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Industrial Energy Efficiency Accelerator - Guide to the maltings sector

Around 1.5 million tonnes of malt is produced in the UK each year by seven large maltsters and seven smaller maltsters. Domestic beer and whisky production accounts for almost 90% of the output from the Malting industry, the remainder being used in a wide range of foods, with some exported. The CO2 emissions associated with the Maltings sector is approximately 340,000 tonnes of CO2 per annum.

Executive Summary This report presents the findings and recommendations of the Investigation and Solution Identification Stage of the Industrial Energy Efficiency Accelerator (IEEA) for the Maltings sector. The aims of this stage were to investigate energy use within the Maltings sector-specific manufacturing processes and to provide key insights relating to opportunities for CO2 savings. Around 1.5 million tonnes of malt is produced in the UK each year by seven large maltsters, and seven smaller maltsters. Domestic beer and whisky production accounts for almost 90% of the output from the Malting industry, the remainder is used in a wide range of foods and some is exported. The CO2 emissions associated with the Maltings sector are approximately 340,000 tonnes of CO2 per annum. Five sites were directly involved in the investigations carried out for this project. Collectively the participating sites represented about 28% of UK malt production. Process and energy data was collected from sub-metering installed at two sites. The methodology used in this study included: Site visits and discussions with host site personnel Gathering and analysing historical energy and process data from host sites Installation of energy sub-metering on two sites Collection and analysis of sub-meter data with process data Desk based research of potential energy efficiency opportunities and innovations A questionnaire to Maltsters on priorities, barriers, progress to date and their ideas A workshop to identify and address barriers to deployment of energy efficiency opportunities


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Energy use within the sector 1

The Maltings sector uses some 1,375 GWh of energy each year. This is dominated by the use of fuels for process heat, with annual fuel consumption being 1,176 GWh (86% of total). The majority of the heat demand is for the kilning process, with grain drying representing the second largest heat energy use. At least 78% of the heat demand in a kiln is thought to be associated with the evaporation of water, in order to dry the malt to its final moisture content (see section 4.1). Most kilns are fitted with glass tube heat exchangers to recover some of the vaporisation energy of water (latent heat) from the „air off‟ from the kiln, to preheat the ambient air coming into the kiln. During the pre-break phase of kilning, a heat exchanger is able to recover some 20% of the energy available in the „air off‟ stream (see section 4.2). The remaining 80% of energy is lost to atmosphere as saturated water vapour. Increasing the recovery of this energy is the key opportunity for the sector. The sector fuel consumption consists of the fossil fuels natural gas, gas oil, LPG, kerosene and coal. Replacement of some of these with biomass, such as woodchip, would reduce energy costs and carbon emissions. During kilning, warm dry air is blown from below through the kiln bed, inducing both a temperature and a moisture gradient across the depth of the bed. These gradients gradually reduce as the kilning cycle progresses, as the moisture evaporates and the malt increasingly heats up. The temperature and moisture gradient throughout the bed means that there is variation within the batch in terms of the length of time that the malt is held at a given temperature. This variation necessitates the need for blending post-kilning, to ensure finished product consistency. It also represents an opportunity to improve energy efficiency (see section 4.4). The standard current practice within the industry is to control the germination and kilning processes primarily on time, air temperatures and humidity. Whilst these control methodologies enable Maltsters to consistently produce high quality malt, energy efficiency could be increased by using direct measurement of temperature and moisture content of the malt bed itself. Direct process control could allow processes to be stopped sooner once the required parameters have been met, thereby shortening the cycle time. This would result in energy savings and potentially increased throughput (see section 4.3). Load to kiln moisture refers to the moisture content of the grain at the end of the germination process. It has a direct bearing on the amount of energy used in the kiln to evaporate the water and is therefore an important driver of variation in batch energy consumption. Tighter process control and the use of statistical management methods would help to drive continuous improvement in consistency and energy efficiency (see section 4.5). Whilst extensive production information is captured within the industry, there is typically little energy use information available at the unit process level to inform management decisions and measure performance improvement. Implementation of automated Monitoring and Targeting (aM&T) systems is becoming more common within the sector, but there is scope for further roll out (see Section 5.2.6).

Carbon Saving Opportunities Significant opportunities for increased energy efficiency exist in the Maltings sector. The main opportunities include increased energy recovery, increasing the final moisture content of the malt, implementation of Combined Heat and Power (CHP) systems as well as increased uptake of Automatic Monitoring and Targeting (AMT) systems. The opportunities have been categorised into innovative and good practice opportunities. It must be noted that the opportunities are not additive. This is due to some opportunities overlapping or being mutually exclusive.

1

Climate Change Agreement data


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Innovative opportunities Energy recovery from the kilning process can be improved in a variety of ways, and three alternative solutions have been outlined. The first, closed cycle heat pumps, can be used as a second stage of energy recovery after the glass tube heat exchanger. It is considered possible to retrofit these to existing kilns. Such a heat pump is considered able to recover an additional 43% of energy, for a total energy recovery of 64% in conjunction with the glass tube heat exchanger. This solution is outlined in section 5.1.1. The second solution for increased energy recovery, open cycle heat pumps, can potentially be adapted to suit the malting process. Open cycle heat pumps differ from closed cycle heat pumps in that they are able to use the water evaporated from the malt as the means to recover energy. A higher energy recovery factor can be achieved than is possible with closed cycle heat pumps. It is not considered viable to retrofit open cycle heat pumps to existing kilns, hence this solution is limited to new build kilns. Further details can be found in section 5.1.1. The third solution for increased energy recovery is to implement a dedicated energy efficient drying system to dry the malt before curing it in a traditional kiln. This solution is outlined in more detail in section 5.1.1. Another significant opportunity for Maltings sites operating hot water, steam or hot oil systems to heat their kilns is the burning of biomass instead of fossil fuels. With the addition of a suitable burner or boiler and associated fuel storage and handling equipment, those sites would benefit from the Renewable Heat Incentive (RHI) for every kWh of woodchip energy. This is discussed further in section 5.1.3. The implementation of kiln bed turning during the kilning process would reduce the humidity and temperature gradient across the depth of the malt bed. This may enable a shorter kilning cycle and hence reduce energy consumption. This is discussed further in section 5.1.5. A further opportunity to increase energy efficiency in the Maltings sector centres on the final moisture content of the finished malt, which is typically 4%. Kiln heat requirements would be reduced if the final moisture content could be increased to, for example to 6%. This opportunity requires negotiation and agreement with customers including Brewers and Distillers. Please refer to section 5.1.7 for further details on this and other supply chain collaboration opportunities. Where possible, outline business cases have been calculated for each the innovative opportunities. The level of confidence associated with these business cases is not currently sufficient for investment decisions to be based on them. Rather, the business cases are intended to highlight areas that Maltsters should pursue and investigate further. Table 1 below outlines the summary business cases for each of the innovative opportunities that we have been able to quantify. A number of these opportunities are likely to require R&D activity as well as a pilot project in order to develop sufficient confidence in their business cases to allow investment decisions to be taken. For further details, please refer to section 5.1.

Table 1 Summary of innovative opportunity business cases, sector level Opportunity

Heat pumps, closed cycle Heat pumps, open cycle Energy efficient drying Burning Maltings co-

Implementation costs (£)

Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable (%)

£24,750,000

£4,500,000

33,000

£750

6

100%

£75,000,000

£14,650,000

115,000

£640

5

100%

£142,500,000

£10,400,000

85,000

£1,675

14

100%

£13,000,000

-£27,000,000

40,000

£320

None

100%


Maltings Sector Guide

products Burning woodchips Direct T & RH measurement Kiln bed turning Process management Supply chain collaboration

4

£21,000,000

£4,200,000

38,000

£550

5

26%

£1,130,000

£580,000

4,700

£240

2

100%

£7,500,000

£1,300,000

10,750

£700

6

67%

£55,000

£200,000

1,750

32

<1

100%

£0

£5,250,000

43,000

£0

0

100%

Good practice opportunities Maltings sites have a typical heat to power ratio around 4.8 to 1. Heat to power ratios within this range are an indicator that the sector generally may be suited to the deployment of Combined Heat and Power (CHP) systems. CHP offers carbon emission reductions as well as energy costs reductions. It is understood that 2 Maltings sites currently have CHP installed. Please refer to section 5.2.2 for further details on this opportunity. Compressed air is used in the sector for valve actuation and similar applications. The compressors used are often relatively old and fitted with simple, decentralised control systems. The compressors typically vent their cooling air into the compressor room. There is scope for improvements and optimisation of compressed air systems within the sector. Our survey indicated that respondents believed that high efficiency motors and VSDs have been installed on around two thirds of suitable applications. The remaining one third of motors may still benefit from replacement with high efficiency motors and addition of VSDs. At the majority of UK Maltings sites the incoming voltage is expected to be higher than that required by the electrical equipment installed on site. There is scope within the sector to consider voltage reduction and optimisation.

Table 2 outlines the summary business cases for each of the good practice opportunities we have been able to quantify. For further details, please refer to section 5.2.

Table 2 Summary of good practice opportunity business cases, sector level Opportunity

CHP Heat recovery survey Compressed air High efficiency motors Monitoring & targeting Variable speed drives Voltage optimisation

Implementation costs (£)

Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

£11,700,000

£2,285,000

29,000

£405

5

Sites applicable (%) 48%

£5,000

£30,000

230

£22

<1

100%

£435,000

£145,000

1,250

£350

3

100%

£72,000

£100,000

940

£75

1

100%

£950,000

£1,650,000

15,300

£62

1

70%

£810,000

£250,000

2,350

£350

3

100%

£925,000

£250,000

2,350

£390

4

70%


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Overall Potential The total savings potential for the sector from the opportunities identified is difficult to quantify with confidence because a number of opportunities are mutually exclusive (i.e. implementing one may preclude another), and others target the same energy using equipment. Therefore the total savings available to the sector are less than the sum of the savings of individual measures. However the total savings potential avoiding duplication and interaction is thought to be in the order of 40%. This would be worth circa £16 million pa and reduce carbon emissions by 134,000 tonnes CO2 pa. It should be noted that a number of the innovative opportunities are likely to require R&D activity as well as a pilot project in order to develop sufficient confidence in their business cases to allow investment decisions to be taken. The following chart shows the relative attractiveness of the most significant innovative (green) and good practice (blue) opportunities. The majority of the savings can be achieved at a payback of 6 years or less.

CO2 Savings - Significant opportunities (>10,000 tonnes CO2) 18

16 85,000 Energy ef f icient drying

14

Payback (Years)

12 10 10,750 Kiln bed turning

8

33,000 Closed cycle heat pumps

6

38,000 Wood chip 4

115,000 Open cycle heat pumps

29,000 CHP 15,300 M&T

2

43,000 Supply chain 0 £0

£50,000,000

£100,000,000

£150,000,000

£200,000,000

Capital Costs Good practice opportunities

Innovative opportunities

The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Maltsters should pursue and investigate further.

Next steps In the current economic climate in the UK at time of writing (March 2011), it is unlikely that funding support will be available from the Carbon Trust for demonstration of projects. Hence Maltsters are encouraged to review the opportunities highlighted, quantify these for their own sites and progress those which are considered most beneficial. Maltsters are encouraged to consider collaboration with other MAGB members, their supply chains and equipment and knowledge providers.


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Table of contents 1

Introduction

8

2

Background to sector

9

2.1

What is manufactured

9

2.2

Process operations

10

2.3

Overall scale (production, energy and carbon)

14

2.4

Legislation impacts

16

2.5

Energy saving progress

17

2.6

Business drivers

20

2.7

Energy saving drivers

23

3

4

5

6

Methodology

25

3.1

Metering and data gathering

26

3.2

Engagement with the sector

27

3.3

Understanding drivers and barriers

27

Key Findings

29

4.1

Kilning energy consumption

29

4.2

Efficiency of glass tube heat exchangers on kilns

30

4.3

Process control

32

4.4

Kiln bed temperature and humidity profile

33

4.5

Variation in load to kiln moisture

34

4.6

High heat to power ratios

34

4.7

Co-products

36

4.8

Supply chain

36

Opportunities

39

5.1

Innovative opportunities

38

5.2

Good practice opportunities

55

Next steps

66

6.1

Significant opportunities

64

6.2

Significant innovative opportunities

65

6.3

Significant good practice opportunities

66

Appendices Appendix 1

Indicative metering locations

Appendix 2

Opportunities not quantified

Appendix 3

Workshop summary


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1 Introduction

This report presents the findings of the Investigation and Solution Identification Stage of the Industrial Energy Efficiency Accelerator (IEEA) for the Maltings sector. The aims of this stage were to investigate energy use within the Maltings sector-specific manufacturing processes and to provide key insights relating to opportunities for CO2 savings. Section 2 provides some background on the Maltings sector in terms of what is produced, the production process, the overall scale of the sector, including energy consumption and carbon emissions, a brief summary of some key energy legislation, and identifies some key business and energy saving drivers for the sector. Section 3 outlines the methodology that was used to investigate energy use within the sector and to help identify opportunities. Section 4 outlines our key findings and briefly discusses what they might mean in terms of opportunities for the sector. Section 5 outlines the specific opportunities identified in the sector, including outline business cases where it has been possible to quantify these. Section 6 describes our recommended next steps for the opportunities identified by this project.


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2 Background to sector

Around 1.5 million tonnes of malt is produced in the UK each year by seven large maltsters, and seven smaller maltsters. The sector is represented by the Maltstersâ&#x20AC;&#x; Association of Great Britain (MAGB) and has had a Climate Change Agreement (CCA) in place for the past ten years. The CCA currently covers 27 of the 30 or so sites in the sector. The CO2 emissions associated with the sectorâ&#x20AC;&#x;s activities are approximately 340,000 tonnes of CO2 per annum. Two Malting sites are part of Phase II of the EU Emissions Trading Scheme (EU ETS), and it is expected that four sites will be involved in Phase III of EU ETS from 2013.

2.1 What is manufactured Malt is made from malting grain cereals, usually barley. The Malting industry purchases nearly two million tonnes of barley annually, approximately one-third of the UK crop. Other large barley consumers are the animal feed industry (3 million tonnes p.a.) and export (1.5 million tonnes)2. The barley is processed into malt, which is the principal raw material for the production of beer and whisky. Domestic beer and whisky production account for approximately 80% of the output from the Malting industry, the remainder is used in a wide range of foods and some is exported. There are five main types of malt produced in the UK: White malts Peated malts Coloured malts (such as crystal and caramel malts) Roasted malts (range including both light and dark roasts) Roasted barley The main steps in the malting process are: Steeping - to raise the moisture content of the grain by soaking in water, such that the grain starts to germinate. Steeping typically lasts 2-3 days. Germination - controlled to achieve modification of the contents of each grain without allowing it to develop into a plant. Germination typically lasts 4-5 days.

2

www.ukagriculture.com


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Kilning - to carefully dry and stabilise the grain for extended storage without damaging the natural enzymes required by brewers and distillers. Kilning typically lasts around 24 hours.

2.2 Process operations Figure 1 shows a schematic diagram of the manufacturing process illustrating major energy consuming steps. The boundary of the IEEA investigation is shown as a red dashed line. Kilning is the dominant user of heat and electricity. Further discussion of energy consumption in the process is provided in Section 0.

Figure 1 Malt Manufacturing Process and IEEA investigation boundary

Raw Barley Intake

Waste Grain

Raw Barley Drying

Heat

Raw Barley Storage

Power

Screening and Weighing

Power

Water to air (evaporation) Grain to air (respiration)

Power

Steeping Grain to Waste Water

Water

Waste Water

Grain to air (respiration)

Germination

Power

Grain to air (evaporation)

Grain to air (respiration)

Heat

Kilning Grain to air (evaporation)

Waste Grain

Power

De-culming

Output to Brewing

Power


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Steeping Steeping is the first stage of the core malting process and takes 2-3 days in total. The moisture content of the barley is raised from around 12% to 43-46%. This is achieved by a series of immersions or "wet stands" followed by â&#x20AC;&#x153;dry standsâ&#x20AC;?. During the wet stands, air is blown through the wet grain, during the dry stands carbon dioxide is removed with extraction fans. At the end of steeping, the root (chit) begins to emerge from the grain, showing as a white dot. The hydrated grain exhibits an increase in grain respiration and demand for oxygen which signals the beginning of germination. There are two main designs of steeping vessel used in the UK; conical bottomed and flat bottomed. Our understanding from speaking with the Maltsters is that conical bottomed vessels are more effective for raising the moisture content of the grain, whereas the flat bottomed vessels are more efficient for CO2 extraction. Therefore, some maltings employ both vessel designs in series.

Germination Commonly, the steeped barley is moved to a custom germination vessel designed to control temperature and provide high flows of moist air to the active barley. During the 4-5 days of germination the barley is modified by the action of specific enzymes on grain structural components, giving it the characteristics required by brewers and distillers. The cell walls are broken down rendering the hard barley as easily crushable malt, allowing the starches to be released during the brewing and distilling processes.

Figure 2 Two common types of germination vessel (a) Circular Saladin and (b) Saladin Box

In the germination vessel the grain is turned every 12 hours or so to prevent rootlets of the developing plant becoming entangled and maintain a loosely packed grain bed. The germination conditions, such as humidity, temperature, air flow and time can be manipulated in order to vary the final characteristics of malt. Figure 2 above shows two common types of germination vessel used in the UK. There are a number of different designs of germination vessel including: Circular Saladins â&#x20AC;&#x201C; a circular vessel fitted with turners attached to an arm that rotates around the vessel Saladin Boxes - horizontal boxes fitted with turners that automatically travel backwards and forwards along the length of the box. An older method of germination, still used at some plants


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Boby Drums – a „gentle‟ method of producing good quality malt, typically used for small production runs. These consist of large horizontal drums which are rotated slowly. The malt is contained within the drums and as a result of the rotary motion of the drum it is kept in continuous motion. Combined Germination and Kilning Vessels (GKVs) – in which the germination and kilning occur in the same vessel i.e. on completion of germination the humidified air is stopped and replaced with heated air from the kiln burners. With the exception of GKVs, the germinated barley, known as „green malt‟, is then transferred from the germinating vessels to the kiln.

Kilning In order to halt germination in advance of significant nutrient losses, the germinated barley (green malt) is dried in a kiln. Great care is taken to minimise enzyme damage as the compounds created at early stages of germination are those needed by brewers. The malt is stabilised by reducing the moisture content to 3-6.5 % over a period of about 24 hours. The kilning process imparts flavour and colour into the malt, and the low moisture content allows safe storage. The final malt superficially resembles the original barley in outward appearance, but is physically and bio-chemically much changed.

There are three main phases to the kilning process: Forced drying‟ phase lasting three to four hours, where moisture is driven from the interior of the grain by Prebreak drying phase lasting approximately twelve hours, where large volumes of air at around 60oC are passed upward through the bed. During the pre-break phase, moisture is driven off from the surface of the grain. The air coming off the bed is at 25-30oC and has a relative humidity of nearly 100%. At many sites, the warm, saturated air is passed through a set of heat exchangers and the heat used to pre-warm the incoming air. Post-break increasing the temperature and decreasing flow of air through the bed. At many sites, the unsaturated air coming off the bed during the post-break phase is re-circulated through the bed. Curing phase lasting two to three hours, where the temperature is increased to 70, 80 or 90oC to impart colour into the malt. During the curing phase the fan speed is reduced and the re-circulation of air is increased.


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Figure 3 Malt kiln

A number of kiln designs are in use in the UK. Approximately one third of the industry uses combined GKVs (described above), the other two thirds use dedicated kilns. Twin kilns which operate in a lead-lag configuration are thought to be more energy efficient than single kilns because they allow unsaturated air from the lead kiln in the post-break phase to be used in the lag kiln that is in the pre-break phase.


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2.3 Overall scale (production, energy and carbon) Table 3 provides a summary of the energy consumption of sites within the in the Malting sector Climate Change Agreement (CCA) for the period 2008/09. During this period, the sector produced around 1.5 million tonnes of malt, with associated emissions of 340,000 tonnes of carbon dioxide.

Table 3 Energy consumption within the Malting sector, 2008/09 Electricity (GWh) Mean site use Total

Fuel Oil (GWh)

Coal (GWh)

LPG (GWh)

Kerosene (GWh)

Gas & Diesel Oil (GWh)

Total (GWh)

7

Natural Gas (GWh) 38

5

0

0

1

1

52

196

998

128

2

0

27

23

1,376

Figure 4 shows that fuel use accounts for about 68% and electricity for about 32% of the sectorâ&#x20AC;&#x;s CO2 emissions. Therefore it is appropriate that fuel use should be the main target of the investigations for this project, but also that electricity should not be ignored.

Figure 4 Contribution of electricity and fossil fuels to total energy consumption and CO2 emissions in the Malting sector 100%

90%

80%

70% Gas Oil/ Diesel Oil

60%

Kerosene LPG used

50%

Coal Fuel Oil

40%

Natural Gas Electricity

30%

20%

10%

0% Energy

Emissions


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Figure 5 shows that there is a strong relationship between output and energy consumption, indicating that energy use is closely aligned with production.

Total Energy Consumption (GWh/yr)

Figure 5 Scatter plot showing the relationship between energy use and output across the sector, 2008/09 160

140 120 100

80 60 40

20 0

0

50,000

100,000

150,000

200,000

Throughput (te/yr)

The weighted average Specific Energy Consumption (SEC) was 961 kWh/tonne. Figure 6 (a) and (b) show that there is a relatively large range of SEC (642 kWh/tonne) between sites. Differences in SEC between sites are influenced by a number of factors including:

Economies of scale i.e. larger sites being able to process larger batches and sites operating close to capacity making better utilisation of plant Differences in core process equipment e.g. separate germination and kilning vessels vs. GKVs, Boby drums vs. Saladin box etc. Efficiency of energy consuming equipment (boilers, motors etc.) Energy management on sites Age of plant Differences in product specification Differences in raw barley Figure 6 Histogram of SEC for 27 Malting Plants (b) Scatter plot showing SEC vs. Throughput 7

(a)

(b)

5

SEC (kWh/te)

Number of sites

6

4 3 2 1 0

1,600 1,400 1,200 1,000 800 600 400 200 0 0

SEC (kWh/te)

50,000

100,000

150,000

Throughput (te/yr)

200,000


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A key point from Figure 6(b) is that there is a wide spread of SEC for smaller scale plants – those with through put of less than 50,000 tonnes pa. If the worst performers were able to match the best, energy use would fall from over 1,200 kWh/tonne to around 800 kWh/tonne. This suggests a significant opportunity from good practice measures.

2.4 Legislation impacts 2.4.1 Climate Change Agreement The sector has had a Climate Change Agreement (CCA) in place for ten years. The Sector CCA currently covers 27 of the 30 or so sites in the sector. Over the period that the sector has had the CCA in place, specific energy consumption (SEC) has reduced by around 10%. Although there are other drivers of energy efficiency (discussed further in Section 2.7), the CCA has had a significant influence on the sector.

2.4.2

EU Emissions Trading Scheme

Two Malting sites are part of Phase II of the EU Emissions Trading Scheme (ETS), and it is expected that four sites will be involved in Phase III of EU ETS from 2013. The combination of the CCA and the EU ETS will be key drivers in pushing forward the uptake of energy efficiency measures within the sector. There is some concern amongst European maltsters (and other sectors) that European greenhouse gas emission reduction targets increase the risk of „carbon leakage‟ from the EU. In a globalised industry, multinational companies can move production to less expensive or less restrictive regions.

2.4.3

CRC Energy Efficiency Scheme

The majority of sites within the sector are covered by either the CCA or EU ETS. Therefore the CRC Energy Efficiency Scheme is not considered to be of major importance to the Maltings sector.

2.4.4

Renewable Heat Incentive

The Renewable Heat Incentive (RHI) is intended to provide long term support for renewable heat technologies such as industrial wood pellet boilers. The scheme will make payments to those installing renewable heat technologies that qualify for support, year on year, for a fixed period of time. It is designed provide an attractive 12% rate of return on the difference in cost between conventional fossil fuel heating and renewable heating systems (which are currently more expensive). The government is currently carrying out work to determine support levels and is expected to be in a position to announce the details of the scheme, including RHI tariffs and technologies supported, shortly. It is expected that the scheme will go ahead after July 2011. The most attractive investments will be found in industry sectors with high, year round heat use, as found in Malting sites. Furthermore, the availability of suitable biomass waste streams and co-products from the malting process, close links with the agricultural sector and the location of maltings in rural areas with good transport links are all factors that may make biomass energy an attractive option for some maltsters.


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2.5 Energy saving progress Figure 7 shows the primary energy use per tonne of malt produced by sites within the sector CCA over the period 2001-2009. The figure highlights the improvement in energy efficiency the sector has achieved over this time. Sector energy efficiency was 1,250 kWh/tonne in 2001, which has improved to 1,181 kWh/tonne in 2009. This represents an improvement in energy efficiency of 5.5%.

Figure 7 Maltings Sector energy efficiency history (primary energy)

As part of the investigations carried out for this project, a questionnaire was completed by 11 respondents from six companies, representing a total of 20 sites. The questionnaire gave a list of „standard‟ energy efficiency measures and asked the respondent to estimate how far their company has implemented them to date. The respondents who completed the survey are responsible for malting plants that account for roughly 75% of the sector‟s output and energy consumption. Therefore we can have a reasonable level of confidence in extrapolating the responses for the sector as a whole. Figure 8 to 11 show the upper and lower estimates provided by energy managers for the current level of implementation of a range of „standard‟ energy efficiency measures. For example, it was estimated that for automated Metering and Targeting, between 20 and 40% of the sector potential has been implemented. Our experience of visiting malting sites would suggest that this is an overestimate .


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Figure 8 Current degree of implementation of ‘standard’ energy management measures in the UK Malting Industry (questionnaire results) Proactive boiler maintenance and servicing Formal energy strategy and policy

Implementation of energy strategy and policy Boiler Plant Metering and Targeting Motor management policy Air leak detection Automated Monitoring and Targeting 0%

20%

40%

60%

80%

100%

Proportion of sector potential

Figure 9 Current degree of implementation of ‘standard’ heat energy efficiency measures in UK Malting Industry (questionnaire results) Insulation of hot water, oil and air ducts Heat recovery from kiln air High efficiency boilers (net thermal efficiency…

PLC combustion control and O2 trim on burners Condensate return heat recovery systems Heat recovery from boiler flue gasses Automatic steam controls Boiler sequencing and pressure optimisation

Ground Source Heat Pump to preheat cold…

0%

20%

40%

60%

80%

Proportion of sector potential

100%


Maltings Sector Guide

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Figure 10 Current degree of implementation of â&#x20AC;&#x2DC;standardâ&#x20AC;&#x2122; electrical energy efficiency measures in UK Malting Industry (questionnaire results)

Electrical power factor correction Variable Speed Drives High efficiency electric motors (EFF1) High efficiency lighting units

Lighting controls e.g. presence detection 0%

20%

40%

60%

80%

100%

Proportion of sector potential implemented

Figure 11 Current degree of implementation of two simple behaviour change measures in UK Malting Industry (questionnaire results)

Energy training for key staff Energy awareness raising campaign for all staff

0%

20%

40%

60%

80%

100%

Proportion of sector potential implemented

The survey results presented in the figures above indicate that although progress has been made and many of the standard energy management measures have been implemented to an extent, there remains significant scope for further adoption of these measures. Figure 12 shows the remaining potential for each of the measures outlined above. The potential has been taken to be the difference between the midpoint of the survey results for each measure and 100% implementation.


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Figure 12 Remaining potential for ‘standard’ practice energy efficiency measures in UK Malting Industry (questionnaire results) Electrical power factor correction Heat recovery from kiln air Proactive boiler maintenance and servicing

Insulation of hot water, oil and air ducts Formal energy strategy and policy Implementation of energy strategy and policy Boiler Plant Metering and Targeting Energy training for key staff

Variable Speed Drives High efficiency boilers (net thermal… Control of germination based on direct… High efficiency electric motors (EFF1) Motor management policy

PLC combustion control and O2 trim on… Control of kilning cycle based on direct… Energy awareness raising campaign for all… Condensate return heat recovery systems Air leak detection

Heat recovery from boiler flue gasses High efficiency lighting units Lighting controls e.g. presence detection Boiler sequencing and pressure optimisation

Automated Monitoring and Targeting Automatic steam controls Renewable energy Turning kiln bed during kilning cycle Combined Heat and Power generation

Ground Source Heat Pump to preheat cold… 0%

20%

40%

60%

80%

100%

Proportion of sector potential remaining

2.6 Business drivers When considering making a capital investment, malting companies go through a process of prioritisation and building an internal business case. The details of this process vary from one company to another, as do the required criteria for investment (payback period, IRR, NPV, etc.). The required payback period for an investment can vary from 2 to 10 years depending on the type and size of the investment, as well as other influencing factors such as complying with customer demands.


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As with all businesses, there are a number of key drivers influencing decisions made. In the questionnaire we asked maltsters to rate the importance to their companiesâ&#x20AC;&#x; decision making of a range of potential drivers. Figure 13 below summarises the survey results for the perceptions of drivers for decision making in malting companies.

Figure 13 Perceptions of drivers for decision making in malting companies (questionnaire results)

Energy Efficiency Production Costs Food safety Customer Satisfaction Energy Security Brand Image Water Security Corporate and Social Responsibility Sustainability 0%

20%

40%

60%

80%

100%

Proportion of respondents

Important

Neutral

Not Important

The survey results shown in Figure 13 indicate that while all of the drivers identified were considered to be important by the majority of respondents, food safety, production cost and energy efficiency ranked highest in terms of their importance to company decision making. Customer satisfaction was identified as being important by 90% of respondents. Figure 14 shows that malt consumption in the UK is driven mainly by brewers and distillers. On a global scale, the customer base for malt is highly consolidated with ten brewing companies accounting for over 70% of world beer production. Brewers and distillers are perceived by maltsters to be in a relatively powerful position. In many cases, the customer specifies not only the final malt characteristics, but also many of the processing parameters, which places some restrictions on their ability to make changes. Examples include specifications on the number and length of wet and dry stands in steeping, maximum bed temperatures and process time in germination and time and temperature profiles for the kilning process.


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Figure 14 Uses of UK Malt in 2008

3

Other food and drink 3%

Export 9%

Distillers 48% Brewers 40%

The involvement of the customer in the malting process points to the importance of collaborative working to achieve significant carbon savings. This is especially true where customers have carbon saving targets of their own. For example, the Scotch Whisky Association (SWA) has committed to a 20% switch to non-fossil energy by 2020 and a target of 80% by 2050. Although the details of how the maltings industry will work with the whisky industry towards this aim are not yet clear, the SWA has expressed a willingness to work with its suppliers (including maltsters) to agree partnership targets and other opportunities for environmental improvement to minimise the total environmental impact of the Scotch Whisky industry. Our survey indicated that issues such as brand image, corporate and social responsibility, and sustainability were considered to be important to company decision making, though to a lesser extent than those discussed so above. All of the companies surveyed had energy efficiency targets, and 80% or respondents said their companies had greenhouse gas emission reduction targets, as shown in Figure 15. Figure 15 Internal monitoring and targeting of energy and carbon (questionnaire results) Does your company monitor energy use? Does your company have energy efficiency targets? Does your company monitor greenhouse gas (GHG) emissions? Does your company have GHG emission reduction targets?

0%

20%

40%

60%

80%

Proportion of respondents Yes

3

Source MAGB

No

Don't know

100%


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Public reporting of energy and carbon was less widespread than internal monitoring and targeting. 40% or respondents said that their company publicly reported energy efficiency and emission reduction targets, but only 30% of respondents said that their company publicly reported its energy use and GHG emissions (Figure 16). Figure 16 Public reporting of energy and carbon (questionnaire results)

Does your company publicly report energy use? Does your company publish energy efficiency targets? Does your company publicly report greenhouse gas (GHG) emissions? Does your company publish GHG emission reduction targets? 0%

20%

40%

60%

80%

100%

Proportion of respondents Yes

No

Don't know

2.7 Energy saving drivers There are a number of factors driving moves towards energy efficiency in the sector. In the questionnaire we asked maltsters to identify the drivers for their energy and carbon reduction activities to date. The results are summarised in Figure 17. . Figure 17 Perception of drivers for energy and carbon reduction activities (questionnaire results) Energy Cost 100% 80% Other

60%

Regulation

40% 20% 0%

Investor Driven

Customer Pressure

Internally Driven


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Energy costs represent the second largest cost to the Maltsters after barley costs and hence are a strong financial driver. Energy typically represents between 6% and 15% of the price of a tonne of malt. Average energy costs of £25 to £29/tonne of malt have been quoted, though these can vary significantly based on malt type and fuel type. Barley purchase costs have ranged from £90/tonne of barley to over £200/tonne recently. Malt selling prices can vary significantly, and have ranged from less than £200/tonne of malt to over £400/tonne over the last few years. The survey results shown in Figure 17 indicate that energy costs are the strongest driver for energy saving activities, followed by regulation (see section 2.4), and internal company policy. Customer pressure and investors were seen as drivers only by a minority of respondents. During the sector workshop, participants were asked to look in more detail at the drivers for energy efficiency within their organisations. A long list of drivers was identified, which were grouped into 5 categories (Policy, Finance, Business, People and Other). This exercise helped to build on the insight gained from the questionnaire and provide a more detailed understanding of the specific drivers of energy efficiency in the Maltings sector. For example, although relatively few respondents to the questionnaire identified customer pressure as a significant driver of carbon reduction activities, attendees of the workshop actually identify a number of examples, such as customer carbon footprinting programmes, where the sustainability actions of brewers and distillers are either currently, or are likely to, have consequences for Maltsters. A summary of the information captured from the workshop, including the list of drivers for energy efficiency identified, is given in Appendix 5.


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3 Methodology

The aim of this project was to investigate sector specific manufacturing processes in order to build a detailed picture of process energy use and identify practical, cost-effective carbon saving opportunities.

Five Malting sites were visited during Stage 1 of the Maltings IEEA. The aim of the site selection process was to establish a sample of sites with a range of representative production levels, location, equipment and age. Table 4 gives some headline information on the host sites.

Table 4 Headline information for the Stage 1 site visits No.

Company

Site

Products

Fuel

1

Diageo

Burghead Maltings

Distiller Maltster

Fuel Oil, Gas Oil and waste heat from distillery

2

Boortmalt

Buckie

Sales Maltster - principally supplying distilleries

Natural Gas

3

Muntons

Stowmarket

Sales Maltster - principally supplying brewers

Natural Gas and Gas Oil

4

Bairds Malt

Witham

Sales Maltster - principally supplying brewers

Natural Gas

5

Crisp Malting

Great Ryburgh

Sales Maltster - principally supplying brewers

Natural Gas and Gas Oil

Collectively the participating sites represented about 28% of UK production. Our methodology was based on the following key elements: Project kick off meeting A teleconference was held with the Maltsters Association of Great Britain (MAGB) in May 2010 to reiterate the aims of the project and outline our plans, what they could expect from us and what we required from them in return. Initial information gathering phase o

An intensive period of site visits, desk based research and consultation with the MAGB to gain a thorough appreciation of the sector and define the programme of work for the rest of the project.


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26

A sector appreciation report was written and feedback sought from the MAGB and host sites to verify that our understanding of the sector was correct, our ideas were sensible and the proposed scope of work for the main data gathering and analysis stage was feasible.

Main data gathering and analysis phase o

Site visits and discussions with host site personnel

o

Gathering and analysing historical energy and process data from host sites

o

Installation of energy sub-metering on two sites:

o

Collection and analysis of sub-meter data with process data

o

Desk based research potential energy efficiency opportunities

o

Desk based research of innovative opportunities in other sectors that may be transferable to the Maltings sector

o

A questionnaire to maltsters on priorities, barriers, progress to date and their ideas

o

A workshops to identify and address barriers to deployment of energy efficiency opportunities

While we have endeavoured to work with a representative sample of sites from the sector, we have not visited or monitored any sites producing <44,000 te/year. There are 16 sites in the UK with an output of less than <44,000 te/year. These sites account for around 30% of the sectors production and energy use. Analysis of the CCA data for the sector indicates that there is no significant difference in SEC between sites with an output <44,000 te/year and larger sites. Also, many of the sites with an output of 20,000 to 40,000 are owned by companies that also have larger sites. However there are a number independent companies with sites producing <20,000 te/year that have not been directly involved in this project. It is likely that there are some operational differences between small sites and larger sites. It is also likely that independently owned companies will face some different challenges when considering investment in energy efficiency. Therefore, while we believe that the findings of this project are relevant to the whole sector, it is accepted that they are based on working with multi-site companies and sites producing >40,000 te/year.

3.1 Metering and data gathering Data from a number of data sources have been used in this study to help build a picture of process energy use and quantify opportunities: Climate Change Agreement (CCA) data showing total fuel and electricity for each site within the sector Umbrella Agreement data for the period 2009/10 was used to gain a sector level overview of production and energy use. Historic energy and process data from the host sites Sub-metered energy and process data from two sites, covering: o

Electricity to grain intake fans

o

Natural gas to grain drying

o

Electricity to steeping fans

o

Electricity to germination fans

o

Kiln temperature (air flow and bed)


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Kiln moisture (air flow and bed)

o

Electricity to kiln fans

o

Gas to kilns

o

Kiln temperature

o

Ambient temperature

o

Ambient humidity

27

A Schematic diagram of the malting process showing indicative metering locations is given in Appendix 1. Our monitoring strategy had two main aims: To assist with the identification and confirmation and quantification of opportunities To provide insight into the energy flows through the Maltings process The metering installed was considered to be the minimum required to meet these two aims and protect the anonymity of the host sites. All metering provided as part of this project is considered temporary, and will be removed at the end of the project where it is cost effective to do so.

3.2 Engagement with the sector The Maltstersâ&#x20AC;&#x; Association of Great Britain (MAGB) were key to engaging with the sector - we are grateful to them for facilitating initial contact with host sites, distributing communications and the questionnaire and providing insight, guidance and feedback throughout the project.

Our strategy for engaging with the sector included the following key elements: Visits to host sites Telephone and email communication with the host sites A questionnaire distributed to the wider sector via the MAGB Communications to the wider sector distributed by the MAGB including the Initial Sector Report, invitation the workshop and a summary of the workshop outputs A workshop - held at a maltings site and attended by maltsters, equipment suppliers and research organisations. A summary of the information captured from the workshop is given in Appendix 5.

Throughout the project we fostered close working relationships with key contacts from the host sites. These relationships were important because the requirements made on the host sites, both in terms of time and making potentially sensitive data available for our analysis, were significant.

3.3 Understanding drivers and barriers In addition to our meetings and discussions with the host sites and the MAGB, a survey was conducted and a workshop held to help us engage with the wider sector and understand key drivers and barriers to the deployment of energy efficiency opportunities.


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We received 11 completed questionnaires from 6 companies. These six companies represent approximately 75% of the sectorâ&#x20AC;&#x;s output and energy consumption. The workshop was attended by representatives from six maltsters as well as research organisations, equipment suppliers, the MAGB, the British Beer and Pub Association (BBPA). The format of the day was designed to very interactive, utilising facilitated group exercises to make the most of the breadth and depth of knowledge and experience in the room. A summary of the information captured from the workshop is given in Appendix 5.


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4 Key findings

4.1 Kilning energy consumption Kilning is the largest energy consumer at a Maltings plant. From an energy consumption perspective, the two major processes which occur during a kilning cycle are evaporation of water and curing of the malt.

The graph below shows the natural gas consumption over the course of a single kilning cycle, and illustrates the drying and curing phases. The data was obtained from a gas meter installed at a kiln at one of the IEEA host sites as part of the evidence collection for this project.

Figure 18 Kiln heat energy demand

Whilst it is too simplistic to say that no further drying occurs in the curing phase (post break), it is thought that the majority of water has been evaporated during the drying phase as indicated in the above graph. The blue area represents 78% of the heat energy used in this particular kilning cycle. The red area, associated with curing, represents 22% of heat energy input.


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It is thought that the general point applies to all kilns, in that the majority of heat energy used in kilning is associated with evaporation of water. Therefore, much of investigation work of this IEEA project has focussed on improving the efficiency of the drying phase or providing the energy in a less carbon intensive way.

4.2 Efficiency of glass tube heat exchangers on kilns Most kilns in the Maltings sector are fitted with glass tube heat exchangers, which recover some of the vaporisation energy of water (latent heat) from the „air off‟ from the kiln, to preheat the ambient air coming into the kiln. The heat exchangers are used throughout the kiln cycle.

The figure below illustrates typical energy flows through a glass tube heat exchanger during the pre-break phase of kilning, for an indirect fired kiln. All air pressures are assumed to be 1 bar. Apparent summation errors are due to rounding.

Figure 19 Typical average energy flows in a glass tube heat exchanger during pre-break kilning

Ambient air has an annual average temperature of approximately 10°C in the UK. At a relative humidity of 50%, the enthalpy (or energy content) of the moist ambient air flow into the glass tube heat exchanger is 19.8 kJ/kg dry air4. During the pre-break phase the „air off‟ from the kiln has a temperature of 30°C and a relative humidity of 94% or more. The enthalpy of this air stream is 96.5 kJ/kg dry air. Figure 20 below illustrates the low temperature and high moisture content of the air off stream during the initial stages of kilning.

4

www.psychrometric-calculator.com/HumidAirWeb.aspx


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Figure 20 Air off temperature and relative humidity during initial stage of a kilning cycle

As the „air off‟ from the kiln cools down, the ambient „air in‟ heats up, up to the inlet temperature of the „air off‟ stream (i.e. 30°C). The ambient air gains 20.3 kJ/kg dry air as it heats up, giving it a heat exchanger exit enthalpy of 40.0 kJ/kg dry air and a relative humidity of 14.5%. The „air off‟ stream from the kiln cools down as it exchanges heat with the ambient air flow. The reduction in enthalpy of 20.3 kJ/kg dry air means its heat exchanger exit enthalpy is 76.3 kJ/kg dry air, at a relative humidity of 100%. This is evidenced by the condensation of water within the glass tube heat exchanger. From these numbers it can be seen that during the pre-break phase of kilning the heat exchanger is able to recover 21% (20.3 / 96.5) of the energy available in the „air off‟ stream. The remaining 79% (76.3 / 96.5) of energy is exhausted to atmosphere as saturated water vapour at a temperature of approximately 25°C. The amount of energy which the glass tube heat exchanger can recover to the ambient air intake is limited by the temperature differential between the air off and ambient intake. This illustration is based on a heat exchanger efficiency of 100%. It is understood glass tube heat exchanger efficiency is likely to be in the region of 80%, which would mean that the amount of energy recovered to the inlet air is lower in reality than in the illustration. This in turn would indicate that the overall opportunity for increased heat recovery is larger than in the illustration. Using the above numbers, and assuming batch moisture contents of 43% (as indicated in Figure 32) at start of kilning and 16% at break point, the enthalpy of the „air off‟ to atmosphere stream of 76.3 kJ/kg dry air is equivalent to 526 kWh/tonne of finished product. It must be noted that it is unlikely that the energy available can be fully recovered.


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Section 5.1.1 outlines two potential solutions for this opportunity. In addition, further energy may be recoverable from the germination exhaust air which has similar properties to kiln exhaust air (i.e. low temperature and high relative humidity). For further information, please refer to the European Brewing Convention Manual of Good Practice â&#x20AC;&#x201C; Malting Technology, pp 58-67 .

4.3 Process control The current practice within the industry is to control the germination and kilning processes primarily on time, air temperatures and humidity. Some examples of manual moisture content sampling and measurement were also observed. These variables are used to kiln fans and gas input to the kiln burners, which heat the kiln air in via a heat exchanger. Whilst these control methodologies enable Maltsters to consistently produce high quality malt, energy efficiency could be increased by using direct measurement of humidity and moisture content of the malt bed in both germination and kilning. As direct measurement is more responsive and more precise, it enables faster response to changing conditions. However it may potentially be less representative of the average bed conditions as it represents a point measurement. The graph below shows results from an experimental sensor measuring the relative humidity of the kiln bed directly. In the experimental set-up the probe measured a single location at the top of the kiln bed. The graph below shows a single kiln cycle.

Figure 21 Graph of burner energy demand, air off and kiln bed moisture content during kilning cycle


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The blue line, kiln burner gas consumption (kW) gives insight into the kilning cycle. The existing relative humidity reading (red line) is taken from a probe located in the air-off air flow. It appears to be reading a continuously high relative humidity, which may indicate humid ambient conditions. The green line shows the readings from the experimental probe (Hydronix) which shows the relative humidity or moisture content of the top of the kiln bed. It can be seen that the probe detects the moisture in the malt from approximately 12:30 onwards. After an initial dip, the moisture reading settles down on a progressively flattening downward curve, until the break point. It is this downward curve that would allow for more accurate process control than the air-off relative humidity sensor alone. It must be noted that the Hydronix probe used in this measurement was not optimised for the measurement of Malt, both in terms of its calibration and in terms of its measurement location. If these were to be optimised, the readings should provide a more robust insight into the moisture (and temperature) profile throughout the full kilning cycle than the existing probe. It could then be used to control the kiln burner, air fans and recirculation systems automatically. This would allow for optimisation in terms of break point detection and final moisture content control. As the blue line shows the firing rate of the gas burner can change rapidly over a short period of time. This suggests that some forms of alternative heat supply may be difficult to retrofit â&#x20AC;&#x201C; as the response time to changes in heat demand may be too slow. An example of this would be solid wood chip, biomass â&#x20AC;&#x201C; where the fuel on the grate will limit the response time. Some forms of biomass burners, such as dust burners may offer the responsiveness required.

4.4 Kiln bed temperature and humidity profile Malt in transferred into the kiln from germination once the appropriate criteria have been met. At transference the malt has a temperature of approximately 30°C and a moisture content of 43%. During kilning, warm dry air is blown from below through the kiln bed, inducing both a temperature and a moisture gradient across the depth of the bed. The bottom of the bed is both warmer and drier than the top of the bed. The gradients gradually reduce as the kilning cycle progresses, as the moisture evaporates and the malt increasingly heats up. The graph below shows the temperature gradient for an individual batch over the kilning cycle. It can be assumed that the moisture gradient has a similar but inverse shape.

Figure 22 Time and temperature profile for a kiln batch

Note: Units have been omitted for confidentiality purposes. The three dips are artefacts of the measurement process.


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It is clear from the temperature gradient that there is variation within the batch in terms of the length of time that the malt is held at a given temperature. The bottom layer is exposed to a different temperature profile than the top of the bed. It is therefore likely that the moisture content is also different, and product quality may also differ between top and bottom. This inconsistency necessitates the need for blending post-kilning, to ensure finished product consistency. It also represents an opportunity to improve energy efficiency, if the gradients could be reduced. It is considered likely that the temperature and moisture gradients are more pronounced in kilns with deeper beds. In other words, it is thought likely that kilns with deeper beds are more prone to moisture and temperature variations within the batch, however further monitoring of a variety of kilns would be required to confirm this.

4.5 Variation in load to kiln moisture Load to kiln moisture refers to the moisture content of the grain at the end of the germination process. It has a direct bearing on the amount of energy used in the kiln to evaporate the water and is therefore one of the most important drivers of variation in batch energy consumption. The figure below shows the moving range (the difference between one batch and the previous batch) for load to kiln moisture content for a series of 45 consecutive batches. The graph is used for illustrative purposes and there may be other reasons, such as product specifications, for differences in load to kiln moisture

Figure 23 Moving range for load to kiln moisture content for a series of 45 consecutive batches

The figure above highlights two periods of exception: A run of 8 consecutive batches with less than average variation in moisture content. A single batch with significantly higher moisture content than the average.

The use of statistical methods to manage important input and process variables would help to identify such exceptional occurrences so that the causes can be identified and the appropriate action taken in order to drive continuous improvement in consistency of performance. This is discussed further in Section 5.1.6.

4.6 High heat to power ratios Figure 24 below shows the distribution of the heat to power ratios for UK Malting sites. The average of those shown is around 4.8:1. Typically heat to power ratios within these ranges are an indicator that the sector generally may be suited to CHP, either conventional or biomass based.


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Figure 24 Frequency distribution of heat to power ratios for sites in the sector CCA (08/09)

Figure 25 shows daily electricity and gas consumption for three â&#x20AC;&#x17E;typicalâ&#x20AC;&#x; Maltings sites. It can be seen in all three cases that gas consumption varied significantly from day to day, whereas electricity consumption showed much less daily variability. The daily variations in gas consumption are predominantly due to the timings of kilning cycles.

Daily energy consumption (kWh)

Daily energy consumption (kWh)

Figure 25 Daily electricity and gas consumption over 1 year for three Maltings sites

Time Natural gas

Electricity

Natural gas

Daily energy consumption (kWh)

Electricity

Time

Time Electricity

Natural gas

Figure 26 shows heat load duration curves for the same three Maltings sites. In each case the heat that could be provided by a CHP plant sized to meet 100% of the site electricity demand has been shown. The heat load duration curves are based on average hourly consumption derived from daily gas consumption data over a period


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36

of 1 year, and therefore does not account for variations in heat load over time periods of less than 24 hours. Sizing the CHP plant to meet site electricity demand gives a fairly conservative estimate of the potential CHP opportunity for similar sites. The estimated payback periods for the three sites shown in Figure 16 are in the region of 5 years.

14,000

6,000

12,000

5,000

10,000

Heat load (kW)

Heat load (kW)

Figure 26 Heat load duration curves for three Maltings sites showing heat that could be provided by a CHP sized to meet 100% of electricity demand

8,000

6,000 4,000 2,000

4,000 3,000

2,000 1,000

CHP Heat

0

CHP Heat

0 0

2000

4000

6000

8000

Hours

0

2000

4000

6000

8000

Hours

7,000

Heat load (kW)

6,000 5,000

4,000 3,000 2,000

1,000

CHP Heat

0 0

2000

4000

6000

8000

Hours

4.7 Co-products The Maltings sector generates an estimated 195,000 tonnes p.a. of organic co-products such as waste grain and culms (rootlets). These co-products are collected and sold to animal feed manufacturers as a valuable feedstock. The co-products could, alternatively, be used as an energy source. Currently, the price received for co-products as animal feed is greater than their value as an energy source. This is discussed further in Section 5.1.2.

4.8 Supply chain The Maltings sector is part of a supply chain which includes farmers, brewers, distillers, food manufacturers and end customers. There are a number of opportunities, such as providing finished malt at higher moisture content, which would require customer acceptance, and hence require some level of collaboration with customers. Other opportunities, such as anaerobic digestion, are unlikely to be viable for Maltsters to pursue in isolation, but could be attractive if pursued in partnership with other links in the supply chain.


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5 Opportunities

This section outlines the opportunities identified in the sector, including outline business cases where it has been possible to quantify these. All business cases are presented on both a sector and an average site basis. The business cases have been constructed based on information from energy meters installed during the IEEA project, from process data made available by IEEA host companies, analysis of responses to the questionnaire, publicly available information and AEAâ&#x20AC;&#x;s internal expertise. References to publicly available information have been provided where possible. Table 5 below outlines the assumptions made during the calculation of the business cases. Table 5 Business case assumptions Assumption Sector annual heat energy consumption Sector annual electricity consumption Average weighted fuel price Average natural gas price Average electricity price Electricity CO2 emission factor Natural Gas CO2 emission factor Number of sites in sector Number of kilns in sector

Value 1,176,854,289 kWh p.a. 196,264,539 kWh p.a. 2.39 p/kWh 2 p/kWh 6 p/kWh 0.545 kgCO2/kWh 0.185 kgCO2/kWh 27 45

The opportunities have been grouped into two broad categories: Innovative opportunities â&#x20AC;&#x201C; those opportunities that are considered to be within the IEEA project brief i.e. they are innovative and specific to the Maltings process Good practice opportunities â&#x20AC;&#x201C; those opportunities that represent established good practice or established technology. These opportunities fall outside the project brief for the IEEA i.e. they are not innovative and specific to the Maltings process. In general, these opportunities have been partly implemented by the sector. The cost and saving numbers in the business cases have been rounded, to reflect their indicative nature. It is also important to note that several of the opportunities listed are mutually exclusive, and others target the same energy using equipment. The total savings available to the sector are therefore less than the sum of the savings of individual measures. The sector emissions were 336,345 tonnes CO2 in 2008/09.


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5.1 Innovative opportunities This section outlines the opportunities which are considered to be within the IEEA project brief i.e. they are innovative and specific to the Maltings process. As these opportunities are innovative in nature, the level of confidence that can be applied to the costs and savings is lower, reflecting the greater uncertainties. With this in mind, the business cases have been constructed conservatively, i.e. the costs have been estimated higher and the benefits lower. The level of confidence associated with these business cases is not currently sufficient for investment decisions to be based on them. Rather, the business cases are intended to highlight areas that Maltsters should pursue and investigate further.

Table 6 Summary of innovative opportunity business cases, sector level No. 1 2 3

4 5 6 7 8 9 10

Opportunity Heat pumps, closed cycle Heat pumps, open cycle Energy efficient drying Burning Maltings coproducts Burning woodchips Direct T & RH measurement Kiln bed turning Process management Supply chain collaboration Microwave technology

Implementation costs (£)

Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable (%)

£24,750,000

£4,500,000

33,000

£750

6

100%

£75,000,000

£14,650,000

115,000

£640

5

100%

£142,500,000

£10,400,000

85,000

£1,675

14

100%

£13,000,000

-£27,000,000

40,000

£320

None

100%

£21,000,000

£4,200,000

38,000

£550

5

26%

£1,130,000

£580,000

4,700

£240

2

100%

£7,500,000

£1,300,000

10,750

£700

6

67%

£55,000

£200,000

1,750

32

<1

100%

£0

£5,250,000

43,000

£0

0

100%

Text description only

Note: No total has been provided as most of the opportunities either overlap or are mutually exclusive.

Figure 27 below shows the location of the opportunities in diagrammatic form. The diagram gives some indication of which opportunities overlap or are mutually exclusive.


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Figure 27 Location of opportunities within the Malting process

Raw Barley Intake

Waste Grain

4

Raw Barley Drying

Heat

Raw Barley Storage

Power

Screening and Weighing

Power

Water to air (evaporation) Grain to air (respiration)

5

Power

Steeping Grain to Waste Water

Water

6

Waste Water

Grain to air (respiration)

Germination

Power

8

Grain to air (evaporation)

1 Grain to air (respiration)

2

Heat

Kilning Grain to air (evaporation)

Power

3

7 9

Waste Grain

De-culming

Power

10

Output to Brewing

5.1.1

Kiln energy recovery

The key energy efficiency opportunity for the Maltings process is the increased recovery of the vaporisation energy of water during the pre-break phase of kilning (and potentially post-break). On average almost 80% of


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energy supplied to the kiln to evaporate water during pre-break is lost to atmosphere. Approximately 45% to 50% of sector emissions are associated with this. Two opportunities (heat pumps and energy efficient drying) are outlined below which may be used to increase the amount of energy recovered and hence reduce carbon emissions and energy costs.

Heat pumps Heat pumps are a means of boosting the temperature of low grade heat energy to a higher temperature, thereby increasing its usefulness. Typical examples of heat pumps (albeit with the principle applied in reverse), include domestic refrigerators and air conditioning systems. Heat pumps are used in the evaporation of water in a range of industries, including food & drink. Heat pumps can be categorised into two categories: Closed cycle heat pumps, where the working fluid does not leave the system Open cycle heat pumps, where the working fluid is vented from the system Both types of heat pump may present opportunities to improve energy efficiency.

Closed cycle heat pumps Closed cycle heat pumps typically use a refrigerant gas as the working fluid. They can be deployed as a second stage of energy recovery, after the glass tube heat exchanger. The diagram in Figure 28 shows how a heat pump could be integrated in a kiln. The heat pump is shown in red.

Figure 28 Diagram of closed cycle heat pump energy recovery system (elevation)


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The warm, saturated air exiting the glass tube heat exchanger enters a second heat exchanger (the heat pump evaporator) where it is cooled by the refrigerant liquid, as energy is transferred. As the refrigerant liquid heats up, it is vaporised. The refrigerant vapour is than compressed which increases its pressure and temperature. It then enters the heat pump condenser. This heat exchanger is located between the air recirculation inlet and the primary heat exchanger (shown as heater in the above diagram). In the heat pump condenser energy is transferred to the air-on stream, heating up the air. The refrigerant vapour is cooled and condensed, and brought back to its initial state of a low pressure low temperature liquid by an expansion valve. Retrofitting heat pumps for energy recovery may be possible in existing kilns. The main barrier is likely to be technical viability, as there may be insufficient space to fit the condenser heat exchanger. The preliminary business case for heat pump energy recovery is provided in Table 7 below. The following assumptions are made: Heat pump evaporator exit temperature of 12°C. Heat pump condenser exit temperature of 65°C. Heat pump heating capacity of 1MW. Compressor electricity demand of 280kW. Daily operation of 14 hours, 365 days per year. Capital cost of £550/kW of heating capacity. Heat pumps used in this way will not be eligible for the RHI

The relatively long payback period of heat recovery heat pumps may be an obstacle to their implementation. Table 7 Business case for heat pump energy recovery Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

Sector Average site £24,7500,000 £920,000 £4,500,000 p.a. £165,000 p.a. 6 years 6 years 33,000 tonnes CO2 p.a. 1,225 tonnes CO2 p.a. 27 (all sites within the CCA) Technical. Retrofit may not be technically viable for all sites. Supplier survey European Brewing Convention Manual of Good Practice – Malting Technology, pages 139 - 140. http://www.r744.com/component/files/pdf/thermea_broschuere_short.pdf http://produktordner.thermea.de/english

Open cycle heat pumps Open cycle heat pumps can use evaporated water itself as the working fluid for heat recovery, which allows for easier integration into water evaporating systems. Such open cycle heat pumps using water vapour as a working fluid can be deployed in single or multiple stages. Electrically driven open cycle heat pumps are known as mechanical vapour recompressors. The heat transfer equipment comes in many forms, including climbing and falling film evaporators, fluidised bed and rotary dryers. Of these, rotary dryers or similar equipment is likely to be most suitable. The type of system referred to above could potentially be adapted for the Maltings sector. The system would rely on the addition of a further heat exchanger, such as a rotary dryer, through which the wet malt passes


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continuously. Water is evaporated from the malt, using initial start-up heat provided by a separate system such as a microwave system. The vapour is extracted and compressed by a Mechanical Vapour Re-compressor (MVR), which boosts the temperature and pressure of the vapour. The higher temperature vapour is then pumped into the heat exchanger (now separated from the malt) where it exchanges heat with the malt. The recompressed vapour condenses in the heat exchanger, ensuring that all its vaporisation energy (latent heat) is recovered to the malt. Finally, a pump removes the condensate from the heat exchanger. In effect, the compressor provides the temperature and pressure rise required to allow condensation of vapour to occur at the same temperature it was generated. It uses electricity to do so. An example of a possible layout is shown below. The dry malt would be transferred from the additional dryer into a kiln where it can be cured. To our knowledge, no such system is in used for the evaporation of water from solids such as malt. Systems like it are used for the evaporation of water from liquids. Research and Development effort will be required to bring the technology to the point of a commercial product.

Figure 29 Example arrangement of single effect Malt drying system

Recompressed vapour

Wet Malt

Vapour extraction

MVR

Malt dryer (heat exchanger)

Dry Malt

Initial heat Condensate Condensate pump

In a multi-effect set-up, the vapour from dryer 1 is used to heat dryer 2, the vapour from dryer 2 is used to heat dryer 3 and the vapour from the last dryer is used to heat dryer 1. In essence the performance of a multi-dryer unit is similar to that of a single effect unit, though as multiple MVRs are used, the total pressure drop across the effects can be greater. This means that the last effect could be operated at a pressure which is a fraction of ambient pressure (i.e. a partial vacuum). If this pressure can be low enough, water will boil at 30째C. As boiling is a much faster method of converting water to vapour than evaporation, this may enable intensification of the drying phase, particularly the falling rate phase (i.e. evaporating water from within the body of each grain). This may result in further energy efficiency improvements. It may be advantageous to slightly heat the malt in the stage where boiling is induced as this reduces the need for a deep vacuum, and hence reduces the electrical demand of the MVRs. A balance would need to be struck between introducing additional heat and reducing electrical input. Such a temperature increase could be accomplished by the use of microwave technology (see section 5.1.8).


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An example multi-effect set-up is shown below. Figure 30 Example arrangement of multi effect Malt drying system Recompressed vapour

MVR MVR Vapour extraction

Wet Malt

Recompressed vapour

Malt dryer (heat exchanger)

MVR Vapour extraction

Recompressed vapour

Malt dryer (heat exchanger)

Vapour extraction

Malt dryer (heat exchanger)

Dry Malt

Initial heat Condensate Condensate pump

Condensate Condensate pump

Condensate Condensate pump

Mechanical Vapour Recompression works most efficiently when operated continuously, as this minimises start-up heat requirements. The equipment required could then also be relatively small, reducing the capital cost. A continuous operation is also likely to reduce the temperature and humidity variation within the drying malt compared with traditional batch fed kilns, as these parameters can be more precisely controlled in continuous systems. The system would require buffer capacity upstream of the multi effect evaporators to allow a full batch to be held following the end of germination, and before processing. A separate kilning stage would still be required downstream from the evaporators to provide curing of the dry malt. It must be noted that references to MVR have been found for the evaporation of water from fluids. No references have been found to their use for the evaporation of water from grain or similar solid materials. This may represent a technical hurdle that would need to be addressed through research and development. Research and development areas that may require addressing include: Feasibility of using open cycle heat pumps to evaporate water from solids Energy transfer from condensing vapour to malt Effects on product quality Potential for integration of open cycle heat pumps with existing kilns The preliminary business case for MVR dryers is provided in Table 8 below. The following assumptions are made: Drying requires 63% of sector‟s heat input (based on kiln energy demand pre-break). MVR electricity requirements are 38.6 kWh / tonne of water vapour5. Assumed initial heat requirement of 627 kWh per batch, to evaporate 1 tonnes of water. 365 batches per year for each of the sector‟s 45 kilns. Assumed capital costs of £75,000,000. It must be noted that this is an estimate, and it subject to significant change based on the outcome of an R&D project.

5

http://profmaster.blogspot.com/2010/07/mvr-use-it-for-higher-benefits.html`


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Table 8 Business case for open cycle heat pumps Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation

References

Sector Average site £75,000,000 £2,800,000 £14,650,000 p.a. £540,000 p.a. 5 years 5 years 115,000 tonnes CO2 p.a. 4,250 tonnes CO2 p.a. 27 (all sites within the CCA) Product quality concerns, technical viability This opportunity requires further R&D work to establish the effect on product quality. This work will also give insight into the technical viability of the opportunity. http://www.barr-rosin.com/applications/evaporation.asp http://www.windsorsathyam.com/evaporation_processes.html

The above opportunity recovers energy from saturated water vapour at a low temperature from the kiln. It may also be possible to recover energy from water vapour available from the germination process exhaust air flow using the same equipment. This energy could potentially be used in the kiln, or to pre-heat steep water. The opportunity to recover energy from the germination process is likely to be relatively small and has not been quantified.

Energy Efficient Drying Tri Phase Drying Technologies LLC, a US company, markets a system that they claim results in highly energy efficient drying. A detailed assessment of the effectiveness of this technology is not within the scope of this report. This system is the only reference to an energy efficient grain drying system found during the project. Extracts of the website are shown below:

‘Tri-Phase Drying Technologies system achieves energy savings by recycling heat of vaporization. A fluid or solid medium circulates within the system to recover the heat of vaporization (Recovery Phase) and returns it to a product stream (Heating Phase). A minimal counter-current air stream carries water vapour from the heated product (Drying Phase) so that the air is saturated at the heat Recovery Phase.’ ‘Energy use of less than 500 Btu/lb of water removed is possible. Results of an economic analysis are presented showing payback period of about 3 years based solely on energy savings.’


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Figure 31 Tri-Phase process diagram

The company‟s website appears to have been updated in 2009. AEA has not established whether the company is actively trading, or if the technology is still in active use for grain drying. The business case outlined below is based on information found on the company‟s website. There appears to be some discrepancy between the payback periods quoted by the company, and those calculated for this business case. The assumptions used are: Energy use of a standard kiln during pre-break is 4,442 kJ/kg Energy use of Tri-Phase technology is 1,815 kJ/kg Tri Phase unit costs of £3,125,000

It must be noted that many configurations of the Tri-Phase technology are possible, according to the website. This may include configurations which can be retrofitted to existing kilns at significantly reduced capital costs. Table 9 Business case for energy efficient drying Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation

References

Sector Average site £142,500,000 £5,300,000 £10,400,000 p.a. £385,000 p.a. 14 years 14 years 85,000 tonnes CO2 p.a. 3,150 tonnes CO2 p.a. 27 (all sites within the CCA) Technical, Financial It appears that the technology is in use in the US, though some technical barriers may remain. The relatively long payback period may indicate implementation is only viable at kiln replacement stage. www.triphasetechnologies.com


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46

Burning malting co-products

The Maltings sector generates organic co-products in the course of its operations. These co-products are collected and sold to animal feed manufacturers as a valuable feedstock.

The co-products could be used for the generation of energy using anaerobic digestion, CHP, or using biomass burners to heat the kilns. As the co-product has a relatively high monetary value as animal feed, this opportunity does not have a financial return. It is listed here purely to illustrate the potential reduction of CO2 emissions (through reduced fossil fuel consumption) that could result from the burning of biomass co-products. Cheaper biomass may be available from elsewhere in the supply chain, or from other sources. The business case assumes: Approximately 300,000 tonnes p.a. of co-product across the sector6, assumed to be 256,500 tonnes of dry mass. Energy value of 1 MWh/tonne Biomass burner costs of £300/kW, and 80% efficiency £125/tonne for co-product sold as animal feed7 It must be noted sites operating hot water, steam or hot oil systems (as opposed to warm air) can qualify for the Renewable Heat Incentive. The RHI is not sufficient to alter the business case below significantly.

Table 10 Business case for burning Maltings co-products Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.1.3

Sector Average site £13,000,000 £480,000 -£27,000,000 p.a. -£1,000,000 p.a. None None 40,000 tonnes CO2 p.a. 1,500 tonnes CO2 p.a. 27 (all sites within the CCA) Financial. Not currently financially viable. Further benefits and value may be available. None http://www.esru.strath.ac.uk/Documents/MSc_2006/hamilton.pdf

Woodchip burner for hot water, steam or hot oil kilns

Biomass burners could replace some or all of the heat energy used for kilning. Several sources of biomass can be used for combustion purposes, including wood chip and wood pellets. Of these, wood chip tends to be used for large scale applications due to it lower price per unit of energy. Whilst all sites could potentially benefit from wood chip burners, this opportunity is most attractive to sites operating hot water, steam or thermal oil systems (as opposed to direct or indirect fired kilns warm air). This is because to the Renewable Heat Incentive, which is due to be introduced this year, will apply to hot water, steam and thermal oil systems, but will not (initially at least) apply to direct or indirect fired warm air systems.

6 7

http://www.ukmalt.com/maltindustry/industry.asp MAGB, personal communication, average of £90/t and £160/t.


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In addition to those sites benefiting from the Renewable Heat Incentive, kilns fitted with such systems are thought to be able to cope with less responsive burners, as the hot water, steam or thermal oil introduces a thermal lag. This makes the kiln less susceptible to a relatively slow responding burner such as a wood chip burner. The business case below outlines the case for the addition of a 5MW wood chip burner to an existing natural gas fired kiln. The benefits at sites with warm water, steam and thermal oil systems fuelled by LPG or gas oil are likely to benefit greater as these fuels are more expensive than natural gas. The business case assumes: 7 sites in the sector operate warm water, steam and thermal oil systems The addition of a 5MW woodchip burner to the existing heating system, fuelled by natural gas The above burner is able to displace 80% of the natural gas currently used Woodchip price of £90/tonne, and an energy content of 3,500 kWh/tonne The woodchip system would qualify for the Renewable Heat Incentive scheme, at a rate of 2.6 p/kWh8. Capital costs include £1,500,000 per site for site fuel storage, fuel handling and de-ashing equipment

Table 11 Business case for burner Maltings co-products Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.1.4

Sector Average site £21,000,000 £3,000,000 £4,200,000 £600,000 5 years 5 years 38,000 5,500 7 Logistics. Woodchip takes space to store. http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energ y_mix/renewable/policy/incentive/incentive.aspx

Process control based on direct measurement of humidity & temperature

The current standard practice within the industry is to control the germination and kilning processes primarily on time, air temperature and humidity. Some examples of manual moisture content sampling and measurement were also observed. Whilst these control methodologies enable Maltsters to consistently produce high quality malt, energy efficiency could be increased by using direct measurement of temperature and moisture content of the malt bed in both germination and kilning. As direct measurement is more responsive and more precise, it enables faster response to changing conditions. It is however a more localised measurement and as such may be less representative of average conditions in the bed. One example of where direct measurement could reduce energy consumption is in the termination of a kilning cycle. It is typically necessary for the malt to have a maximum moisture content of 4% or less. If a manual sampling and testing regime is used, it may take 30 minutes between time of sampling and the decision time to stop the kilning process. Such a delay would lead to energy being used to provide heat which is no longer necessary, as well as a kilning cycle which is longer than required.

8

Must be confirmed


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The business case below outlines an example where the finished moisture content is lower than required, and hence more than the minimum amount of energy and time have been used. The business case assumes: 1.2% additional moisture in load to kiln moisture content. The above additional moisture resulting in 13 minutes additional pre-break kilning time. A total of 225 sensors (45 in kilns, and 4x 45 in germination vessels). Sensors can be integrated into manual or automated control processes. Barriers to this opportunity include: Sensors exist with the capability to measure moisture and temperature at the same time. These sensors may require some adaptation to ensure best fit (operationally) for the Maltings sector. For best value the sensors should be integrated into automated control systems. Where this is not practical or viable, the output from the sensors should be used to manually control the processes. Both automated and manual control based on these sensors may be difficult.

Table 12 Business case for process control based on direct measurement of humidity & temperature Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.1.5

Sector Average site £1,130,000 £42,000 £580,000 p.a. £21,500 p.a. 2 years 2 years 4,700 tonnes CO2 p.a. 175 tonnes CO2 p.a. 27 Technical (sensor and sensor integration) R&D project http://www.hydronix.com/

Kiln bed turning

If kilns were fitted with turning mechanisms, similar to those in germination vessels, those turning facilities could be used to reduce the temperature and moisture gradients across the bed. The benefits are thought to include faster, more consistent drying of the bed, thereby reducing the length of the kilning cycle. In addition turning during the kilning cycle may improve the distribution of air flow across the area of the bed, as short-circuits are reduced. The major risk associated with this opportunity is likely to be the stirring up of additional dust into the kiln air stream during turning. This could potentially increase fouling of the glass tube heat exchanger, with negative implications for energy recovery. Mitigation of this risk is likely to be a combination of timing of turning, and ensuring kiln air velocities are as low as possible to ensure dust is minimised and settles quickly. However, if air velocities are too low, the kilning cycle would need to be extended, thereby increasing energy consumption. In addition, some kilns may not be structurally strong enough to cope with the additional machine weight. It may be more feasible to turn the top half of the bed rather than the whole bed. This has not been taken into account in the business case below. The business case outlined below assumes the following: An estimated 7.5% reduction in energy demand during pre-break phase of kilning. Equipment and installation costs of £250,000 per kiln, applied to 30 kilns in the sector. All GKVs where kiln bed turning during kilning is viable do so already.


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Table 13 Business case for kiln bed turning Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.1.6

Sector Average site £7,500,000 £420,000 £1,300,000 p.a. £72,000 p.a. 6 years 6 years 10,750 tonnes CO2 p.a. 600 tonnes CO2 p.a. 18 sites, (30 kilns) Operational. Dust control may be an issue. Technical. Some existing kilns may not be suitable for retrofit. Confirm benefit through measurement of GKV kiln bed turning.

Statistical management of input and process variables

The consistent production of high quality malt relies on the management of key input and process variables, including moisture content, temperatures and time cycles. The aim of managing key input and process variables is twofold: To continuously increase the consistency (i.e. continuously reduce variation) of input and process variables to improve the consistency and predictability of the output To optimise the level of output to as close to the target as the consistency of output allows. Several techniques and methods have been developed to assist with the aim of continuous systems improvement. These form part of an approach known as continuous improvement or lean manufacturing. AEA has used this technique to develop a series of charts that provide insight into the control of the core process. The example below shows a control chart (one of the 7 basic quality tools, and also known as a process behaviour chart) of the moisture content of „load to kiln‟ batches, for a series of 45 consecutive batches. The load to kiln moisture content has a direct bearing on the amount of energy used in the kiln to evaporate the water. It is therefore important to ensure the minimum moisture content possible consistent with product quality. Control charts are a useful and objective way of detecting unusual behaviour in processes. They are constructed using two basic time series graphs, and include control limits which are calculated based on the variation present in the data (i.e. they are not user defined and they are therefore objective). Control charts are interpreted using a set of detection rules (see below) that will objectively indicate when the process is behaving in a manner that is different to normal. This allows for investigations to be carried out and improvement action to be taken. The upper chart (known as the X-Bar chart) shows the process variable (load to kiln moisture content), together with its average and an upper and lower control limits. The lower chart (known as the moving range chart) shows the moving range between points, i.e. the absolute difference between one point and the next. This chart also shows the average for the moving range and an upper control limit. There is no lower control limit in the moving range chart. The formula‟s used to calculate the control limits are shown below.

The factors used in the calculation of control charts have been empirically derived and have been in use in industry for more than 50 years.


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Figure 32 Control charts for load to kiln moisture content

Control charts allow for the robust and objective detection of unusual performance in processes. This detection is based on a set of detection rules, two of which have been illustrated in the above example. The same detection rules apply to both graphs. The illustrated rules are: Any individual point outside of the control limits indicates an exception. Any run of 8 or more consecutive points either above or below the average indicates an exception. In the above example, the X-bar chart shows no unexpected behaviour, i.e. the process is operating within its capabilities. The Moving Range chart however shows two exceptions: A run of 8 consecutive batches with less than average variation in moisture content. The causes should be investigated and encouraged to re-occur. A single batch with significantly different moisture content than expected. The causes should be investigated and eliminated. Both actions will result in process improvement, which shows up on control charts in two ways: Narrower control limits on the X-bar chart and a lower average and lower upper control limit on the moving range chart. This is the result of the process becoming more consistent. A shift in the average of the X-bar chart in the desired direction. Control charts, and the other techniques and methods referred to above, can be used to improve the outputs from any type of process. They are at their most valuable when used to minimise variation in input and process variables.


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The same data is shown in the scatter diagram below. The equation of the line of best fit is shown in the top right, as is the R2 value (R2 is a measure of how closely the estimated the trend line corresponds to the actual data). The value of R2 is quite low, indicating that the data does not correspond closely with the trend line and that other factors exist which have a more dominant effect on kiln gas consumption.

Figure 33 Scatter diagram of batch moisture content and kiln gas consumption

Scatter diagrams are part of the 7 basic quality tools, which can be used to improve processes by management of key input and process variables. The business case below is based on the following assumptions: Training costs of £2,000 per site Application of skills to reduce load to kiln average moisture content by 0.5%. No benefits have been calculated of applying skills to other process improvements

Table 14 Business case for statistical management of input and process variables Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

Sector £55,000 £200,000 p.a. <1 1,750 tonnes CO2 p.a. 27 (all sites within the CCA) Knowledge/skills Training and experience

Average site £2,000 £7,500 p.a. <1 60 tonnes CO2 p.a.


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52

Supply chain collaboration

The Maltings sector is part of a supply chain which includes farmers, brewers, distillers, food manufacturers and end customers. They are also supported by equipment and knowledge providers. Further collaboration with the supply chain offers opportunities to reduce the carbon footprint, and potentially energy costs, of the sector. Examples of such opportunities include: Negotiating a higher finished product moisture content with brewers. This reduces the energy consumption required during kilning. Collaborating with farmers on the deployment of renewable energy systems, such as a wind turbine or anaerobic digester constructed on a farmer‟s land under a lease agreement, funded by a Maltster. Development of barley varieties which require less energy consumption during processing. Negotiating supply of other biomass from farmers or customers to a Maltings site, specifically to fuel biomass burners, biomass CHP or anaerobic digesters.

Final moisture content The business case below outlines the energy cost and carbon emission implications of an agreement with the sector‟s customers to increase the finished product moisture content. It assumes: Brewers agreed to a change in moisture content from 3% to 4%. Management time is expended for negotiations. No capital costs are involved in changing moisture content. Relative carbon emissions are improved by 25%9

Table 15 Business case for supply chain collaboration – final moisture content Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

Sector £0 £5,250,000 p.a. 43,000 tonnes CO2 p.a. 27 (all sites within the CCA) Customer acceptance Negotiation

Average site £0 £195,000 p.a. 1,600 tonnes CO2 p.a.

Renewable energy systems Sector members have opportunities to deploy Renewable Energy (RE) systems at their own sites. Examples include biomass combustion (see section 5.1.3) and Anaerobic Digestion, as well as wind turbines at suitable locations. For systems that generate up to 5 MW of electricity from renewable sources the new Feed-In-Tariff provides a significant new financial incentive.

9

http://www.muntons.com/downloads/carbon%20emissions%20in%20malting%202010%202.pdf accessed 10/02/11


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The location of a Maltings site may place restrictions on the types or sizes of RE systems that could be deployed at a particular site. As there are often economies of scale associated with RE systems often (i.e. larger systems offer a higher rate of return), any restrictions may make deployment of RE system less favourable.

Such constraints can be overcome by investing in RE systems on a less restrictive site away from the main Maltings plant. The benefits of RE, including carbon credits, electricity and revenue are tradable. For example, a Maltster could enter into a contract with a farmer where the farmer agrees to lease a small parcel of land to the Maltster for the (co)funding, construction and operation of a wind turbine for a number of years. The farmer receives an annual lease payment, whilst the Maltster receives the carbon credits and income from the sale of electricity. The carbon credits can be used to effectively reduce the carbon footprint of the Maltster, or they can be sold to increase the financial return. Similar methods can be used to deploy other RE systems, including solar thermal, photo voltaic, anaerobic digestion, biomass, ground source heat pumps, etc. It must also be noted that this opportunity is not limited to the Maltsters supply chain as it could be conducted anywhere within the UK. The main barrier to this opportunity is likely to be organisational, in that Maltsters are not in business to generate RE and hence the above scenario may be too much of a distraction from the core business.

Barley varieties development New species of barley are continuously under development. It may be possible for new species to be developed which require less energy in processing. This may take the form of lower moisture content required for germination or lower energy requirement for drying. This opportunity is technically difficult, and the influence of the Maltsters over the development of new barley species is limited. In addition, it is thought that any benefits could take a long time to materialise.

Biomass supply The agricultural suppliers to the Maltings industry could potentially supply biomass for use in biomass burners CHP plant or an Anaerobic Digester. This opportunity could have similar carbon benefits to those outlined in section 5.1.2, but with financial savings as well.

5.1.8

Microwave technology

Microwave technology can be used to input energy to wet malt in the initial stages of kilning. The potential benefits of microwave technology include: Allows for fast energy transfer â&#x20AC;&#x201C; as energy reaches the core of each grain Allows for precise control Energy efficient Established technology Following discussions with the National Centre for Industrial Microwave Processing (NCIMP) at Nottingham University, we understand that whilst microwave technology can be applied to the Maltings process, it does have some restrictions. These include: Microwave technology is not suited to batch processing for the size of batches currently used in the Maltings sector. The technology is more suited to continuous processes, as these allow for smaller hardware.


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Microwave technology has high energy efficiency (80-85%) when used for heating. This high efficiency alone does not necessarily make microwave technology more attractive than other drying/heating technologies, due to the relatively high cost and carbon intensity of the electricity compared with gas. Microwave technology could be deployed in conjunction with other drying / heating technology, such as multieffect evaporators/dryers, in order to provide initial energy input, or final drying. As microwave technology is unlikely to be deployed other than as part of a larger improvement measure, no separate business case has been presented here.

5.1.9

Summary

Table 16 below outlines the advantages and disadvantages of each of the innovative opportunities, including the carbon emission reduction and payback periods. Table 16 Advantages and disadvantages of the innovative opportunities Opportunity Heat pumps, closed cycle

Advantages 33,000 t CO2, 6 years Retrofit opportunity Does not affect product quality

Heat pumps, open cycle

115,000 t CO2, 5 years Largest energy efficiency opportunity identified Expected to be relatively cost effective May speed up kilning process

Energy efficient drying

85,000t CO2, 14 years Existing technology

Burning Maltings co-products

Large carbon saving Established technology

Burning woodchips

Direct T & RH measurement

Kiln bed turning

38,000 t CO2, 5 years Large carbon saving Established technology Attracts Renewable Heat Incentive 4,700 t CO2, 2 years Relatively low cost of implementation Short payback expected Improved process control 10,750 t CO2, 6 years Existing technique in GKVs

Disadvantages Relatively long payback period Space requirements for heat exchangers may be limited Technology may not be adaptable to evaporating water from solids â&#x20AC;&#x201C; Requires R&D Effects on product quality not known New build / replacement opportunity only as it would represent a significant change to existing kilning process Long payback period Availability of market-ready solutions uncertain Use of Maltings co-products is not financially viable at current animal feed prices Fuel handling and storage may be an issue

Requires R&D to optimise technical solution Savings potential uncertain

Process management

1,750 t CO2, 1 year No/low cost Existing techniques, applied to process and input variables Flexible techniques, can be applied to many processes

Relatively small energy efficiency gains Requires management time and expertise to analyse data and identify savings Savings result only if action is taken on the information

Supply chain collaboration

43,000 t CO2, immediate Large, low risk opportunity (higher finished malt moisture content)

Requires on-going agreement with customers

Microwave technology

Fast, precise and energy efficient

Only considered suitable in addition to other innovative technology such as open cycle heat pumps


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The following chart shows the relative capital costs (x-axis) payback period (y-axis) and CO2 savings (label and diameter of bubble) for each of the innovative opportunities. As these opportunities are innovative in nature, the level of confidence that can be applied to the costs and savings is lower, reflecting the greater uncertainties. The business cases are not intended to form the basis of investment decisions, rather they are intended to highlight areas that Maltsters should pursue and investigate further. Figure 34 Bubble diagram of capital costs, payback period and carbon savings for innovative opportunities

18 16

85,000 Energy ef f icient drying

14

Payback (Years)

12 10 10,750 Kiln bed turning 8

33,000 Closed cycle heat pumpts

6 38,000 Woodchip

115,000 Open cycle heat pumps

4 2

4,700 Direct measurement 43,000 Supply chain collaboration 1,750 Process Management

0

£0

£50,000,000

£100,000,000

£150,000,000

£200,000,000

Capital Costs

5.2 Good practice opportunities This section outlines opportunities to reduce energy costs and CO2 emissions that are considered to represent established good practice or established technology. These opportunities fall outside the project brief for the IEEA i.e. they are not innovative and specific to the Maltings process. However, we believe that there is significant scope for emissions savings through further dissemination and implementation of good practice within the sector. Moreover, implementation of these measures may represent the best opportunity for carbon savings in the short to medium term.


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The opportunities are listed here to allow the sector to gain additional insight and confidence in their potential. Table 17 Summary of good practice business cases at sector level Opportunity

Implementation costs (£)

Anaerobic digestion

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable (%)

Text description only

CHP Heat recovery survey Compressed air Condensate recovery High efficiency motors Monitoring & targeting Variable speed drives Voltage optimisation

5.2.1

Saving (£ p.a.)

£11,700,000

£2,285,000

29,000

£405

5

48%

£5,000

£30,000

230

£22

<1

100%

£435,000

£145,000

1,250

£350

3.0

100%

Text description only £72,000

£100,000

940

£75

1

100%

£950,000

£1,650,000

15,300

£62

1

70%

£810,000

£250,000

2,350

£350

3

100%

£925,000

£250,000

2,350

£390

4

70%

Anaerobic digestion

Anaerobic digestion (AD) involves the conversion of organic matter to into a methane rich biogas that can be used to generate localised heat and power. AD can be a viable proposition for industrial sites that produce large volumes of organic wastes and have a high demand for heat. The output from the process, known as digestate, tends to be high in nutrients and can be used to substitute conventional fertilisers. While maltsters do produce organic wastes, much of this waste stream has a relatively high monetary value as animal feed. Therefore AD is unlikely to be an economic proposition for a typical Maltings site in isolation. However, maltsters are part of a supply chain that includes farmers, brewers, distillers and other food and drink sector companies. AD plants are likely to be more attractive where maltsters can collaborate with parts of their supply chain.

5.2.2

CHP

Combined Heat and Power (CHP) is a highly efficient method of simultaneously generating electricity and heat at or near the point of use. By capturing and utilising the heat that is a by-product of the electricity generation process, CHP can achieve overall efficiencies of up to 80% in industry. As well as reduced emissions, CHP offers reduced energy and fuel costs, and is suitable for a wide range of applications. It is also viable for a whole range of fuels, including gas, oil, biomass, and biogas and waste.10 With their high demand for heat, sites in the Maltings industry are likely to be suitable for CHP. To operate successfully CHP will need to be integrated with the heat demand and control systems in the kiln. Feasibility studies would need to be carried out for individual sites.

10

Department of Energy and Climate Change (DECC) http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/distributed_en_heat/chp/chp.aspx Accessed 10/02/11


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57

The business case outlined below makes the following assumptions: CHP is in the form of a reciprocating gas engine sized to meet the total electricity demand of a medium sized site with natural gas (around 900 kWe). Heat capacity is 1,350 kW. The electrical generation efficiency is 32% and the overall efficiency is 80%. Ratio of heat to power output is 1.5:1. CHP availability is 90%. Electricity (grid) price 6 p/kWh, electricity export price 4 p/kWh and natural gas price 2 p/kWh. OPEX is in line with typical costs for reciprocating engines (£0.01/kWh electricity generated excluding natural gas costs). CHP heat used to displace steam generated heat with boiler efficiency of 80%. The capital cost of the CHP installation is in line with typical costs for reciprocating gas engines (£1,000/kWe installed). CHP can be deployed in 50% of the sector (13 sites).

Table 18 Business case for CHP Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.3

Sector Average site £11,700,000 £900,000 £2,285,000 p.a. £175,000 p.a. 5 years 5 years 29,000 tonnes CO2 p.a. 2,200 tonnes CO2 p.a. 13 Technical. Integration with existing system may be difficult.

Comparison of maintenance and efficiency of existing heat recovery equipment

Correct and adequate maintenance of heat exchangers has a direct impact on energy efficiency, as the performance of systems degrades naturally over time. This is of course true for all equipment, not just heat exchangers. Maintenance of heat exchangers results in improved heat transfer and heat recovery. Given the nature of the operations and equipment, in particular the humid and dusty atmosphere, this maintenance task is difficult. It is recommended that the sector carries out a survey of heat exchanger maintenance methods in use within the sector, in order to establish and disseminate best practice. The business case outlined below assumes the following: Costs of £5,000 for a survey and site visits Benefits amount to a 1% improvement in heat recovery in the glass tube heat exchangers It is thought that no significant barriers exist to the implementation of a survey and best practice.


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Table 19 Business case for comparison of maintenance and efficiency of existing heat recovery equipment Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.4

Sector Average site £5,000 £200 £30,000p.a. £1,100 p.a. <1 years <1 years 230 tonnes CO2 p.a. 10 tonnes CO2 p.a. 27 (all sites within the CCA) Operational. Heat exchanger maintenance can be difficult. Adoption of best practice.

Compressed air optimisation

Compressed air is used in the sector primarily for valve actuation and similar applications. The compressors used are often relatively old and fitted with simple, decentralised control systems. The compressors typically vent their cooling air into the compressor room. Several opportunities have been observed which each may reduce energy consumption. These include: Heat recovery from compressor cooling. Compressed air leak detection and repair. Replacement of old fixed speed compressors with modern high efficiency, variable speed units. Compressed air generation pressure reduction. Centralised computerised control system for systems with multiple compressors. Using electrical alternatives to compressed air consumers, where it is safe and viable to do so. All the above opportunities will reduce the energy consumption of the compressors, whilst providing the same level of functionality provided at present. The business case outlined below illustrates the benefits of this opportunity and it is based on the following assumptions: Based on heat recovery, VSD compressors and optimisation Assumes 2 x 37 kW compressors, duty/standby 50% of heat generated can be used to displace other heat 50% of compressors benefit from VSD technology, and these gain a 20% improvement in energy efficiency 10% energy efficiency gain due to optimisation

Table 20 Business case for compressed air optimisation Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

Sector Average site £435,000 £16,000 £145,000 p.a. £5,500 p.a. 3 3 1,250 tonnes CO2 p.a. 50 tonnes CO2 p.a. 27 (all sites within the CCA) None None http://www.carbontrust.co.uk/publications/pages/home.aspx


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59

High efficiency motors

The efficiency of electric motors is defined as the ratio of shaft power to the input power. Most modern electric motors are already quite efficient, with efficiencies between 90 and 95% being common. Given the high price and carbon intensity of electricity, and typically a high annual utilisation of electric motors, further roll out of high efficiency should be pursued. It is considered likely that the majority of electric motors do not warrant pro-active replacement based on the energy cost savings alone. Hence this opportunity should be taken forward when electric motors are due for replacement. It is therefore important that sector members pre-plan the replacement for each significant electric motor with the highest efficiency alternative, before replacement becomes necessary. The business case outlined below assumes the following: Implementation costs cover the marginal cost of replacement only (i.e. the additional cost of a high efficiency motor over a standard motor). 67% of electricity used by the sector is used by electric motors11 67% of all suitable motors are high efficiency already, according to questionnaire responses. The efficiency of the remaining 33% is assumed to improve by 4%. Energy efficient motors are assumed to cost 25% more than standard motors. Savings are based on an extrapolation of an 11 kW motor operating 4,000 hours per year. It is thought that no significant barriers exist to the installation of further high efficiency motors in the sector.

Table 21 Business case for high efficiency motors Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.6

Sector Average site £72,000 £2,700 £100,000 p.a. £3,700 p.a. 1 year 1 year 940 tonnes CO2 p.a. 35 tonnes CO2 p.a. 27 (all sites within the CCA) None None http://www.carbontrust.co.uk/publications/pages/home.aspx

Monitoring and Targeting

Automated Monitoring and Targeting (aM&T) systems enable improved management of energy use, including the highlighting of wasteful consumption patterns. aM&T systems consist of energy meters for each of the major process at a site, local data storage using a data logger as well as analysis software. aM&T systems can deliver savings of 5-10% of energy costs, but only if the data they collect is analysed and acted upon. The Maltings sector has some existing energy metering installed, consisting primarily of electricity and natural gas meters. In addition, analysis of the questionnaire responses indicated that 30% of sites already have some form of aM&T system. As such, the summary outlined below covers the remaining 70% of the sector. An average saving of 7.5% has been assumed for all utilities. Besides funding its implementation, it is thought that no significant barriers exists to the deployment of aM&T systems in the sector.

11

Carbon Trust - Motors and Drives Technology Overview (2007) CTV016


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Table 22 Business case for monitoring and targeting Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.7

Sector Average site £950,000 £50,000 £1,650,000 p.a. £87,000 p.a. 1 year 1 year 15,300 tonnes CO2 p.a. 800 tonnes CO2 p.a. 19 None None http://www.carbontrust.co.uk/publications/pages/home.aspx

Variable speed drives

Variable speed drives (VSDs) allow electric motors to run at speeds other than their nominal speed. This is achieved by altering the frequency of the alternating current supplied to the motor. Energy savings result from the electric motor being able to better match the supply of energy with the demand for energy. Applications that benefit most from variable speed drives include centrifugal fans and pumps. The Maltings sector has a large number of variable speed drives installed, though the driving factor for this has often been improved process control rather than energy savings. Analysis of the questionnaire responses indicates that the respondents considered that 67% of all applications that could benefit from VSDs have them installed already. Examples include the large kiln fans and some compressors. Regardless of the driving factor, energy savings will result from the installation of variable speed drive on the majority of applications. The business case summary below is based on the following assumptions: 67% of electricity used by the sector is used by electric motors12 67% of all motors already have VSDs installed Of the remaining 33% of applications, 50% can benefit from a VSD An average saving of 20% can be achieved on the remaining applications Besides funding its implementation, it is thought that no significant barriers exist to the deployment of variable speed drives in the sector.

Table 23 Business case for variable speed drives Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.8

Sector Average site £825,000 £30,500 £250,000 p.a. £9,250 p.a. 3 years 3 years 2,350 tonnes CO2 p.a. 90 tonnes CO2 p.a. 27 (all sites within the CCA) None None http://www.carbontrust.co.uk/publications/pages/home.aspx

Voltage optimisation

Voltage optimisation equipment reduces the voltage of the incoming supply to a site. This is viable for the majority of UK sites, as the incoming voltage is higher than that required by the electrical equipment installed on

12

Carbon Trust - Motors and Drives Technology Overview (2007) CTV016


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site. By reducing the voltage, energy consumption can be reduced for certain types of electrical loads, including electric motors. Based on the site visits it has been estimated that 5% of sites have already implemented some form of voltage optimisation, which may include tapping down owned transformers. The business case summary below assumes the following: Voltage optimisation is possible at 70% of the remaining sites in the sector 33% of all electrical equipment at those sites will show a saving due to voltage optimisation That equipment will show an average electricity cost saving of 10% It is considered that there are no significant barriers to the implementation of voltage optimisation, beyond the need to fund the improvement. The site electricity supply will need to be de-energised during the installation of the equipment. It is thought this can be achieved with appropriate planning.

Table 24 Business case for voltage optimisation Summary Implementation costs Cost reduction Payback period CO2 reduction Number of sites where applicable Barriers Barrier mitigation References

5.2.9

Sector Average site £925,000 £50,000 £250,000 p.a. £13,000 p.a. 4 years 4 years 2,350 tonnes CO2 p.a. 125 tonnes CO2 p.a. 19 Operational. The electricity supply must be de-energised during installation. Appropriate scheduling

Condensate recovery

The glass tube heat exchangers are used to recover a proportion of the energy available in the kiln exhaust air flow. As a result of the humid and warm exhaust air flow cooling down, a proportion of the moisture content of the air flow is condensed and this exits the heat exchanger as warm water. Analysis indicates that the amount condensed is approximately 22.4% of the amount of water evaporated from each batch on average. Recovery of this water may allow its direct or indirect re-use in other parts of the process, including steeping and germination. A potential secondary benefit is that the water exits the glass tube heat exchanger at a temperature of 20-25°C. This is warmer than borehole or mains water (at approximately 10°C) and as such it may offer benefits in steeping or germination, in terms of process speed. It is thought that no significant barriers exist to the recovery of condensate in the sector. No attempt has been made to quantify the benefits of recovering the condensate, due to lack of information on water costs and water use in the industry.


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5.2.10

62

Summary

Table 25 below outlines the advantages and disadvantages of each of the good practice opportunities, including the carbon emission reduction and payback periods.

Table 25 Advantages and disadvantages of the good practice opportunities Opportunity

Anaerobic digestion

Advantages Generates bio-gas suitable for combustion in boilers or CHP, use as vehicle fuel or injection to the gas grid Feedstock flexibility Displacement of mineral fertiliser with digestate can reduce the GHG impact of agriculture

CHP

29,000t CO2, 5 years Highly efficient means of generating heat and electricity Potential to generate revenue from sale of excess electricity to the grid

Heat recovery survey

230 t CO2, 1 year No / low cost Easily implemented

Improved management of compressed air Condensate recovery High efficiency motors

Monitoring & targeting

Variable speed drives Voltage optimisation

1,250 t CO2, 3 years Established techniques and savings Simple implementation 940 t CO2, 1 year Established technology Efficiency is key in motors with high annual operating hours 15,300 t CO2, 1 year Established techniques and savings Enables detailed insight into how and when processes use energy Rapid return on investment possible 2,350 t CO2, 3 years Established technology 2,350 t CO2, 4 years Suitable for most sites Very high reliability

Disadvantages Requires dedicated feasibility study for each site Require access to adequate land to accept digestate Additional operating costs Process integration can be difficult, particularly for heat Relative movement of gas and electricity prices can alter the economics of CHP over time Additional operating costs No direct savings as a result i.e. savings only realised when survey recommendations are implemented Savings can be difficult to measure Low savings Cost effective only when existing motor is due for replacement Collection of reliable data can be an issue Requires management time and expertise to analyse data and identify savings Savings result only if action is taken on the data collected Largest opportunities already implemented Tapping down own transformers may be cheaper and give a partial saving

The following chart shows the relative capital costs (x-axis) payback period (y-axis) and CO2 savings (label and diameter of bubble) for each of the good practice opportunities.


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Figure 35 Bubble diagram of capital costs, payback period and carbon savings for good practice opportunities

6

Payback (Years)

5

29,000 CHP 2,350 Voltage optimisation

4

1,250 Compressed air

3

2,350 VSDs 940 High efficiency motors

2

1

0

15,300 aM&T 230 Heat recovery survey £0

£5,000,000

£10,000,000

£15,000,000

Capital Costs

This shows: M&T as key measure with relatively low costs, short payback and significant CO2 savings. CHP is the most capital intensive and longest payback of the good practice measures, but CHP offers very significant CO2 savings. Other measures offer much lower CO2 savings, but at lower costs and paybacks up to 4 years .


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6…Next steps

This section describes our recommended next steps for the significant opportunities (larger than 10,000 tonnes CO2 p.a. sector-scale emissions reduction) discussed in Section 5.

6.1

Significant opportunities

Table 26 and Figure 36 below outline the significant opportunities, together with their estimated capital investment, payback period and CO2 savings. The level of confidence associated with these business cases is not currently sufficient for them to form the basis of investment decisions, rather they are intended to highlight areas that Maltsters should pursue and investigate further.

Table 26 Significant opportunities Opportunity Heat pumps, closed cycle Heat pumps, open cycle Energy efficient drying Burning woodchip Supply chain collaboration Kiln bed turning CHP Monitoring & targeting

Capital investment (£) £24,750,000 £75,000,000 £142,500,000 £21,000,000 £0 £7,500,000 £11,700,000 £950,000

Payback period (years) 6 5 14 5 0 6 5 1

CO2 savings (Tonnes CO2 p.a.) 33,000 115,000 85,000 38,000 43,000 10,750 29,000 15,300


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Figure 36 Bubble diagram of significant opportunities

18

16 85,000 Energy ef f icient drying

14

Payback (Years)

12 10 10,750 Kiln bed turning

8

33,000 Closed cycle heat pumps

6

38,000 Wood chip 4

115,000 Open cycle heat pumps

29,000 CHP 15,300 M&T

2

43,000 Supply chain 0 £0

£50,000,000

£100,000,000

£150,000,000

£200,000,000

Capital Costs Good practice opportunities

6.2

Innovative opportunities

Significant innovative opportunities

Following the completion of the investigation stage of the IEEA project, individual Maltsters and the MAGB are encouraged to review the opportunities and their business cases and decide which opportunities are the highest priorities for their sites, companies and the sector. Consideration should be given to collaboration with academia and equipment or knowledge providers. In the current economic climate in the UK at time of writing (March 2011), it is unlikely that funding support will be available from the Carbon Trust for demonstration of projects. The opportunities listed below are each likely to require R&D activity as well as a pilot project in order to develop sufficient confidence in their business cases to allow investment decisions to be taken. Heat pumps Direct temperature and humidity measurement Kiln bed turning Microwave technology There is a clear role for the MAGB to liaise with the relevant industry bodies for the Brewing and Distilling sectors on progressing certain opportunities that require supply chain collaboration, such as increasing final product moisture content. Other supply chain opportunities, such as biomass and AD, can be taken forward by individual Maltsters.


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The remaining innovative opportunities are considered to be more mature and able to be progressed by Maltsters relatively quickly. It is thought that suppliers can be identified and suitable systems can be designed and priced. In all cases, the innovative opportunities should be considered at times when major capital projects, such as kiln replacement, are being planned. Including innovation within major capital projects is likely to reduce their capital costs as inclusion in design is typically cheaper than retrofit. In summary, Maltsters are encouraged to: 1. 2. 3. 4. 5. 6.

6.3

Consider which innovative opportunities they can take forward themselves Consider which innovative opportunities require collaboration with other MAGB members, the MAGB itself, the supply chain, equipment or knowledge providers Confirm the development needs for each opportunity Conduct any necessary R&D work, potentially in collaboration with others Implement a pilot project Roll-out once sufficient confidence has been developed

Significant good practice opportunities

The good practice opportunities reflect well established methods for reducing energy consumption and these are considered to be cost effective. In particular, further implementation of Combined Heat and Power systems and Automated Monitoring and Targeting systems are considered to be significant opportunities for the sector. Maltsters are encouraged to: 1. 2. 3. 4. 5.

Confirm and quantify each opportunity for their sites individually, potentially using suppliers to do so Arrange for solution quotations from suppliers Secure funding Implement the projects Confirm the benefits of each project

Maltsters may find that implementing the remaining good practice opportunities may still be beneficial, and they are encouraged to review these in the same manner.


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Acknowledgements

The Maltstersâ&#x20AC;&#x; Association of Great Britain (MAGB) were key to engaging with the sector - we are grateful to them for facilitating initial contact with host sites, distributing communications and the questionnaire and providing insight, guidance and feedback throughout the project.

AEA are also grateful to the host sites for providing access to their sites and sharing process and energy data with the project.

AEA also wishes to thank all individuals who assisted us throughout this project.


Maltings Sector Guide

Appendices Appendix 1: Indicative metering locations Appendix 2: Opportunities not investigated Appendix 3: Workshop summary

68


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69

Appendix 1: Indicative metering locations Figure 37 Indicative metering points Raw Barley Intake

Ambient measurements

Waste Grain

Raw Barley Drying

Heat

Raw Barley Storage

Power

Screening and Weighing

Power

Water to air (evaporation) Grain to air (respiration)

Power

Steeping Grain to Waste Water

Water

Waste Water

Grain to air (respiration)

Germination

Power

Grain to air (evaporation)

Grain to air (respiration)

Heat

Kilning Grain to air (evaporation)

Waste Grain

Power

De-culming

Output to Brewing

Symbol

Parameter measured Electricity Natural Gas Relative humidity Temperature

Power


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Appendix 2: Opportunities not quantified During the course of the investigative stage of the IEEA project, several potential opportunities were identified for which business cases have not been quantified. These opportunities have been listed here, together with the rationale for not quantifying them. The criteria applied when deciding which opportunities to progress included whether opportunities were innovative to the sector, offer significant carbon emissions reductions across the sector and present low barriers to implementation. Individual Maltsters may still derive benefit from further investigation, and potentially implementation, of these opportunities.

Cooling of germination air with borehole water Germination air may require cooling in the height of summer, in order to keep the bed temperature within acceptable limits. Some Maltings sites employ refrigerant cooling system for this purpose. Where these are used, it may be possible to use borehole or mains water instead, especially if this water is to be used for steeping or other purposes already (i.e. not used for this purpose specifically). Benefits of cooling germination air with water include: Improved germination during periods of high ambient temperature Reduced electricity consumption (for sites with refrigerant germination air cooling systems) It has not been possible to quantify the benefits of this opportunity, as insufficient information was available. Only a single example of such a refrigerant system was seen during the site visits conducted in this project.

Freeze drying during pre-break phase Freeze drying was raised as a potential alternative for hot air drying during pre-break kilning. This option has been discounted due to the higher energy requirements of this form of drying compared with existing or alternative drying methods. The table below illustrates the difference in energy requirements between sublimation (transition from ice to vapour) and evaporation (transition from liquid to vapour) for water. It must be noted that the evaporation energy requirement is sensitive to pressure. Table Phase transition energy requirements

Phase transition Sublimation Evaporation

Energy requirement (kJ/kg water) 2,838 2,444

Other Heat recovery opportunities The largest heat recovery opportunity in the sector is identified in section 4.2, and potential solutions are shown in section 5.1.1. Several smaller heat recovery opportunities exist in the sector. These include heat recovery from the compressors (section 5.2.4) as well as two additional opportunities listed below.


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Heat recovery from germination exhausts The airflow coming from the germination beds has a slightly elevated temperature and moisture content due to the respiration of the malt in the beds. It may be possible to recover some of this energy in a similar manner, or into the same system, proposed in section 5.1.1. It must be pointed out that this source of energy would be renewable, as it is derived from the respiration of plants.

Heat recovery to offices The offices of a Maltings site use a relatively small amount of energy for heating purposes, during the heating season. It may be possible to recover process heat for use in the offices. This opportunity has not been taken forward as the demand is relatively small and seasonal.

Improved conveying technology Within a Maltings plant, Malt is typically moved between processes by conveyors. Whilst a typical Maltings plant has numerous conveyors, each of these is only a small electricity consumer which operates intermittently. No opportunities with significant carbon reduction potential were identified; hence this opportunity was not taken forward.

Improved water uptake in steeping Improved water uptake in steeping would reduce the length of the steeping process and hence the amount of energy required. As steeping is the least energy intensive of the major Maltings process steps, improving its energy efficiency will not lead to significant energy cost and carbon emission reductions. It is also thought that as long as the appropriate moisture content criteria are met, steeping does not have a major influence on energy consumption in the remainder of the process.

Maltings losses control Maltings losses control, or optimising yield, is something the Maltsters work at on a daily basis. Though yield has a direct bearing on the energy efficiency of a Maltings plant, no innovative improvements to current practices were identified. A general process improvement method is outlined in section 5.1.6 and this could be used to improve yield further.

Promote use of recycled water in process Maltings plants use significant amounts of water in their processes, particularly in steeping and germination. The steeping water can be recycled using suitable treatment processes such as Reverse Osmosis (RO) plants. RO plants have a significant energy demand and as a result increase the carbon emissions from a Maltings plant. Another source of recycled water may be the glass tube heat exchangers fitted to the kilns. These generate water by condensing vapour from the air flow coming from the kiln. This water may be suitable for re-use in steeping or germination, without the need for treatment. This opportunity has not been taken forward as it does not have a significant impact on the energy efficiency of the Maltings plant. It should be noted that this is a relatively simple and low cost opportunity to implement and it may recover some 20% of the water evaporated in a typical kiln.

Reduce malt blending requirements Malt is blended following kilning to ensure a consistent product quality. This process consumes a relatively small amount of energy. No innovative opportunities were identified which would offer significant reduction in carbon emissions associated with this process. However, it should be noted that implementation of kiln energy recovery (section 5.1.1) would reduce the need for blending if the heat exchangers are of the rotary dryer type. Kiln bed turning (section 5.1.5) would also reduce the need for malt blending.


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Appendix 3: Workshop summary The following workshop summary was prepared and circulated to the participants and MAGB mailing list following the workshop. As such it represents views that were held at the time, which may have changed since it was prepared. It is provided here for information. The findings of this IEEA Stage 1 project are presented in the main body of the report. Maltsters, equipment suppliers, research organisations and trade associations all came together to explore how opportunities to accelerate energy efficiency in the maltings sector can be taken forward. The workshop, held at Boortmaltâ&#x20AC;&#x;s Bury St Edmunds site on the 7th October, was part of the Carbon Trustâ&#x20AC;&#x;s Maltings Industry Industrial Energy Efficiency Accelerator (IEEA) project.

The day began with update on project progress to date from Jan Bastiaans, project manager at technical consultants, AEA. Jan outlined some of the carbon saving opportunities that have been identified through energy audits of maltings plants. His presentation also included some preliminary data from energy sub-metering that has been installed at two sites as part of the project and a discussion of some barriers to energy efficiency as identified through a recent survey of the industry. If you would like a copy of the presentation, please email MaltingsIEEA@aeat.co.uk .

The first group activity of the day utilised the depth and breadth of knowledge and experience in the room to generate as many potential opportunities for saving carbon in the maltings industry as possible. Almost 60 potential opportunities were identified, ranging from standard energy management practices like automated metering and targeting (aM&T), to truly innovative ideas that would require extensive R&D before they could be implemented, such as microwave drying. A list of the potential opportunities is given in tables A5.4 and A5.5 at the end of this paper.


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Each group was then asked to priorities these opportunities according to their ease of implementation and how effective they are likely to be at reducing the sectorâ&#x20AC;&#x;s carbon emissions. Opportunities were scored on scales from 1-3 for both ease and effect, with low scores indicating an opportunity is difficult to implement or is likely to have little effect on the sectors carbon emissions. A list of the potential opportunities is with their average ease and effect scores is given in tables A5.4 and A5.5 at the end of this paper. The Figure below shows the overall distribution of opportunities on the Ease and Effect scale. The size of the bubble indicates the number of opportunities at that position, the number within the bubble refers to the opportunity number in table A5.4.

Figure A5.1 Distribution of opportunities on the Ease and Effect scale

3

30, 31

13, 14, 15, 16

1

High

33

2

34, 35, 36

26 25 27 29

Medium

Effect score

32 9 8

17, 18, 19, 20, 21

5

2

10

28 12

6

11 7

1

22, 23, 24

3, 4

Low

37, 38

0 0

Difficult

1

Medium

2

Easy

3

Ease score

This analysis helped to separate out those opportunities that should be taken forward by the industry right away i.e. those that have a large carbon saving impact and are easy to implement, from the opportunities that are likely to require some time and/or external support to bring to reality i.e. those that have a large carbon saving impact but are difficult to implement. Based on the prioritised opportunities, an exercise was carried out to identify the drivers and barriers to improving energy efficiency in the maltings industry.


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These drivers and barriers were sorted into categories. Table A5.1 below lists the drivers for improving energy efficiency that were identified.

Table A5.1 Drivers for energy efficiency Category Policy

Finance

Business

People

Other

Driver description Government Policy and Legislation Regulation, including the maltings sector Climate Change Agreement, EU Emissions Trading Scheme and IPPC Rising and volatile cost of energy Energy cost savings Opportunity of making other cost savings Opportunity of carbon savings Improving plant utilisation Availability of external funding including soft loans and grants Business Objectives Competitiveness Customers Good for PR Branding Corporate Social Responsibility / Sustainability agenda within malting companies Personnel in the company already engaged and therefore drive energy efficiency from within Customer carbon footprint programme flows through to suppliers Brewers Corporate Reports asks questions of Maltsters Distillers (SWA) Environmental Initiative asks questions of Maltsters Customers favour improved environmental performance from suppliers Consumer preference for improved environmental performance Energy Security (long term)


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The table below lists the barriers to energy efficiency that were identified. Table A5.2 Barriers to energy efficiency Category Policy

Finance

Technology

People

Barrier Description Market Uncertainty Perceived lack of government incentive Issues of â&#x20AC;&#x17E;Carbon Leakageâ&#x20AC;&#x; Legislation Payback period for investments is too long in some cases Large capital expenditure is difficult to justify in the current economic environment Shortage of funding, both internally and externally Internal funding ceiling within companies Innovation has high initial outlay and uncertain returns Market and margin instability Operating expenditure Lack of resources e.g. management time to implement solutions Improvements are not always easy to demonstrate e.g. because monitoring data is inadequate Improvements are not always disseminated to other sites and companies Technical difficulty / availability Timescale to develop new technology suppresses innovation Executive buy in required Management commitment / drive required Shortage of expertise within companies /sector Supply chain acceptance of changes to process Lack of inter-sector communication around energy e.g. between maltsters, brewers and distillers Sacred cows - things that must not be changed e.g. due to importance of tradition Company awareness of energy / culture Customer requirements / specifications

Towards the end of the day, attendees were each asked to identify one concrete action that they could take away from the day. An impressive list of actions were produced, some of which can be progressed immediately by individual malting companies, some will required the coordination of the MAGB, and others will require further


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investigation by AEA and the Carbon Trust as part of the IEEA programme. The table below summarises the actions. Table A5.3 Actions from the workshop

Lead organisation(s) Actions to be progressed by individual malting companies

Actions to be progressed by the MAGB

Actions to be investigated further through the IEEA programme

Actions Investigate improved energy metering and monitoring Hold an internal energy meeting and prepare an energy plan for 2011 Raise awareness of energy on the shop floor Agree a company approach/strategy for energy efficiency Energy awareness training for all staff Share outputs of this workshop with others in the company Update the company energy plan Have a review of energy on the agenda for weekly meetings Continue to influence supply chain regarding uptake of biofertilisers Implement a structured Energy Management System Establish an MAGB Energy Forum Set up a meeting between the MAGB and the British Beer and Pub Association to discuss shared opportunities to improve the energy efficiency of both sectors Supporting R&D in new malting technology Investigate partial vacuum kilning pilot facilities Feasibility of increased moisture for MMI Malt Demonstration of improved metering and targeting In-process moisture measurement Feasibility of innovative kiln technology


Maltings Sector Guide

Table A5.4 Opportunities that fall within the scope of the IEEA project No.

1 2

77

13

Potential Carbon Saving Opportunities

Comparison of maintenance and efficiency of existing heat recovery equipment Automated Kiln Moisture Measurement - End point determination

Ease (average score) 3

Effect (average score) 3

3

2

3

Reduce the requirement for malt blending (handling) through better control of process variables to

3

1

4

Voltage optimisation

3

1

5

Compressed air optimisation

2.75

2

6

Direct Humidity measurement

2.75

1.5

7

Variation Measurement and Analysis

2.67

1.33

8

Monitoring and Targeting

2.6

2.2

9

Variable speed drives

2.5

2.5

10

Management of input and process variables

2.5

1.75

11

Direct moisture measurement

2.5

1.5

12

High efficiency motors

2.25

1.5

13

Challenge process specification by customers

2

3

14

Use of germination vessels for heat recovery to pre heat steep water

2

3

15

Use of microwaves in kilning process

2

3

16

Moving bed kilning

2

3

17

Cooling of germination air with borehole water

2

2

18

2

2

19

Steep to higher moisture, allow to dry during germination, go to kiln at lower moisture Improved conveying technology

2

2

20

Promote recycled water use in process

2

2

21

Investigate feasibility of changes to core process

2

2

22

Improve water uptake of barley during steep by vibratory EEPT

2

1

23

Recovery of heat from germination exhausts

2

1

24

Recycle waste heat for offices

2

1

25

Supply chain collaboration

1.8

2.4

26

Heat recovery

1.75

2.5

27

CHP

1.75

2

28

Kiln bed turning

1.75

1.75

29

Anaerobic Digestion

1.5

1.75

30

Falling bed kilning

1

3

31

Alternative heat sources e.g. biomass

1

3

32

Partial vacuum kilning

1

2.8

13

Opportunities were scored from 1-3 for ease and effect, with low scores indicating an opportunity is difficult to implement or is likely to have little effect on the sectors carbon emissions.


Maltings Sector Guide

78

33

Freeze drying during pre-break phase

1

2.5

34

Coordinating use of co-products through supply chain

1

2

35

Green malt syrup - revisit

1

2

36

Cold' milling

1

2

37

Condensate recovery (glass tube heat exchange)

1

1

38

Maltings losses control

1

1


Maltings Sector Guide

79

Table A5.5 Opportunities that would fall outside the scope of the IEEA project Potential Carbon Saving Opportunities

Ease (average score)

Effect (average score)

Education of staff / managers

3

3

Phasing production to suit cheaper night tariffs

3

3

Senior level lead on energy efficiency

3

3

Energy purchasing economies

3

3

BBPA / MAGB Energy Forum

3

2

Brewing sector to encourage maltsters to increase energy efficiency Closer collaboration with universities and research associations ISO 16000 Systematic approach. Dedicated person/team

3

2

3

2

3

2

MAGB Sector Energy Forum

3

2

Achievement of water and energy targets to be in each person’s results and objectives All non-energy efficiency investment to consider energy efficiency Full time energy manager

3

2

3

1.5

3

1

Energy efficiency investment given preferential treatment Positioning: Technical support organisation to prioritise demonstration projects / research Crossover technology with other industries

2.5

2.5

2

2

2

2

Optimisation of air flows

2

2

Look at all novel green fertilisers (farming)

2

2

Solar PV

1.33

2.67

Encourage banks to support green technology

1

2

Encourage government to hypothecate green taxes to support green research Influence marketing / brand managers to 'go green'

1

2

1

2

The Carbon Trust receives funding from Government including the Department of Energy and Climate Change, the Department for Transport, the Scottish Government, the Welsh Assembly Government and Invest Northern Ireland. Whilst reasonable steps have been taken to ensure that the information contained within this publication is correct, the authors, the Carbon Trust, its agents, contractors and sub-contractors give no warranty and make no representation as to its accuracy and accept no liability for any errors or omissions. Any trademarks, service marks or logos used in this publication, and copyright in it, are the property of the Carbon Trust or its licensors. Nothing in this publication shall be construed as granting any licence or right to use or reproduce any of the trademarks, service marks, logos, copyright or any proprietary information in any way without the Carbon Trust‟s prior written permission. The Carbon Trust enforces infringements of its intellectual property rights to the full extent permitted by law. The Carbon Trust is a company limited by guarantee and registered in England and Wales under Company number 4190230 with its Registered Office at: 6th Floor, 5 New Street Square, London EC4A 3BF. Published: May 2011.

© The Carbon Trust 2011. All rights reserved. CTG053

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