Industrial Energy Efficiency Accelerator - Guide to the ... · Industrial Energy Efficiency...

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

Maltings Sector Guide 2

Energy use within the sector

The Maltings sector uses some 1,375 GWh1 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


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 Implementation costs (£)

Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable

(%)

Heat pumps, closed cycle

£24,750,000 £4,500,000 33,000 £750 6 100%

Heat pumps, open cycle

£75,000,000 £14,650,000 115,000 £640 5 100%

Energy efficient drying

£142,500,000 £10,400,000 85,000 £1,675 14 100%

Burning Maltings co-

£13,000,000 -£27,000,000 40,000 £320 None 100%


products Burning woodchips

£21,000,000 £4,200,000 38,000 £550 5 26%

Direct T & RH measurement

£1,130,000 £580,000 4,700 £240 2 100%

Kiln bed turning

£7,500,000 £1,300,000 10,750 £700 6 67%

Process management

£55,000 £200,000 1,750 32 <1 100%

Supply chain collaboration

£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


Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable

(%)

CHP £11,700,000 £2,285,000 29,000 £405 5 48%

Heat recovery survey

£5,000 £30,000 230 £22 <1 100%

Compressed air

£435,000 £145,000 1,250 £350 3 100%

High efficiency motors

£72,000 £100,000 940 £75 1 100%

Monitoring & targeting

£950,000 £1,650,000 15,300 £62 1 70%

Variable speed drives

£810,000 £250,000 2,350 £350 3 100%

Voltage optimisation

£925,000 £250,000 2,350 £390 4 70%


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.

29,000 CHP

15,300 M&T

33,000 Closed cycle heat pumps

115,000 Open cycle heat pumps

85,000 Energy ef f icient drying

38,000 Wood chip

43,000 Supply chain

10,750 Kiln bed turning

0

2

4

6

8

10

12

14

16

18

£0 £50,000,000 £100,000,000 £150,000,000 £200,000,000

Payb

ack (

Years

)

Capital Costs

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

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.


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 Methodology 25

3.1 Metering and data gathering 26

3.2 Engagement with the sector 27

3.3 Understanding drivers and barriers 27

4 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

5 Opportunities 39

5.1 Innovative opportunities 38

5.2 Good practice opportunities 55

6 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


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.


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 Maltsters‟ 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 sector‟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

http://www.ukagriculture.com/


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

Raw Barley Drying

Raw Barley Storage

Screening and Weighing

Steeping

Germination

Kilning

De-culming

Output to Brewing

Heat

Power

Power

Power

Power

Heat

Power

Power

Waste Grain

Water to air (evaporation)

Grain to air (respiration)

Grain to Waste Water

Waste Water

Water


Grain to air (evaporation)



Waste Grain


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 “dry stands”. 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 – 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


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 Pre-

break 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.


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.


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)

Natural Gas

(GWh)

Fuel Oil (GWh)

Coal (GWh)

LPG (GWh)

Kerosene (GWh)

Gas & Diesel Oil (GWh)

Total (GWh)

Mean site use

7 38 5 0 0 1 1 52

Total 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 sector‟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

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Energy Emissions

Gas Oil/ Diesel Oil

Kerosene

LPG used

Coal

Fuel Oil

Natural Gas

Electricity


Figure 5 shows that there is a strong relationship between output and energy consumption, indicating that energy

use is closely aligned with production.

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

0

20

40

60

80

100

120

140

160

0 50,000 100,000 150,000 200,000

Tota

l En

erg

y C

on

sum

pti

on

(G

Wh

/yr)

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

0200400600800

1,0001,2001,4001,600

0 50,000 100,000 150,000 200,000

SEC

(kW

h/t

e)

Throughput (te/yr)

(b)

0

1

2

3

4

5

6

7

Nu

mb

er

of

site

s

SEC (kWh/te)

(a)


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.


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.


Figure 8 Current degree of implementation of ‘standard’ energy management measures in the UK Malting Industry (questionnaire results)

0% 20% 40% 60% 80% 100%

Automated Monitoring and Targeting

Air leak detection

Motor management policy

Boiler Plant Metering and Targeting

Implementation of energy strategy and policy

Formal energy strategy and policy

Proactive boiler maintenance and servicing

Proportion of sector potential

Figure 9 Current degree of implementation of ‘standard’ heat energy efficiency measures in UK Malting Industry (questionnaire results)

0% 20% 40% 60% 80% 100%

Ground Source Heat Pump to preheat cold …

Boiler sequencing and pressure optimisation

Automatic steam controls

Heat recovery from boiler flue gasses

Condensate return heat recovery systems

PLC combustion control and O2 trim on burners

High efficiency boilers (net thermal efficiency …

Heat recovery from kiln air

Insulation of hot water, oil and air ducts

Proportion of sector potential


Figure 10 Current degree of implementation of ‘standard’ electrical energy efficiency measures in UK Malting Industry (questionnaire results)

0% 20% 40% 60% 80% 100%

Lighting controls e.g. presence detection

High efficiency lighting units

High efficiency electric motors (EFF1)

Variable Speed Drives

Electrical power factor correction

Proportion of sector potential implemented

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

0% 20% 40% 60% 80% 100%

Energy awareness raising campaign for all staff

Energy training for key staff

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.


Figure 12 Remaining potential for ‘standard’ practice energy efficiency measures in UK Malting Industry (questionnaire results)

0% 20% 40% 60% 80% 100%

Ground Source Heat Pump to preheat cold …

Combined Heat and Power generation

Turning kiln bed during kilning cycle

Renewable energy

Automatic steam controls

Automated Monitoring and Targeting

Boiler sequencing and pressure optimisation

Lighting controls e.g. presence detection

High efficiency lighting units

Heat recovery from boiler flue gasses

Air leak detection

Condensate return heat recovery systems

Energy awareness raising campaign for all …

Control of kilning cycle based on direct …

PLC combustion control and O2 trim on …

Motor management policy

High efficiency electric motors (EFF1)

Control of germination based on direct …

High efficiency boilers (net thermal …

Variable Speed Drives

Energy training for key staff

Boiler Plant Metering and Targeting

Implementation of energy strategy and policy

Formal energy strategy and policy

Insulation of hot water, oil and air ducts

Proactive boiler maintenance and servicing

Heat recovery from kiln air

Electrical power factor correction

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.


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 companies‟ 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)

0% 20% 40% 60% 80% 100%

Sustainability

Corporate and Social Responsibility

Water Security

Brand Image

Energy Security

Customer Satisfaction

Food safety

Production Costs

Energy Efficiency

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.


Figure 14 Uses of UK Malt in 20083

Distillers48%

Brewers40%

Other food and drink

3%Export

9%

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)

0% 20% 40% 60% 80% 100%

Does your company have GHG emission reduction targets?

Does your company monitor greenhouse gas (GHG) emissions?

Does your company have energy efficiency targets?

Does your company monitor energy use?


Yes No Don't know

3 Source MAGB


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)

0% 20% 40% 60% 80% 100%

Does your company publish GHG emission reduction targets?

Does your company publicly report greenhouse gas (GHG) emissions?

Does your company publish energy efficiency targets?

Does your company publicly report energy use?


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)

0%

20%

40%

60%

80%

100%Energy Cost

Regulation

Customer Pressure

Internally Driven

Investor Driven

Other


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.


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.


o 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)


o Kiln moisture (air flow and bed)

o Electricity to kiln fans

o Gas to kilns

o Kiln temperature

o Ambient temperature

o Ambient humidity

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 Maltsters‟ 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.


We received 11 completed questionnaires from 6 companies. These six companies represent approximately

75% of the sector‟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.


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.


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

http://www.psychrometric-calculator.com/HumidAirWeb.aspx


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.


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 – 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


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 – as the response time to changes

in heat demand may be too slow. An example of this would be solid wood chip, biomass – 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.


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.


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 „typical‟ 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.

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

Daily

energ

y c

onsum

ptio

n (kW

h)

Time

Electricity Natural gas

Daily

energ

y c

onsum

ptio

n (kW

h)

Time


Daily

energ

y c

onsum

ptio

n (kW

h)

Time


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


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.

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

0

1,000

2,000

3,000

4,000

5,000

6,000

0 2000 4000 6000 8000

Heat

load

(kW

)

Hours

CHP Heat

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

0 2000 4000 6000 8000

Heat

load

(kW

)

Hours

CHP Heat

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

0 2000 4000 6000 8000

Heat

load

(kW

)

Hours

CHP Heat

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.


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 AEA‟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 Value

Sector annual heat energy consumption 1,176,854,289 kWh p.a.

Sector annual electricity consumption 196,264,539 kWh p.a. Average weighted fuel price 2.39 p/kWh Average natural gas price 2 p/kWh Average electricity price 6 p/kWh Electricity CO2 emission factor 0.545 kgCO2/kWh Natural Gas CO2 emission factor 0.185 kgCO2/kWh Number of sites in sector 27 Number of kilns in sector 45

The opportunities have been grouped into two broad categories:

Innovative opportunities – 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 – 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.


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. Opportunity Implementation

costs (£) Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t

CO2)

Payback (years)

Sites applicable

(%)

1 Heat pumps, closed cycle

£24,750,000 £4,500,000 33,000 £750 6 100%

2 Heat pumps, open cycle

£75,000,000 £14,650,000 115,000 £640 5 100%

3 Energy efficient drying

£142,500,000 £10,400,000 85,000 £1,675 14 100%

4 Burning Maltings co-products

£13,000,000 -£27,000,000 40,000 £320 None 100%

5 Burning woodchips

£21,000,000 £4,200,000 38,000 £550 5 26%

6 Direct T & RH measurement

£1,130,000 £580,000 4,700 £240 2 100%

7 Kiln bed turning

£7,500,000 £1,300,000 10,750 £700 6 67%

8 Process management

£55,000 £200,000 1,750 32 <1 100%

9 Supply chain collaboration

£0 £5,250,000 43,000 £0 0 100%

10 Microwave technology

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.


Figure 27 Location of opportunities within the Malting process

Raw Barley Intake

Raw Barley Drying

Raw Barley Storage


Steeping

Germination

Kilning

De-culming

Output to Brewing

Heat

Power

Power

Power

Power

Heat

Power

Power

Waste Grain




Waste Water

Water





Waste Grain

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

4

1

2

3

8

7

9

6

10

5


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)


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 Sector Average site

Implementation costs £24,7500,000 £920,000 Cost reduction £4,500,000 p.a. £165,000 p.a. Payback period 6 years 6 years CO2 reduction 33,000 tonnes CO2 p.a. 1,225 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Technical. Retrofit may not be technically viable for all sites. Barrier mitigation Supplier survey References 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

http://www.r744.com/component/files/pdf/thermea_broschuere_short.pdf

http://produktordner.thermea.de/english


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

Malt dryer(heat exchanger)

MVR

Condensatepump

Wet Malt

Condensate

Vapourextraction

Initial heat

Dry Malt

Recompressedvapour

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 30°C. 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).


An example multi-effect set-up is shown below.

Figure 30 Example arrangement of multi effect Malt drying system

Malt dryer (heat exchanger)

MVR

Condensate pump

Wet Malt

Condensate

Vapourextraction

Recompressed vapour


MVR

Condensate pump

Condensate

Recompressed vapour


Condensate pump

Condensate

MVR

Vapourextraction

Vapourextraction

Recompressed vapour

Dry Malt

Initial heat

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`


Table 8 Business case for open cycle heat pumps


Implementation costs £75,000,000 £2,800,000 Cost reduction £14,650,000 p.a. £540,000 p.a. Payback period 5 years 5 years CO2 reduction 115,000 tonnes CO2 p.a. 4,250 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Product quality concerns, technical viability Barrier mitigation 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.

References 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.’

http://www.barr-rosin.com/applications/evaporation.asp

http://www.windsorsathyam.com/evaporation_processes.html


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


Implementation costs £142,500,000 £5,300,000 Cost reduction £10,400,000 p.a. £385,000 p.a. Payback period 14 years 14 years CO2 reduction 85,000 tonnes CO2 p.a. 3,150 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Technical, Financial Barrier mitigation 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.

References www.triphasetechnologies.com

http://www.triphasetechnologies.com/


5.1.2 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


Implementation costs £13,000,000 £480,000 Cost reduction -£27,000,000 p.a. -£1,000,000 p.a. Payback period None None CO2 reduction 40,000 tonnes CO2 p.a. 1,500 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Financial. Not currently financially viable. Further benefits and value

may be available. Barrier mitigation None References http://www.esru.strath.ac.uk/Documents/MSc_2006/hamilton.pdf

5.1.3 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 http://www.ukmalt.com/maltindustry/industry.asp

7 MAGB, personal communication, average of £90/t and £160/t.

http://www.esru.strath.ac.uk/Documents/MSc_2006/hamilton.pdf

http://www.ukmalt.com/maltindustry/industry.asp


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


Implementation costs £21,000,000 £3,000,000 Cost reduction £4,200,000 £600,000 Payback period 5 years 5 years CO2 reduction 38,000 5,500 Number of sites where applicable 7 Barriers Logistics. Woodchip takes space to store. Barrier mitigation References http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energ

y_mix/renewable/policy/incentive/incentive.aspx

5.1.4 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

http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/policy/incentive/incentive.aspx

http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/policy/incentive/incentive.aspx


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


Implementation costs £1,130,000 £42,000 Cost reduction £580,000 p.a. £21,500 p.a. Payback period 2 years 2 years CO2 reduction 4,700 tonnes CO2 p.a. 175 tonnes CO2 p.a. Number of sites where applicable 27 Barriers Technical (sensor and sensor integration) Barrier mitigation R&D project References http://www.hydronix.com/

5.1.5 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.

http://www.hydronix.com/


Table 13 Business case for kiln bed turning


Implementation costs £7,500,000 £420,000 Cost reduction £1,300,000 p.a. £72,000 p.a. Payback period 6 years 6 years CO2 reduction 10,750 tonnes CO2 p.a. 600 tonnes CO2 p.a. Number of sites where applicable 18 sites, (30 kilns) Barriers Operational. Dust control may be an issue.

Technical. Some existing kilns may not be suitable for retrofit. Barrier mitigation Confirm benefit through measurement of GKV kiln bed turning. References

5.1.6 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.


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.


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


Implementation costs £55,000 £2,000 Cost reduction £200,000 p.a. £7,500 p.a. Payback period <1 <1 CO2 reduction 1,750 tonnes CO2 p.a. 60 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Knowledge/skills Barrier mitigation Training and experience References


5.1.7 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


Implementation costs £0 £0 Cost reduction £5,250,000 p.a. £195,000 p.a. Payback period - - CO2 reduction 43,000 tonnes CO2 p.a. 1,600 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Customer acceptance Barrier mitigation Negotiation References

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

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


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 – 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.


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 multi-

effect 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 Advantages Disadvantages

Heat pumps, closed cycle

33,000 t CO2, 6 years

Retrofit opportunity

Does not affect product quality

Relatively long payback period

Space requirements for heat exchangers may be limited

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

Technology may not be adaptable to evaporating water from solids – 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

Energy efficient drying 85,000t CO2, 14 years

Existing technology

Long payback period

Availability of market-ready solutions uncertain

Burning Maltings co-products Large carbon saving


Use of Maltings co-products is not financially viable at current animal feed prices

Burning woodchips

38,000 t CO2, 5 years

Large carbon saving


Attracts Renewable Heat Incentive

Fuel handling and storage may be an issue

Direct T & RH measurement

4,700 t CO2, 2 years

Relatively low cost of implementation

Short payback expected

Improved process control

Requires R&D to optimise technical solution

Kiln bed turning 10,750 t CO2, 6 years

Existing technique in GKVs 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


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

33,000 Closed cycle heat pumpts



4,700 Direct measurement


1,750 Process Management

43,000 Supply chain collaboration

38,000 Woodchip

0

2

4

6

8

10

12

14

16

18

£0 £50,000,000 £100,000,000 £150,000,000 £200,000,000

Payb

ack (

Years

)

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.


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


Saving (£ p.a.)

Saving (t CO2 p.a.)

Cost (£/t CO2)

Payback (years)

Sites applicable

(%)

Anaerobic digestion


CHP £11,700,000 £2,285,000 29,000 £405 5 48%


£5,000 £30,000 230 £22 <1 100%

Compressed air

£435,000 £145,000 1,250 £350 3.0 100%

Condensate recovery



£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%

5.2.1 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

http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/distributed_en_heat/chp/chp.aspx


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


Implementation costs £11,700,000 £900,000 Cost reduction £2,285,000 p.a. £175,000 p.a. Payback period 5 years 5 years CO2 reduction 29,000 tonnes CO2 p.a. 2,200 tonnes CO2 p.a. Number of sites where applicable 13 Barriers Technical. Integration with existing system may be difficult. Barrier mitigation References

5.2.3 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.


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.


Table 19 Business case for comparison of maintenance and efficiency of existing heat recovery equipment


Implementation costs £5,000 £200 Cost reduction £30,000p.a. £1,100 p.a. Payback period <1 years <1 years CO2 reduction 230 tonnes CO2 p.a. 10 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers Operational. Heat exchanger maintenance can be difficult. Barrier mitigation Adoption of best practice. References

5.2.4 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


Implementation costs £435,000 £16,000 Cost reduction £145,000 p.a. £5,500 p.a. Payback period 3 3 CO2 reduction 1,250 tonnes CO2 p.a. 50 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers None Barrier mitigation None References http://www.carbontrust.co.uk/publications/pages/home.aspx

http://www.carbontrust.co.uk/publications/pages/home.aspx


5.2.5 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.


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


Implementation costs £72,000 £2,700 Cost reduction £100,000 p.a. £3,700 p.a. Payback period 1 year 1 year CO2 reduction 940 tonnes CO2 p.a. 35 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers None Barrier mitigation None References http://www.carbontrust.co.uk/publications/pages/home.aspx

5.2.6 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



Table 22 Business case for monitoring and targeting


Implementation costs £950,000 £50,000 Cost reduction £1,650,000 p.a. £87,000 p.a. Payback period 1 year 1 year CO2 reduction 15,300 tonnes CO2 p.a. 800 tonnes CO2 p.a. Number of sites where applicable 19 Barriers None Barrier mitigation None References http://www.carbontrust.co.uk/publications/pages/home.aspx

5.2.7 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


Implementation costs £825,000 £30,500 Cost reduction £250,000 p.a. £9,250 p.a. Payback period 3 years 3 years CO2 reduction 2,350 tonnes CO2 p.a. 90 tonnes CO2 p.a. Number of sites where applicable 27 (all sites within the CCA) Barriers None Barrier mitigation None References http://www.carbontrust.co.uk/publications/pages/home.aspx

5.2.8 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




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


Implementation costs £925,000 £50,000 Cost reduction £250,000 p.a. £13,000 p.a. Payback period 4 years 4 years CO2 reduction 2,350 tonnes CO2 p.a. 125 tonnes CO2 p.a. Number of sites where applicable 19 Barriers Operational. The electricity supply must be de-energised during

installation. Barrier mitigation Appropriate scheduling References

5.2.9 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.


5.2.10 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 Advantages Disadvantages

Anaerobic digestion

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

Requires dedicated feasibility study for each site

Require access to adequate land to accept digestate

Additional operating costs

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

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


230 t CO2, 1 year

No / low cost

Easily implemented

No direct savings as a result i.e. savings only realised when survey recommendations are implemented

Improved management of compressed air


Established techniques and savings Savings can be difficult to measure

Condensate recovery Simple implementation Low savings


940 t CO2, 1 year


Efficiency is key in motors with high annual operating hours

Cost effective only when existing motor is due for replacement


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

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



Suitable for most sites

Very high reliability

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.


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

29,000 CHP

230 Heat recovery survey

1,250 Compressed air

940 High efficiency motors

15,300 aM&T

2,350 VSDs

2,350 Voltage optimisation

0

1

2

3

4

5

6

£0 £5,000,000 £10,000,000 £15,000,000

Payback (Y

ears

)

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.


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 Capital investment

(£) Payback period

(years) CO2 savings

(Tonnes CO2 p.a.)

Heat pumps, closed cycle £24,750,000 6 33,000 Heat pumps, open cycle £75,000,000 5 115,000 Energy efficient drying £142,500,000 14 85,000 Burning woodchip £21,000,000 5 38,000 Supply chain collaboration £0 0 43,000 Kiln bed turning £7,500,000 6 10,750 CHP £11,700,000 5 29,000 Monitoring & targeting £950,000 1 15,300


Figure 36 Bubble diagram of significant opportunities

29,000 CHP

15,300 M&T

33,000 Closed cycle heat pumps



38,000 Wood chip

43,000 Supply chain


0

2

4

6

8

10

12

14

16

18

£0 £50,000,000 £100,000,000 £150,000,000 £200,000,000

Payb

ack (

Years

)

Capital Costs

Good practice opportunities Innovative opportunities

6.2 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.


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. Consider which innovative opportunities they can take forward themselves 2. Consider which innovative opportunities require collaboration with other MAGB members, the MAGB

itself, the supply chain, equipment or knowledge providers 3. Confirm the development needs for each opportunity 4. Conduct any necessary R&D work, potentially in collaboration with others 5. Implement a pilot project 6. Roll-out once sufficient confidence has been developed

6.3 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. Confirm and quantify each opportunity for their sites individually, potentially using suppliers to do so 2. Arrange for solution quotations from suppliers 3. Secure funding 4. Implement the projects 5. 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.


Acknowledgements

The Maltsters‟ 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.


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


Appendix 1: Indicative metering locations Figure 37 Indicative metering points

Raw Barley Intake

Raw Barley Drying

Raw Barley Storage


Steeping

Germination

Kilning

De-culming

Output to Brewing

Heat

Power

Power

Power

Power

Heat

Power

Power

Waste Grain




Waste Water

Water





Waste Grain

Symbol Parameter measured Electricity

Natural Gas

Relative humidity

Temperature

Ambient

measurements


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 Energy requirement (kJ/kg water)

Sublimation 2,838 Evaporation 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.


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.


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

Boortmalt‟s Bury St Edmunds site on the 7th October, was part of the Carbon Trust‟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

[email protected] .

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.

mailto:[email protected]


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 sector‟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

37, 38

34, 35, 36

33

32

30, 31

29 28

27

2625

22, 23, 24

17, 18, 19, 20, 21

13, 14, 15, 16

12 11

10

9

8

7

6

5

3, 4

2

1

0

1

2

3

0 1 2 3

Effe

ct s

core

Ease score

Difficult Medium Easy

Med

ium

Low

Hig

h

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.


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 Driver description

Policy Government Policy and Legislation

Regulation, including the maltings sector Climate Change Agreement, EU Emissions Trading Scheme and IPPC

Finance 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 Business Objectives

Competitiveness

Customers

Good for PR

Branding

Corporate Social Responsibility / Sustainability agenda within malting companies People 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 Other Energy Security (long term)


The table below lists the barriers to energy efficiency that were identified.

Table A5.2 Barriers to energy efficiency

Category Barrier Description

Policy Market Uncertainty

Perceived lack of government incentive

Issues of „Carbon Leakage‟

Legislation Finance 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 Technology 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 People 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


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

Actions to be progressed by individual malting companies

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

Actions to be progressed by the MAGB

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

Actions to be investigated further through the IEEA programme

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


Table A5.4 Opportunities that fall within the scope of the IEEA project13

No. Potential Carbon Saving Opportunities Ease (average

score)

Effect (average

score)

1 Comparison of maintenance and efficiency of existing heat recovery equipment

3 3

2 Automated Kiln Moisture Measurement - End point determination 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 Steep to higher moisture, allow to dry during germination, go to kiln at lower moisture

2 2

19 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.


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


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

3 2

Closer collaboration with universities and research associations

3 2

ISO 16000 Systematic approach. Dedicated person/team 3 2

MAGB Sector Energy Forum 3 2

Achievement of water and energy targets to be in each person’s results and objectives

3 2

All non-energy efficiency investment to consider energy efficiency

3 1.5

Full time energy manager 3 1

Energy efficiency investment given preferential treatment

2.5 2.5

Positioning: Technical support organisation to prioritise demonstration projects / research

2 2

Crossover technology with other industries 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

1 2

Influence marketing / brand managers to 'go green' 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

Industrial Energy Efficiency Accelerator - Guide to the ... · Industrial Energy Efficiency...

Documents

Transcript of Industrial Energy Efficiency Accelerator - Guide to the ... · Industrial Energy Efficiency...