Opportunities and barriers for efficient energy use in a medium-sized brewery

B. Sturm Sir Joseph Swan Centre for Energy Research, Newcastle University

Thermal Energy Management in the Food and Drink Industry

Introduction

1. History of Brewing

2. Key figures of the British Brewing Sector

3. The Brewery investigated 1. Key figures

2. Data availability

3. State of the brewery

4. Waste heat recovery

5. Energy generation

6. Barriers to energy efficiency

4. Conclusions

History of Brewing

• Roman-Celtic Britain

• Middle ages

• 1400-1699

• 1700-1899 Industrialisation

Empire

• 1900 to present Megabreweries

Microbreweries

J. Amman, 16th century, The Brewer

Key Figures British Brewing Sector

Source: Hugenschmidt, 2011

0

20

40

60

80

100

120

0

100

200

300

400

500

600

700

800

2002 2003 2004 2005 2006 2007 2008 2009 2010

bee

r p

rod

uct

ion

[h

l 10

6]

per

cap

ita

con

sum

pti

on

[l]

Nu

mb

er o

f b

rew

erie

s

Year

annual production

annual consumption

per capita

breweries

Source: Pattinson, 2010

Beer Sales by Type

Energy Demands in Industrial Breweries

Source: Bonnaccelli et al. 2006

Wort boiling 30.0%

Mashing 30.0%

Packaging 20.0%

Warehouse 2.0%

Utilities 6.0%

Beer Processing 10.0%

Others 2.0%

Brewhouse 48% Fermentation and

storage 9%

Filtration 3%

Filling bottles 26%

Filling kegs 9%

Administrative department

6%

Source: Esslinger, 2009

Distribution of Thermal Energy Consumption

Development of specific energy demand

Source: British Beer and Pub Association, 2005

Energy demand as a function of size

0

40

80

120

160

200

240

1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

sp

ecif

ic e

nerg

y d

em

an

d [M

J/h

l]

annual beer production [hl]

e_el

e_th

Source: Feltschlaeger et al., 2003

Key figures of the brewery investigated

• Commercial brewery since early 18th century

• Current production: 250,000 hl/a

• 15 beers (ales and stouts)

• 90 % “standard“ beer (bottom fermented ale, 3.5 %)

• High gravity brewing

• 24 brews/week

• 195...240 MJ/hl 45...60 MJel/hl (ca. 25 %)

150...180 MJth/hl (ca. 75 %)

• 6.4...7.2 hlwater/hlbeer

Data available for the audit

• Gas and electricity bills • General information on the process and datasheets of

components • Protocols of wort boiling and other process steps

where available • Information from engineering manager and brew

master • Estimations and literature data as well as

measurements where necessary • Problem: statements like “a medium porridge“ are

difficult to quantify

State of the brewery set up

• Conventional gas boiler, no flue gas heat recovery

• Wort boiling Calandria more than 20 years old

Internal structure of copper wrong

No steam recovery

• Insufficient data acquisition

• Automatic process control only in parts of the fermentation and conditioning processes

• New variable power refrigeration system

• No variable speed drives in place

Process set up

Mashing

(65 °C)

Copper

(101 °C)

Fermentation

(20 °C)

Conditioning

(1 °C)

WP

HLT

(80 °C)

Malted grain

Chilled water (4...12 °C)

Trub

Spent Grain

Process Water (68...70 °C)

Steam

6 barBoiler

Hops

Wort

CAL

Water

Steam

Heating 65...101 °C

Steam

Cooling plant

238 kW max

17 % base load

Water

Thermal losses in the process

MT WC WP FV CT Total

0

50

100

150

200

250

300

350

400

He

at

Lo

sse

s [M

J]

Theoretical Energy Demand

0

500

1000

1500

2000

2500

3000

3500

Water (HLT) Wort heating Wort evap. Heat losses

En

erg

y D

em

an

d [

MJ]

Easily applicable measures

• Insulation, where they are worn out or not existing Pipes

HLTs

Vessels

• Enclosure Tanks and Vessels (close lids)

• Use waste heat for space heating, e.g. air compressors

• Use automated process control where it is already installed

Potentials for waste heat recovery and energy consumption reduction

• Boiler Flue gas heat recovery for existing boilers

Condensing boiler

• Copper Vapour heat recovery

Replacement of calandria or even copper

• Motors and Pumps Variable speed drive

Motor size reduction

• Air compressors

• Process control systems

Energy Supply

• Combined Heat and Power (CHP)

• Tri-Generation

• Renewable Energy Sources Solar PV

Solar thermal

Wind

• Energy from Waste Direct combustion (after drying)

Bio gasification

Barriers to Energy Efficiency

• Availability of data

• Lack of time

• High capital expenditures, prioritisation of investment

• Disruption of the production process during the installation period

• Possible Impact on beer flavour

• Possible Impact on beer quality

• New equipment has to be adjusted (to fulfil product specifications)

• Staff must get used to the modified production process

Conclusion

• Great potential for reduction of energy consumption

• Growing awareness and need for changes due to Rising energy costs

Growing pressure to become more sustainable

• Lack of knowledge and/or time to look into energy efficiency measures

• Financial constraints

• Reluctance due to Fear of changes in product quality

Lack of information

Thank You for Your Attention

Questions?