November / December 2014 NLGI Spokesman

NLGI

SPOKESMAN

Serving the Grease Industry Since 1933 – VOL. 78, NO. 5, NOV/DEC 2014

In this issue . . .

• Critical Variables in Lithium Complex Grease Manufacturing • When the going gets tough...A heavy specialty oil for grease formulations (Part II) •C hallenges in Manufacturing of BioBased Greases

NLGI 82nd Annual Meeting

June 6 – 9, 2015 Coeur D’Alene Resort • Coeur D’Alene, Idaho “Digging into Grease Lubrication” Lubricating professionals from across the globe in attendance, manufacturers, suppliers, marketing and more!

Technical Presentations • Formulation • Manufacture • Handling • Application World Renowned Education • Basic • Advanced • Application & Maintenance

Commercial Forum • Products • Services CLGS® Examination • Are you a Grease Expert?

Networking Opportunities • 3 Receptions • Final Gala Dinner

Save the Date!

ct A Produ l meet il w t a th st your mo ing g n e chall needs!

PRESIDENT:

VICE-PRESIDENT:

Bruce M. Urban FMC-Lithium Division 2801 Yorkmont Rd., Ste. 300 Charlotte, NC 28208

David Como Dow Corning Corp.

P.O. Box 0994 Midland, MI 48686

SECRETARY:

TREASURER:

Kim Smallwood Citgo Petroleum Corp.

1293 Eldridge Pkwy.

Houston, TX 77077

Joe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

PAST-PRES./ADVISORY:

EXECUTIVE DIRECTOR:

Chuck Coe Grease Technology Solutions LLC 7010 Bruin Ct. Manassas, VA 20111

Kimberly Hartley NLGI Inter­national Headquarters 249 SW Noel, Suite 249 Lee’s Summit, MO 64063

DIRECTORS

Break through your most challenging issues with VANLUBE ® 0902, a new multi-purpose package for industrial gear oils and greases.

®

Richard Burkhalter Covenant Engineering Services 140 Corporate Place Branson, MO 65616

Thomas J. Pane King Industries, Inc. Science Road Norwalk, CT 06852

Curt Ellison Chemtool/Metalcote P.O. Box 538 Crystal Lake, IL 60039-0538

Dennis Parks Texas Refinery Corp.

One Refinery Place Ft. Worth, TX 76101

Dave Facchiano The Lubrizol ­Corpo­ration 29400 ­Lakeland Blvd.

Wickliffe, OH 44092

Tom Schroeder Axel Americas, LLC P.O. Box 12337 Kansas City, MO 64116

Gian L. Fagan Chevron Lubricants 100 Chevron Way Room 71-7338 Richmond, CA 94802-0627

Raj Shah Koehler Instrument Co. 1595 Sycamore Ave. Bohemia, NY 11716 Dr. Huafeng “Bill” Shen Bel-Ray Co. P.O. Box 526 Farmingdale, NJ 07727

Paul Grives Exxon Mobil Corporation 3225 Gallows Road Room 7C1906 Fairfax, VA 22037

✪ Global Registration

Terry Smith Lubrication Engineers, Inc. P.O. Box 16447 Wichita, KS 67216

Jim Hunt Tiarco Chemical 1300 Tiarco Drive Dalton, GA 30720

✪ Metal-Free

Thomas W. Steib The Elco Corporation 1000 Belt Line Street Cleveland, OH 44109

Tyler Jark Lubricating Specialties Co. 8015 Paramount Blvd.

Pico Rivera, CA 90660

✪ Protects Against Corrosion

Lisa Tocci Lubes ’n’ Greases 6105 Arlington Blvd., Suite G Falls Church, VA 22044

Dr. Anoop Kumar Royal Manufacturing Co., LP 516 S, 25th West Ave. Tulsa, Oklahoma 74127

✪ Reduces Oxidation

Ruiming “Ray” Zhang R.T. Vanderbilt Company, Inc. 30 Winfield St. Norwalk, CT 06855

Wayne Mackwood Chemtura 199 Benson Rd. Middlebury, CT 06749

✪ Minimizes Wear ✪ Carries a High Load at Extreme Pressure Conditions

Ed Oravec Shell Canada Products 400-4th Avenue S.W. Calgary, Alberta Canada T2L 1Y8

NLGI

BREAK OUT!

OFFICERS

SPOKESMAN

Serving the Grease Industry Since 1933 – VOL. 78, NO. 5, NOV/DEC 2014

5 NLGI President’s Podium 7

Ask the Expert

8 Critical Variables in Lithium Complex Grease

Manufacturing - David Morgan - STRATCO, Inc., John S. Kay, P.E., CLGS – STRATCO, Inc., Chuck R. Coe, CLGS, CLS - Grease Technology Solutions, LLC

18 When the going gets tough...A heavy specialty oil for grease formulations (Part II) - Mehdi FathiNajafi, Rene Abrahams and Linda Malm

24 Challenges in Manufacturing of Bio-Based

Greases - Dr. Anoop Kumar and Bill Mallory, Royal Mfg Co. LP

36 W elcome New 2014 NLGI Members!

38 A dvertiser’s Index

TECHNICAL COMMITTEE

VANLUBE 0902 ®

Lubricant Additive

CO-CHAIRS:

CHAIR, SESSION PLANNING:

J oe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

Joe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

David Turner Shell Global Solutions (US) Inc. 3333 Hwy. 6 South Houston, TX 77082

ON THE COVER NLGI 82nd Annual Meeting at Coeur D’Alene Resort

SERVICE INDUSTRY ASSISTANCE COMMITTEE

For additional information or to request a sample, please visit us at www.vanderbiltchemicals.com CHAIR:

J im Hunt Tiarco Chemical 1300 Tiarco Drive Dalton, GA 30720

EDITORIAL REVIEW COMMITTEE Registered and pending trademarks appearing in these materials are those of R.T. Vanderbilt Holding Company, Inc. or its respective wholly owned subsidiaries. For complete listings, please visit this location for trademarks, www.rtvanderbiltholding.com.

CHAIR: Joe Kaperick Afton Chemical Corporation 500 Spring St. Richmond, VA 23218-2158

Published bi-monthly by NLGI. (ISSN 0027-6782) KIMBERLY HARTLEY, Editor NLGI International Headquarters 249 SW Noel, Suite 249, Lee’s Summit, MO 64063 USA Phone (816) 524-2500, FAX: (816) 524-2504 Web site: http://www.nlgi.org — E-mail: nlgi@nlgi.org One-year subscriptions: U.S.A. $65.00; Canada $80.00; International $109.00; Airmail $147.00. Claims for missing issues must be made within six months for foreign subscribers and three months for domestic. Periodicals postage paid at Kansas City, MO. The NLGI Spokesman is indexed by INIST for the PASCAL database, plus by Engineering Index and Chemical Abstracts Service. Microfilm copies are available through University Microfilms, Ann Arbor, MI. The NLGI assumes no responsibility for the statements and opinions advanced by contributors to its publications. Views expressed in the editorials are those of the editors and do not n­ ecessarily represent the official position of NLGI. Copyright 2014, NLGI. Postmaster: Send address corrections to the above address.

NLGI

Every search pays off.

PRESIDENT’S PODIUM

President’s Podium Bruce Urban

From NLGI Executive Director Kim Hartley Another year has come and gone! Like for most of you I’m sure, the holidays always seem to catch me by surprise that they’re already here again! But it’s a good time to reflect on achievements and events that occurred the last year, and look forward to the coming year with anticipation and excitement.

2014 saw NLGI with a continued healthy financial picture, which will enable us to further the organization by offering even more value to our current and future members. Membership increased by almost 30% last year, a record for NLGI. Thank you to our members who pass the word about us!

www.LNGsourcebook.com Your source for:

Customers • Contacts • Suppliers • Products • Brands

For advertising information, contact Gloria Steinberg Briskin gloria@LubesnGreases.com -4VOLUME NUMBER 5 800-474-8654; +178,703-536-7676

Attendance was increased, once again, at the 2014 Annual Meeting in Palm Beach Gardens, FL. And we are happy to report that we will NOT be visiting Florida, in June, again anytime in the near future! I visited the Coeur d’Alene Resort, site of the 2015 NLGI Annual Meeting, for the planning visit last month.

What a spectacular destination we have for you! This year, we will be trying a new format for the meeting, in particular, Tuesday night. The past couple of surveys we have done regarding the meeting, we heard loud and clear that the Tuesday night format was not conducive to further conversation and networking. (It was also apparent from the mass exit from the ballroom once the entertainment began, I’ve seen people move from a burning building slower!) We will be having a “Dine Around the World” theme, with various food stations from around the globe, optional interactive

entertainment, a quiet “conversation pit” and more.

Be sure to stay tuned for all the details which will be outlined in the Preliminary Program, ready by early March.

We increased our scholarship commitment to Auburn University, and the new Tribology Minor program.

NLGI plans to search for other universities to partner with, and have formed a Student Committee to study this. We will also begin offering a Student Membership to NLGI. More information will be forthcoming.

Early in 2015, the 6th Edition of the NLGI Lubricating Grease Guide will be available in digital and print.

A big thank you to Bill Tuszynski with Ivanhoe Industries for his tireless work in getting this done! An announcement will be sent when it is completed.

The Spokesman will be available in digital format in 2015! We’ll be notifying all who receive the Spokesman of this upon it’s availability.

The addition of Denise Roberts to the home office this past year was one of the highlights! She has brought great ideas and organization to the office.

In closing, I’d like to say, on behalf of NLGI, we would not be the outstanding organization we are today, without you, our members and supporters. I wish you all a very happy, healthy and memorable holiday season!

-5NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI

INTRODUCING

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NLGI

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W N M FTOW I C O R N L M O IC IV S R E IT O

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GREASE

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NUMBER 5 Corporation (NYSE:NEU). © 2013. Afton Chemical Corporation VOLUME is a wholly owned78, subsidiary of NewMarket AFTON®, HiTEC®, MicrobotzTM and Passion for Solutions® are trademarks owned by Afton Chemical Corporation. Passion for Solutions® is a registered trademark in the United States.

Ask the Expert

Q: A:

I would be interested in knowing what types of greases are used in the following mills: steel mills, lumber mills, sugar mills & paper mills.

Steel mills – The steel industry originally used clay greases, as they were the only high-temperature products of the time. The industry moved to aluminum complex when it was introduced. Some steel mills continue to use aluminum complex grease, while others have moved to lithium complex products for general lubrication. Some applications use polyurea greases with synthetic base fluid.

Lumber mills – This application does not have the extreme conditions found in the steel or paper industries. The lumber industry has typically used lithium, lithium/calcium, or lithium complex greases.

Sugar mills – The sugar industry is characterized by heavy-loaded, slow-moving plain bearings. The greases used in the sugar industry have historically been calcium soap or clay thickened, with high (ISO 1000 or higher) base oil viscosity and lubricating solids, such as molybdenum disulfide.

Paper mills – The typical paper machine has both high water (wet end) and high temperature (dry end) applications. In general, lithium complex greases are used, while some specialized applications require products such as polyurea grease with a synthetic base fluid.

-7NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

Critical Variables in Lithium Complex Grease Manufacturing Presented at the 80th NLGI Annual General Meeting Tucson, Arizona 15th – 18th June 2013

Abstract

Lithium complex greases represent a high performance grease type with specialized applications, and these greases are steadily growing in widespread markets.

Several options are available to the grease manufacturer regarding raw materials and manufacturing methods.

The selection of the complexing agent has economic ramifications and also performance and procedural considerations. Due to the differences in reactivity of the complexing agents, there may be optimum temperature profiles for each material. A lab scale STRATCO® Contactor™ reactor is used to make lithium complex greases using two common complexing agents, namely azelaic acid and sebacic acid. This type of reactor is used in order to have better control of the temperature profile during the process. Holding the base oil and soap concentrations constant, the temperature profiles are varied and the physical properties are analyzed and compared to establish optimum reaction conditions.

Introduction

Greases made from Lithium possess many desirable properties, such as good water resistance, high temperature properties, shear resistance and pumpability as compared to other alkali metal based greases. Lithium complex grease is a great all-purpose lubricant because of its uses over a wide range of temperatures. According to a recent NLGI Production Survey, approximately 75 percent of the grease sold worldwide is based on either simple lithium soap or lithium complex thickener [1].

By David Morgan - STRATCO, Inc. John S. Kay, P.E., CLGS – STRATCO, Inc. Chuck R. Coe, CLGS, CLS - Grease Technology Solutions, LLC

Lithium complex grease continues to slowly displace simple lithium grease because of its higher dropping point. This makes lithium complex ideal for higher temperature applications.

Lithium complex grease has a higher dropping point because of the presence of a complexing agent.

Lithium complex grease is made with two molecules: the co-crystallization of a lithium soap molecule and a lithium dibasic salt molecule [2]. These dibasic salts are made by the saponification of a dicarboxylic acid with lithium hydroxide. Dicarboxylic acids have an acid functional group on both ends of the short-chain carbon molecule. Typical complexing agents are: azelaic acid, sebacic acid, adipic acid and sometimes boric acid [2]. Of these, azelaic acid and sebacic acid are the most widely used. The fluctuating raw material cost of these two chemicals can be a deciding factor on which complexing agent is used by a manufacturer. Due to the differences in reactivity of these two materials, it is important to recognize the differences in manufacturing processes inherent in each.

The general consensus, based on experience, regarding the strategy of reacting lithium complex greases is the need for allowing the initial simple saponification reaction to precede the reaction of the complexing agent. This is generally accomplished by maintaining the ingredients at a lower temperature range for a period of time to allow the simple reaction to be

-8VOLUME 78, NUMBER 5

completed, followed by the elevation to the final reaction temperature. As with most grease manufacturing practices, procedures vary from manufacturer to manufacturer. The use of conventional kettles for the reaction stage involves some inherent limitations of heating rates due to the heating surface available and the limited heat transfer rate associated with this type of vessel. The use of the pressure rated Contactor reactor allows faster heating and improved temperature control due to its greater heating surface and higher heating and cooling rates. The goal of this study is to determine the optimum heating profile and manufacturing practice using the Contactor reactor in order to achieve desirable properties with the limited residence time in the reactor.

This will allow the manufacturer to manufacture produce this high performance product in the shortest time for a quicker turnover and the minimum lead time for their customer’s product. Differences in manufacturing procedures include heating rates, holding times, the employment of a quench stage before transfer to the finishing kettle, and the consideration of a one-step versus two-step procedure.

The use of a quench stage in the Contactor reactor offers decidedly different conditions when compared to quenching, or cooling, in the finishing kettle, namely: (1) the quenching can be accomplished much quicker in the Contactor reactor and (2) the crystallized fibers will experience a higher shear in the Contactor reactor, resulting in a moderate milling effect. There is certainly a processing time advantage in having the base grease start at a lower temperature in the finishing kettle.

The strategy of a one-step versus two-step procedure represents a compromise between minimizing the manufacturing time and ensuring that the complexing reaction does not interfere with the simple reaction.

The one-step method is characterized by the addition of all ingredients at the beginning of the reaction stage while the two-step method involves the addition of the complexing agent only after the simple reaction has been completed. Regarding the two-step method, the authors are aware of two different practices employed with the Contactor reactor: (1) cooling the Contactor reactor product after the simple reaction is completed and introducing the complexing agent for the balance

NLGI

of the reaction process in the Contactor reactor and (2) transferring the simple base grease and adding the complexing agent in the finishing kettle. This study will employ the former practice in order to minimize manufacturing time.

In summary, the key issues addressed in this study include:

• Identifying the optimum intermediate temperature target representing the upper limit of the range of the simple reaction • Establishing the minimum time required in the simple reaction region • Establishing the minimum time required for the complex reaction • Determining the effects of quenching in the Contactor reactor • Verifying the need for a two-step process

Equipment and Procedures

Lithium complex grease batches were produced in the laboratory of Stratco, Inc. in Scottsdale, Arizona using a lab scale Stratco® Contactor™ reactor. Critical variables such as heating rates, intermediate temperatures, reaction times and quenching techniques were studied through analysis of the batch properties. Properties evaluated were dropping point and penetration, including unworked, worked and 10,000 stroke. The dropping point was indicative of the quality of the complexing reaction while the penetrations were used to evaluate yield efficiency and mechanical stability.

In order to simplify the comparisons, a single, simple base oil was used, which was not specifically selected to optimize yield or dropping point. It was also decided to use the same soap content (11%) and not to use additives to avoid synergistic effects on the complexing agents.

The equipment used for this project included the following: • STRATCO® Model VJS 8-12.5-17.2 Contactor™ reactor • Groen Model NSP Double-Motion kettle • Viking Model H32 gear pump • Cuno Auto-Klean filter (0.005 in. spacing) • Chemicolloid Labs Model G-5 mill

-9NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI

NLGI

Figure 1 provides a picture of the equipment configuration.

Chart 1. Testing design conditions for azelaic acid

Figure 1. Equipment Arrangement The general procedure was to perform the reaction phase in the Contactor reactor and then manually transfer the product to the finishing kettle. The procedures varied in the reaction phase with the different raw materials. The product, once transferred to the kettle, was recirculated by-passing the mill and filter to facilitate cooling.

A portion of the base oil was withheld from the contactor and added to the kettle for cooling and dilution. When suitably cooled, the circulation was stopped, the mill set at 5 microns and energized and milling performed prior to drawing samples. All the batches throughout this study were quenched with a portion of base oil in the kettle and milled at 5 microns when the product dropped to 100°C for 10 minutes before taking samples.

The base oil used was a Group II 500 Neutral paraffinic oil. The other raw materials supplied were standard grade materials that are used in the grease industry. As mentioned previously, the additives were left out of the greases for this project to avoid synergistic effects with the chemically different complexing agents. The raw materials used were 12-hydroxystearic acid, lithium hydroxide monohydrate, azelaic acid and sebacic acid.

All batches started at 80°C after the initial ingredients were added and melted. They were then heated to an intermediate temperature over a specified period of time, then heated to 204°C to complete the complexing reaction, although one batch was allowed to reach 210°C. For the twostep method the batch was cooled from the intermediate temperature to below boiling temperature to add the complexing agent, then heated to 204°C. Although the water of reaction was vented to control the pressure at 5.5 bar, the residual water/steam was allowed to remain for the addition of the complexing agent in the two-step process in order to utilize the pressure when reheating to maintain flow and assist in the discharge. Several batches were allowed to cool (quench) in the Contactor reactor following the reactions, while the other batches were discharged and transferred immediately to the finishing kettle at the maximum reaction temperature. Several of the sebacic acid trials were performed as a two-step process while all the others were a single step process. Quenching in the lab scale Contactor reactor was accomplished by cooling the thermal oil in the vessel jackets. In commercial operations, quenching is typically accomplished with the addition of base oil.

The variables manipulated were: heating rates between the beginning, intermediate and final temperatures, the intermediate temperature itself, as well as holding times at different temperatures.

Charts 1 and 2 illustrate the test design and variable conditions for the two complexing agents.

- 10 VOLUME 78, NUMBER 5

 Chart 2. Testing design conditions for Sebacic Acid - Highlighted batches used the two-step process

Experimental Results and Data

The greases were made in the Contactor reactor starting with the azelaic acid complexing agent then moving on to the sebacic acid complexing agent. Data recorded included product temperature, thermal oil supply temperature, vessel pressure and motor amperage versus time. Motor amperage remained steady throughout testing. Time vs. Temperature plots were generated for all batches, which are shown in Graphs 1 through 5.

- 11 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

- 12 VOLUME 78, NUMBER 5

- 13 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI  Chart 4. Test results for sebacic acid complexing agent - Highlighted Batches used the two-step process 

Chart 5. Total residence time in Contactor reactor The grease batches were tested for unworked penetration, 60 stroke penetration, as well as 10,000 stroke penetration. These tests were performed in accordance with Cone Penetration ASTM D 217. Dropping points were also determined using standardized test ASTM D 2265, °C. Charts 3 and 4 show the results of the aforementioned tests. Chart 5 summarizes total residence time in the Contactor reactor for all test batches, including charging time.

Chart 3. Test results for azelaic acid complexing agent

- 14 VOLUME 78, NUMBER 5

- 15 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI Analysis and Conclusions

For the azelaic acid trials, the initial intermediate temperature selected was 150°C based on previous experience. The first trial ramped the temperature to the intermediate target over 60 minutes, then rapidly heating to 204°C over 35 minutes and transferred immediately without a quench to the finishing kettle. This resulted in a reasonable DP of 250°C, bearing in mind that this was not additized and the base oil not optimized. The next trial reduced the intermediate ramp time to 35 minutes, which resulted in a lower DP and lower yield. The third trial replicated the first except for increasing the final ramp time to 60 minutes. This resulted in no change in the DP, although a slight reduction in yield and greater spread between penetrations. The fourth trial replicated the first trial except reducing the intermediate ramp time by approximately 15 minutes; this had negative effects worse than the second trial. The fifth trial allowed a 35 minute intermediate ramp time and 65 minute final ramp time with a comparable overall residence time. This resulted in a marginal increase in DP at close to 260°C with a slight reduction in yield compared to trial 1.

The last three trials included a quench stage in the Contactor reactor. Trial #6 replicated the first trial but included a quench to 182°C over a 25 minute span.

This resulted in a DP of over 260°C and a much better yield. The next two trials explored a lower intermediate temperature of 130°C. The seventh batch had a lower intermediate ramp time, but included a hold at the intermediate temperature resulting in holding it at this lower range for 60 minutes, similar to trial #6. However, the final ramp time was slightly longer. This resulted in slight improvements in all test properties. The last trial for azelaic acid reduced the intermediate residence time to 35 minutes, which resulted in a marked negative impact to DP.

sealed and heated. This is certainly very desirable in simplifying the manufacturing process and minimizing the manufacturing time. Quenching in the Contactor reactor also saves time in finishing. The trials also suggest that allowing approximately 60 minutes in the lower intermediate range produces better dropping points.

The study demonstrates that a good dropping point can be achieved with a reaction residence time for azelate complex grease of approximately two hours.

The sebacic acid trials demonstrated a distinctly different reaction profile. In order to achieve a dropping point of 260°C, a two-step procedure was required. The base oil, lithium hydroxide and 12-hydroxystearic acid are placed in the Contactor reactor first, sealed and heated to the intermediate temperature. The contents are then cooled to below 100°C with jacket cooling and the sebacic acid is then added to the Contactor reactor and heated to 204°C. Final quenching in the Contactor reactor had a negative impact on the physical properties of the grease. Batches 14, 15 and 20 had the highest dropping points without the final quenching and were all two-step procedures. As with the azelaic acid, these trials also demonstrated achieving optimum dropping points with reaction stage residence times of approximately two hours, even with the two-step procedure implemented.

The complexing agent chosen for production could be due to monetary reasons, production reasons or both.

Azelaic acid and sebacic acid can both make good lithium complex greases with excellent dropping points (over 260°C) having good yield and mechanical stability as shown by the data. The study clearly demonstrates that these two complexing agents require distinctly different reaction procedures. Further optimization is likely possible with the fully formulated greases to consider the synergistic effects of base oils and additives, which could provide higher dropping points and better yields.

The azelaic acid trials showed that a quench in the Contactor reactor yields positive effects for dropping point. These were all one-step procedures, meaning that all the contents were added to the Contactor reactor at the beginning of the reaction stage and then

- 16 VOLUME 78, NUMBER 5

Acknowledgements:

The authors would like to thank John Lorimor CLS/ CLGS of Axel Americas, LLC, Buck Evans of Sea-Land Chemical, Co. and Aaron Read of North American Lubricants, Co. for supplying all the raw materials and base oil for this project.

References:

NLGI

urner, D., “Grease Selection: Lithium vs. Lithium T Complex” Machinery Lubrication, January 2011 Polishuk, A.T., A Brief History of Lubricating Greases, 1998.

CALL FOR PAPERS

NLGI 82nd Annual Meeting A call is hereby issued for technical papers for presentation at the NLGI 82nd Annual Meeting, which will be held at the Coeur d’Alene Resort, Coeur d’Alene, Idaho, USA from June 6th-9th, 2015. You do not need to be an NLGI member in order to present a technical paper at our Annual Meeting.

The NLGI 82nd Annual Meeting theme is: ‘Digging into Grease Lubrication’. Therefore, papers related to grease applications, environmental concerns, performance or testing for mining equipment are of special interest and will be given priority. How can greases contribute to cost savings, improved performance and efficiency in mine operations?

Commercial Papers: NLGI will also accept up to 5 papers of a commercial nature. Presentation of commercial papers will be on Tuesday afternoon during the NLGI Annual Meeting and will not conflict with any other presentations or events. Commercial papers will be accepted on a first come, first served basis. (A fee of $500 will be charged for all commercial papers accepted for presentation.)

You may download the Author Information and Author Instructions forms for your technical presentation, as well as the Commercial Presentation Application form, on our website: https://www.nlgi. org/call-for-papers/

Some lubricating products used in mines are: Heavy duty and EP greases, wire-rope lubricants, open gear lubes and penetrating oils/greases.

If you are interested in submitting a technical or commercial paper for presentation, please send your name, contact information and abstract to:

Papers covering any other phase of grease chemistry, grease formulation or grease manufacturing technology are also welcomed.

NLGI INTERNATIONAL OFFICE

Technical papers approved for presentation at the Annual Meeting may be published in the NLGI Spokesman after evaluation by the NLGI Editorial Review Committee.

249 SW Noel St. Suite 249 Lee’s Summit, MO 64063 USA Phone: 816-524-2500 Fax: 816-524-2504 Email: marilyn@nlgi.org

- 17 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

When the going gets tough...

A heavy specialty oil for grease formulations (Part II) Mehdi Fathi-Najafi* Rene Abrahams and Linda Malm Nynas AB Sweden Presented at the NLGI 80th Annual Meeting Tucson, Arizona, USA June 15 -18, 2013

Abstract

The global ongoing rationalization of Group I production and its potential impact on the future availability of paraffinic bright stock has led several lubricant formulators to start evaluating alternative products. A highly viscous base fluid containing residue from the vacuum distillation process with a kinematic viscosity of approximately 700 (mm2/s) at 40°C has been developed.

This base fluid can be used for various applications where the color is not an issue, since it is black. However, it is well known that bright stocks are usually used in combination with solvent neutral 500 or/and naphthenic oil with the same above-mentioned viscosity for applications where higher film thickness is required such as in the mining application.

In order to explore the potential of this heavy specialty oil as a substitute to bright stock in grease formulations, several greases based on the different viscosities [235, 370 and 505 (mm2/s) respectively] have been prepared and characterized. The residue oil based greases showed interesting characteristics such as having a positive impact on the thickener content, shear stability, water resistance and rheological behavior.

However, the overall conclusion is that it is possible

to substitute this fluid for bright stock in grease formulations with equivalent or better performance.

Consequently, a more cost effective grease formulation could be achieved, assuming that color is not an issue.

Introduction

The global ongoing rationalization of Group I production and its potential impact on the future availability of paraffinic bright stock has led several lubricant formulators to start evaluating alternative products.

The alternative available in the market right now is to reformulate by using a mix of heavy grade neutrals plus a synthetic oil component such as polyalphaolefin, heavy naphthenic and other sources.

This paper suggests a cost-effective alternative which may replace bright stocks in various grease lubricated applications where the color is not an issue. The first part of this work was presented by Dr. Valentine Serra-Holm at the 79th NLGI annual meeting where some of the presented results measured by a mini traction machine showed excellent tribological behavior at various temperatures. This part of the work has been more dedicated to a comparative study between a bright stock and this residue-based naphthenic oil in lithium grease formulation.

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Preparation of the Oils and the Greases

It is well known that for industrial lubricated applications, higher base oil viscosities are required which usually consist of heavy neutral and bright stock blends. Hence, the starting point for the experimental work was to prepare some blends based on these two oils.

In order to make the comparison as realistic as possible, two paraffinic oils (BS200 & SN500) and a highly viscous naphthenic oil (R1) have been chosen, the characteristics of the base oils can be seen in Table 1.

Characteristics

Method (ASTM)

Viscosity at 40°C (mm2/s) Viscosity at 100°C (mm2/s) Viscosity index Flash Point, PM (°C) Pour point, (°C) Aniline point, (°C) Density at 15°C (g/dm3)

D 445 D 445 D 2270 D 93 D 92 D 611 D 4052

BS200

SN500

838.3 43.2 92 275 -6 113 918.9

95.4 9.6 71 227 -24 98.75 892.4

R1 690.8 29.2 50 220 -15 90 940

Table 1 shows the characteristics of the base oils.

Preparation of the base oils: Three different viscosities (235, 370 and 505 mm2s-1) have been prepared by diluting BS200 and R1 with SN500 respectively. Table 2 shows the characteristics of these blends; A, B and C are blends of the two paraffinic oils (SN500+BS200), while A´, B´ and C´ are blends of paraffinic and naphthenic (SN00+R1).

Characteristics Viscosity at 40°C (mm2/s) Viscosity at 100°C (mm2/s) Viscosity index Flash Point, PM, (°C) Pour point, (°C) Aniline point, (°C) Density at 15°C, (g/dm3) Cu corrosion, rating

Method (ASTM)

Blend A Blend B Blend C Blend A´

Blend B´

Blend C´

D445

234.6

372.2

503.6

235.2

369.0

506.6

D445

17.9

24.7

30.4

16.2

20.8

24.8

D2270 D93 D92 D611 D4052 D130

81 229 -12 105.3 907.9 1a

86 239 -12 109.9 912.2 1b

88 247 -12 110.4 914.5 1b

60 223 -24 94.3 921.3 1a

56 223 -24 92.8 930.5 1a

54 223 -15 91.7 936.1 1a

Table 2 shows the characteristics of the base oil blends, used for production of the greases.

Results ad Discussion

The grease samples have been prepared in an open kettle in which the pre-blends (see Table 2) were used. The target consistency for these samples was NLGI grade 2. Notable is that the greases used in this study do not contain any additives.

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Table 3 shows the characteristics of the greases based on the blends in Table2.

Characteristics

Grease A

Thickener content (%) Penetration (60) Dropping point (°C) Cu-corrosion * Penetration (100,000) Water wash out (%) ** Water spray off (%) ***

6.2 276 208 2c 296 1.37 55.6

Grease B

Grease C

6.6 268 206 1b 291 1.61 53.8

Grease A´

5.6 272 208 1a 294 2.00 31.2

5.1 277 202 1a 275 2.73 43.8

Grease B´

Grease C´

4.8 268 203 1a 278 1.38 N/A

5.0 274 199 1a 277 2.12 18.8

*) 100 °C/24h; **) 79 °C/1h; ***) 38 °C/5min/40psi (276 kPa) Based on the measured properties of the greases, shown in Table 3, some interesting behaviors for R1 based greases can be recognized, such as: lower thickener content, good mechanical stability and superior water spray off.

Figure 2 shows the Storage modulus as a function of Strain for B and B´ at 25 °C Temperature sweep: The low temperature behaviour of the greases was investigated by using temperature sweep program, from +50 to -30 °C. Then the change of G´ as a function of temperature was measured. Figure 3 shows the obtained results for A, B and C and Figure 4 shows those for A´, B´ and C´.

Tribological measurements

The load carrying capacity of the grease samples was measured by using a four ball machine. As can be seen in Table 4, the wear scar of all 6 grease samples indicates that there is no significant difference between the samples. This is interesting since Grease A´, B´ and C´ contain lower thickener content as well as lower viscosity index than grease A, B and C respectively.

Table 4 shows the measured wear scars of the greases.

Remarks Wear scar (mm)

Grease A 2.73

Grease B 2.71

Grease C 2.77

Grease A´ 2.73

Grease B´ 2.70

Grease C´ 2.67

The condition of the four ball test was: 140 kg, 60 sec, 1440 rpm

Rheological measurements

It is well known that lubricating grease is a viscoelastic material, in other words a material with a viscous part (the base oil) and an elastic part (the thickener). Parameters such as temperature and shear stress affect the oil and the thickener differently. Hence, flowability of the grease sample under controlled conditions can generate valuable information such as storage or elastic modulus (G´) of the grease which could be interpreted as the real consistency of the grease, at the applied temperature.

Strain Sweep: In an attempt to study the rheological behaviour of the greases described above, a strain sweep program was applied in which the frequency and the temperature were kept constant (10 rad/s and 25 °C respectively), and the strain was increased logarithmically from 0.01 to 1000%. Figure 2 describes the elastic (storage) modulus as a function of the strain for B and B´. As it can be seen G´ for B is 13605 (Pa) while it is 878 (Pa) for B´ which is consistent with the thickener contents which are 6.6% and 4.8% respectively. Notably, they have the same penetration number after 60 strokes. However, LVR (the linear viscoelastic region) for B´ appears to be bigger than for sample B which is indeed interesting since it indicates that B´ is a more mechanically stable product than sample B, in accordance to the worked penetration after 105 strokes (see Table 3).  - 20 VOLUME 78, NUMBER 5

Figure 3 shows the behaviour of storage modulus of SN500+BS200 based greases vs. temperature.

Figure 4 shows the behaviour of storage modulus of SN500+R1 based greases vs. temperature.

Figures 3 and 4 reveal some interesting information which could be summarized as: a) the change of the slope for greases, A, B and C is around -5 °C which can be attributed to the presence of bright stock (BS200) and subsequent assumed wax formation, despite a lower pour point for all paraffinic blends which is -12 °C. This phenomenon was discussed in a separate publication [2]. And b) for all paraffinic based greases G´ is significantly higher at -30 °C than paraffinic/naphthenic based, as a consequence of the impact of the further wax crystallization of the bright stock.

However, it is reasonable to believe that SN500, at least, is not the main source of this increase since both greases contain SN500.

Differential Scanning Calorimeter measurements

In an attempt to verify the wax crystallization, described above, a differential scanning calorimeter (DSC) was used.

The condition of the test series was; cooling process (from 70 °C to -40 °C) followed by heating process (from -40 °C to 240 °C) with a rate of 5 °C per minute.

Figure 5 describes the data generated for Grease B and Grease B´. As it can be seen Grease B starts to crystalize at a temperature of about -3.5 °C which is not far from the pour point of the bright stock (BS200) despite the - 21 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI measured pour point of the Blend B which is -12 °C (see Table 2). Furthermore, it was discovered that the starting temperature for the crystallization (transition temperature) was more or less the same for Grease C (- 3.1 °C) while for Grease A (where less bright stock was involved) was significantly lower, about -9.5 °C. This behavior is in fact in-line with the previous published finding [2] where it was e.g. shown that the wax crystallization (in a paraffinic oil) starts far above its pour point. 

Figure 5 shows the thermal behavior of Grease B & B´ respectively.

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Summary

• A highly viscous naphthenic oil, as a substitute to bright stock, has been evaluated for grease formulations. Based on the obtained results in this study, it can be concluded that by substituting bright stock with R1: • Significant reduction in thickener content.

• Better mechanical stability, in spite of lower thickener content.

• Excellent copper corrosion inhibiting, without any copper passivator additive.

• Very good water spray off, probably due to higher adhesivity of R1 • Similar wear scar as the bright stock based greases despite lower thickener content and lower viscosity index.

• Pour low temperature behaviors of Greases that contain bright stock in comparison to R1 could be explained by carrying out a multidisciplinary study, using Rheometer and DSC.

Reference

1. When the going gets tough... A heavy specialty oil for grease formulations; Serra-Holm V; 79th NLGI Annual Meeting, June 2012 (US) 2. Low temperature tribology; Fathi-Najafi M. et.al, 24th ELGI Annual meeting, May 2012 (Germany)

However, the overall conclusion should be that it is possible to provide a substitute for bright stock in grease formulations with equivalent or better performance.

Consequently, a more cost effective grease formulation could be achieved, provided the color is not an issue.

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Challenges in Manufacturing of Bio-Based Greases Dr. Anoop Kumar and Bill Mallory

Royal Mfg Co. LP, 516 s, 25th W Ave., Tulsa, 74127, Oklahoma, USA

Abstract:

The buzzwords like “Biodegradable”, “Bio-based”, “Ecofriendly”, and “Green” etc., appear to be complimentary to each other in lubricant industry and are often referred to the lubricants/greases prepared in either vegetable oils or ester fluids. The awareness to use such vegetable oil based lubricants dates back to 1400 BC where Egyptian used animal fat or olive oil mixed with lime, a kind of crude lubricating grease to lubricate their Chariots. By the end of 19th century, majority of lubricants and greases were replaced by mineral oil based products. Since then great advances in manufacturing technology of these lubricating greases have taken place.

A wide variety of processes for manufacturing of these lubricating greases have been developed and adopted by the industry. When it comes the manufacturing of vegetable oil based greases, these processes becomes rather complex. One of the reasons for this complexity is the chemically different nature of mineral and vegetable oils. What makes manufacturing of vegetable oil based greases even more complex is the fact that under certain conditions of reaction, these vegetable oils itself potentially tends to become chemically reactive to the some ingredients or possibly tends to polymerize.

The bio-based greases, generally being marketed industry wide are based on lithium, lithium complex, clay base, aluminum complex prepared in different types of vegetable oils depending upon the availability of these oils locally. While manufacturing these types of greases, we faced some real challenges in scaling up the processes,

meeting process parameters versus intended quality. This paper covers some of the aspects of these manufacturing challenges faced while making lithium, lithium complex, and aluminum complex greases under varying processing conditions. The Physico-chemical properties of thus produced greases have also been covered in this paper.

Key Words: Lubricating grease, canola oil, vegetable oil, lithium, lithium complex, aluminum complex, sulfonate etc.

1.0 Introduction:

The first ever lubricants used by mankind to reduce friction and wear were perhaps the one derived from vegetable oils and/or animal sources. It has been reported that scrapings from the hub of Egyptian chariot showed the presence of quartz, iron, fat and lime indicating the use of a kind of lime based grease [1-3]. The use of these natural resources based lubricants continued to be used until 19th century, where the discovery of crude oil and advancement in their refining processes revolutionized the entire lubricant industry. This gradually replaced almost all vegetable oils/animal fat based lubricants and greases by mineral oil based products. The main reason for their dominance was probably the better performance, adequate availability and cheaper cost.

Even NLGI 2011 worldwide grease market survey indicates about 2.4 billion lbs of total worldwide grease volume, where mineral oil based greases have dominated by about 92% followed by synthetic and semi-synthetic

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oil based greases totaling about 7%. Bio-based greases found their entry for the first time in 2010 survey, has now about meager 1% market share [4].

Since then the technologies have progressed remarkably, especially in last 200 years. However, the developments in field of lubricating greases have been much slower and less scientific. The process of making lubricating greases in those days probably would have been much closer to the washing soap making techniques [5] like the one by boiling wood ash lye with fat Miller [6] stated that until close to 1800, the universal lubricants were beef / mutton tallow or a vegetable oil. Hamill [7] in 1863 formed grease by simply adding pulverized soap stone to coal/petroleum oil. Lawrence commented that even the 1930’s method of making lubricating greases closely resembles to cookery-book stuff [8]. However, post WWII era has witnessed remarkable progress in the field of lubricating grease developments. Products based on different kind of thickeners using wide variety of base oils and additives system came in to the market. The manufacturing of lubricating greases, unlike lubricating oils, has now been regarded as complex and highly sensitive to processing equipment and parameters. On the other hand, in late 20th century due to environmental concerns, drive for green products and renewability factors once again revived the need of vegetable oil based lubricants and greases. The support from various government agencies across the globe, primarily in Europe, legislative compliance, incentives offered both by government and non-government agencies have further spurt the demand of biodegradable / vegetable oil based lubricants and greases.

The challenges in front of bio-based lubricating grease manufacturers are mainly two fold. One meeting the performance requirements in terms of oxidation stability, extreme-pressure, water resistance, high temperature thermal degradation etc. vis-à-vis its mineral oil counterpart. As the majority of the market is flooded with mineral oil based products, it’s likely that these bio-based greases are going to replace mineral oil based greases. Therefore, user’s expectations from the bio-based greases demands comparable or better performance than mineral oil based products. The other one which

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is more important from manufacturing stand point is how to produce these greases in conventional plants where mineral and synthetic oil based greases are being produced using those conventional processes. The real challenge lies in the fact that the chemical composition and thermal stability of mineral and bio-fluids is considerably different, it’s very difficult to manufacture a consistent quality product adopting processes that are being used conventionally for making mineral/bio-based greases. For instance, mineral oil based lithium greases are normally produced by heating up to 400 0F (204 0C) whereas many of the bio-fluids start degradating / polymerizing at such high temperatures.

1.1 Compositions of mineral and bio-based oils:

Mineral oils primarily consist of mixture of variety of hydrocarbons which include straight chain, branched chain, olefins, cyclic compounds, aromatics, naphthalenes etc [1-3]. These bases oils could be aromatic, paraffinic, naphthenic, group I, group II, group III and even synthetic hydrocarbon oils like polyalpha olefins (PAO) etc. Both naphthenic and paraffinic type base oils are being used to make lubricating greases, though the saponification takes place better in naphthenic oils. These oils are almost non-polar and non-reactive to the ingredients used for making lubricating greases.

Figure-1: Triglyceride of long chain fatty acid Vegetable oils on the other hand are triglyceride of long chain fatty acids (Figure-1). These vegetable oils contain unsaturated double bonds, ester linkage and vary in composition depending upon type of oil. These oils as we see do carry reactive sites and under the influence of temperature and certain functional group, tend to become reactive. Honary [9] indicated the certain

- 25 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

NLGI vegetable oils tend to oxidize and polymerize at temperature exceeding 150 0C (302 0F) and this behavior becomes irreversible. The soap formed in such cases looks like a polymeric material with little lubrication value. Similarly, polymerization of vegetable oils under different conditions has widely been reported [10-12]. As both acids and bases like lithium hydroxides are used to make greases, there is a possibility of reaction of greases making ingredients with the carrier oil like vegetable oil and possibly a uncontrolled reaction. This in turn may disturb the stoichiometric ratios of various ingredients. Therefore, there is a possibility that vegetable oils may not behave the same fashion as mineral oils perform.

1.2 Conventional Manufacturing Processes:

Unlike lubricating oils, manufacturing of lubricating greases is considered complex and highly sensitive to manufacturing process parameters. The NLGI Grease Production Survey indicate that over 90% of worldwide greases produced are based on soap or their complex soap base greases and are conceptually prepared by the saponification process; alkali hydrolysis of fat / fatty acids.

For making lubricating grease long chain fatty acids/esters (preferably C18) are hydrolyzed by hydroxides of lithium, calcium, or sodium etc.

Lubricating greases in general can both be prepared by continuous manufacturing process and batch process. The majority of lubricating greases are prepared by batch process as it has more flexibility in making a variety of products in the same plant. Batch process could both be open kettle or closed kettle. Both open and closed kettle processes are practiced in the industry depending upon the type of greases being processed. Most of the lithium and lithium complex greases are processed in closed kettles under pressure due to better saponification, less process time and better quality. This is attributed due to the fact that most of the saponification reactions - 26 VOLUME 78, NUMBER 5

are carried out between a weak acid which normally a long chain fatty acid and weak base like lithium hydroxide and therefore accelerated condition,s like reaction under pressure, promotes the reaction faster in forward direction. However, the cost of pressurized reactors is much more than an open kettle and therefore, many small manufacturers still use open kettle process as for making even lithium greases. Other greases like calcium sulfonate, aluminum complex, calcium, sodium, polyurea, clay etc. are generally made in open kettles. The invention of the contactor process by Stratco has indeed revolutionized the manufacturing of lubricating greases. The most widely produced lithium greases are preferred to me made through the contactor process [1, 2, 13]. The unique feature of the contactor process is its high turbulent circulation in a closed cycle path. It is claimed that lithium greases made by this process provide about 20-30% better yield compared to open kettle process, in addition to the better quality and efficiency. More recently Honary et.al, reported a microwave process of making lubricating greases which is claimed to be more efficient and convenient [9]. The various processes of making different greases are depicted schematically as figure-2.

Figure-2 In this paper some interesting results and challenges faced during manufacturing of bio-based greases using conventional processes and plant has been covered. The lubricating greases covered in this paper are based on lithium, lithium complex, and aluminum complex.

- 27 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

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2.0 Experimental:

The term bio-based greases refer here to the greases prepared in 100% vegetable oil. The vegetable oil used in these studies is technical grade canola oil (AP 60), a type of rape seed oil, supplied by Cargill. Mineral base oils used for making these greases are a blend of paraffinic and naphthenic oils. The thickeners selected for making bio-based and mineral oil based greases were of three types, namely lithium 12-hydroxy stearate, lithium complex, and aluminum complex. The greases prepared by open kettle process were both prepared in lab as well as commercial plant. The grease prepared in commercial plant were of 6000-8000 lbs batch size using thermic fluid heated kettle with counter rotating paddles hooked with scrappers. The lubricating greases prepared by closed process were prepared in commercial plant in Stratco contactor at batch size of 7000 lbs.

The greases prepared by contactor processes were first cooked in contactor and then transferred to open kettle for dehydration, cooling and finishing. The greases were either milled through Charlotte grease mill or homogenized through APV Gaulin homogenizer. The lab samples were prepared using Hobart mixture and milled through lab mill. All the greases were tested as per standard ASTM test methods.

3.0 Manufacturing of Bio-Based Lithium Greases:

As per the NLGI Grease Production Survey [4] about 75% of total worldwide greases are based on lithium and are the most widely used greases worldwide. These greases are prepared normally with reaction of 12-hydroxystearic acid (12 HSA) with lithium hydroxide. Alternatively, other fatty acids or esters being used for making this class of greases are hydrogenated castor oil (HCO), stearic acid and tallow etc., however most preferred one is 12 HSA. As we use 12 HSA as main fatty acid to make these greases, our studies are limited to grease prepared with 12 HSA. The a saponification reaction taking place is shown as under. This reaction can be carried out both in open kettle process or closed (stratco contactor) process.

4. Homogenization / Milling: Grease is homogenized / milled to get uniform structure and tested Typical lithium 12-hydroxy stearate extreme pressure (EP) grease prepared by above process exhibited the properties as indicated the table -1. Table -1 indicate that the that the grease prepared by open kettle process uses about 12% soap, exhibited good extreme pressure, rust prevention and good mechanical stability. In order to check the consistency of grease on storage, the grease was also tested for worked penetration periodically as indicated by table-1. The test result for over the period of 1 year indicates that there is practically no change in penetration over the test period of 1 year.

A batch of canola oil based lithium 12-hydroxy stearate grease was prepared in open kettle adopting the similar process as mentioned above by heating up to 400°F. The finished grease was milled and tested for intended properties. Test results are tabulated in table-1 under lithium 12 hydroxy stearate grease by conventional process. It was interesting to note that when grease was made using 12% soap as was done in case on mineral oil base grease, it failed to make proper grease and consistency was too thin. Therefore the grease was prepared using a higher percent of thickener (18%). The resultant grease was NLGI 1 consistency and appeared to be stringy as if some polymerization has taken place. The progress of reaction was also studied by FT-IR recorded at different times. Figure 3 indicate a comparative FT-IR spectrum of canola oil, lithium 12 hydroxy grease prepared in mineral oil and a canola oil based grease spectrum recorded after 8 hrs of reaction. Both greases clearly indicate 1578 cm-1 and 1560 cm-1 band corresponding to the formation of lithium 12-hydroxy stearate, however no significant difference in two greases was noticed.

3.1 Open Kettle Process:

Lithium 12-hydroxy stearate greases in open kettle are normally made by following commonly adopted method 1. Charging the ingredients:

a. Mineral /synthetic base oil (10-30%) is charged in the kettle

b. Charge fatty acid (12 HSA), lithium hydroxide and water 2. Cooking and Dehydration:

a. H eat slowly by continuously stirring to about 400°F (204°C). Care need to be taken to minimize foaming.

3. Cooling and finishing:

a. M ass is cooled down to < 190°F (90°C) either by circulating cold oil in kettle jacket and /or by adding finish remainder of oil

b. Additives are added and mixed - 28 VOLUME 78, NUMBER 5

Figure-3 Table indicates that the mechanical stability of the grease made by this process using canola oil resulted into comparatively inferior product. The storage stability of the grease ran over a period of 1 year indicate that grease has tendency to harden over a period of time, though the tendency of hardening reduces with time.

- 29 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

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This difference in resultant grease made in canola oil using conventional process may be attributed due to the different nature of the vegetable oil. Mineral oils are the mixture of hydrocarbons and considered non-polar and non-reactive to the fatty acid or lithium hydroxide, whereas the vegetable oil (canola oil) are triglyceride of fatty acid/esters and possesses some label of polarity and may be reactive at elevated temperature. These oils even may have tendency to self-polymerize or react with fat or alkali to form undesirable polymeric product. However no efforts have been made to study intricacies of the reaction pathways. In view of thermal degradation nature of vegetable oils at elevated temperatures the cooking temperature of grease was reduced from 400± 5°F (204± 5°C) to 350 ± 5°F (175 ± 5°C). This has given product with better appearance and the resultant properties of the grease are tabulated in table-1 under lithium 12-hydroxy grease (modified process). Table-1 indicates that the end product resulted into NLGI 2 consistency with 14.5% soap compared to 18% with conventional process. The product indicated improved mechanical stability (+ 39 change after 100,000 double strokes) when compare to +69 unit change for the product that was produced by conventional processes. However, the grease was still inferior to mineral oil based lithium 12 hydroxy stearate grease. Nevertheless, this grease still shows storage hardening when tested over a period of one year. The grease hardened about 25 units in one year.

3.2 Closed Kettle (Contractor) Process:

Efforts were made to manufacture the grease in contactor both mineral oil based and canola oil based grease. The process adopted to make lithium grease in contactor involve following steps.

I. Charging the ingredients: a. Mineral /synthetic base oil (30-50%) is charged in the kettle b. Charge fatty acid (12 HSA), lithium hydroxide and water II. Cooking: a. Heat slowly by continuously stirring to about 400 ± 5°F (204± 5°C) under controlled pressure

III. Dehydration and Cooling: a. Cool the grease for few degrees by quench and rinse process and transferred to finishing kettle b. Dehydrate the grease to remove moisture c. Cool the mass is to < 190°F (90°C) either by circulation cold old in kettle jacket and /or by adding finish remainder of oil d. Additives are added and mixed IV. Homogenization / Milling: Grease is homogenized / milled to get uniform structure and tested The mineral oil based grease prepared by above mentioned process has been tested and test data are tabulated in table-2. The test results indicate that grease turned out to be consistent grease. The penetration of this grease did not change on storage, meaning good shelf life of the grease. The grease made with canola oil using the above formula turned out to be very thin, may be due to the reason as explained above. This product did not thicken even on cooling and addition of finish oil made this grease further worse. This grease did not come back to its expected consistency and drop point was low as well indicating some irreversible reaction during processing. The literature survey [10-12] indicate that at higher temperature these vegetable oil possess the tendency of self-polymerization, the cooking temperature of the grease was reduced to 320-330°F and pressure on the reactor was reduced to only 40 PSI and addition of water prior to cooking stage was reduced by 50%. The grease when transferred to kettle appeared to be better than the one made with conventional process.

The product was cooled down and additives including anti-oxidant were added. The test results are tabulated and compared with mineral oil based product (table-2).

The mechanical stability of the grease was + 37 change which is inferior to mineral oil based grease but better than grease prepared by conventional process. However, this grease also showed the tendency of hardening with time (table-2).

4.0 Manufacturing of Bio-Based Lithium Complex Greases The lithium complex grease was prepared using conventional manufacturing process as indicated above in case of lithium greases. The only difference was the

- 30 VOLUME 78, NUMBER 5

addition of complexing agent, the complexing agent used to make these greases was azelaic acid. In case of mineral oil based lithium complex greases, the maximum temperature of cooking the soap in both open and contactor process was 400°F/ 204°C. The properties of mineral oil based greases are tabulated in table-3. By and large the mineral oil based greases prepared in closed or open kettle process are pretty stable having good shelf life as indicated by tested penetration over period of time.

The bio-based lithium complex greases, prepared both in open kettle and closed by kettle heating up to 400 0F/ 204 0C temperature did not gave the desired product.

In open kettle process, reaching to 400°F (204°C) was challenging as it became too smoky at +350 0F (193°C) and maintaining at this temperature for more time resulted into a polymerized product did not turn into grease on oil addition. The grease which was prepared in contactor under similar condition of heating up to 400°F (204°C) gave a very thin product like polymerized fluid which did not turn into grease at all. These two observation are on the similar lines as was observed in case of making lithium 12-hydroxy stearate grease manufacturing as described above.

In view of this the different reaction condition and compositions were studied in order to get a NLGI #2 grease with comparable extreme pressure (EP) properties. It was found interesting to observe that reaction of fatty acids, complexing agent and lithium hydroxide was highly sensitive to processing parameter like temperature, time, pressure, quantity of water and agitation. Out of many combinations one of the compositions with 15.5% soap in open kettle gave rise to satisfactory lithium complex grease. This grease was additized with ashless EP-Antiwear and oxidation inhibitors. The test results are tabulated in table 3. Careful analysis of the test data indicate that the difference between the lithium complex grease prepared in open kettle process is that the higher% of soap (15.5%) has been used to make same consistency grease as compared to mineral oil based grease. Other considerable difference is the tendency of canola oil based grease to harden over time, however the extent of hardening does not seem as pronounced as in case on canola oil based lithium 12 hydroxy grease prepared

by open kettle process. In case of contactor process, as initially we failed to make grease with conventional lithium complex grease process, the different processing parameters were considered in order to get a NLGI #2 grease. The processing temperature and time was reduced considerably to 320 ± 10°F and grease was cooked by providing slow heating and carefully observing the changes. The maximum pressure of reaction was also reduced to 40-50 PSI in place of 80 PSI. The total soap used to make NLGI #2 grease in this case unexpectedly was 16.5% which came out to be more than open kettle process. The finished grease exhibited the properties as indicated in table-3. The resultant grease exhibited poor mechanical stability as compared to mineral oil based lithium complex grease. The drop point of the finished grease was also found to be lower than mineral oil based grease. This grease like other canola oil based greases indicated significant hardening on storage.

5.0 Manufacturing of Bio-Based Aluminum Complex Greases

Aluminum complex greases are conventional prepared by reaction of benzoic acid, stearic acid and alkoxide of aluminum. Originally this grease were prepared using aluminum isopropoxide. However these processes use to liberate comparatively large quantity of isopropanol, a low flash by product and fire hazard for manufacturing plant.

Subsequently, the better process and a substituted trimer of Aluminum isopropoxide has been developed which is being successfully used to make this class of greases. The aluminum trimer has the advantage of producing less amount of isopropyl alcohol and can potentially be made in open kettle.

- 31 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

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Figure 4; Trioxyaluminum triisopropoxide Cyclic Trimer The mineral oil based grease was prepared by charging mineral base oil in kettle (60-70%) and then benzoic acid and stearic acid are added, heated till melting and then Trioxyaluminum triisopropoxide Cyclic Trimer was added. The mass was slowly heated to 390-400°F (190-200°C). The progress of the reaction was monitored by FT-IR (figure-4). FT-IR spectra of both mineral oil and canola oil based indicate band 1605 cm-1, 1587 cm-1 and 1566 cm-1 indicating the formation of aluminum complex soap thickener, otherwise there was not much of noticeable change in FT-IR spectra of aluminum complex grease when compared to just the mineral or canola oil.

exhibited improved mechanical and roll stability as compared to the grease prepared in canola oil with conventional process and inferior to the mineral oil based grease. The storage stability test of this grease over periods of 1 year showed hardening tendency but less oil separation compared to the grease prepared with conventional process.

6.0 Conclusions:

The lubricating greases based on bio-based fluids are gaining increasing application in the industry. These greases are either based on lithium, lithium complex, calcium, clay, and aluminum complex etc. based. One would expect the manufacturing of these greases to be the same as that of mineral and synthetic oil based greases. However, the studies presented in this paper indicate significant change in the processing parameters is required. The problem is that the vegetable oils decompose and polymerize at higher temperatures used in manufacturing of mineral oil and/or synthetic fluid based greases. This is attributed due to the fact that that chemistries of mineral and vegetable oils significantly differ. Lowering the temperature of reaction does have significant impact of the properties of the resultant grease and lower yield. The hardening of grease overtime also gives an indication of either incomplete reaction or some side chain reaction. This study indicate that manufacturing technology of bio-based greases, meeting industry standards, is still at infancy state and more attention is needed to streamline the manufacturing technologies of these type of greases.

7.0 Acknowledgement:

Authors gratefully acknowledge the help and guidance provided by Dr Cathy Mallory in finalizing this manuscript. Authors are thankful to grease plant personnel especially Monte Walton and Jimmy Koetter in helping to get samples ready.We are also thankful to Mr. Craig Copper for his help in running FT-IR spectrum of the greases.

8.0 References: Figure-5 The products were then cooled, doped with requisite additives and milled. The grease exhibited the characteristics as indicated in table-4. The bio-based grease produced by conventional method was very stringy compared to mineral oil based grease that was translucent and smooth. In addition, bio-based grease was much softer than mineral oil based grease, NLGI 1 versus NLGI 2, although it contained higher percentage of thickener, 18-19% versus 10-11%. The mechanical stability and roll stability of the resultant grease were quite poor +74 and + 58 unit change respectively in penetration after 10,000 strokes as compared to only +35 unit change with mineral oil based grease. Interestingly this grease did not harden over time when tested for storage stability over a period of 1 year, though lot of oil separation was observed. The processing parameters were further optimized and reaction temperature was reduced to 320-330°F (160-165°C) and the stoichiometric ratios were further optimized. The resultant product using improved process and composition gave rise to acceptable product. The test data of finished grease are tabulated in table4 as aluminum complex grease (modified process). The grease prepared with improved process - 32 VOLUME 78, NUMBER 5

[1] Boner, C. J., “Manufacturing and Applications of Lubricating Greases” Reinhold Publishing Corp., 430 Park Ave. NY, 1954, pp 136-138.

[2] Polishuk, A. T., “A Brief History of Lubricating Greases” Llewellyn & McKane Inc. PA, 1998, pp. 35-72 [3] NLGI, “Lubricating Grease Guide” Published in Kansas City, Missouri, 2006, pp. 11.

[4] NLGI, “Grease Production Survey Report” Kansas City, Missouri, 2011.

[5] Marietta Ellis; www.alcasoft.com/soapfact/historycontent.html [6] Miller, George W., “Lubricating Grease” Lubrication Engineering, 7, 2 February, 1951 [7] Hamill, Alexander, USP 38,822, June 9, 1863 [8] Lawrence, A.S.C., “Lubricating Grease” J. Institue of Petroleum, 31, 260, pp. 303-314, 1945 [9] Honary, L., “Bio-based lubricants and greases” Wiley publication, PP. 160 (2011) [10] Petrovic, Z.S., “Phenolation of vegetable oil” J.Ser.Chem.Soc. 76(4) 591-606, 2011 [11] Petrovic, Z.S., “Polymerization of soyabean oil with superacids” www.intechopen.com [12] www.vegetableoilbasedpolymers.wikispaces.com [13] www.stratcoinc.com - 33 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

Table-1: Comparative Test Data of Lithium 12 Hydroxystearate Greases Prepared in Open Kettle

Table-2: Comparative Properties of different Lithium 12 Hydroxystearate Greases Prepared in Closed (Stratco) Process

Table-3: Comparative Properties of different Lithium Complex Greases

Table-4: Characteristics of Different Aluminum Complex Greases

- 35 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

Welcome New 2014 NLGI Members!

Accent Advisors - Technical 2200 Founders Bridge Rd Midlothian, VA 23113 USA Phone: 804-794-2624 www.accentadvisorsinc.com

Certified Labs – Technical 2900 Castle Sage Ct. Reno, NV 89503 Phone: 904-673-7400 www.certifiedlabs.com

Additives International - A Lockhart Chemical Company - Manufacturer 4302 James P Cole Blvd Flint, MI 48505 USA Phone: 248-656-4079 www.additivesinternational.com

Changamcals (Cals Corp) – Technical 123-63 Injusandan-ro, Inju-myeon, Asan-si, Chungcheongnam-do, 336-831 South Korea Phone: +82-70-7864-5213 www.changam.co.kr/

Alnor Oil Company, Inc. – Supplier 70 East Sunrise Hwy, Suite 418 Valley Stream, NY 11581 USA Phone: 516-561-6146 www.alnoroil.com BNSF Railway – Consumer 1011 NE River Road Topeka, KS 66616 USA Phone: 785-851-8257 www.bnsf.com Robert Belic – Consumer 20 Jacana Place West Pennant Hills NSW, Australia 2125 Phone: 61-49-002-5256 Boss Lubricants – Marketing #112, 6303-30th St. SE Calgary, Alberta T2C 1R4 Canada Phone: 800-844-9457 www.bosslubricants.com

Chengdu Xinyuxiang Trading Co., Ltd. - Supplier Room 707, Jiangxin Building, 56, Taisheng Road North Chengdu 610000 China Phone: +86-28-83219136 www.xyxtrading.com Corfin Lubrication - Manufacturing Organize Sanayi Bolgesi #1 Sk. No: 7 Toprakkale Osmaniye, 80950 Turkey Phone: 00.90.328.826.8626 www.corfin.tc Croda – Supplier 315 Cherry Lane New Castle, DE 19720 USA Phone: 302-429-5443 www.croda.com - 36 VOLUME 78, NUMBER 5

CSSC – Technical Dammam-Khobar Hiway Opp. SCECO East Head Office Al-Khobar, Eastern Province 31952 Saudi Arabia Phone: 00966138577710 FMC Measurement Solutions Inc. – Technical 222 W. Adams, Suite 400 Chicago, IL 60606 USA Phone: 312 803 4183 www.fmctchnologies.com German Mirror Lubricants & Greases – Manufacturer I-E-02, Hamriyah Free Zone P.O. Box 42405, Sharjah, UAE Phone: +971 55 1555548 www.germanmirror.com Golden Oil Inc. - Manufacturer 5751 NW 98 Ave. Doral, FL 33178 USA Phone: 305-600-0477 www.superkote2000.com Industrial Oils Unlimited, LLC – Supplier 3633 Charles Page Blvd.

Tulsa, OK 47127 USA Phone: 918-583-1155 www.iouinc.com

Ingrax - Ind e Com de Graxas SA – Manufacturer 181 Senegali St Parana, 83413250 Brazil Phone: 44-41-21067700 www.ingrax.com.br/

Monson Companies - Koda Distribution Group – Supplier 154 Pioneer Dr. Leominster, MA 01453 USA Phone: 978-840-7045 www.monsonco.com Nanotech Industrial Solutions Manufacturer 42 Mileed Way Avenel, NJ 07001 USA Phone: 732-882-1808 www.nisusacorp.com

Inter Atlas Chemical Inc. – Marketing (2015 Member) 63 Church St., Suite 301 St. Catharines, Ontario L2R 3C4 Canada Phone: 905-684-9991 www.interatlaschemical.com Kandla Agro & Chemicals Pvt. Ltd. Manufacturer Plot No BBZ-S-49 & 50 Zanda Chowk Gandhidham-Kutch 370 201 India Phone: +91 9004 601860 www.xyxtrading.com LB Foster Rail Technologies – Manufacturer (2015 Member) 4041 Remi Place Burnaby, British Columbia V5A 4J8 Canada Phone: 604-415-3002 www.lbfoster.com Lubricantes Syntheticos S.A. de C.V. – Marketing Carretera Apodaca Km 0.6. N.L. C. P. Apodaca, N.L. 66600 Mexico Phone: 00-181-8385-4511 www.lufhissa.com

Nator Lubrication Co., Ltd – Manufacturer No. 57 Longxin Rd Tangzhen Industrial Zone Pudong, Shanghai, 201 201 P.R. China Phone: 86-137-0186-9465 Nexeo Solutions, LLC – Supplier 3 Waterway Square Place, Suite 1000 The Woodlands, TX 77380 USA Phone: 281-297-0972 www.nexeosolutions.com NYCO America LLC – Manufacturer 3900 E Indiantown Rd, Suite 607 #161 Jupiter, FL 33477 USA Phone: 908-334-7176 www.nycoamerica.com Petro-Lube Test Labs – Technical PO Box 300 Lafayette, NJ 07848 USA Phone: 973-579-3448 www.petrolube.com Pigging Solutions – Supplier 1915 W. Woodland, Suite 132 Springfield, MO 65807 USA Phone: 417-708-8797 www.piggingsolutions.com

Raloy Lubricantes, S.A. de C.V. – Manufacturer (2015 Member) Av. del Convento No. 111 Parque Industrial Santiago, Estado, 52600 Mexico Phone: 713-133-5906 www.raloy.com.mx/ Savant Labs - Technical 4800 James Savage Rd. Midland, MI 48642 USA Phone: 989-496-2301 www.savantlab.com Stanhope-Seta – Technical (2015 Member) London St Chertsey, Surrey KT16 8AP United Kingdom Phone: 44-01-93-256-4391 www.stanhope-seta.co.uk Storchem - Supplier 855 Harrington Court Burlington, Ontario L7N 3P3 Canada Phone: 905-639-9700 www.storchem.com Western Marketing, Inc. – Marketing 900 E County Road 123 Midland, TX 79706 USA Phone: 432-528-4322 www.westmktg.com Zolleks Avto d.o.o. - Marketing Kidriceva Cesta 97 Shofja Loka 4220 Slovenia Phone: 386-6413-1488 www.zolleks.si/en/

- 37 NLGI SPOKESMAN, NOVEMBER/DECEMBER 2014

Covenant Engineering Services, Inc. Quality Engineering Services Backed with Integrity

Advertiser’s Index Vanderbilt Chemicals, LLC, Inside Front Cover Lubes N Greases, pg 4

Specialists:

Afton Chemical, pg 6

Grease Manufacturing and Lube Oil Blending

Covenant Engineering, pg 38

Conceptual, Process, and Detail Design 140 P.O. Corporate Place Box 761 Branson, MO Chesterton, IN 65616 46304 Phone: 417-243-4133 219-728-1054 Phone: 219-929-5781

Tribotec, pg 38 Oil Doc, Inside Back Cover

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Optimize your visit!  Register for the special workshops on January 29th with Jim Fitch (NORIA) and/or Jack Poley (CMI)  Visit the state-of-the-art OELCHECK analysis-laboratory for oils and greases.  Bring your spouse, extend your conference journey and go to Munich, Innsbruck, Salzburg or Italy. We advise you how to travel and where to stay.

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Helping the World Run a Little Smoother Lubrizol is helping companies worldwide as a grease additive technology partner. In today’s complex marketplace, you need a company that understands the demands of ever-changing applications, environmental concerns, LEAN manufacturing and worldwide standards and protocols.

Lubrizol is at the forefront of industry advancements offering our customers superior functionality, product consistency, R&D and testing. We are improving grease performance and processes worldwide. To learn more visit www.lubrizol.com.

With you every step of the way.

- 40 VOLUME 78, NUMBER 5

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