Canada: PAPTAC. 18. WRIGHT, M. and BROWN, R.C. Establishing the optimal sizes of different kinds of biorefineries. Biofuels, Bioproducts & Biorefining, 2007. 1(3): p. 10.

19. LYND, L.R., et al., Strategic Biorefinery Analysis: Analysis of Biorefineries. 2005, NREL National Renewable Energy Laboratory. p. 40.

Résumé: Les technologies de plateforme de traitement thermochimique et de traitement des sucres permettent de transformer les matières premières lignocellulosiques en éthanol. Le taux de rendement interne après impôts peut servir à déterminer la faisabilité économique de ces technologies. Une usine de pâte kraft a évalué plusieurs concepts d’installations de bioraffinage forestier avant de prendre une décision. Si l’on se base sur les prix de l’usine et la disponibilité des matières premières, ainsi que sur les données publiées sur le bioraffinage, il est clair que l’éthanol produit à partir du maïs est la meilleure option possible, suivie de la synthèse thermomécanique des alcools mixtes.

LITERATURE

1. PERLACK, R.D., et al., Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, U.D.o.A. U.S. Department of Energy, Editor. 2005, U.S.DOE. p. 78.

2. USDA Forest Service, Timber Products Output (TPO).

2001, USDA Forest Service.

3. BRECHBILL, S.C. and TYNER, W.E. The Economics of Biomass Collection, Transportation, and Supply To Indiana Cellulosic and Electric Utility Facilities.

2008, Dept. of Agricultural Economics, Purdue University. p. 87.

4. LYND, L.R., et al. Strategic Biorefinery Analysis: Review of Existing Biorefinery Examples. 2005, NREL National Renewable Energy Laboratory. p. 51.

5. SCHUETZLE, D., et al., Alcohol Fuels from Biomass – Assessment of Production Technologies. 2007, TSS Consultants. p. 125.

6. HAYES, D.J., State of Play in The Biorefining Industry.

2007, University of Limerick. p. 107.

32

Reference: HYTÖNEN, E., STUART, P.R. Integrating Bioethanol Production into a Kraft Pulp

Mill - Technology Assessment. Pulp & Paper Canada 110(5): T58-T65 (May/June 2009). Paper presented at the 95th Annual Meeting in Montreal, Que., February 3-4, 2009. Not to be reproduced without permission of PAPTAC. Manuscript received September 1, 2008. Revised manuscript approved for publication by the Review Panel March, 2009.

Keywords: integrated forest biorefinery, integrated kraft pulp and paper mill, lignocellulosic, thermochemical, sugar platform, ethanol, mixed alcohol synthesis, Internal Rate of Return

May/June 2009 Pulp & Paper Canada

p 25-32 Hytonen TP.indd 32

20. FLYNN, P., Biomass Energy: Cost and Scale Issues.

2006.

21. ARTHUR D. LITTLE INC. Aggressive Growth in the Use of Bio-derived Energy and Products in the United States by 2010. 2001, Arthur D. Little, Inc. 22. TIFFANY, D.G. and EIDMAN, V.R., Factors Associated with Success of Fuel Ethanol Producers. 2003. p. 62.

23. BAIN, R.L., World Biofuels Assessment, Worldwide Biomass Potential: Technology Characterizations. 2007, NREL National Renewable Energy Laboratory. p. 164.

24. BAIN, R.L., Material and Energy Balances for Methanol from Biomass Using Biomass Gasifiers. 1992, NREL National Renewable Energy Laboratory. p. 136.

25. SPATH, P.L. and DAYTON, D.C., Preliminary Screening — Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas. 2003, NREL National Renewable Energy Laboratory. p. 160.

26. WEI, L., et al. Process engineering evaluation of ethanol production from wood through bioprocessing and chemical catalysis. Biomass and Bioenergy 33 (2) 2009.

27. WYMAN, C.E., et al. Coordinated development of leading biomass pretreatment technologies. Bioresource Technology, 2005. 96: p. 8.

28. VAN KASTEREN, J.M.N., et al. Bio-ethanol from Syngas. 2005, Eindhoven University of Technology (TU/e), Telos Ingenia Consultants & Engineers. p.

53.

29. BADGER ENGINEERING INC., Economic Feasibility Study of an Acid Hydrolysis-Based Ethanol Plant. 1987, Badger Engineering Inc. p. 497.

30. WOOLEY, R., et al. Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis current and Futuristic Scenarios. 1999, NREL National Renewable Energy Laboratory. p. 130.

31. DALE, R.T. and TYNER, W.E. Economic And Technical Analysis Of Ethanol Dry Milling: Model User’s Manual.

2006, Agricultural Economics Department Purdue University. p. 28.

32. DALE, R.T. and TYNER, W.E. Economic And Technical Analysis Of Ethanol Dry Milling: Model Description.

2006, Agricultural Economics Department Purdue University. p. 44.

33. FREDERICK, W.J., Jr., et al. Production of ethanol from carbohydrates from loblolly pine: A technical and economic assessment. Bioresource Technology, 2008.

99: p. 7.

pulpandpapercanada.com

12/06/09 7:36 AM

drying performance

T66

Effect of the Dryer Fabric on Energy Consumption in the Drying Section

By I. Lang

Abstract: The dryer fabric plays a role in both heat and mass transfer in the paper drying process. Cylinder drying relies on conduction heat transfer to the web. Acting through fabric tension, the dryer fabric exerts a pressure on the web holding it in intimate contact with the cylinder. Increased fabric tension improves contact heat transfer resulting in an increased overall heat transfer coefficient, steam to paper. The dryer fabric exerts an influence on mass transfer through its ventilating effect. Owing to the entrainment of boundary layer air, a moving fabric will contribute to dryer pocket ventilation resulting in lower humidity levels, which increases the driving force for evaporation. This effect will be felt more on machines having no pocket ventilation systems or systems which are inefficient.

Higher heat transfer coefficients and improved mass transfer allow the papermaker to operate the dryer section at lower steam pressure. This provides for steam savings owing to reduced heat losses through the unwrapped part of the dryer shell and heads. Compared to the energy transferred to the paper web, heat losses from the dryers to the surrounds are small, in the order of 5%. Energy savings from operation at reduced pressure will be smaller still, but given the large consumption of energy by the drying process they are still significant.

E

nergy consumption in the dryer section accounts for more than half of the energy consumed by the entire paper machine, as can be seen in Fig. 1. Rising energy costs have, once again, put the focus back on energy consumption in the drying section.

Heat transfer from the condensing steam to the web is limited by a number of factors; namely, thickness of the condensate layer, dryer scale, cylinder resistance, and contact resistance between the web and cylinder. This can be represented by the following simplified equation: R total = R stm + R cyl + R cont According to some researchers, the contact resistance accounts for 35 to 70% of the overall heat transfer resistance [1].

The role of the dryer fabric is to convey the web through the dryer section and maintain intimate contact between the web and cylinder. Fabric tension acts on the paper web through contact pressure at the fabric-web-cylinder interface and has a direct influence on contact resistance.

The contact pressure (P) is determined by the following equation: t P = –– r

(A)

Heat transfer from the cylinder to the web can be given by the following equation:

pulpandpapercanada.com

p 33-37 Lang TP.indd 33

Q = Uoa * A * (Tstm – Tweb) (B) where Uoa, the overall heat transfer coefficient is equal to:

1 Uoa = ––––––––––––––––––––– R stm + R cyl + R cont

(C)

Reducing contact resistance increases the overall heat transfer coefficient. Previous work by the author [2, 3] has reported on the effect of dryer fabric tension on contact heat transfer resistance from measurements on laboratory drying apparatus as well as paper machines. For a fixed machine speed condition a higher “Uoa” value will allow operation with reduced steam temperature.

This has an influence on heat losses in the dryer ­section.

Another aspect of the dryer fabric influence on heat transfer is the effect of the fabric on convection heat transfer. Heat transfer by convection may occur from the surrounding air to the web or from the web to the surrounding air depending on the temperature difference. The fabric plays a role in the convection coefficient which is largely permeability dependent. In general, however, convection heat transfer in conventional cylinder drying is quite small owing to the relatively low air speeds and temperature differences. One exception would be in the case of a convection dryer (impingement hood) blowing through a fabric – however this case is not examined in this work.

The second area of impact of the drying fabric on the drying process relates to its effect on mass transfer. In a simple air/water drying process the

I. Lang Asten Johnson, Kanata, Ont.

Pulp & Paper Canada May/June 2009

33

11/06/09 12:49 PM

T67

drying performance driving force for evaporation is the difference in the partial pressure of water vapour at the web surface and the surrounding air, as shown below by the Stefan equation:

[

]

K * M * Ptot * A Ptot – Pa m = –––––––––––––– 1n –––––––– R * T Ptot – Ps

(D)

Reducing the humidity of the surrounding air (air in pocket) increases the driving force for evaporation. The increase in evaporative cooling in the draw leads to cooler sheet in the subsequent heating cycle and increased temperature difference. The net effect is that for constant machine speed (evaporation), operating at lower pocket humidity allows for operation at lower steam pressures.

The dryer fabric exerts an influence on mass transfer in two ways. This can be examined by considering the paper drying process as 4 separate phases, as described by Nissan [4], shown for the double felted case in Fig. 2. Phase I and III correspond to the sheet on the dryer with no covering fabric, Phase II consists of the fabric covered part of the sheet wrapping the cylinder and phase IV the open draw.

In the fabric-covered part of the sheet run the fabric will act as a barrier to the migration of water vapour to the surrounds.

The second way that the fabric influences mass transfer (and drying) is due to its air pumping ability. Dryer fabrics carry air into the dryer pocket due to the effect of entrained boundary layers. This effect is well known. For the case of machines with no pocket ventilation system or poorly operating systems, the pumping of entrained boundary layer air into the pocket may reduce moisture levels and consequently improve evaporation rates.

Compared to the dry air delivered by the machine ventilation system, which has an absolute humidity of 0.01 kg/kg, the humidity of the air entrained by the fabric will be quite high, in the range of 0.1 to 0.15 kg/kg. Consequently, about 10 to 15 times the mass flow of air must be “pumped” by the fabric into the pocket to achieve the same ventilating effect as a well designed ventilation system. The air pumping effect is of no benefit on machines with well designed ventilation systems and may lead to undesirable effects such as sheet flutter and breaks. With the exception of very slow machines or machines producing heavyweight grades the upper limit for fabric permeability is always determined by runnability requirements.

ENERGY CONSUMPTION IN THE DRYER SECTION

Energy is consumed in the drying process to heat the web and its associated water, evaporate the water, and heat the process air used to evacuate the water vapour. In addition energy is consumed by heat loss through the dryer heads and the unwrapped part of the shell.

Energy consumption in the drying process can be broken down as follows: • Sensible heating of web and water 7-8% • Latent heat to evaporate water 75% • Losses through dryer head and shell 4-5% • Heat to PM Hood Supply Air Systems 12-14% The amount of energy consumed to dry a unit mass of paper is dependent on a number of factors, the most significant one being the incoming solids content from the press. This can be seen clearly in Table I. 34

May/June 2009 Pulp & Paper Canada

p 33-37 Lang TP.indd 34

TABLE I. Energy consumed in the drying process at differing sheet solids Energy Consumption (kJ/kg Paper @ 92% Reel Solids 40% 45% 50%

Solids In Solids In Solids In Sensible Heating 308 248 200 of Water and Fibre Latent Heat of 2984 2398 1928 Evaporation Dryer Head and 165 132 106 Shell Losses Dryer Air Systems 496 399 321 TOTAL 3953 3177 2555

table iI. Machine conditions

Base

No. of Dryers No. of Steam Groups Dryers by Group: #1, 1-4, #2, 5-10, #3, 11-21, #4, 22-41 Dryer Diameter (m) Width (m) Solids In % Solids Out % Single Felted Dryers Condensing Coef.(W/m²/°C) Basis Weight (g/m2) Speed – base case (m/min) Contact Coefficient , x=1.0 (W/m²/°C) Contact Coefficient , x=0 (W/m²/°C)

41 4

1.8 9.1 43 91 1-19 1000 45 965 1431 344

table iII. Operating Parameters

Base

Case II

Case III

Speed Steam Pressure Group #1 Steam Pressure Group #2 Steam Pressure Group #3 Steam Pressure Group #4

(m/min) (kPa)

965 130.3

965 130.3

983 130.3

(kPa)

151.4

151.4

151.4

(kPa)

283.7

239.9

283.7

(kPa)

283.7

283.7

283.7

The values indicated above can be considered as minimum values as they do not include other miscellaneous heat losses such as blow-through steam or leaking steam joints. Energy carried away by the dryer via blow-through steam, may be substantial depending on the design of the steam and condensate system and siphon type. Venting steam to a condenser is a highly wasteful use of blow-through steam.

As mentioned previously the dryer fabric exerts an influence on drying performance through its effect on contact heat transfer coefficient or mass transfer coefficient.

To help demonstrate these fabric effects on energy consumption, a dryer simulation program was employed to carry out the simulation of different drying scenarios. The model was developed by the Institute of Paper Science and Technology (IPST) at Georgia Tech and has been described in detail by Ahrens [5]. The model is a lumped parameter model which solves for pulpandpapercanada.com

11/06/09 12:49 PM

drying performance

Fig. 3. Heat transfer coefficients vs. contact pressure Newsprint, dryer group #4.

transient one-dimensional heat transfer using a partial difference method. A new feature added to the program described above is a calculation to determine the heat loss through the dryer head and shell. Head losses were based on the equations developed by Chance [6]. Losses through the unwrapped part of the dryer shell are based on simple convection equations for flow over a flat plate.

DRYER MODELING

Two conditions were examined in this study. The first examined the effect of increasing the contact heat transfer coefficient – simulating increased dryer fabric tension. The second examined the effect of a step change in pocket humidity owing to increased fabric permeability.

Increasing Contact Heat Transfer Coefficient

Previous studies on fabric tension have shown the relationship between fabric tension and heat transfer coefficient [3]. The result of one measurement on a lightweight sheet can be seen in Fig. 3.

In this case a 50% increase in contact pressure, corresponding to a rise in fabric tension from 1.5 to 2.7 kN/m, yielded a 14% increase in overall coefficient. Although this is within the range of operation that is realistic for many machines – it would be strongly suggested that the design limits of the machine be considered before making such a change.

In carrying out the simulation of a dryer section a suitable model must first be developed. The basic machine considerations are listed in Table II. pulpandpapercanada.com

p 33-37 Lang TP.indd 35

Fig. 2. Four phases of paper drying.

Temperature (C)

Heat Transfer Coefficient (W/m2C)

Fig. 1. Energy consumption in the paper machine.

T68

Fig. 4. Steam, sheet, and cylinder temperatures for the base case.

The condensate heat transfer coefficient used in the simulation was assumed for a machine running at approx. 1000 m/min, without spoiler bars. It is well known that the contact coefficient varies with moisture content. Numerous authors have shown this although the precise relationship appears to be elusive given the range in results reported. For the model used here it was assumed to be linearly increasing with moisture content, an assumption based on the results for lighter grades as reported by Wilhelmsson [1]. The values for the contact heat transfer coefficient were determined by trial and error based on the machine speed and steam pressures for the base case.

Figure 4 shows the development of the steam, cylinder, and web temperatures through the drying section for the base case simulation.

Subsequently, two additional conditions were run. In case II a step increase in contact coefficient of 10% was assumed and the machine speed held constant. The steam pressure in the third dryer group was reduced to maintain constant speed. In case III the steam pressures of the base case were maintained and the speed allowed to increase. Steam pressure and steam data is shown in Table III. Comparing the base case with case II it was observed that steam pressure in the third group could be reduced by approximately 45 kPa as a result of the increase in contact coefficient.

Maintaining constant steam pressure for case III resulted in an increase in machine speed of approximately 2%.

Of particular interest to this study was the determination of Pulp & Paper Canada May/June 2009

35

11/06/09 12:50 PM

T69

drying performance table iV. Shell, head loss and heat to sheet

Speed Shell Losses Head Losses Heat to Sheet TOTAL Difference Difference

Base Case

Case II

table V. Machine conditions variable pocket humidity Case III

(m/min) 965 965 983 (kW) 1109 1058 1074 (kW) 280 274 279 (kW) 18632 18624 18966 (kW) 20021 19956 20319 (kW) 0 -65 297 (%) -0.32 1.49

the change in contact coefficient on energy consumption. From a heat balance the energy consumption was determined for each individual dryer, including heat loss through the dryer head and shell, and heat to sheet. The results are shown in Table IV. For the base case it was seen that heat consumption was approximately 1.5%, 5.5%, and 93% for the head loss, shell loss, and heat to the sheet, respectively.

Comparing the base case with case II it is seen that the reduction in heat loss due to increase in heat transfer coefficient is small. Compared to the base case, overall heat consumption is reduced by less than 0.5%. The majority of the savings are the result of the reduction of head and shell loss due to reduced steam pressure in the third steam group. as well as the reduction in cylinder temperature due to the increased heat transfer coefficient.

Comparing case III with the base case it can be seen that heat consumption increased, by an amount approximately equal to the increase in production, due to the increase in the sensible heating and drying load. Losses through the dryer head are essentially unchanged - not surprising as steam and ambient temperatures are unchanged. Losses through the unwrapped part of the dryer shell are reduced slightly - the result in the drop in shell temperature with the improved contact coefficient.

Effect of Pocket Humidity Levels

As mentioned earlier, operation with high humidity levels in the dryer pocket results in a reduction in the driving force for mass transfer and drying rate.

For simplicity’s sake, pocket humidity was assumed to be constant through the dryer section – a gross simplification compared to practice but useful to explain the effect of a humidity change.

The same machine geometry was employed as in the previous example, likewise the same base case conditions, with a pocket humidity of x = 0.2 kg/kg. The first alternate scenario, case II‑A looked at a slight increase in pocket humidity from 0.2 kg/kg to 0.3 kg/kg, reflecting a change in pocket humidity due to a reduction in ventilation or air pumping. In Case II-A no change was made to the steam pressures and consequently speed dropped.

Case III-A shows the results with higher humidity but with steam pressure increased in the fourth dryer group to maintain the same machine speed (and evaporation) as in the base case.

Steam pressure and steam data are shown in Table V. A step increase in humidity resulted in a drop of machine speed of approximately 4%. To maintain constant speed it was necessary to increase steam pressure in the third group by approximately 25 kPa. The results of the heat balance are shown in Table VI. Compared with the base case the energy consumption in case II-A was reduced by slightly more than 3%, roughly the amount 36

May/June 2009 Pulp & Paper Canada

p 33-37 Lang TP.indd 36

Speed (m/min) Steam Pressure (kPa) Group #1 Steam Pressure (kPa) Group #2 Steam Pressure (kPa) Group #3 Steam Pressure (kPa) Group #4

Base

Case II-A

Case III-A

965 130.3

926 130.3

965 130.3

151.4

151.4

151.4

283.7

283.7

283.7

283.7

283.7

309.9

table VI. Shell and head loss and heat to sheet

Speed Shell Losses Head Losses Heat to Sheet TOTAL Difference Difference

Base Case

Case II-A

Case III-A

(m/min) 965 926 965 (kW) 1109 1123 1150 (kW) 280 274 282 (kW) 18632 17972 18736 (kW) 20021 19369 20168 (kW) -652 147 (%) -3.26 0.74

by which the speed was reduced. Comparing case III-A with the base case, it was seen that the overall energy consumption increased, in part due to the slight increase in shell and head losses as well as an increase in sensible heating of the sheet, largely the result of the higher web temperatures in the drying process, the result of the increased humidity.

The High Cost of Drying When Things Don’t Go Well

From the two conditions examined, increase in heat transfer coefficient and increase in humidity, it was observed that drying energy consumption stayed essentially the same (at constant speed), within 1%, the difference being due to change in head and shell losses or heat to the sheet.

In practice however, it is not uncommon to see changes in energy consumption in conjunction with a dryer fabric change that are well in excess of those determined from the simulation.

One frequently observed condition that affects energy consumption is dryer fabric contamination. This condition may result in non-uniform drying across the width of the paper machine and uneven moisture profiles. This inevitably results in over drying of the sheet in some areas to correct for wet streaks and an increase in steam consumption. The increase in drying energy is further compounded by the increase in the amount of energy required to evaporate a unit mass of water owing to the increase in sorption heat with solids content.

A very important factor in determining energy consumption in the drying process is the design and operation of the steam and condensate system. Efficient removal of condensate by the siphon requires maintaining pressure differential across the dryer can in a specific range. Stationary siphons will generally operate over the range of machine speeds found in practice with a differential of 30 kPa. Rotary siphons, on the other hand, require increasing pressure differential to maintain condensate removal as machine speeds increase. The pressure differential required for condensate removal with rotary siphons may vary from a low of 30 kPa at pulpandpapercanada.com

11/06/09 12:50 PM

drying performance speeds of 300 m/min to 100 kPa or more at 1200 m/min [7].

Siphon type also has a significant effect on blow-through steam requirements (steam consumed in the dryer section – not contributing to evaporation). Blow-through steam consumption is generally lower with stationary siphons, from 8 to 12% of total steam consumption, while rotary siphons may require 20 to 25% blow-through steam to adequately remove condensate. For best energy efficiency blow-through steam should be used in the low pressure dryers.

On a typical dryer section with rotary joints, with a cascade steam system, when operated at or near the limits of its design capacity, it may not be unusual to see a dryer group vent directly to a condenser in order to maintain the necessary differentials to keep up with drying demand. In such a case energy consumption by the dryers – as measured by total steam consumption – will be high. Any improvement in drying performance, be it from improved heat transfer coefficient, a reduction in pocket humidity, or uniform moisture profiles, that leads to a reduction in steam pressure can have significant effect on reducing dryer section energy consumption – far in excess of what may result from the improvement of drying conditions alone.

CONCLUSIONS

Fabric design or operation that contributes to increased contact heat transfer coefficient and/or reduced pocket humidity yields an increase in drying capacity. At constant speed operation this leads to a reduction in energy consumption.

A numerical model was employed to determine the effect of 1) a step change in heat transfer coefficient and 2) a step change in pocket humidity. The calculations show that a 10% improvement in contact coefficient (at constant machine speed) yields a reduction in drying energy consumption of less than 1%. Operation with pocket humidity of 0.2 kg/kg versus 0.3 kg/kg results in a reduction of drying energy consumption of less than 1%.

Operating the dryer section at less than ideal conditions can result in energy consumption far in excess of the theoretical minimum. Operation with plugged felts causes moisture profile problems and operation with excessively high pocket humidity will lead to higher energy consumption. Poor design of the steam and condensate system – or operation at or beyond the limits of system design – can lead to high energy consumption, far in excess of what is theoretically required for the drying process.

NOMENCLATURE H K m M P Q r R t T U

= = = = = = = = = = =

area mass transfer coefficient mass transfer rate molecular weight pressure heat transfer radius gas constant tension temperature heat transfer coefficient

pulpandpapercanada.com

p 33-37 Lang TP.indd 37

(m²) (m/s) (kg/s) (kg/mol) (kPa) (W) (m) (J/mol/°K) (kN/m) (°C) (W/m²/°C)

T70

Subscripts a = air cont = contact cyl = cylinder oa = overall s = sheet stm = steam tot = total

LITERATURE

1. WILHELMSSON, B., FAGERHOLM, L., NILSSON, L., STENSTROM, S. An Experimental Study of Contact Coefficients in Paper Drying, TAPPI Journal, 77(5),159-168 (1994).

2. LANG, I. Dryer Fabric Tension–Revisited, Proceedings, 88th Annual Meeting, Pulp and Paper Technical Association of Canada, Preprint A, A 255-258, (2002).

3. LANG, I. Drying Performance and Fabric Tension: Mill Trials, Pulp & Paper Canada, 105:11(2004).

4. NISSAN, A. H., HANSEN, D. Heat and Mass Transfer Transients in Cylinder Drying Part II Felted Cylinders, A I Ch E Journal 7 (4), 635-641 (1961).

5. AHRENS, F., RUDMAN, I. The Impact of Dryer Surface Deposits and Temperature Graduation in The First Dryer Section on Drying Productivity, Preprints, TAPPI Spring Technical Conference, 2003.

6. CHANCE, J. L. Dryer Head Heat Losses, Proceedings TAPPI Engineering Conference, 139-143, (1981).

7. HILL, K. Five Rules for Energy Efficiency to Improve Dryer Operations, Pulp and Paper, 52-57, September 2006.

Résumé: La toile sécheuse joue un rôle important dans le transfert de la chaleur et le transfert de masse lors du séchage du papier. Le séchage sur cylindres mise sur le transfert de la chaleur par conduction à la feuille. Grâce à la tension de la feuille, la toile sécheuse exerce une pression sur la feuille et la maintient contre le cylindre.

La tension améliore le transfert de la chaleur lors du contact, ce qui permet d’augmenter le coefficient de transfert de la chaleur dans toute la feuille, de la vapeur au papier. La toile sécheuse exerce une influence sur le transfert de masse par un effet de ventilation. En raison de l’entraînement de la couche d’air, la toile en mouvement contribue à ventiler les poches d’air et fait diminuer l’humidité, ce qui améliore l’évaporation. Cet effet sera constaté davantage sur les machines non dotées d’un système de ventilation des poches ou dont le système est inefficace.

Un coefficient de transfert de chaleur plus élevé et un transfert de masse amélioré permettent de faire fonctionner la sécherie à une plus faible pression de vapeur. Il est ainsi possible d’économiser la vapeur parce qu’on réduit les pertes de chaleur dans la partie non enveloppée de la virole et de la tête des sécheurs. Comparativement à l’énergie transférée à la feuille en continu, les pertes de chaleur des sécheurs dans l’environnement sont faibles, soit environ 5 pour cent. Les économies d’énergie réalisées lorsqu’on fonctionne à pression réduite seront moindres, mais, étant donné la forte consommation d’énergie lors le séchage, elles sont encore appréciables.

Reference: LANG, I. Effect of the Dryer Fabric on Energy Consump-

tion in the Drying Section, Pulp & Paper Canada 110(5): T66-T70 (May/June 2009). Paper presented at the 93rd Annual Meeting of PAPTAC in Montreal, Que., February 5-9, 2007. Not to be reproduced without permission of PAPTAC. Manuscript received February 21, 2007. Revised manuscript approved for publication by the Review Panel November 2008.

Keywords: DRYER FABRICS, DRYER SECTION, DRYING, ENERGY CONSUMPTION, DRYING PERFORMANCE, HEAT TRANSFER.

For up-to-date news and events visit www.pulpandpapercanada.com

Pulp & Paper Canada May/June 2009

37

11/06/09 12:50 PM

T71

mechanical pulping

A Perspective on Expanded Use of Secondary Species in Mechanical Pulping

By K. Law and R. Lanouette Abstract: This paper gives an account on the progress in mechanical pulping of various softwood and hardwood species from eastern Canada, such as aspen, birch, larch, and jack pine. Here, we attempt to put the use of these secondary species into perspective and put forward some strategies relative to the use of such wood raw materials in mechanical pulping.

T

K. Law , Centre intégré en Pâtes et Papiers Université du Québec à Trois-Rivières Trois-Rivières, Qué.

Kwei-Nam_Law@Uqtr.Ca

R. Lanouette, Centre intégré en Pâtes et Papiers Université du Québec à Trois-Rivières Trois-Rivières, Qué.

38

he anticipated shortfall in traditional fibre resources in Quebec, noted by the recent Coulombe report [1], has set off disturbing concerns for the wood products industry, including the pulp and paper sector. Consequently, a search for alternative fibre resources to fill the resource gap — other than the traditional spruce and balsam fir — was set in motion. The issue of raw materials for papermaking may be tackled on four fronts: (a) increased incorporation of minerals, (b) augmentation of recovered paper use, (c) expanded utilization of non-wood fibres, and (d) widened use of secondary wood species which are currently under-exploited. Each option has its own merits and limitations. Advances in nanotechnology would improve the use of minerals, while the substitution of recycled fibre could be associated with the costs of production and quality of end production. The potential utilization of nonwood in the Canadian pulp and paper industry will remain of academic interest only for the foreseeable future in as much as we still have sufficient supply of woody raw material. The scope of discussion here is restricted to that of the use of secondary species such as jack pine, larch, birch, maple, and aspen, in ultra-high-yield pulping. In this regard, it is worthwhile to note that our past efforts on pulping of secondary species at the Université du Québec à Trois-Rivières began a little more than two decades ago [2-51]. Here, we would put our findings into perspective for ultra-high-yield pulping of these species, particularly thermomechanical pulping.

With our experiences in this area we can recommend a few strategies to overcome certain difficulties associated with using these secondary species.

Difficulty in Mechanical Pulping

The underlying problem of mechanical pulping is associated with fibre morphology, more precisely, with the cell wall thickness (Table I). Irrespective of wood species among the conifers, the presence of thick-walled latewood fibres contributes to pulp

May/June 2009 Pulp & Paper Canada

p 38-43 Law TP.indd 38

quality problems. Even with the most favoured species of black spruce, its latewood fibre in TMP contributes to high refining energy and poor bonding potential [52, 53]. In contrast to the thinwalled earlywood counterpart, the latewood fibre withstands better the harsh mechanical actions of screw compression and refining, and maintains relatively good fibre length for sheet structure. The long-fibre fraction in a TMP, mostly latewood fibres, is a double-edged sword; it gives good tearing resistance to the sheet but poor tensile strength. On the contrary, the earlywood fibre, which presents mainly in the shorts and fines of a TMP, is the principal source of inter-fibre bonding in a TMP sheet. This complementary effect is indeed what is needed to make a strong sheet in terms of tear and tensile strength. However, the proportion of latewood fibre is critical. High density wood such as jack pine and larch can seriously compromise inter-fibre bonding [41-43, 45, 49, 50, 56, 57].

The above diagnosis implies that the ease of mechanical pulping is related to the double-cellwall thickness of latewood fibre and the proportion of these fibres within the growth increments.

Spruce is a preferred species in mechanical pulping because its latewood fibre has a relatively thinner cell wall and it has smaller amounts of latewood, when compared with other softwoods such as pines and larches.

The scenario for hardwoods is slightly different; there is relatively small morphological difference between earlywood and latewood fibres (Table I), except for the dimension of vessel elements.

However, the basic problem remains the same: the double-cell-wall thickness in terms of refining energy and sheet properties. Each species is unique and influences differently sheet quality; thin fibres make a a stronger sheet while thick fibres produce bulky and weak one [55], setting aside the effect of fibre length. In reality, we have been blessed by the nature which offers us a variety of raw materials pulpandpapercanada.com

11/06/09 1:04 PM

mechanical pulping

FIG. 1. Relations of refining energy with pulping condition and raw material at a given pulp property.

T72

FIG. 2. Freeness vs. refining energy.

TABLE I. Fibre morphology data.

Property

Black Spruce [52] Jack Pine [52] Hybrid Larch [52] Tremb. Aspen [53] White Birch [53] Red Maple [53]

W.w. length, mm 2.75 3.31 2.91 Dia., mµ Earlywood 38 34 58 Latewood 14 19 29 Coarseness, mg/m 50% yield 0.200 0.193 0.327 92% yield Cell wall thick., mµ Earlywood 2.78 2.78 2.78 Latewood 4.09 4.55 5.67

to generate synergetic effects, improving product quality [25]. What we need is to properly exploit their different attributes to tailor the sheet properties that serve us the best – strength and bulk (or opacity).

Pulping Facts

Regardless of wood species, there are some basic pulping facts that we cannot ignore, as schematically shown in Fig. 1.

For a given raw material, the pulp properties increase with the severity of chemical action; pure mechanical pulping yields poor pulp quality, expectedly. Meanwhile, pulp characteristics depend on the properties of the raw material, of which cell wall thickness is by far the most important; fibres with thick cell walls make dense wood (high density). As mentioned earlier, thick-walled fibres produce bulkier sheet with relatively poor bonding strength, in comparison with their thin-walled counterparts. What’s more, the pulp quality also depends on pulp yield; the ultra-highyield mechanical pulps are weaker than the chemi-mechanical pulps which in turn are poorer than chemical pulps. Evidently, we can tailor the pulp quality by means of pulpandpapercanada.com

p 38-43 Law TP.indd 39

0.96

1.46

0.58

20.8

21.6

14.5

0.131 0.241

0.161 0.296

0.111 0.204

1.93

2.44

2.22

TABLE II. Properties of TMP of spruce/jack pine mixtures at 150 mL CSF [14] .

Spruce, % 100 80 Pine, % 0 20 Property Sp. Energy MJ/kg Rejects, % (4-cut) Density g/cm3 Tensile in. N.m/g Burst In. kPa.m2/g Tear In. mN.m2/g LW F. L. mm Brightness % ISO Opacity, % L. Scat., m2/kg Extractives %

8.18 0.19 0.30 41.5 2.30 10.4 1.84 54.8 94.5 52.0 0.86

10.93 0.34 0.34 43.5 2.65 11.1 1.97 58.2 91.6 49.7 0.47

80 60 20 40 * 10.69 0.13 0.37 47.4 2.98 11.2 2.06 55.7 90.5 46.7 0.52

10.56 0.46 0.32 41.2 2.45 12.0 2.14 58.0 92.1 50.7 0.53

60 40 ** 11.89 0.15 0.38 46.2 3.13 10.8 2.00 59.6 89.7 48.2 0.44

*: Injection of 0.5% hydrogen peroxide; **: 2.5% hydrogen peroxide

chemical treatments.

High specific energy consumption of TMP is a major concern, in addition to its relatively poor sheet strength. Apparently, the mechanical energy required to produce pulps for a given quality depends on the degrees of chemical treatment or the pulp yield. A low level of chemical action produces high yield pulps which require, as a result, a relatively higher refining energy (Fig. 2). Wood density is another impor-

tant factor determining the energy consumption; thick-walled fibres (high density woods such as jack pine, larch, birch, and maple) need more mechanical energy to reach a given level of pulp quality, when compared with the fibres that have a thinner cell wall [41-43, 55].

Some Pulping Data

Black spruce vs. balsam fir Despite the fact that spruce and balsam Pulp & Paper Canada May/June 2009

39

11/06/09 1:09 PM

T73

mechanical pulping

FIG. 3.. Handsheet bulk vs. refining.

fir are commonly pulped in mixtures, in both chemical and mechanical pulping, concerns over the adverse effect of balsam fir in mechanical pulping persists. To elucidate this concern we used good quality, fresh white spruce, black spruce, and balsam fir chips to produce TMP using a Metso (Sunds Defibrator) 300CD refiner [58]. We found that balsam fir required less refining energy at a given freeness when compared to the spruces (Fig. 3).

However, they both had similar bulk and tensile index (Figs. 4 and 5). The tear index was lower for balsam fir than for the spruces (Fig. 6), but the former had considerably higher specific light scattering coefficient (Fig. 7). Using a similar pilot refiner to produce TMP from balsam fir and spruces (red, black and white) originating from Quebec, Johal et al [59] observed lower energy and lower strengths but higher bulk and optical properties for balsam fir compared with the spruces. On the other hand, little difference in energy consumption and properties between balsam fir and black spruce had been noted in RMP [60].

Spruce-jack pine blend A substitution of up to about 30% jack pine in a spruce TMP can be achieved, without significant deterioration in quality [56, 57]. However, using a relatively small charge of hydrogen peroxide increases the substitution rate up to 40% and improves significantly the overall pulp properties, as shown in Table II [14].

Spruce-larch blend A hybrid larch (Larix eurolepis Henry) from plantations gives noticeably poor 40 

FIG. 4. Tensile index vs. refining energy.

TABLE III. Properties of TMP of spruce/larch mixtures at 150 mL CSF [15].

Spruce, % Larch, % Property

100 0

80 20

60 40

40 60

0 100

Sp. Energy MJ/kg Rejects, % Density g/cm3 Tensile in. N.m/g Burst In. kPa.m2/g Tear In. mN.m2/g LW F. L. mm Brightness % ISO Opacity, % L. Scat., m2/kg

8.22 0.72 0.35 48.5 2.86 10.1 1.93 52.4 95.3 51.6

8.92 1.17 0.34 44.4 2.53 10.2 1.87 48.7 96.6 52.0

9.01 1.14 0.35 41.6 2.25 9.2 1.81 47.4 96.9 51.9

8.74 1.38 0.33 35.5 2.12 9.3 1.71 44.1 97.4 50.9

7.78 1.53 0.33 30.1 1.55 8.4 1.51 40.3 98.1 49.6

TABLE IV. Properties of TMP of spruce/birch mixtures at 150 mL CSF [15].

Spruce, % Birch, % Property

100 0

80 20

60 40

40 60

0 100

Sp. Energy, MJ/kg Rejects, % Density, g/cm3 Tensile In., N.m/g Burst In., kPa.m2/g Tear In., mN.m2/g LW Length, mm Brightness, % ISO Opacity, % Sp. Light Scat., m2/kg

8.22 0.72 0.35 48.5 2.86 10.1 1.93 52.4 95.3 51.6

9.06 1.01 0.35 41.3 2.20 9.2 1.71 52.0 95.6 52.1

8.42 0.96 0.33 34.2 1.78 7.8 1.57 52.4 96.2 53.0

9.22 0.94 0.31 27.6 1.34 6.1 1.31 57.1 96.8 54.4

10.33 0.14 0.31 14.8 0.53 2.4 0.81 55.3 97.2 62.0

TMP properties when compared with black spruce (Table III). Without chemical addition, a substitution of about 20% larch in spruce furnish could be applied, resulting in a relatively small reduction in tensile and burst indices [15]. While the tear index can be maintained, the drop in brightness is substantial, which is typical with Larix species. In future, some kind of chemical application is worthwhile to explore to improve the strength and optical properties.

May/June 2009  Pulp & Paper Canada

p 38-43 Law TP.indd 40

Spruce-birch blend We have learned that white birch, a dense hardwood, produces poor mechanical pulp [20, 22, 25, 28, 31]. A replacement of as little as 20% in a spruce furnish can lead to an important drop in physical properties of the TMP, as shown in Table IV [15]. The problem of linting could also be a concern when untreated white birch is incorporated in TMP [31].

It has been found that chemical treatment significantly improves the properties pulpandpapercanada.com

11/06/09 1:09 PM

mechanical pulping

FIG.5. Tear index vs. refining energy.

of pulp produced from white birch [6, 11-13, 21, 22, 24, 27, 28]. For example, an application of 2.5% NaOH plus 2.5% Na2SO3 produced a CTMP composed of up to 60% white birch with relatively acceptable sheet properties, as seen in Table V [11].

Hardwood blends CTMP is a preferred pulping technology over the TMP for enhancing the utilization rate of hardwoods [14-17, 19, 20, 22, 26]. As shown in Table VI, each species responds differently to the same chemical treatment, due to their inherent differences in fibre morphology. Trembling aspen gives the best properties and red maple the worst; white birch lies in between. As a result, the properties of CTMP made from mixtures of these three species depend on the proportion of each species making up the furnish, as indicated in Table VII. In practice, the percentage of aspen should be maintained at a relatively high level to produce good quality pulps.

Strategies for Using Different Species

In Canada, we have long been spoiled by the abundance of forest resources. The availability of spruce in vast supply helps set our mind that this is the only species can make good quality paper. It is time to change our antiquated belief; imagination is vital.

It is essential to understand that pure mechanical action cannot produce good quality pulp, even with spruce. Due to the inherent chemical nature of wood, there is a limit to what one can achieve using mechanical treatment alone. The addition of thermal treatment is beneficial up to a pulpandpapercanada.com

p 38-43 Law TP.indd 41

T74

FIG. 6. Specific light scattering vs. refining energy.

TABLE V. Properties of CTMP from spruce/birch [11].

Spruce, % Birch, % Property

100 0

70 30

40 60

0 100

Sp. Energy, MJ/kg CSF, mL Rejects, % Density, g/cm3 Tensile In., N.m/g Burst In., kPa.m2/g Tear In., mN.m2/g LW Length, mm Brightness, % ISO Opacity, % Sp. Light Scat., m2/kg

16.35 93 0.08 0.41 60.1 3.98 10.5 1.93 44.5 94.8 46.7

15.77 84 0.44 0.40 54.2 3.48 9.8 1.71 45.8 94.9 46.0

15.18 90 0.40 0.39 53.4 3.12 10.3 1.31 47.1 94.5 45.4

12.72 107 0.30 0.34 14.8 1.81 6.4 0.81 54.0 93.9 44.7

relatively restricted extent because thermal action is a temporary effect; the lignin, the binding agent in wood, hardens upon cooling, rendering the separated fibrous elements stiff with little bonding affinity.

In papermaking we need flexible fibres with a strongly hydrophilic surface and abundant bonding sites. To achieve this we have to resort to chemical actions such as in chemi-thermomechanical, chemi-mechanical, and chemical pulping.

Mechanical pulp producers who rule out any chemical treatment in their pulping process would certainly face insurmountable obstacles in making good paper. This is a fact of life.

The choice of chemical treatment depends on the species used and the final product. For instance, in ultra-high-yield pulping, softwoods work better with sulfonation while hardwoods require alkaline action. The objective is to permanently soften the wood matrix and produce functional sites for bonding. The degrees of treatment would depend upon the desired properties for a particular product.

Incorporation of secondary species such as jack pine, larch, birch, or aspen into a traditional furnish of spruce is a simplistic approach with limited success in meeting the baseline quality of a mechanical pulp.

The rate of substitution can rarely exceed 30%, more or less, without significant deterioration in pulp quality.

To expand the use of secondary species in mechanical pulp, e.g. refining of mixed species, we must turn to chemical treatment, otherwise a dead end is certain.

Light sulfonation and/or alkaline action, either in pulping or in post-pulping stage, of the entire pulp mass or the fractionated long fraction, would prove to be effective.

In addition, the properties of mechanical pulps can be improved by ozonation as shown in previous works in this area [61].

Separate pulping lines for traditional and secondary species might be worthwhile to look into. Such an approach requires different chemical treatments for the two types of raw materials, allowing us to tailor the desired properties from different furnishes and enhancing the quality of Pulp & Paper Canada  May/June 2009 

41

11/06/09 1:09 PM

T75

mechanical pulping TABLE VI. Properties of hardwood CTMP [26].

Property Energy MJ/kg CSF mL Tensile N.m/g Tear mN.m2/g L. Scat. m2/kg

100% Aspen 4.1 445 23 3.5 40

6.5 275 36 5 42

8.6 210 40 5.4 45

100% Birch 9.4 180 41 4.3 47

5.5 450 18 3 38

6.1 350 19 3.9 38

7.0 290 24 4.5 47

100% Maple 9.4 270 25 3.3 43

7.0 360 9 2.7 43

7.9 210 10 2 47

8.9 175 15 1.6 47

13 180 15 1.2 47

Pulping conditions: 2% NaOH, 4% Na2SO3, 130°C, 15 min

TABLE VII. Properties of mixed-hardwood CTMP) - Blend ratio: aspen/birch/maple by weight % [26].

Property Energy, MJ/kg CSF, mL Tensile, N.m/g Tear, mN.m2/g L. Scat., m2/kg

66/17/17 5 350 22.5 3.75 42

8.25 175 32 4.8 45

17/66/17 10.9 85 35.5 4.75 46

6.2 325 18 2.9 43

7.6 226 26 3.5 44

17/17/66 9.1 185 27.5 3.4 45

6.5 300 9 2.4 45

7.2 250 17.5 2.8 47

8.75 225 18 2.75 47

Pulping conditions: 2% NaOH, 4% Na2SO3, 130°C, 15 min

the final blended product. This strategy is particularly appealing when hardwoods are used for partial substitution of softwood furnish because the former has different morphological attributes and requires different chemical treatment in comparison to the latter.

one-size-fits-all concept. We have already learned that simple substitution of species in current mechanical pulping is inadequate for making full use of our forest resources. Consequently, species-specific pulping processes are essential to the expansion in using the secondary species.

CONCLUSION

ACKNOWLEDGEMENT

Obviously, the potential use of our raw material cannot be fully exploited by using mechanical attrition alone, and thermal treatment can only marginally improve pulp quality. Chemical applications have long been proved to be necessary to produce pulps with added quality. If mechanical pulps such as TMP are to be improved, some sorts of chemical treatment on either the whole pulp or the long-fibre fraction [62, 63] seem to be unavoidable. This point of view is particularly pertinent when the under-exploited secondary wood species are to be incorporated into the main raw material stream. We need to accept the fact that each wood species is unique, just like any other biological being, and it is necessary to treat each differently to produce pulps with desired characteristics.

Equally, we have to recognize the hard fact that the two most used species of black spruce and balsam fir are not totally interchangeable in TMP. For example, the increased substitution of spruce by balsam fir could cause quality problems.

We have to develop smarter pulping techniques to deal with a variety of raw materials at our disposal and revamp the 42

We want to express gratitude towards the Natural Sciences and Engineering Research Council of Canada and the Ministry of Natural Resources of Quebec for their financial support in our works on pulping studies.

Literature

1. Coulombe Report, Ministry of Natural Resources of Quebec (December, 2004).

2. RIOUX, P. Production de pâte chimico-thermomécanique du bouleau blanc. Master’s thesis, Université du Québec à Trois-Rivières, 152 pages, 1984.

3. LAUZON, F. Production de pâtes thermomécaniques et chimico-thermo-mécaniques de mélèze laricin. Master’s thesis, Université du Québec à Trois-Rivières, 155 pages (1986).

4. BOUSQUET, J.-P. Production de pâtes mécaniques et chimico-mécaniques à partir de mélèze laricin. Master’s thesis, Université du Québec à Trois-Rivières, 208 pages (1986).

5. LEBEUF, S. Mise en pâte à très haut rendement de jeunes mélèzes de plantation. Master’s thesis, Université du Québec à Trois-Rivières, 158 pages (1987).

6. MONDOR, D. Mise en pâte chimico-mécanique du mélèze laricin - comparaison avec l’épinette noire. Master’s thesis, Université du Québec à Trois-Rivières, 304 pages (1989).

7. DUBOIS, A. Mise en pâtes du mélèze par le procédé au sulfite alcalin. Master’s thesis, Université du Québec à Trois-Rivières, 141 pages (1989).

8. LACROIX, G. Propriétés papetières des fibres de pâte thermomécanique de bouleau à papier. Master’s thesis, Université du Québec à Trois-Rivières, 159 pages (1989).

9. PROULX, R. Propriétés papetières des pâtes de TMP et CTMP en mélange (sapin/épinette/bouleau). Master’s thesis, Université du Québec à Trois-Rivières, 233

May/June 2009 Pulp & Paper Canada

p 38-43 Law TP.indd 42

pages (1991).

10. RIOUX, S. Étude des propriétés papetières de peupliers hybrides choisis pour le sud du Québec. Master’s thesis, Université du Québec à Trois-Rivières, 134 pages (1997).

11. WU, M.R. Production of newsprint furnish from mixtures of white birch and black spruce. Doctorate thesis, Université du Québec à Trois-Rivières, 204 pages (2003).

12. WU, M.R., LANOUTETTE, R. and VALADE, J.L., “Understanding the fibre development during co-refining of white birch and black spruce mixtures, Part 1. Chemithermomechanical pulping.”, Pulp Paper Can. 105(12): 83-87 (2004).

13. WU, M.R., LANOUETTE, R. and VALADE, J.L., “Understanding the fibre development during co-refining of white birch and black spruce mixtures, part 2. Thermomechanical pulping”, Pulp Paper Can.105(12):88-93 (2004).

14. BERGERON, F. Mise en pâte mécanique au peroxyde alcalin de mélanges pin gris-épinette noire. Master’s thesis, Université du Québec à Trois-Rivières, 118 pages (2004).

15. ZHA, Q.Q. Mise en pâte à haut rendement d’un mélange incorporant des copeaux de mélèze hybride et de bouleau. Master’s thesis, Université du Québec à TroisRivières, 76 pages (2005).

16. LAW, K.N., MARCHILDON, L., LAPOINTE, M. and VALADE, J.L. Pâtes chimico-thermomécaniques - Production à partir de bouleau blanc. Revue A.T.I.P. 38(9):497-504 (1984).

17. LO, S.N., LAW, K.N., KORAN, Z. and VALADE, J.L. “Very high-yield pulps from aspen and birch”.

AIChE Symposium Series, 80(232): 3439 (1984).

18. LAW, K.N., RIOUX, P., LAPOINTE, M. and VALADE, J.L. “Chemithermomechanical pulping of white birch for newsprint”. Can. J. For. Res.14:488-492 (1984).

19. LAW, K.N., LAPOINTE, M. and VALADE, J.L. “Production of CTMP from aspen”. Pulp Paper Can. 86(3):T77-T80 (1985).

20. KORAN, Z., PICHÉ, A. and BOUCHARD, R. “White birch TMP in newsprint manufacture”. Pulp Paper Can. 86(10):T298-T300 (1985).

21. RIOUX, P. « Production et utilisation de pâte chimico-thermomécanique de bouleau blanc ». Pâtes et Papier :46, 48, 50, 60 (Mai 1986).

22. VALADE, J.L. and LAW, K.N. “Some properties of white birch ultra-high yield pulps”. Cell. Chem. Technol.

22:525-529 (1988).

23. PROULX, R., VALADE, J.L. and LAW, K.N. « Les caractéristiques d’un raffinage en mélanges de sapin/ épinette et de bouleau blanc ». Les Papetières du Québec 1(6) :24-32 (1990).

24. VALADE, J.L., LAW, K.N. and LANOUETTE, R.

pulpandpapercanada.com

11/06/09 1:10 PM

mechanical pulping “Chemithermomechanical pulping of mixtures of aspen and birch”. Tappi J. 75(11):93-98 (1992).

25. VALADE, J.L., LAW, K.N. and LANOUETTE, R. “Upgrading softwood CTMP by the use of hardwood”.

Pulp Paper Can. 94(4):T91-T99 (1993).

26. KORAN, Z. “Thermomechanical pulp properties of white birch”. Wood Fiber Sci. 27(2):98-104 (1995).

27. SARR, M.N.D. Valorisation des bois feuillus à haute densité pour la production de papiers à valeur ajoutée.

Internal Research Report, Centre de recherche en pâtes et papiers, Université du Québec à TroisRivières, 50 pages (1998).

28. LAW, K.N., LANOUETTE, R. and VALADE, J.L. “Properties of CTMP from mixtures of aspen, birch and maple”. Pulp Paper Can. 100(12):T389-T394 (1999).

29. LAW, K.N., LANOUETTE, R. and VALADE, J.L. “Influence of mixtures of hardwood species on CTMP”.

Preprints 85th An. Meet. PAPTAC:B29-B36 (1999).

30. LAW, K.N., RIOUX, S. and VALADE, J.L. “Wood and paper properties of short rotation poplar clones”.

Tappi J. 83(5):1-6 (2000).

31. WU, M.R., LANOUETTE, R. and VALADE, J.L. « Traitement des copeaux de bouleau blanc en vue de leur incorporation à l’épinette pour la production de papier journal ». Revue A.T.I.P. 56(4) :10-13, 16-17 (2002).

32. BARBE, M.C. and MACDONALD, J.E. Properties of jack pine chemimechanical pulps. Preprints CPPA (PAPTAC) An. Meet., Book B:B261-B272 (1986).

33. JOSSART, D., BARBE, M.C., LAPOINTE, M. and LAW, K.N. “Properties of mechanical and chemimechanical jack pine pulps: Part I - Thermomechanical pulps”. Pulp Paper Can. 89(4):T115-T122 (1988).

34. BARBE, M.C., RÉMILLARD, B. et LAPOINTE, M. « Mise en pâte mécanique et chimico-mécanique de pin gris ». Pulp Paper Can. 90(12) :T476-T488 (1989).

35. BARBE, M.C., JANKNECHT, S., RÉMILLARD, B. and LAPOINTE, M. Properties of mechanical and chemimechanical jack pine pulps. Part III - Inter-stage treated pulps. Proc. Tappi Pulp. Conf.:117-129 (1989).

36. GAGNÉ, C., BARBE, M.C., RÉMILLARD, B. and LAPOINTE, M. “Properties of mechanical and chemimechanical jack pine pulps. Part IV: Bleaching studies”. Pulp Paper Can. 91(6):T222-T230 (1990).

37. AHMED, A., CARRASCO, F. and KOKTA, B.V. “Explosion pulping of jack pine: Effect operating conditions on explosion pulp properties”. Inv. Téc.

Papel n_m 108:233-254 (1991).

38. TYRVÄNEN, J., LAW, K.N. and VALADE, J.L. “Akaline-peroxide inter-stage treated mechanical pulp from jack pine, Part I: Introduction and pulp physical properties”. Pulp Paper Can. 98(6):T191-T196 (1997).

39. TYRVÄNEN, J., LAW, K.N. and VALADE, J.L. “Alkaline-peroxide inter-stage treated mechanical pulp from jack pine, Part II: Pulp optical properties, color reversion, extractives content, and process implications”. Pulp Paper Can. 98(7):T223-T227 (1997).

40. LANOUETTE, R., VALADE, J.L. and THIBAULT, J. “Optimization of an alkaline peroxide interstage treatment of jack pine (Pinus banksiana Lamb.) using a D-Optimal Design”. Can. J. Chem. Eng. 75:1-9 (Feb.

pulpandpapercanada.com

p 38-43 Law TP.indd 43

1997).

41. LAW, K.N., VALADE, J.L. and YANG, K.C. “Fibre development in thermomechanical pulping: comparison between black spruce and jack pine”. J. Pulp Paper Sci. 24(2):73-76 (1998).

42. LANOUETTE, R., THIBAULT, J. and VALADE, J.L. “High-yield pulping jack pine”. Tappi J. 81(10):143-149 (1998).

43. LANOUETTE, R., GAGNON, P., VALADE, J.L. and LAW, K.N. Effect of the introduction of hybrid larch (Larix eurolepis Henry) within the jack pine/spruce mixture used in kraft pulping. Proc. Tappi Pulp. Conf.:975-981 (1998).

44. LANOUETTE, R., VALADE, J.L. and LAW, K.N. “Influence of chip pre-treatments on the reduction of extractives content in high yield pulping of jack pine”.

Pulp Paper Can. 101(5):T143-T146 (2000).

45. LANOUETTE, R., BERGERON, F. and DANEAULT, C. “Characterization of jack pine-spruce mixtures”. Proc. Tappi Pulping Conf., Seattle, WA, USA:13-18 (2001).

46. LAW, K.N., VALADE, J.L. and DANEAULT, C. “Pâtes mécaniques de mélèze - RMP-CRMP-TMPCTMP- Propriétés”. Revue A.T.I.P. 41(4) :187-192 (1987).

47. LAW, K.N., LAPOINTE, M. and VALADE, J.L. “Chemimechanical pulping of tamarack. Part I Effects of chip compression and cold water extraction”. Pulp Paper Can. 88(8):T262-T267 (1987).

48. LAW, K.N., VALADE, J.L. and DANEAULT, C. “Chemimechanical pulping of tamarack. Part II Effects of pH and sodium sulphite”. Cellulose Chem.

Technol. 23:733-741 (1989).

49. LAW, K.N., VALADE, J.L. and LAPOINTE, M. “Mechanical pulping (RMP and TMP) of young larches”. Cellulose Chem. Technol. 25:41-47 (1991).

50. VALADE, J.L., LAW, K.N. and DUBOIS, A. “High yield sulphite pulping of European and Japanese larches: comparison with black spruce”. Cellulose Chem.

Technol. 25:247-253 (1991).

51. LANOUETTE, R., GAGNON, P.F., Valade, J.L. and LAW, K.N. Optimisation des conditions de caisson kraft de mélèxe hydride (Larix eurolepis Henry). Preprints of Conf. Technologique Estivale : 1-6 (1998).

T76

52. Law, K.N. “An autopsy of refiner mechanical pulp”. Pulp Paper Can. 106(1):T5-T8 (2005).

53. LAW, K.N. Refining earlywood and latewood - A difficulty balance. Preprints PAPTAC An. Meet.:D545D550 (2005).

54. LANOUETTE, R., LAW, K.N. and VALADE, J.L. Utilisation optimale du mélèze. Research Report prepared for Cartons St.-Laurent Inc. March 1997.

55. LAW, K.N. and VALADE, J.L. “Fibre morphology and its importance to the paper properties of hardwood chemithermomechanical pulps”. Proc. Intl. Symp. On Emerging Technologies of Pulping & Papermaking of FastGrowing Wood, South China University of Technology Press, pp. 66-74, Nov. 1998.

56. LALIBERTÉ, D., SHALLHORN, P.M. and KARNIS, A. “Comparison of TMP and CTMP properties from spruce and pine sawmill chips”. Pulp Paper Can. 88(3):T71-T77 (1987).

57. CHISHOLM, R.J., MUNGER, L. and WOOD, J.R. “Elevated levels of jack pine in newsprint can we do it? Yes we can!”. Proc. Intl. Mech. Pulp. Conf.:477-485 (2003).

58. LANOUETTE, R. Impact de la carie du sapin et de l’épinette blanche sur la mise en pâte par le procédé thermomécanique et le procédé kraft. Internal Research Report, Centre de recherche en pâtes et papiers, UQTR, 33 pages (1999).

59. JOHAL, S., YUEN, B. and WATSON, P. “The effects of species on the thermomechanical pulping of balsam fir, black spruce, red sp;ruce and white spruce”, Preprints of 91st Paptac Annual Meet.: D671-D679 (2005).

60. WOOD, J., MILES, K., WONG, D. and SITHOLÉ, B. “Wood quality variations in black spruce and balsam fir: Do they explain seasonal variations in pulp properties?”, Preprints of 91st Paptac Annual Meet.: D681-D692 (2005).

61. PETIT-CONIL, M. “Use of ozone in mechanical pulping processes”. Revue A.T.I.P. 57(2):17-26 (2003).

62. LAW, k.N., DANEAULT, C. and GUIMOND, R. “Enhancement of TMP long fibres”. J. Pulp Paper Sci 33(3):138-142 (2007).

63. HAN, Y., LAW, K.N., DANEAULT, C. and LANOUETTE, R. “Chemical and mechanical techniques for improving the papermaking properties of jack pine TMP fibres”. TAPPI J. (May issue):13-18 (2008).

Résumé: La présente communication retrace les progrès réalisés en matière de mise en pâte mécanique de divers feuillus et résineux de l’Est du Canada, notamment le tremble, le bouleau, le mélèze et le pin gris. Nous tentons ici de placer les essences secondaires en perspective et de suggérer des stratégies d’utilisation de ces matières ligneuses lors de la mise en pâte mécanique.

Reference: K. LAW, R. LANOUETTE. A Perspective on Expanded Use of Secondary Species In

Mechanical Pulping. Pulp & Paper Canada 110(5):T71-T76 (May/June 2009). Paper presented at the 92nd Annual Meeting in Montreal, QC, February 6-10, 2006. Not to be reproduced without permission of PAPTAC. Manuscript received October 13, 2005. Revised manuscript approved for publication by the Review Panel November, 2008.

Keywords: MECHANICAL PULPING, CMP, CTMP, TMP, ABIES BALSAMEA, PICEA MARINA, LARIX, PINUS BANKSIANA, BETULA PAPYRIFERA, POPULUS TREMULOIDES, ACERA RUBRUM

Pulp & Paper Canada May/June 2009

43

11/06/09 1:10 PM

T77

bleaching

Towards Overcoming the Brightness Ceiling of Mechanical Pulps Prepared from Blue-Stained Lodgepole Pine Chips

By T. Q. Hu, T. Williams, S. Yazdi, and P. Watson Abstract: A method to overcome the brightness ceiling of hydrosulfite (Y)-bleached TMP made from 25% blue-stained chips involves the addition of 0.2% of sodium borohydride to Y bleaching of the pulp. A high bleaching end pH (~10.0) in peroxide bleaching removes most to all of the blue stain in TMP made from the blue-stained chips. Under optimal peroxide bleaching conditions, TMP or CTMP made from 50 or 100% blue-stained chips was bleached to the same brightness as TMP or CTMP from the green chips.

T

he intrinsic strength and brightness of value-added mechanical pulps made from western spruce, lodgepole pine (LPP), and Douglas fir in British Columbia set such pulps apart on the world stage. Previously, we found that mechanical pulps prepared from beetle-infested, blue-stained LPP had a poor hydrosulfite bleach response and we observed a brightness ceiling on the bleached pulp [1]. The blue-stained TMP, when treated with low doses of peroxide, also exhibited a poor bleach response relative to the control.

Industrial bleaching of mechanical pulps is achieved mainly by the use of peroxide [2] and/or hydrosulfite [3]. Several other reducing agents capable of bleaching mechanical pulps have been reported. They include sodium borohydride, NaBH4 [4], formamidine sulfinic acid (FAS), (H2N)2CSO3 [5], and sodium bisulfite, NaHSO3 [6].

Recently, Hu, James and co-workers have discovered that H2O-soluble, tertiary hydroxyalkylphosphines or quaternary hydroxymethylphosphonium salts are effective bleaching and brightness stabilizing agents for mechanical pulps [7-10].

One of these agents, tetrakis(hydroxymethyl)phosphonium sulfate (THPS), [P(CH2OH)4]2SO4, has been successfully tested on a commercial scale and used as a complementary bleaching agent to hydrosulfite in the bleaching of a spruce stoneground wood pulp to higher brightness [10]. Use of THPS, NaBH4, or FAS as a complementary bleaching agent to hydrosulfite may enable the bleaching of mechanical pulps prepared from bluestained chips to higher brightness.

The focus of this project is to develop ­novel, cost-effective approaches to overcoming the brightness ceiling of bleached mechanical pulps prepared from beetle-infested, blue-stained LPP chips.

44

May/June 2009 Pulp & Paper Canada

p 44-50 Hu TP.indd 44

Methods and Materials

Chip samples chemical doses Six LPP trees (Pinus contorta var. latifolia) (Pli) were harvested from one site in the MSxk biogeoclimatic subzone near Kamloops, British Columbia. Three of these stems were healthy (green) live Pli, and three were in the red-stage of beetle attack (with time-since-death estimated to be 2-3 years) as confirmed by the presence of pitch tubes on the bark, blue stain fungi in the sapwood, and red foliage. Disks of the green and the red-stage, blue-stained LPP trees were collected from ~1.0 m intervals starting at breast height (1.3 m) to 6.3 m. Mature (over 40 years) sapwood sections of the disks were obtained using a portable sawmill, and chipped using a CM&E 10-knife disc chipper. The green and the blue-stained chips were screened, respectively, on a Burnaby Machinery and Mill Equipment Ltd. two-deck laboratory chip classifier to remove oversize (>31 mm) and fine (<8 mm) material. Portions of the two screened chips were combined into blends with blue-stained chip contents of 25, 50, and 75%. The blue-stained chip content (%) is defined as [weight of blue-stained chips/(weight of blue-stained chips + weight of green chips)] x 100; all weights are on oven-dried (o.d.) basis. Throughout this report, 0, 25, 50, 75 and 100% blue-stained (C)TMP refer to (C)TMP prepared from chips (or blends) with 0, 25, 50, 75 and 100% blue-stained chip contents, respectively.

All chemicals used for the pulping or bleaching are reported in percent with respect to o.d. weight chips or pulps.

Pilot-plant TMP and CTMP pulping The chips (or blends) were first subjected to firststage refining in a 30.5-cm Sunds Defibrator TMP 300 single-disc laboratory refiner. For CTMP pulping, 3.8-4.4% of sodium sulfite, Na2SO3, was

T. Q. Hu FPInnovations – Paprican Vancouver, BC thomas.hu@fpinnovations.ca

T. Williams FPInnovations – Paprican Vancouver, BC

S. Yazdi FPInnovations – Paprican Vancouver, BC

P. Watson Canfor Pulp Limited Partnership, R&D Vancouver, BC pulpandpapercanada.com

11/06/09 1:12 PM

bleaching

FIG. 1. Bleaching of the 0% and 100% blue-stained TMP with sodium hydrosulfite at 5.0% Cs, pulp initial pH ~5.6 and 70°C for 1 h.

applied to the chips at the built-in screw impregnator in the refiner. The refiner housing pressure for the 1st-stage TMP or CTMP refining was 179 kPa and dilution H2O was added to the refiner to give a constant, discharge pulp consistency (Cs) of 23-29%. Other refining conditions were identical to those used previously [1]. The first-stage refined pulps were given two (for TMP) or four (for CTMP) further passes through a 30.5-cm Sprout Waldron open-discharge laboratory refiner equipped with type D2A507 plates to give TMP and CTMP (~2.5 kg o.d. each) with Canadian standard freeness (CSF) values of ~100 mL. Sodium hydrosulfite (Y) bleaching A sample (12 g o.d.) of TMP or CTMP was diluted with deionized (DI) H2O to 5.0% Cs. The pulp slurry (pH typically ~5.5) was titrated with 0.1 N NaOH and the amount required to reach a known pH (5.7-10.0) was recorded.

A known amount of DI H2O needed to give a 5.0% Cs for the bleaching of 12 g (o.d.) of TMP or CTMP was weighed out.

Fifty milliliters of the water was reserved/ stored in a refrigerator. The remaining water was added to the pulp in a polyethylene bag, and the bag was sealed and placed in a water-bath heated to 70°C for 10 min.

To the reserved water, a known amount of 0.1 N NaOH was added to give a desired “pulp initial pH” (pH 5.7-10.0) (i.e. the pH of the pulp at the start of bleaching if no bleaching chemicals were added) based on the results from the titration of the pulp. A commercial, powder sodium hydrosulfite (Y) (0.6-1.2%) whose active concentration was determined according pulpandpapercanada.com

p 44-50 Hu TP.indd 45

T78

FIG. 2. CIE b* vs. ISO brightness of the unbleached and the hydrosulfite-bleached, 0% and 100% blue-stained TMP.

TABLE I. Specific refining energy requirements for the preparation, CSF and ISO brightness of the TMP and CTMP. Pulp

Specific Refining Energy (MJ/kg)

CSF (mL)

ISO Brightness (%)

100% blue-stained TMP 75% blue-stained TMP 50% blue-stained TMP 25% blue-stained TMP 0% blue-stained TMP

9.78 10.50 10.59 10.47 11.07

99 110 99 107 99

55.1 55.1 58.4 60.9 60.1

100% blue-stained CTMP 75% blue-stained CTMP 50% blue-stained CTMP 25% blue-stained CTMP 0% blue-stained CTMP

11.72 12.33 12.42 12.50 12.75

92 109 103 110 101

57.4 58.6 58.5 60.1 61.6

to TAPPI test method T622 cm-01 [11] was also added. The “NaOH + Y” solution was then added to the preheated pulp. The bag was quickly sealed after exclusion of air from the headspace of the bag. The pulp inside the sealed bag was homogenized by hand mixing of the pulp from the outside of the bag. The sealed bag was placed in a water-bath heated to 70°C for 1 h. The bag was then cooled in a cold water-bath to room temperature (~20°C). The pulp was diluted with DI H2O to 1.0% Cs. The pH (end pH) of the pulp slurry was recorded, and adjusted to 6.0 with 0.1 N H2SO4 if needed. The pulp slurry was filtered, with the filtrate being recycled once to recover the fines. The same dilution, pH adjustment (if needed) and filtration were then repeated once. The filtered pulp was used to make three handsheets (200 g/ m2) according to PAPTAC test methods, Standard C.5 [12]. The ISO brightness and CIE b* of the sheets were determined on a Technibrite Micro TB-1C instru-

ment according to PAPTAC test methods, Standard E.1 [13], and their average values were recorded.

One-stage “Y + THPS (NaBH4 or FAS)” bleaching For one-stage “Y + THPS” bleaching, the Y bleaching procedure was used, except that THPS (Cytec Canada) (0.1-0.4%) was added to the reserved water between the addition of NaOH and Y. For onestage “Y + NaBH4” bleaching, the Y bleaching procedure was used, except that NaBH4 (Fisher Canada) (0.1-0.4%) and the “NaOH + Y” solution were added to the TMP simultaneously. For one-stage “Y + FAS” bleaching, the Y bleaching procedure was used, except that 0.4% of FAS (Aldrich) and additional NaOH (0.1-0.4%) were added to the pulp.

Chelation and alkaline hydrogen peroxide bleaching A known amount of DI H2O was comPulp & Paper Canada May/June 2009

45

11/06/09 1:12 PM

T79

bleaching bined with a TMP (or CTMP) (typically 24 g o.d.) to give a 1.5% Cs in a 2L beaker. Diethylenetriaminepentaacetic acid (DTPA) in the form of its pentasodium salt (0.5%) was added to the pulp, and the pH of the pulp slurry was adjusted to 5.0 with 0.1 N H2SO4. The pulp slurry was then transferred to a polyethylene bag. The bag was sealed. The pulp inside the sealed bag was homogenized by hand mixing of the pulp from the outside of the bag. The sealed bag was then placed in a waterbath heated to 50°C for 30 min. The bag was then cooled in a cold water-bath to room temperature (~20°C). The pulp was diluted with DI H2O to 1.0% Cs, and filtered, with the filtrate being recycled once to recover the fines. The same dilution and filtration were then repeated once.

To a DTPA-chelated pulp (12 g o.d.) in a Hobart mixer were added, sequentially, NaOH (1.0-4.0%); 1.0% (when H2O2 <2.0%) or 3.0% of sodium silicate, Na2SiO3; 0.05% of magnesium sulfate, MgSO4; hydrogen peroxide, H2O2 (1.06.0%) and DI H2O to give, unless otherwise specified, a 20% Cs pulp. The pulp and the bleaching chemicals were mixed for 2-3 min in the Hobart mixer, and then transferred to a polyester or polyethylene bag. The air in the headspace of the bag was excluded, and the bag was sealed and immersed in a hot water-bath at 60°C for 3 h with manual mixing every hour. The bag was then cooled in a cold water-bath to room temperature (~20°C) and enough filtrate was squeezed out by hand and analyzed for end pH, and for residual peroxide, according to PAPTAC test methods, Standard J.16P [14]. The pulp was diluted with DI H2O to 1.0% Cs. The pH of the pulp slurry was lowered to 6.0 with 6% SO2 solution. The pulp slurry was filtered, with the filtrate being recycled once to recover the fines, and washed with 400 mL of DI H2O. The same dilution, pH adjustment and filtration, and washing with 800 mL of DI H2O were then repeated once.

The filtered pulp was used to make three handsheets for the determination of ISO brightness and CIE b* similar to that of the filtered, hydrosulfite-bleached pulp.

Results and Discussion

Energy requirement and initial brightness The TMP or CTMP made from chip blends containing ≥25% blue-stained chips 46

Table II. Unbleached and hydrosulfite-bleached ISO brightness (%) of the TMP, and the brightness difference (DBa) between the blue-stained and the 0% bluestained TMP. TMP Unbleached

brightness

(DB)

Bleached brightness with end pH of ~4.5 (DB)

Bleached brightness with end pH of ~5.7 (DB)

0% blue-stained 25% blue-stained 50% blue-stained 100% blue-stained

67.0 67.4 (+0.4) 64.8 (-2.2) 61.1 (-5.9)

69.7 68.4 (-1.3) 66.0 (-3.7) 61.9 (-7.8)

DB = ISO brightness of the unbleached or bleached, blue-stained TMP – ISO brightness of the unbleached or bleached, 0% blue-stained TMP.

a

Table III. ISO brightness and CIE b* of the 100% blue-stained TMP (55.1% ISO brightness) bleached with Y, “Y + THPS (or NaBH4 or FAS)” at 5% Cs and 70°C for 1 h, respectively.

Bleaching chemical Pulp initial

pH

ISO brightness (%) / CIE b* after bleaching

1.0% 1.2% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0%

61.1/11.7 60.5/11.8 61.9/11.5 62.3/11.4 62.6/11.1 63.1/10.9 62.7/10.3 61.5/11.7 62.6/11.4 62.6/11.4

Y Y Y Y+ Y+ Y+ Y+ Y+ Y+ Y+

0.1% 0.1% 0.2% 0.4% 0.4% 0.4% 0.4%

THPS NaBH4 NaBH4 NaBH4 FAS + 0.1% NaOH FAS + 0.2% NaOH FAS + 0.4% NaOH

5.7 5.7 7.0 or 8.0 5.5 8.0 8.0 8.0 5.5 5.5 5.5

Table IV. Additional brightness gain from “1.0% Y + 0.2% NaBH4” bleaching over 1.0% Y bleaching for the TMP; all the bleaching was done at 5% Cs, pulp initial pH 8.0 and 70°C for 1 h.

TMP

ISO brightness after 1.0% Y bleaching

ISO brightness (%) (%) after “1.0% Y + 0.2% NaBH4 bleaching

Additional brightness gain (ISO point)

0% blue-stained 25% blue-stained 50% blue-stained

69.7 68.4 66.0

71.0 70.1 67.4

+1.3 +1.7 +1.4

appeared to require slightly less energy than the pulp from the green chips (with 0% blue-stained chip content) to reach the same freeness, Table I. The brightness of 100 or 75% bluestained TMP and that of the 50% bluestained TMP were 5.0 and 1.7 ISO points, respectively, lower than that of the green TMP, Table I. Interestingly, the brightness of the 25% blue-stained TMP was slightly higher than that of the green pulp.

Previously we did not observe any significant difference in the initial brightness of the blue-stained and the green TMP [1], likely due to the lightly-infested/stained chips used. The extent of blue stain in the chip sample used for our previous studies

May/June 2009 Pulp & Paper Canada

p 44-50 Hu TP.indd 46

60.1 60.9 (+0.8) 58.4 (-1.7) 55.1 (-5.0)

may have been similar to that of the chip blend with 25% blue-stained chip content used in the present studies.

Overall, the initial brightness of the CTMP was higher than that of the TMP at the same blue-stained chip content. The initial brightness difference between the various blue-stained CTMP and the green CTMP was still significant.

Effect of blue stain content on hydrosulfite bleaching Figure 1 shows the Y bleach responses of the 0 and 100% blue-stained TMP pulps, respectively. The 100% blue-stained TMP had a poorer response to Y bleaching than the 0% blue-stained TMP. The pulpandpapercanada.com

11/06/09 1:12 PM

bleaching

FIG. 3. Effect of peroxide and blue stain content on ISO brightness of peroxide-bleached TMP.

T80

FIG. 4. CIE b* vs. ISO brightness of the unbleached TMP and the TMP bleached with various amounts of peroxide.

Table V. ISO brightness (%) and CIE b* of the DTPA-chelated TMP pulps before and after alkaline hydrogen peroxide bleachinga at 20% Cs and 60°C for 3 h; bleaching end pH values are shown in brackets.

H2O2 / NaOH (%)

Brightness/CIE b* for 0% blue-stained TMP

none 1.0 / 1.0 1.5 / 1.5 2.0 / 2.0 4.0 / 3.0 5.0 / 3.5 6.0 / 4.0

60.1 69.3 71.3 72.7 76.0 76.9 77.9

/12.8 / 12.3 (7.8) / 11.9 {7.6} / 11.4 {8.2} / 10.3 {9.6} / 9.7 {9.9} / 9.2 {10.2}

Brightness/CIE b* for 50% blue-stained TMP 58.4 66.1 67.6 69.6 73.8 76.0 77.4

/ / / / / / /

13.0 11.5 {7.5} 11.2 {7.8} 10.8 {7.8} 10.5 {9.3} 10.0 {9.5} 9.3 {9.8}

Brightness/CIE b* for 100% blue-stained TMP 55.1 63.0 65.2 66.0 73.3 75.5 76.6

/ / / / / / /

13.0 11.6 {7.5} 11.3 {7.6} 11.2 {n.a.}b 10.6 {9.4} 10.1 {9.6} 9.6 {9.9}

see Material and Methods section for sodium silicate and magnesium sulfate dosages for the bleaching experiments; bend pH data not available.

a

initial (unbleached) ISO brightness of the 100% blue-stained TMP was 5.0 points lower than that of the 0% blue-stained TMP. However, after bleaching with, for example, 1.0% of Y, the ISO brightness of the Y-bleached, 100% blue-stained TMP was 5.9 points lower than that of the Y-bleached, 0% blue-stained pulp, Fig. 1.

To determine whether the blue stain had been removed during Y bleaching of the 100% blue-stained TMP, we employed the method that we described previously [1] and plotted the CIE b* vs. ISO brightness of the unbleached and the Y bleached pulps, Fig. 2. The presence of blue stain lowers the CIE b* at the same brightness value, or lowers the ISO brightness at the same CIE b* value [1]. Since the CIE b* vs. brightness curve for the unbleached and Y-bleached, 100% blue-stained TMP was largely parallel to that for the unbleached and Y-bleached, 0% blue-stained TMP, Fig. 2, we concluded that no blue stain removal had occurred.

During the Y bleaching discussed above, we noticed that the bleaching end pH was ~4.5. Such an end pH is lower than the optimal end pH typically found pulpandpapercanada.com

p 44-50 Hu TP.indd 47

in Y bleaching of mechanical pulps. To see how the TMP would respond to Y bleaching at a higher end pH, we raised the pulp initial pH from ~5.6 to 7.0 and 8.0, respectively, to give end pHs of ~5.3 and 5.7. The optimal pulp initial pH for the bleaching of the various TMP was 8.0, with the corresponding optimal end pH being ~5.7. At such an optimal pH, the green TMP could be bleached with 1.0% of Y from 60.1 to 69.7% ISO brightness, but the 100% blue-stained TMP could only be bleached from 55.1 to 61.9% ISO brightness, Table II. Thus, at the optimal bleaching pH, the 100% blue-stained TMP had an even poorer bleach response than the green pulp; the bleached ISO brightness of the 100% blue-stained TMP was 7.8 points lower than that of the green pulp, compared to 5.9 and 5.0 points lower at non-optimal pH and before bleaching, Table II. The blue stain in 100% blue-stained TMP not only lowered the unbleached brightness of the TMP pulp, but it also made it more difficult to bleach with Y and introduced an additional ISO brightness ceiling of 7.8 – 5.0 = 2.8 points.

The blue-stained CTMP also had a lower bleach response to Y bleaching than the green CTMP. For example, with 1.0% of Y at optimal bleaching pH (initial pulp pH = 9.0; and end pH = 5.45.9), the green CTMP could be bleached from 61.6 to 70.6% ISO brightness, but the 100% blue-stained CTMP could only be bleached from 57.4 to 64.7% ISO brightness. This means that the blue stain introduced an additional brightness ceiling of (70.6 – 64.7) – (61.6 – 57.4) = 1.7 ISO points to the blue-stained CTMP during Y bleaching.

In separate experiments, we found that the unusually high pulp initial pHs (8.0 or 9.0 for TMP or CTMP bleaching) needed to obtain an end pH of ~5.7 was due to the use of DI H2O in the bleaching experiments. When mill or tap water with a higher conductivity than that of DI H2O was used, the pulp initial pH only needed to be adjusted to ~6.5 to give an end pH of ~5.7 under otherwise same bleaching conditions.

The unbleached and bleached brightness of the various pulps presented, for example, in Table II, are high compared Pulp & Paper Canada May/June 2009

47

11/06/09 1:13 PM

T81

bleaching to actual mill experience. This is because the wood chips used in our studies were fresh chips. The absolute brightness values observed in mills will be lower due to aging of the chips in chip piles, but the trends (effects of blue-stained chip contents on the initial brightness and bleach response) are expected to be the same.

One-stage “Y + THPS (or NaBH4 or FAS)” bleaching In an attempt to develop a cost effective means to overcome the brightness ceiling of the Y-bleached, blue-stained TMP, we performed one-stage “Y + THPS”, “Y + NaBH4” and “Y + FAS” bleaching of the 100% blue-stained TMP, respectively, with 1.0% of Y and ≤0.4% of THPS, NaBH4, or FAS at various pulp initial pHs. All the one-stage “Y + reducing agent” bleaching led to a higher bleached brightness than Y bleaching alone, Table III, with “1.0% Y + 0.1 or 0.2% NaBH4” being the most effective in terms of brightness gain/chemical dose. The brightness of the 100% blue-stained TMP bleached with “1.0% Y + 0.2% NaBH4” was 1.2 ISO points higher than that of the pulp bleached with Y under the most optimal conditions (1.0% Y at pulp initial pH of 7.0 or 8.0), Table III. The additional brightness gain from “1.0% Y + 0.1-0.2% NaBH4” over 1.0% Y bleaching appeared to be due mainly to the further bleaching of lignin when the CIE b* vs. ISO brightness data from “1.0% Y + 0.1-0.2% NaBH4” bleaching were plotted onto Fig. 2. If this was so, one would expect similar, additional brightness gains from such bleaching of other blue-stained TMP and the green TMP. More importantly, one would be able to overcome the brightness ceiling of Y-bleaching of the 25% blue-stained TMP, since the Y-bleached brightness of this pulp (68.4% ISO) was only 1.3 ISO points lower than that of the Y-bleached, green TMP (69.7% ISO), Table II. Indeed, this was found to be the case. Bleaching of the 0, 25 and 50% blue-stained TMP pulps with “1.0% Y + 0.2% NaBH4” gave additional brightness gains of 1.3, 1.7 and 1.4 ISO points, respectively, over Y bleaching of the pulps, Table IV. The ISO brightness of the 25% blue-stained TMP bleached with “1.0% Y + 0.2% NaBH4” was 70.1%, which was slightly higher than that of the green TMP bleached with 1.0% Y. Thus, 48

Table VI. Effect of NaOH charges and end pH on peroxide bleachinga of the DTPA-chelated TMP with 6.0% of H2O2 at 20% Cs and 60°C for 3 h, bleaching end pH values are shown in bracket.

NaOH (%)

ISO brightness (%) for 0% blue- stained TMP

ISO brightness (%) for 50% blue- stained TMP

ISO brightness (%) for 100% bluestained TMP

4.0 4.5 5.0

77.9 {10.2} 78.7 {10.1} 78.5 {10.3}

77.4 {9.8} 78.8 {10.0} 78.6 {10.3}

76.6 {9.9} 77.7 {10.1} 77.6 {10.1}

see Material and Methods section for sodium silicate and magnesium sulfate charges for the bleaching experiments.

a

Table VII. ISO brightness (%) and CIE b* of the DTPA-chelated CTMP before and after peroxide bleachinga at 20% Cs and 60°C for 3 h; bleaching end pH values are shown in brackets.

H2O2 / NaOH (%)

Brightness/CIE b* for 0% blue-stained CTMP

Brightness/CIE b* for 100% blue-stained CTMP

none 2.0 / 2.0 4.0 / 3.0 5.0 / 3.5 5.0 / 4.0 6.0 / 4.0

62.5 74.4 77.3 77.8 78.0 78.4

57.6 72.0 76.7 77.8 77.6 78.4

13.0 /11.0 {9.3} 9.6 {10.5} 9.1 {10.5} 9.1 {10.7} 9.0 {10.8}

/ / / / / /

12.5 10.5 {9.1} 9.5 {10.4} 9.0 {10.5} 9.0 {11.0} 8.8 {10.8}

see Material and Methods section for sodium silicate and magnesium sulfate dosages for the bleaching experiments.

a

a possible means to overcome the brightness ceiling of Y-bleached, blue-stained TMP is to use a one-stage, “1.0% Y + 0.2% NaBH4” bleaching, if the TMP is made from a chip furnish containing ≤25% bluestained chips.

Effect of blue stain content on peroxide bleaching of TMP To study the effect of blue stain content on alkaline hydrogen peroxide (P) bleaching of the TMP, we first preformed P bleaching on 0, 50 and 100% blue-stained, DTPA-chelated TMP. The brightness of the P-bleached TMP pulps depended not only on the P bleaching chemical doses, but also on the blue stain content, Table V and Fig. 3. The higher the blue stain content and the lower the bleaching chemical dose, the more difficult it is to bleach the blue-stained TMP close to the brightness level of the green TMP. When we plotted data of CIE b* vs. the ISO brightness of the unbleached and various P-bleached pulps, Fig. 4, and analysed the data using our method of determining lignin chromophore vs. blue stain removal described earlier, we found that bleaching the 100 and 50% blue-stained pulps at ≤2.0% of H2O2 (ISO brightness ≤69.6%) did not remove the blue stain to any significant extent, but bleaching the

May/June 2009 Pulp & Paper Canada

p 44-50 Hu TP.indd 48

/ / / / / /

pulps at ≥4.0% of H2O2 removed most of the blue stain.

The removal of blue stain coincided with an increase of bleaching end pH from 7.5-7.8 to 9.3-9.9, Table V. These results show that, for effective removal of the blue stain, a higher initial H2O2 concentration and/or higher peroxide bleaching end pH are/is required. The initial H2O2 concentration for the bleaching at 20% Cs with 4.0% of H2O2 is 10 g/L, compared to 5.0 g/L with 2.0% of H2O2. When we performed additional bleaching on the 0 and 100% blue-stained TMP with fixed, 5.0% of H2O2 and 4.0% of NaOH at 60°C and 10, 20 and 25% Cs, respectively, for 3 h, we found that the P-bleached brightness difference between the 0% and the 100% blue-stained pulps was independent of the Cs. Thus, the higher bleaching end pH, not the higher initial H2O2 concentration, was responsible for the blue stain removal in the bleaching of the blue-stained TMP at ≥4.0% of H2O2.

Overcoming the brightness ceiling of P bleaching of the 50% blue-stained TMP The demonstration of the ability of high peroxide bleaching end pH (9.3-9.9) to remove blue stain prompted us to examine the possibility of bleaching the bluestained TMP to higher brightness by pulpandpapercanada.com

11/06/09 1:13 PM

bleaching raising the end pH further. To this end, we performed the bleaching of the 0, 50 and 100% blue-stained, DTPA-chelated TMP pulps with 6.0% H2O2 and 4.5 and 5.0% NaOH, respectively. Increasing the dose of NaOH from 4.0 to 4.5% (or the end pH from 9.8 to ~10.0) allowed the P-bleaching of the 50% blue-stained TMP to the same ISO brightness as the P-bleaching of the green TMP, Table VI. However, the brightness of the P-bleached, 100% blue-stained TMP was still lower than that of the P-bleached, green TMP by 1.0 ISO point. Further increase of the dosage of NaOH to 5.0% slightly decreased the brightness of all the three pulps, likely due to the increased, alkali-induced darkening of the pulp during bleaching.

We also studied the peroxide bleaching of 0 and 100% blue-stained TMP with 5.0% of H2O2 and 4.5% NaOH at temperatures >60°C for <3 h. One additional ISO brightness point (from 76.6 to 77.6%) could be obtained on the P-bleached, 100% blue-stained TMP when the bleaching temperature was raised from 60 to 80°C and the bleaching time reduced from 3 to 2 h. The brightness of the 100% bluestained TMP bleached at 80°C for 2 h (end pH = 10.2) was practically identical to that of the green TMP bleached at 60°C for 3 h (77.7% ISO), but it was still 0.8 ISO point lower than that of the green TMP (78.4% ISO) bleached under optimal temperature (70°C) and time (3 h).

Effect of blue stain content on peroxide bleaching of CTMP Similar to TMP, the P-bleached brightness difference between the 0% and the 100% blue-stained CTMP became smaller at a higher peroxide dose or a higher end pH (≥10.4), Table VII and Fig. 5, due to the increased removal of the blue stain.

Different from TMP, however, the 100% blue-stained CTMP could be bleached to the same brightness level as green CTMP with ≥5.0% of H2O2 due to the complete removal of the blue stain, as deduced from the practically identical ISO brightness and CIE b* of the bleached, blue-stained CTMP to those of the P-bleached, green CTMP. The higher reactivity of the blue stain in CTMP towards alkaline hydrogen peroxide than that of the blue stain in TMP is likely due to the sulfonation of the blue stain during CTMP pulping.

The above results show that CTMP pulpandpapercanada.com

p 44-50 Hu TP.indd 49

T82

FIG. 5. Effect of hydrogen peroxide and blue stain content on ISO brightness of the peroxide-bleached CTMP.

mills which use high doses of peroxide (≥5.0% H2O2) in their bleaching processes are not expected to have any problems reaching brightness targets for their pulps made from chip furnishes containing high levels of mountain pine beetle, “red-stage”infested, blue-stained LPP. In addition, CTMP mills that use medium doses of peroxide (2.0 – 4.0% H2O2) would need a smaller amount of extra bleaching chemicals than TMP mills to achieve brightness targets for their bleached pulps made from blue-stained chips.

CONCLUSIONS

The initial ISO brightness of TMP and CTMP made from chip blends containing mountain pine beetle-infested, red-stage, blue-stained LPP chips is up to 5.0 points lower than that of the pulps made from the green chips. In general, the higher the blue-stained chip content in the chip blends, the lower the initial brightness of the pulps.

TMP made from chip blends with various blue-stained chip contents all have lower sodium hydrosulfite (Y) bleach responses than TMP made from the green chips; the brightness of the Y-bleached, blue-stained TMP is up to 7.8 ISO points lower than the Y-bleached, green TMP. A method to overcome the brightness ceiling of Y-bleached TMP made from a chip blend with 25% blue-stained chip content has been developed. The method involves the addition of 0.2% of sodium borohydride to Y bleaching in one stage;

it works by further removal of lignin chromophores.

A high bleaching end pH (~10.0) in peroxide bleaching removes most to all of the blue stain in TMP made from blue-stained chips. Under optimal peroxide bleaching conditions, TMP made from 50% blue-stained chips or CTMP made from 100% blue-stained chips was bleached to the same brightness as TMP or CTMP from the green chips.

ACKNOWLEDGEMENTS

This project was funded by the Government of Canada through the Mountain Pine Beetle Initiative, a six-year, $40 million program administered by Natural Resources Canada, Canadian Forest Service. Publication does not necessarily signify that the contents of this report reflect the views or policies of Natural Resources Canada – Canadian Forest Service. We would like to thank: Tennessee Trent for providing us with the green and bluestained LPP disks; Surjit Johal and Bernard Yuen for performing the pulping experiments; and Dr. John Schmidt for an internal review of this report; all of them are from FPInnovations – Paprican.

LITERATURE

1. HU, T.Q., JOHAL, S., YUEN, B., WILLIAMS, T., OSMOND, D.A., WATSON, P., Thermomechanical Pulping and Bleaching of Blue-stained Chips. Pulp Paper Can. 107(9): 38-45 (2006).

2. PRESLEY, J.R., HILL, R.T. The Technology of Mechanical Pulp Bleaching, Chapter 1: Peroxide Bleaching of (Chemi)mechanical Pulps”, in: Pulp Bleaching - Principles and Practice, Eds. DENCE, C.W., REEVE, D.W., Tappi Press, Atlanta, p.457-489

Pulp & Paper Canada May/June 2009

49

11/06/09 1:13 PM

T83

bleaching (1996).

3. ELLIS, M.E., The Technology of Mechanical Pulp Bleaching, Chapter 2: Hydrosulfite (Dithionite) Bleaching, in: Pulp Bleaching - Principles and Practice, Eds. DENCE, C.W. and REEVE, D.W., Tappi Press, Atlanta, p.491-512 (1996).

4. MAYER, W.C. DONOFRIO, C.P. Reductive Bleaching of Mechanical Pulp with Sodium Borohydride.

Pulp Paper Mag. Can. 157-166 (1958).

5. BLECHSCHMIDT, J., WURDINGER, S., ZIESENIS, G. Single- and Multistage Bleaching of High-yield Pulps with Hydrogen Peroxide and Formamidine Sulfinic Acid. Papier 45(5): 221-225 (1991).

6. KUYS, K., ABBOT, J. Bleaching of Mechanical Pulps with Sodium Bisulfite. Appita 49(4): 269-273 (1996).

7. HU, T.Q., JAMES, B.R., YAWALATA, D., EZHOVA, M.B. A New Class of Bleaching and Brightness Stabilizing Agents - Part I. Bleaching of Mechanical Pulps.

J. Pulp Paper Sci. 30(8): 233-240 (2004).

8. HU, T.Q., JAMES, B.R., YAWALATA, D., EZHOVA, M.B., CHANDRA, R. A New Class of Bleaching and Brightness Stabilizing Agents. Part II. Bleaching Power of a Bisphosphine. J. Pulp Paper Sci. 31(2): 69-75 (2005).

9. HU, T.Q., JAMES, B.R., YAWALATA, D., EZHOVA, M.B. A New Class of Bleaching and Brightness Stabilizing Agents. Part III: Brightness Stabilization of Mechanical Pulps. J. Pulp Paper Sci. 32(3): 131-136 (2006).

10. HU, T.Q., WILLIAMS, T., SCHMIDT, J., JAMES,

Résumé: Il est possible d’éliminer les limites en matière de blancheur de la PTM blanchie (Y) à l’hydrosulfite fabriquée avec une teneur en bois bleui de 25 %, si l’on ajoute 0,.2 % de borohydrure de sodium à l’étape du blanchiment (Y) de la pâte. Un pH élevé (~10.0) à la fin d’un blanchiment au peroxyde permet d’éliminer presque tout, et quelquefois tout, le bleuissement dans la PTM fabriquée à partir de copeaux bleuis. Dans des conditions optimales de blanchiment au peroxyde, la PTM ou la PCTM fabriquée avec une teneur en bois bleui de 50 % ou 100 % a pu être blanchie au même degré de blancheur que la PTM ou la PCTM fabriquée à partir de copeaux verts.

Reference: HU, T.Q., WILLIAMS, T., YAZDI, S., WATSON, P. Towards Overcoming the Bright-

ness Ceiling of Mechanical Pulps Prepared from Blue-Stained Lodgepole Pine Chips. Pulp & Paper Canada 110(5):T77-T83 (May/June 2009). Paper presented at the 2008 PACWEST Conference in Jasper, AB, Canada, June 18-21, 2008. Not to be reproduced without permission of PAPTAC. Manuscript received on January 1, 2008. Revised manuscript approved for publication by the Review Panel on April 2, 2009.

Keywords: BLEACHING, BLUE STAIN, BRIGHTNESS, CHELATION, CHEMI-THERMOMECHANICAL PULPS, HYDROGEN PEROXIDE, LODGEPOLE PINE, MECHANICAL PULPS, MOUNTAIN PINE BEETLE, SODIUM BOROHYDRIDE, SODIUM HYDROSULFITE, THERMOMECHANICAL PULP.

B.R., CAVASIN, R., LEWING, D., Mill Trial and Commercial Implementation of the New Bleaching Agent - THPS. Pulp Paper Can. (in press) 2009.

11. Analysis of Sodium Hydrosulfite - TAPPI Standard Testing Method T 622 cm-01 (2001).

12. Forming Handsheets for Optical Tests of Pulp

(British Sheet Machine Method) - PAPTAC Standard Testing Method C.5 (1993).

13. Brightness of Pulp, Paper and Paperboard - PAPTAC Standard Testing Method E.1 (1990).

14. Analysis of Peroxide - PAPTAC Standard Testing Method J.16P (1992).

2009 ANNUAL MILL DIRECTORY Has Arrived!

A Complete Web-Enhanced Industry Guide to Canadian Pulp, Paper & Board Producers

Regular Price: $149.99

YOUR PRICE: $99.00

BONUS:

Gain access to data you won’t find anywhere else!

The 2009 Annual Mill Directory contains the complex operational details you need on all Canadian Pulp and Paper Mills:

Download the entire Mill Database of over 1,300 contacts in CSV format Convenient Digital Format!

˛

Production Focus

This digital publication allows you to flip through the pages laid out on your screen just like a real book; zoom in on listings or graphics; clip and save selected entries and much more:

˛

Power Consumption

˛

Direct links to Mill websites and e-mail addresses

˛

Environmental Policies

˛

Search and find your desired Mill within seconds

˛

Plant Manufacturing Capacity

˛

Save the entire directory as a PDF document

˛

Personnel Data and Contact Info

˛

Access from any web-enabled computer

˛

Company Background and History

˛

Facility and Equipment Specifications

50

May/June 2009 Pulp & Paper Canada

p 44-50 Hu TP.indd 50

ORDER TODAY!

HOW TO ORDER:

Tel: (416) 442 - 2122 E-mail: customercare@bizinfogroup.ca Web: www.pulpandpapercanada.com

pulpandpapercanada.com

11/06/09 1:13 PM

chemical recovery

T84

Demonstration of the Green Liquor Splitter (GLS) System at Millar Western’s Meadow Lake Closed-Cycle BCTMP Mill

By N. Jemaa, M. Paleologou, A. Thibault, J. Fleck, K. Miller, M. Sheedy, and C. Brown Abstract: Smelt from Millar Western’s Meadow Lake closed-cycle BCTMP mill contains mainly sodium hydrosulphide and sodium carbonate/hydroxide. Removal of sodium hydrosulphide from dissolved smelt (green liquor) using the green liquor splitter (GLS) system would allow the sodium carbonate/hydroxide content to be used in the bleach plant. The GLS system was demonstrated at the mill over a 5.5 month period. The system removed 91 to 98% of the sodium hydrosulphide from the liquor. The recovery of sodium hydroxide and sodium carbonate averaged 85 and 95%, respectively.

T

he Millar Western (Meadow Lake) mill is located about 300 km north of Saskatoon, Saskatchewan.

This bleached chemi-thermomechanical pulp (BCTMP) mill, started in 1992, was the world’s first “zero effluent” BCTMP mill. The zero-effluent process was developed by Millar Western and NLK Consultants Inc. [1, 2]. During start-up, the mill produced about 240,000 tonnes of pulp per year from 100% aspen white.

Today, the mill produces over 300,000 tonnes per year. Chips from the woodroom pass through a three-stage impregnation system (plug screw feeders, impregnators, and metering surge bins) and are then fed to primary Hymac single-disc refiners. The resulting pulp enters a secondary refiner, and is then screened and cleaned, before going to a medium consistency storage tower. The pulp is then bleached in two towers using peroxide and sodium hydroxide. The pulp is then dried and compressed into bales.

The effluent produced by the mill is sent to flotation clarifiers. Chemicals are added to improve flocculation and flotation of the solids. The clarified effluent goes to a set of falling film vapour recompression evaporators, where the solids are concentrated from about 2% to 35%. The condensate from this step is reused in pulp washing and as make-up water in other processes. The 35% solids liquor is sent to two falling-film concentrators which use steam produced by the recovery boiler to further concentrate the liquor to 68% solids.

The heavy liquor is burned in a Babcock & Wilcox recovery boiler. Inorganic smelt from the recovery boiler is cast into ingots to facilitate landfilling.

A small portion of the smelt (approximately 15%) is dissolved in evaporator condensate and the resulting green liquor is used to neutralize purchased sodium hydrosulphite (NaHSO3) used in chip impregnation. The remainder is sent to pulpandpapercanada.com

p 51-57 Jemaa TP.indd 51

landfill. Figure 1 shows a simplified diagram of the closed-cycle BCTMP mill.

About 90 tons/day of recovery boiler smelt is sent to landfill. Closing the cycle, in terms of solid discharge, would allow valuable chemicals in the smelt to be recovered and reused while providing the environmental benefit of reduced landfill volumes.

Sodium carbonate represents about 65-80% by weight of the smelt. BCTMP mills can use sodium carbonate in their bleach plant as a partial substitute for sodium hydroxide. Raw green liquor cannot be used directly for bleaching due to the presence of sodium hydrosulphide (NaHS), which consumes peroxide [3-5]. Removal of NaHS from the green liquor would allow the sodium carbonate/hydroxide content to be used in the bleach

N. Jemaa FPInnovations-Paprican Division Pointe-Claire, QC naceur.jemaa@ fpinnovations.ca

M. Paleologou FPInnovations-Paprican Division Pointe-Claire, QC

A. Thibault FPInnovations-Paprican Division Pointe-Claire, QC

J. Fleck Millar Western Pulp Ltd. Meadow Lake, SK

K. Miller Husky Energy LIoydminster, SK formerly with Millar Western Pulp Ltd.

M. Sheedy Eco Tec Inc. Pickering, ON

C. Brown Chemionex Pickering, ON formerly with Eco Tec Inc.

Pulp & Paper Canada May/June 2009

51

12/06/09 7:57 AM

T85

chemical recovery

FIG. 1. Diagram of Millar Western’s Meadow Lake closedcycle BCTMP mill.

FIG. 2. Main steps in the operation of the GLS system.

FIG. 3. Proposed approach for the recovery of valuable chemicals from smelt at closed-cycle BCTMP mills.

FIG. 4. GLS demonstration unit at the mill.

plant. The green liquor splitter (GLS), developed by Paprican and Eco-Tec Inc., can achieve this separation.

The GLS system was developed to split kraft green liquor into a sodium hydrosulphide-rich and a sodium carbonate-rich stream. Applications of the GLS system in kraft mills have been discussed in previous papers [6, 7]. The objective of this report is to discuss the applicability of the GLS system to closed-cycle BCTMP mills for recovering and reusing a portion of the smelt and to present the results of the demonstration of this technology at Millar Western (Meadow Lake).

The GLS system employs a shortbed resin technology using a proprietary amphoteric resin specifically designed to separate sodium hydrosulphide from sodium carbonate/hydroxide present in green liquor. The major steps in the operation of this system, Fig. 2, are: NaHS uptake onto the resin (sorption) and NaHS elution off the resin by water (desorption).

As shown in Fig. 3, the separated NaHS can be acidified with CO2 to produce a sodium carbonate/bicarbonate solution which can be used in smelt dissolving, 52

and the H2S can be oxidized to SO2 by incineration. The SO2 can be added to a portion of the sodium carbonate/ hydroxide product to produce Na2SO3 at a concentration and pH suitable for chip impregnation.

Demonstration of GLS system

The GLS system had been previously studied and optimized in a pilot plant at Paprican. A demonstration of the system was conducted at Millar Western (Meadow Lake) in collaboration with Eco-Tec Inc., the manufacturer of the GLS unit and the multi-media (MM) filter. The objectives of the trial were to: • Evaluate the performance of the MM filter and the GLS system over an extended period of time (5.5 months), under industrially realistic conditions; • Evaluate resin fouling by multi-valent metal ions and restoration of resin bed performance using periodic acid washes; • Evaluate resin durability • Accumulate sufficient sodium carbonate/ hydroxide-rich solution to perform a fourday bleaching trial.

May/June 2009 Pulp & Paper Canada

p 51-57 Jemaa TP.indd 52

GLS system arrangement at the mill

A demonstration of the GLS system was conducted over a 5.5 month period. The physical arrangement of the system is shown in Fig. 4. Clarified green liquor at 27-35°C was first fed to a MM filter to remove the suspended solids. The MM filter consisted of a 2.5 m long column partially packed with micro media (20 cm in height), topped by coarse media (90 cm in height). The unit had a PLC to control the initiation and termination of a given step or cycle. The MM filter had several operating steps. The first step involved rinsing and emptying the column by passing green liquor from the top.

The product from this step, about 2 bed volumes (82 L), was sent to the sewer.

During the on-stream step, green liquor was fed, under pressure, from the top of the column. The filtered green liquor exited the column from the bottom into a 1000 L tank before being fed to the GLS unit. Suspended solids were trapped in the coarse and fine media layers. When the pressure drop across the column increased to a prescribed maximum, the green liquor pulpandpapercanada.com

12/06/09 7:58 AM

chemical recovery

FIG. 5. Particle size distribution analysis of the suspended solids in raw green liquor. table i. Smelt composition.

Species Na2CO3 NaOH NaHS NaCl Na2SiO3 Total S Insolubles

p 51-57 Jemaa TP.indd 53

FIG. 6. Removal of suspended solids from green liquor using the MM filter over the course of the trial.

TABLE II. Typical GLS results during the mill trial.

Weight % 70 7 6 1.6 3 6-7 5-7

flow was stopped and air was applied to the top of the column to empty the column (drain step). Air scouring, a technique in which air bubbles were applied from the bottom of the column, was then used to facilitate removal of suspended solids from the media. Instrumental air available at the mill was used. There was a pause of 5 seconds before the back-wash step. During the back-wash step, water was passed up through the bed, from the bottom of the column, to remove the suspended solids.

The back-wash stream was sent to the sewer. Sewered water is recycled within the mill. In a last step, the media was allowed to settle over 60 seconds.

The GLS unit was equipped with two cartridge filters in series (5 µm and 0.5 µm absolute) which acted as safety filters.

These filters were replaced periodically, depending on the raw green liquor quality and the performance of the media filter.

The unit was equipped with a 14.5-cm diameter by 60-cm high resin bed (corresponding to a volume of about 10 L). The unit had two small reservoirs, one for green liquor and one for water. The volume fed to the resin bed was controlled by a set of float switches located inside each reservoir.

The pressure drop across each filter and across the resin bed was monitored with pressure gauges. pulpandpapercanada.com

T86

Stream

Vol.

NaHS

NaOH

L

Feed 9.5 Na2CO3–rich 9.5 stream NaSH-rich 9.5 stream % in removal stream % in recovery stream

Na2CO3

Cl-

S2O32-

g/L

15.57 0.34

20.52 18.21

173.9 168.5

2.69 0.10

4.68 2.95

15.54

1.88

12.0

2.5

1.67

98

11

4

93

36

2

89

96

7

64

ANALYTICAL PROCEDURES

Samples taken during the trial were analyzed at room temperature. The sodium hydrosulphide concentration was measured on site by potentiometric titration with mercuric chloride, using a sulphideselective electrode [8]; the precision of the potentiometric titration was ±1.5%. The following chemical species were analysed at Paprican: carbonate, sulphate, sulphite, thiosulphate and chloride by ion chromatography (IC); sodium and potassium by atomic absorption (AA) spectroscopy; and multi-valent metal ions by inductively coupled plasma (ICP) spectroscopy. The precision of the AA spectroscopy, IC, and ICP methods was ±5%. At the mill site, a calibrated turbidity meter was used to obtain a quick indication of the suspended solids in the filtered and unfiltered green liquor. The particle size distribution of suspended solids in green liquor was measured by a Mastersizer S particle size analyzer (Malvern Instruments) at Paprican.

RESULTS AND DISCUSSION Smelt analysis

The major constituents of the smelt are listed in Table I. Sodium carbonate comprised 70 wt%. Sodium hydroxide and

sodium hydrosulphide contents were 7 wt% and 6 wt%, respectively. Sodium sulphate, sodium sulfite and sodium thiosulphate were also present. The concentration of the various sulphur species in the smelt varied depending on the recovery boiler reduction efficiency. The total sulphur was 6 to 7%. Sodium chloride accounted for about 1.6 wt% of the smelt. The sodium silicate content was about 3%. Dregs or non-soluble materials accounted for about 5 to 7% of the smelt.

Green liquor filtration

During the first few weeks of the trial, there were two operating problems with the MM filter. Some liquor foaming caused plugging of some valves with the media.

One of the flow meters did not accurately record the flow rate and low flow alarms caused frequent shut downs of the unit.

The use of an antifoaming agent and a few adjustments to the PLC system addressed these problems, ensuring smooth operation during the rest of the mill trial.

Figure 5 shows the size distribution of particles present in several raw green liquor samples. The size of the particles varied from about 0.1 to about 100 µm in all of the samples. Smelt was dissolved at the Pulp & Paper Canada May/June 2009

53

12/06/09 7:58 AM

T87

chemical recovery

FIG. 7. Recovery of sodium carbonate and sodium hydroxide by the GLS unit over the course of the trial period.

FIG. 8. Removal of NaHS by the GLS system over the course of the trial period.

TABLE III. Multi-valent cations picked-up by the resin.

Stream RO water in, (ppm) NaHS-rich stream (water out), ppm % retained on resin

Ca

Mg

Fe

0.58 0.5

0.56 0.1

0.05 <0.1

14

82

–

TABLE IV. Overall concentration in the final sodium carbonate-rich solution.

FIG. 9. Restoration of the initial NaHS removal efficiency using two acid washes of the resin bed.

mill as needed, about 2 to 3 times a week.

When fresh green liquor was sent to the clarifier, the settled suspended solids were disturbed and, hence, the liquor fed to the media filter had higher suspended solids content. The concentration of suspended solids in the liquor ranged from about 10 to 200 ppm. The quality of filtered liquor depended heavily on the quality of the raw green liquor.

The particulate removal performance of the MM over the 150-day trial is shown in Fig. 6, based on a comparison of the turbidities of the filtered and unfiltered green liquors. In general, the filtered solution had a turbidity of 1-5 nephelometric turbidity units (NTU) and contained about 2-10 ppm of suspended solids, which were efficiently removed by the cartridge filters placed ahead of the resin bed. Suspended solids concentrations higher than 70 ppm were beyond the capability of the MM filter and caused frequent water back-washes and lower removal efficiencies.

GLS system performance

The performance of the GLS unit during 54

the trial was comparable with the pilot plant results at Paprican. No operating problems were encountered during the trial. Several parameters, such as the cycle time, temperature, pressure drop across the filters and the resin bed, and the sulphide content in all streams were checked and recorded daily or weekly. Boiler feed water, from the mill reverse osmosis (RO) system at about 25°C, was used to regenerate the resin bed.

Table II shows results from a typical operating cycle of the GLS system. Sodium carbonate recovery was about 96%, while the removal efficiency for NaHS into the desorption stream was about 98%. NaOH recovery was 89% during this cycle. The removal efficiencies for sodium chloride and sodium thiosulphate were 93% and 36%, respectively. Sodium thiosulphate was partially retained by the resin. Even though sodium chloride was removed from the green liquor, it will not exit the mill, since the NaHS stream would be recycled to the recovery system as indicated in Fig. 3. The green liquor contained sodium silicate (used in bleaching); most of it passed

May/June 2009 Pulp & Paper Canada

p 51-57 Jemaa TP.indd 54

NaHS NaOH Na2CO3 S2O32-

Concentration g/ L 0.42 13.2 129.9 1.71

through the resin bed into the recovered stream without interacting with the resin.

Figure 7 shows the efficiencies for sodium hydroxide and sodium carbonate recovery during the course of the trial.

The sodium hydroxide recovery efficiency ranged from 79% to about 90%. The recovery efficiency for sodium carbonate ranged from 90 to 100%. At the end of the trial, the overall recovery efficiencies for sodium hydroxide and sodium carbonate were 84% and 95%, respectively, after accumulating over 320 m3 of sulphide-free solution.

Figure 8 shows the hydrosulphide removal efficiency over the course of the mill trial. The decline from 99 to 91% over the first 50 days of operation was attributed to the accumulation of multivalent metal ions on the resin bed, which caused a reduction in the available ion-exchange capacity of the resin for sodium hydrosulphide retention. These multi-valent metal ions could not be removed by a simple water wash. An acid wash, using hydrochloric acid, was needed to remove them.

Two acid washes were performed during pulpandpapercanada.com

12/06/09 7:59 AM

chemical recovery

FIG. 10. Variation in the GLS system cycle time during the trial.

this trial, as indicated in Fig. 9. Immediately after each acid wash, the sodium hydrosulphide removal efficiency was restored to the initial level of about 98%.

Maintaining a high hydrosulphide removal efficiency is important with respect to the consumption of hydrogen peroxide in the bleach plant.

Accumulation of multi-valent metal ions on the resin bed

The sodium hydrosulphide concentration in the sodium carbonate-rich stream (bleaching solution) was monitored during the trial. After about 18000 cycles (about 50 days of operation), the NaHS concentration in the sodium carbonate product increased from about 0.25 g/L to about 1.1 g/L. As discussed above, this increase was attributed to the accumulation of multi-valent metal ions on the resin.

Metal ions could not be displaced by water during regeneration of the resin bed. An acid wash (with 6N HCl) was required for this purpose; sulfuric acid was not used, to avoid precipitation of insoluble sulphate salts (i.e. CaSO4) on the resin.

Immediately after the wash, the initial sodium hydrosulphide removal efficiency was restored, as indicated in Fig. 9. Three bed volumes of waste acid were generated from this step. The acid was neutralized with sodium hydroxide as it exited the bed in order to avoid the generation of hydrogen sulphide. Hydrogen sulphide was generated at the beginning of the acid wash due to the residual sulphide left on the resin. Chemical analysis of the waste stream revealed that Ca, Mg and Fe were the major cations removed. Traces of Al and Cu were also detected. A second acid wash was proactively performed 37 days later. A material balance for Ca, Mg and pulpandpapercanada.com

p 51-57 Jemaa TP.indd 55

T88

FIG. 11. Resin degradation in kraft and closed-cycle BCTMP mill green liquors.

Fe in the RO water before and after the resin bed is shown in Table III. It is clear from this table that Mg was predominantly retained by the resin. Even though Fe was present at very low concentrations in the RO water, it did accumulate on the resin bed, as indicated by chemical analysis of the waste stream. Even though raw green liquor contained multivalent metals as well, a material balance on Ca, Mg, and Fe in the green liquor flowing in and out of the bed did not reveal the accumulation of these metals on the resin. It thus appears that these were removed from the raw green liquor during the filtration steps in their sulphide, carbonate or hydroxide forms (undissolved salts).

GLS system cycle time

The cycle time, which is the time required to accomplish all steps (sorption, feed void, desorption and water void), was monitored during the trial. It was a good indication of resin fouling by precipitated salts, since the GLS was operated at constant pressure.

At no time during the trial did the cycle time increase to sufficiently high levels to suggest fouling by precipitated multivalent metal salts or other undissolved material.

The raw green liquor temperature varied from about 27 to 35°C and the dissolved solids content of the green liquor from the clarifier fluctuated.

These variations affect the cycle time through changes in the viscosity of the green liquor. An increase in the green liquor temperature made the liquor less viscous, allowing it to flow faster through the resin bed, and decrease the overall cycle time. A decrease in the green liquor density (dissolved solids concentration) reduced the cycle time. Figure 10 shows the variation of the cycle time during the

trial period. It varied from 5.5 to 7.5 minutes, depending on the temperature and the dissolved solids concentration of the green liquor. The resin bed was opened and inspected a few times during the trial.

No sign of significant fouling or physical degradation were observed.

Use of evaporator condensate as regenerant

The use of evaporate condensate as a regenerant during the desorption of sodium hydrosulphide would be a more realistic option than boiler feed water. During the last two weeks of the trial, evaporator condensate was employed instead of RO water. The GLS unit operated continuously for about ten days and all the parameters described above were monitored. No operational problems or decline in the system performance were observed. The organic material present in the condensate did not seem to have any negative effect on the resin.

Final sodium carbonate/hydroxide product

The GLS system was shut down when about 320 m3 of sodium carbonate/ hydroxide-rich solution were accumulated.

At the end of this 150-day trial, the overall concentrations of sodium hydrosulphide, sodium hydroxide, sodium carbonate and thiosulphate ions were measured, Table IV. The measured concentrations were lower (by about 20 %) than those given in Table II because green liquor in the clarifier was diluted inadvertently in the middle of the trial.

Resin durability

To evaluate resin durability during the course of the trial, a sample of ion-exchange Pulp & Paper Canada May/June 2009

55

12/06/09 7:59 AM

T89

chemical recovery resin was exposed to filtered green liquor by installing a perforated bottle filled with resin in the storage tank. Samples collected after 1, 2, 4, and 5 months were analyzed for total anion exchange capacity.

The results are shown in Fig. 11. After 5 months of continuous exposure to green liquor at temperatures ranging from 26 to 35°C, the loss in the total ion exchange capacity was only about 4%. As expected, this loss is lower than that obtained after exposing the resin to kraft mill green liquor, which contains a higher hydrosulphide content. A mechanism for resin degradation in white and green liquors has been discussed elsewhere [9]. The results of a static resin durability study using kraft mill green liquor at 25 and 35°C are also presented in Fig. 11. The anion exchange resin capacity loss at 35°C is more pronounced than that at 25°C. At the end of the mill trial, resin samples collected from the bed, at various locations along the bed depth, were analyzed. These results indicated an average loss in ion-exchange capacity of about 11%. The resin sample from the entrance of the bed (during the sorption step) was the most affected and showed the largest loss in ion-exchange capacity (13.2%). At the exit of the resin bed, the total ion-exchange capacity loss was about 10%. The loss in ion-exchange capacity did not affect the resin performance during the mill trial.

The analysis of the resin taken from the GLS system at the conclusion of the trial is expected to be the most indicative of the resin changes under industrial conditions.

This resin had been well exposed to the chemical, physical (swelling and shrinking of the resin), and mechanical stresses (hydraulic pressure) created by the GLS operation. From our previous work using kraft white liquors, a decline of the system performance (in terms of NaHS removal) was observed when the resin lost about 30% of its initial anion-exchange capacity [9]. Based on these previous findings and the analysis of the resin after this trial,

we expect the resin to function without any significant decline in efficiency for about 18 months under the conditions of this application. However, any significant changes in the NaHS/NaOH concentrations in the feed solution and the operating temperature will affect resin life.

Potential savings

The BCTMP mill performed two successful two-day bleaching trials using the accumulated sodium carbonate/sodium hydroxide solution. During these trials, a significant portion of the NaOH used in the bleach plant was substituted with the GLS system product, without any negative effect on pulp properties.

Based on this work, about 60% of the smelt could be utilized to prepare sodium carbonate/sodium hydroxide to be used in the bleach plant. The remaining smelt portion will be sent to landfill. The BCTMP mills will reduce the usage of NaOH and Na2SO3. The equipments required in this case are: the GLS unit, the acidification/ stripper units and the H2S burner, as shown in Fig. 3. The expected net savings are estimated to be about $2,600,000 per year.

In another configuration, a causticizer could be installed to convert the sodium carbonate/hydroxide stream into NaOH, which would allow the mill to make use of all the smelt. The causticizer would be treating about 370 L/min (about 100 USGPM) of green liquor. The BCTMP mill would need to buy CaO on a continuous basis for this purpose. However, a lime kiln would not be required if precipitated calcium carbonate could be sold for papermaking. The use of calcium carbonate in papermaking has been reported elsewhere [10]. In this option, the expected net savings were estimated to be about $6,200,000 per year for this BCTMP mill. All the NaHS will be converted to Na2SO3. To maintain the sulphur balance, the mill might need to sewer some of the ESP dust.

CONCLUSIONS

The GLS system was operated at Millar Western (Meadow Lake) over a 150-day period and achieved: • About 98% sodium hydrosulphide removal; • About 95% sodium carbonate recovery; • About 85 % sodium hydroxide recovery.

• The Na2CO3 /NaOH product from the GLS system was used successfully in the bleach plant as an alternative source of alkali.

• The GLS system would reduce the amount of smelt being landfilled by 60%, or perhaps completely eliminate landfilling.

The potential net savings for this BCTMP mill were estimated to range from $2.6 to $6.2 million per year depending on the option chosen.

ACKNOWLEDGEMENTS

The authors thank M. Dubé and P. Wong of Paprican and Donald Swaine and Timoore Baber of Eco-Tec for their technical assistance during the trial. We thank the management at Millar Western (Meadow Lake) for offering to host the demonstration of the GLS system. The review of this paper by Brian Richardson is gratefully acknowledged.

LITERATURE

1. SHERBANIUK, R. Millar Western starts APP/ BCTMP mill at Meadow Lake in Canada. Tappi J. 75(1):61-66 (1992).

2. WILFING, K., HARDMAN, D., HODDENBAGH, J.M.A. Recent advances toward closing the solids loop at Millar Western’s Meadow Lake BCTMP Mill. Proc.

PAPTAC PACWEST Conference, Whistler, Paper 3A (1999).

3. AYALA, V., O’CZERNEY, A., ZANCHIN, R., MAGNOTTA, V., ZIERDT, J. R. Evaluation of oxidized white liquor as an alkali source. TAPPI Oxygen Delignification Symposium, Tappi Press, Atlanta, pp.

153-161 (1990).

4. GALLUCH, R.J. Quantum Q-OWL™ white liquor oxidizer. Proc. 84th Annual Meeting, PAPTAC, Montreal, pp. A173-A177 (1998).

5. JEMAA, N., DUHAMEL, M., VAN LIEROP, B., PALEOLOGOU, M., THOMPSON, R., BERRY, R., BROWN, C., SHEEDY, M. Removal of sodium thiosulphate from partially oxidized white liquor and use of the thiosulphate-lean solution in bleaching. Pulp Pap. Can. 104 (12):63-68 (2003).

6. THOMPSON, R., PALEOLOGOU, M., JEMAA, N., BERRY, R.M., BROWN, C.J., SHEEDY, M. Toward improving the pulping process: A new method for

For up-to-date news and events visit www.pulpandpapercanada.com 56

May/June 2009 Pulp & Paper Canada

p 51-57 Jemaa TP.indd 56

pulpandpapercanada.com

12/06/09 7:59 AM

chemical recovery producing split sulphidity liquors. Pulp Pap. Can. 101(1), 63-67 (2000).

7. THOMPSON, R., JEMAA, N., PALEOLOGOU, M., CORMIER, M., DOKIS, R., SHEEDY, M., BROWN, C. Caustic soda production from green liquor using the Green Liquor Splitter System. TAPPI International Chemical Recovery Conference, Tappi Press, Atlanta, pp. 323-332 (2004).

8. PAPP, J. Potentiometric determination of sulphur compounds in white, green and black liquors with sulphide ion-selective electrode. I. Cellul. Chem. Technol.

5:147-159 (1971).

9. THOMPSON, R., JEMAA, N., PALEOLOGOU, M., SHEEDY, M., BROWN, C. Caustic soda production from green liquor using Green Liquor Splitter system.

Proc. IEX Conference, Cambridge, U.K. (2004).

10. KANAI, K. TKAHASHI, K., KONNO, H., GOTO, H. An innovative process to produce high quality precipitated calcium carbonate using the causticizing process in kraft pulping. TAPPI International Chemical Recovery Conference, Tappi Press, Atlanta, pp.

369-372 (2004).

T90

Résumé: Le salin de l’usine de PCTMB en circuit fermé de Millar Western à Meadow Lake contient principalement de l’hydrosulfure de sodium et de l’hydroxyde/carbonate de sodium.

Le retrait de l’hydrosulfure de sodium du salin dissous (liqueur verte) à l’aide du séparateur de liqueur verte permettrait d’utiliser l’hydroxyde/carbonate de sodium à l’atelier de blanchiment.

Ce séparateur a fait l’objet d’une démonstration à l’usine durant une période de 5,5 mois. Le système a retiré de 91 à 98 % de l’hydrosulfure de sodium de la liqueur. En moyenne, 85 à 95 % de l’hydroxyde de sodium et du carbonate de sodium, respectivement, a été récupéré.

Reference: JEMAA, N., PALEOLOGOU, M., THIBAULT, A., FLECK, J., MILLER, K., SHEEDY,

M., BROWN, C. Demonstration of the Green Liquor Splitter (GLS) System at Millar Western’s Meadow Lake Closed-Cycle BCTMP Mill. Pulp & Paper Canada 110(5): T85-T91 (May/June 2009). Paper presented at the 93rd Annual Meeting in Montreal, QC, February 5-9, 2007. Not to be reproduced without permission of PAPTAC. Manuscript received October 19, 2006. Revised manuscript approved for publication by the Review Panel on October 29, 2008.

Keywords: GREEN LIQUOR, SPLITTING, ION EXCHANGE, CHEMICAL RECOVERY,

CHEMI-THERMOMECHANICAL PULPING (CTMP), SODIUM CARBONATE, SODIUM HYDROXIDE, SODIUM HYDROSULFIDE.

events calendar International Conference on Woody Biomass Utilization August 4-5 Mississippi State University, Starkville, Mississippi www.forestprod.org/confbiomass09. html

XIVth Fundamental Research Symposium Sept. 13-18 Oxford, UK www.frc14oxford2009.org.uk

TAPPI Engineering, Pulping, Environmental Conference Oct. 11-14 Memphis, TN www.tappi.org

IFRA Expo 2009 Oct. 12-15 Vienna, Austria Email: expoifra.com; www.ifraexpo.com

15th Asian-Pacific Corrosion Control Conference Oct. 18-21 Manila, Philippines

International Chemical Recovery Conference March 29 – April 1, 2010 Williamsburg Lodge, Williamsburg, VA Shauna Rice, 770-209-7237 or srice@ tappi.org

PAPTAC EXFOR and Annual Meeting Feb. 2-3, 2010 Montreal, Que. Andrea Borelli, 514-392-6961, aborrelli@ paptac.ca, www.paptac.ca

ABTCP-PI Pulp and Paper International Congress & Exhibition 26-29 Oct. Sao Paulo, Brazil www.abtcp-pi2009congressoexpo.org. br/ingles/

Events

Send events info and news announcements to media@pulpandpapercanada.com pulpandpapercanada.com

p 51-57 Jemaa TP.indd 57

Pulp & Paper Canada May/June 2009

57

12/06/09 8:00 AM

technology news Black liquor gasification reactors can be new revenue stream

As demand for pulp and paper continues to slide, mill operators and their investors might consider breathing new life into the industry by transforming mills into biorefineries that use a fuels-from-the-forest black liquor gasification process.

“Mills that make this investment are strongly positioning themselves as more competitive by adding 30% to 50% of revenue from the production of renewable motor fuels, for which the market is growing steadily, while replacing or adding recovery capacity facilitating profitable pulp production,” explains Richard J. LeBlanc, CEO of Chemrec SE and its U.S. subsidiary, Chemrec USA, which owns a patented fuels-from-theforest biorefinery technology.

Data analysis software helps with continuous improvement

TestSoft Inc. has released Explicore, the latest version of its software for evaluating and monitoring process, product, and system health. Explicore is a data analysis scorecard utility used to tackle statistical data analysis at the heart of Six Sigma. It quickly captures, characterizes, and analyzes all test data (parameters) to help identify those areas in need of improvement.

“If you are involved in quality, you will understand that Explicore will enable you to identify issues very quickly and effectively,” says TestSoft president Lee Brown.

Explicore provides essential “soft” tools to evaluate all test data or data that is within the design specifications. It includes the ability to evaluate a particular revision level or evaluate the overall product.

TestSoft Inc. 866-978-4572, testsoftinc.com

Lightweight core plugs for tissue winding applications

The Chemrec fuels-from-the-forest black liquor gasification reactor and cooling units can transform a pulp and paper mill into a high-margin biorefinery producing green motor fuels (methanol and dimethyl ether (DME)), while enabling profitable pulp production.

A fuels-from-the-forest biorefinery, an investment that can reach well above US$200 million, consists of several components well-proven in petrochemical applications or long-term industrial-scale operations. The components of Chemrec’s system are: an oxygen plant, a black liquor gasifier and gas cooler/steam generator (illustration), a plant for removing carbon dioxide and hydrogen sulfide from the raw syngas that is produced, a fuel synthesis plant where liquid fuel is synthesized from the syngas, and a distillation plant where the fuel produced is purified to meet product specifications, i.e. methanol, dimethyl ether or other green fuel.

According to Chemrec, mills producing as little as 500 tons of black liquor solids per day are proving to be commercially viable as fuels-from-the-forest biorefineries using this method. At the minimum capacity size, such a biorefinery mill would produce upwards of 32 million litres a year of green motor fuels.

Adding biofuels capacity can also generate additional employment, primarily for the extraction of biomass from the forest and operation of the biofuels plant.

Chemrec USA 847-580-4267 chemrec.se

58

May/June 2009 Pulp & Paper Canada

p 58-61 tech news and classifieds.indd 58

Goldenrod Corp. has introduced a new line of core plugs specifically designed for tissue, tissue converting, and nonwovens industry applications.

The new 1490NX is an extremely lightweight yet heavy duty core plug. This easy to handle product is constructed of aluminum and designed for use with 10 in. to 16 in. and larger ID cores.

“These new core plugs will be most appreciated by the tissue and nonwovens plant personnel in charge of rolls and core maintenance,” says David Sullivan, vice-president sales at Goldenrod. “Their lightweight design makes them extremely easy to handle and will reduce back injuries due to heavy lifting.”

Goldenrod Corp. 800-GOLD-ROD (465-3763), goldenrodcorp.com.

Honeywell expands wireless portfolio with gauge reader

The OneWireless gauge reader from Honeywell wirelessly monitors manual gauge readings from existing dial gauges, allowing operators to analyze critical equipment health and process information, and make decisions to improve plant operations.

The OneWireless gauge reader will integrate with Honeywell’s OneWireless mesh network.

The gauge reader non-intrusively attaches to existing dial gauges without requiring the plant to disrupt on-going processes or remove old gauges, break pressure seals, or run wires. The device provides gauge measurement data that is displayed quickly on operator consoles in the control room and on mobile field devices. The control system can proactively send alerts to operators to notify them when gauges exceed certain limits. The additional data now available to the operator helps improve plant energy efficiency by monitoring compressed air, steam, water, exhaust and venting, and compiling data for energy audits and baselines.

“The gauge reader network was up and running in approximately three hours. In the first two weeks of using it, we were able to detect and develop corrective measures for a potentially costly issue in our plant that we never suspected with our daily manual gauge rounds,” says Mike Long, control system supervisor at Tri-State Generation and Transmission.

“The reader’s monitoring capabilities allow plant operators to spend less time reading gauges and more time on other critical tasks, such as optimizing plant performance based on this additional data,” reports Harsh Chitale, Honeywell Process Solutions vice-president for strategy and global marketing. “It will help our customers analyze trends, save energy, and streamline operator tasks.”

Honeywell Process Solutions, honeywell.com/ps pulpandpapercanada.com

11/06/09 1:19 PM

technology news Compliance kit for fire safety of fluid storage and dispensing systems

Advanced electromagnetic flowmeter for process applications

ABB Instrumentation has launched a new range of electromagnetic flowmeters specifically targeted at the chemical, power, oil and gas, pulp and paper, and metals and mining markets.

Part of the new FlowMaster portfolio of flowmeters, ProcessMaster is available in an unmatched range of sizes -- 1/10 inch to 80 inches.

The new modular design offers a wide range of liners and electrodes. Whether an integral, remote or pipe mounted installation is required, a configurable common electronics platform provides the best tailor-made solution.

ProcessMaster incorporates self-cleaning and double sealed electrodes, enhancing reliability and performance. By using a higher excitation frequency combined with advanced filtering, ProcessMaster improves measurement accuracy by reducing the impact of fluid and electrode noise.

The high temperature design in combination with a reinforced PFA liner improves vacuum stability, prevents potential liner deformation and makes ProcessMaster a perfect fit for all hot-fluid applications.

The backlit, graphical display can be easily rotated through 270 degrees without the need for any tools, allowing field teams to customize the display that best fits their needs.

All product versions utilize a common electronics cartridge to simplify installation and lower spare part costs and inventory.

ABB abb.com/instrumentation

pulpandpapercanada.com

p 58-61 tech news and classifieds.indd 59

IFH Group, a manufacturer of storage and dispensing systems for industrial fluids, oils, and lubricants, is offering a fire safety kit for customers who need to be in compliance with strict fire safety regulations.

The kit replaces the standard PVC sight gauge on the front of the containers with a fire-resistant glass sight gauge equipped with ball check fittings at both ends to prevent any product spillage if the glass should break.

Underneath the containers, the standard PVC hose is replaced with a steel hose that connects to a fusible link valve with a spring-activated handle. If the temperature reach es 165º F (73.9 º C ), the handle is automatically triggered and shuts off any possible leakage of fluid from the container.

The fire safety kit can be supplied with new IFH storage and dispensing systems or as a retrofit to existing systems, according to the company. “It provides a ready-made solution for our customers who need to be in compliance with stricter fire safety regulations,” said Larry King, Midwest regional sales manager for IFH. The IFH Group, Inc. 800-435-7003, ifhgroup.com

Robust side-entry mixers are easy to maintain

A broad line of heavy-duty side entry mixers designed with easy access to all bearings and seals, which are commercially available to simplify user maintenance, is av ailab l e f ro m Sharpe Mixers.

S h a r p e V-Series Side Entry Mixers feature steel housings, rigid motor mounts, oversize shafting, premium Dodge type “E” piloted dual taperedroller bearings, belt drives with “QD” style bushings, and HYFLO 4-blade impellers to produce maximum fluid flow per unit horsepower.

Sharpe Mixers 800-862-3736, sharpemixers.com

Portable crane products have full hydraulic power

Ruger Industries, Inc. has announced a new series of hydraulic floor crane products that can lift and transport up to 6000 lbs. without effort using electrically-actuated hydraulics. They are particularly valuable in replacing manual lifting equipment, as they provide an ergonomic, strain-free solution to moving heavy loads.

Many firms use Ruger full power portable cranes as safer, smaller, and more economical alternatives to traditional tow-motor type lift trucks. Full power floor cranes are nimble, and can navigate door openings, narrow aisles, and elevators.

Suspended loads are held in place without motor or mechanical brake. The lifting mechanism does not require air or electricity.

Ruger manufacturers adjustable leg style, reverse leg style, and standard style powered portable cranes.

Ruger Industries 800-535-2725, rugerindustries.com

Pulp & Paper Canada May/June 2009

59

11/06/09 1:20 PM

technology news Energy cost reduction through load balancing

Eurotherm, a manufacturer of industrial instrumentation for process control and data acquisition, has published a white paper on the use of predictive load management (PLM) to improve motor performance for SCR controllers through even power distribution and load balancing strategy, reducing energy costs for manufacturers by thousands of dollars annually.

The white paper details how Eurotherm’s EPower™ SCR Controller with its PLM function helps manufacturers get a cleaner, more balanced power supply.

SCR Controllers firing in phase angle degrade the power factor, affecting the Demand Charge from utility companies and driving up energy costs. Most utility companies apply a surcharge when the power factor goes below 0.9 (or 90 percent), resulting in costs in the thousands to tens of thousands of dollars, depending on the size of the installation.

The power factor is improved through an easy and reliable transition from phase angle to zero cross firing, while eliminating concerns about flicker effect and potential overload caused by high power peaks. The PLM function balances the power, regulating disparity between individual heating zones.

Eurotherm, eurotherm.com/products/power/PLM-whitepaper.htm

Metso to deliver Yankee dryer head insulation to Metsä Tissue

Metso will supply two Yankee dryer head insulation systems to Metsä Tissue. The systems will be installed at the company’s tissue mills in Sweden and Finland to decrease the mills’ energy consumption.

Installation of the systems will start in June 2009. The value of the order has not been disclosed.

The Yankee dryer head insulation systems will be installed on PM 36 at the Mariestad mill in Sweden and on PM 9 at the Mänttä mill in Finland. The contract also includes an option for six additional Yankee dryer head insulation systems for the company’s mills in the Nordic countries and Europe.

Metso Yankee dryer head insulation systems have been installed on more than 120 Yankee dryers since the 1960s.

The system has proved very reliable, contributing to an energy saving of 5-8 % on an average.

Metso is a global supplier of sustainable technology and services for mining, construction, power generation, automation, recycling and the pulp and paper industries.

Metso, metso.com

Andritz to rebuild and upgrade two recovery boilers in North America

Andritz has received two major orders for recovery boiler rebuilds/upgrades from Domtar and Weyerhaeuser. For Domtar Corporation, Andritz Pulp & Paper will rebuild the existing boiler at the Kamloops, B.C., mill to enhance its long-term efficiency and reliability.

The mill has a capacity of 477,000 tonnes per year of paper grade bleached softwood kraft and specialty pulp grades, according to Domtar’s web site.

The scope of supply includes a new furnace floor and generating bank, air system modifications, gas burners, furnace panels, circulation improvements, and a new dissolving tank and vent system. The rebuild is scheduled to take place early next year and the recovery boiler should be re-started in May 2010.

For Weyerhaeuser Company, Andritz Pulp & Paper will upgrade the existing recovery boiler at New Bern, N.C. The supply includes additional heating surfaces, air system modifications, and systems for burning diluted and concentrated gases collected from mill processes.

Andritz Ltd. 514-631-7700, andritz.com

Professional Connections Equipment

Advertiser Index Buckman Ltd.. . . . . . . . . . . . . . . . . . . . . . www.buckman.com. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Freeman Staffing Inc.. . . . . . . . . . . . . . . www.freemanstaffing.com. . . . . . . . . . . . . . . . . . . . . . 61 Gamajet Cleaning Systems. . . . . . . . . www.gamajet.com. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Indeck Power Equipment Co.. . . . . . . www.indeck.com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Jeffrey Rader Corporation. . . . . . . . . . www.jeffreyrader.com/ppc. . . . . . . . . . . . . . . . . . . . . . . 8 Kemira Chemicals Inc.. . . . . . . . . . . . . . www.kemira.com. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 NSERC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11, 12, 15 PAPTAC. . . . . . . . . . . . . . . . . . . . . . . . . . . . www.paptac.com. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Phoenix Process Equipment Co. . . . . www.dewater.com. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Poyry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . www.poyry.com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Wabash Power Equipment Co.. . . . . . www.wabashpower.com. . . . . . . . . . . . . . . . . . . . . . . . 61 Zellcheming. . . . . . . . . . . . . . . . . . . . . . . www.zellcheming.com. . . . . . . . . . . . . . . . . . . . . . . . . . . 5

60

May/June 2009 Pulp & Paper Canada

p 58-61 tech news and classifieds.indd 60

To inquire about advertising in Pulp & Paper Canada Contact

Jim Bussiere 800-363-1327, ext 222 Fax: 514-630-5980 pulpandpapercanada.com

11/06/09 1:20 PM

Professional Connections

Equipment

Clean Any Tank...

• Any Chest, Digester, Pulper, Vessel or Tote • Fastest & Most Efficient Technology • Rotary Impingement GAMAJET® Cleaning Systems, Inc., 604 Jeffers Circle - Exton, PA 19341 Gamajet.com • sales@gamajet.com • 1-877-GAMAJET

Careers PulP & PaPer Jobs Freeman Staffing, Inc. specializes in the placement of engineers (all disciplines), production type supervisors, managers, mill and/or plant managers and corporate executives in the pulp & paper industry, North America-wide. For specific current job searches call us or contact our web site. All resumes are treated with complete confidentiality.

Freeman Staffing, Inc.

(800) 221-9629 or FAX (360) 653-8271 email: markp@freemanstaffing.com

web site: www.freemanstaffing.com

Consultants

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

BOILERS SELL • RENT • LEASE

24 / 7 EMERGENCY SERVICE

IMMEDIATE DELIVERY

CALL: 800-704-2002 10HP TO 250,000#/hr

250,000#/hr Nebraska 750 psig 750OTTF 150,000#/hr Nebraska 1025 psig 900OTTF 150,000#/hr Nebraska 750 psig 750OTTF 150,000#/hr Nebraska 350 psig 115,000#/hr Nebraska 350 psig 80,000#/hr Nebraska 750 psig 80,000#/hr Erie City 2000 psig 800OTTF 75,000#/hr Nebraska 350 psig 70,000#/hr Nebraska 750 psig 750OTTF 60,000#/hr Nebraska 350 psig 40,000#/hr Nebraska 350 psig 20,000#/hr Erie City 200 psig 10-1000HP Firetube 15-600 psig ALL PRESSURE AND TEMPERATURE COMBINATIONS SUPERHEATED AND SATURATED

RENTAL FLEET OF MOBILE TRAILER-MOUNTED BOILERS 75,000#/hr.

75,000#/hr.

60,000#/hr.

50,000#/hr.

40,000#/hr.

30,000#/hr.

75-300HP

Nebraska Optimus Nebraska Nebraska Nebraska Nebraska Firetube

350 psig 750 psig 350 psig 500 psig 350 psig 350 psig 15-600 psig

750°TTF

ALL BOILERS ARE COMBINATION GAS/OIL

ENGINEERING • START-UP FULL LINE OF BOILER AUXILIARY SUPPORT EQUIPMENT. Electric Generators: 50KW-30,000KW

WEB SITE: www.wabashpower.com 847-541-5600 • FAX: 847-541-1279 E-mail: info@wabashpower.com

wabash

POWER EQUIPMENT CO.

444 Carpenter Avenue, Wheeling, IL 60090

BELT PRESS DEWATERING SYSTEMS • 0.8 – 3.0 METER BELT WIDTHS • HEAVY-DUTY CONSTRUCTION • PACKAGED SKID SYSTEMS • FREE LAB TESTING • FACTORY START-UP SERVICE

Phoenix Process Equipment Co. www.dewater.com (502) 499-6198

Product Showcase Engineering services for the pulp and paper industry

Telephone 416. 391. 2322 E-mail mail@dickeng.com Web site www.dickeng.com

Best Gloves BEST GLOVES research and development has led to a full line of work gloves featuring the latest in glove technology. Each is covered in a specific coating designed with the appropriate protective requirements necessary to service a wide variety of industrial and work applications. Fully integrated – from knitting to sewing and dipping the company takes pride in the quality of its extensive product line.

Best Glove ManufacturinG liMited 253 Michaud Street Coaticook, QC, J1A 1A9 Customer Service 1-800-565-BEST

pulpandpapercanada.com

p 58-61 tech news and classifieds.indd 61

Pulp & Paper Canada May/June 2009

61

11/06/09 1:20 PM

point of view

Tough decisions for tough times Howe Sound Pulp & Paper CEO Mac Palmiere talks about the culture change occurring at this West Coast newsprint and pulp mill.

P

ort Mellon, British Columbia, has a rich history in the pulp and paper industry. There’s been a mill on this site on the shores of Howe Sound since 1909. The longevity of the mill is a testament to the resourcefulness and adaptability of its people, which are being put to the test once again by the current turmoil in newsprint and pulp markets.

In the care of its most recent owners, Howe Sound Pulp and Paper, the Port Mellon operation was expanded and modernized to serve one market and then redirected toward another. When HSPP began, the bulk of the mill’s newsprint was sold to the Japanese market. Now, it has a North American focus, which required tweaking both the product and the process, and substantial changes to the sales effort.

“In the last few years, we’ve had to totally change our marketing strategy and our product to the typical North American product,” explains Mac Palmiere, president and CEO. North American newsprint buyers want a brighter sheet than what was destined for Japan.

More recently, the company had to lay off workers and take downtime to adjust to the rapid deterioration in both the newsprint and pulp markets.

Palmiere took the reins in early 2008, brought in by owners who weren’t happy with the mill’s performance. Since arriving, he has spearheaded a culture change that affects both employees and suppliers. Last year, he began a more rigorous performance management process, and this year the workforce was downsized by 19% and the workload re-distributed.

“We’ve worked hard with the union on getting costs out of the process. We’ve done some very tough things, and we’ve done them quickly.”

HSPP has cut costs through energy conservation and generation initiatives; improved the fibre mix and reworked fibre sourcing; and worked with suppliers to optimize the mill’s chemical usage and supply chain.

Which begs the question, why weren’t these changes made earlier? Palmiere is of the opinion that such rapid and dramatic changes were only possible because of current economic crisis.

“It takes courage and absolute commitment, and a belief that what you’re doing is right, to make these kinds of changes,” he 62

May/June 2009 Pulp & Paper Canada

p 62 point of view.indd 62

comments. “It’s very uncomfortable to go out and make these kinds of changes. You question yourself a lot.

“You’re putting a lot of people’s lifestyles at risk if you’re wrong.”

Palmiere is convinced that the traditional relationship between unions and mill management in Canada has to change, and he has hope that the transformation is beginning.

“The relationship needs to be much more proactive and co-operative. I think Harmac’s got it right, with its engaged workforce.”

And, he adds, “I’m happy with what I’ve seen from our local of the union.”

He also cites Alberta-Pacific Forest Industries and Alberta Newsprint Company as examples of efficient mills, and points to the low staffing levels of Finnish mills.

Palmiere’s biggest worry these days is that the recession will go on longer than experts are forecasting. “First-quarter results for forest products companies were dismal. That can’t go on for much longer.”

Regarding the market for kraft pulp, Palmiere says it caved in very quickly last fall. HSPP’s kraft mill took almost four weeks of inventory-adjustment downtime in the final quarter of 2008.

“The [newsprint] market is contracting much more quickly than we’d like,” Palmiere says dryly, “but we do have some customers that we’ve grown with.” He notes that HSPP produces a hiqh-quality, virgin sheet that has a good reputation for printability and runnability.

On the newsprint side, HSPP’s first market-related downtime occurred over a 10-day period in April 2009.

In the long term, for newsprint, “there’s no question that demand and consumption will be down, but there are regions that are growing.”

Some of those growing regions will be accessible to HSPP, thanks to its deep-sea port. “We can move paper and pulp very cost-effectively to Asia and some areas of Latin America,” notes Palmiere.

So despite market conditions that are changing at breakneck speed, Palmiere is confident that the changes HSPP is making will put the company on sound footing for the next chapter in its history. pulpandpapercanada.com

11/06/09 1:22 PM

CALL FOR PAPERS – EXFOR & ANNUAL MEETING 2010 PAPTAC is currently planning the program for EXFOR & Annual Meeting 2010, which will take place February 2-3 at the Queen Elizabeth Hotel in Montreal. The new format at the Queen Elizabeth Hotel in February 2009 proved very successful and conducive to networking and exchange.

Abstract submissions are actively sought and we encourage all mill personnel, researchers and suppliers to submit their latest work. Submit your abstract by September 10, 2009 directly to Greg Hay at ghay@paptac.ca.

The technical sessions are sponsored by PAPTAC’s Standing and Special Committees. In order to help us forward your abstract to the appropriate committee(s), please refer to the list of committees below and indicate those that relate to your subject by order of priority when submitting your abstract. The committees will select abstracts on a first come first serve basis. Submissions are welcome in English and French.

Based on the level of submissions, the following committees are planning to sponsor sessions at the Annual Meeting: Bleaching / Energy Cost Saving / Non-Wood Fibres / Paper Machine Technology / Process Control / Research / Engineering & Maintenance / Environment / Fine & Coated Papers / Mechanical Pulping / Paperboard Packaging / Recycling / Biorefining / Supplier Showcase (10-min presentations)

Start up of the Engineering and Maintenance Committee In order to better address the needs of our industry, the executives of both the Mechanical Engineering and Maintenance Committee and the Electrical/Instrumentation Engineering and Maintenance Committee have recently met to develop a new group and merge these two committees into the Engineering & Maintenance Committee.

This new committee will be using conference calls and web-based meetings in order to discuss common issues and invite speakers to present related material.

Some of the key issues that the group will focus on are: ¾ Safety ¾ ROI ¾ How to save time ¾ Common new technology that’s available ¾ What are other countries doing? ¾ Reliability (predictive/preventive maintenance) ¾ Energy Efficiency ¾ Sharing of resource sites ¾ Strategies to deal with loss of expertise ¾ And more…

We strongly believe that, with the proper environment and a solid participation base, this committee will provide value back to you, your company and the Canadian industry.

Should you be interested in joining this committee, please contact Greg Hay at 514-3926964 or email ghay@paptac.ca.

p 63 Paptac ad.indd 63

NEW

Proceedings Paper Modelling Symposium 2008 August 27-29, 2008 Trois-Rivières (QC) EXFOR & Annual Meeting 2009 February 3-4, 2009, Montreal (QC) Purchase your copies at www.paptac.org/store

www.paptac.ca 11/06/09 1:23 PM

35

Š2008 Buckman Laboratiories

p 64 Buckman ad.indd 64

11/06/09 1:24 PM