Life cycle analysis of bread production

– a comparison of eight different options –

G.A. Reinhardt, J. Braschkat, A. Patyk & M. Quirin

ifeu – Institute for Energy and Environmental Research Heidelberg

4th International Conference: Life Cycle Assessment in the Agri-food sector

Horsens (DK) from 6. – 8. October 2003

Questions

• How to produce bread being most environmentally friendly ?

• Which of the process steps, including transports, do account for the highest or lowest environmental effects ?

• At which processes is it feasible to introduce ecologicaloptimisations or to reduce environmental implications, andwhat are the corresponding recommendations ?

Goal definition

• Functional unit:

1 kg bread ready for consumption at home.

• Others:

Basic data, assumptions, allocation issues et cetera:see paper.

• System boundaries:

Production in Germany. Pre-chains: split worldwide.

Impact Assessment

Environmental impact Indicator Parameter

Resource depletion cumulated Crude oil, natural gas, non-renewable mineral coal, lignite, primary energy uranium ore

Greenhouse effect CO2-equivalents CO2, N2O, CH4

Ozone depletion N2O N2O

Acidification SO2-equivalents SO2, NOx, NH3, HCl

Eutrophication PO4-equivalents NOx, NH3

Photo smog Ethene-equivalents CH4, NMHC

Land use ha ha

Life Cycle of the bread productionfuelseed pesticide fertiliser

fuel oil drying T flour-production T baking

process

retailer

electricity

natural gas

fuel oil

electricity

grain flour

bread

transport

grain

cultivation

TThome

bakingprocess:= factory

flourproduction:

= industrial mill

cropproduction:

= conventional

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

MJ/

kg b

read

seed

harvest

Energy demand

transport to the farm

potassiumphosphorus

pesticide applicationfertilizer applicationseed applicationplowingharrowing

bread transport

baking: factoryprocess heat

gas boiler

process heat oil-boiler

electricity supplyflour transportindustrial mill

Electricity supplygrain transportdrying, stocking

pesticide

nitrogen

Differentiation of important processes

• Crop production:

conventional organic

• Baking technologies:

large bread factory bakery domestic bread maker

• Flour production:

industrial mill domestic mill

1 2 3 4 5 6 7 8

8 scenarios to produce bread

organicconventional

industrialmill

industrial mill

factory homebakery home bakeryhome factoryhome

domesticmill

0,0

2,0

4,0

6,0

8,0

10,0

MJ/

kg b

read

industrial mill domestic mill

factory bakery home

Energy demand

farming milling baking transport

0.0

2.0

4.0

6.0

8.0

10.0

0,0

2,0

4,0

6,0

8,0

10,0

MJ/

kg b

read

Energy demand

farming milling baking transportconventional farming organic farming

0.0

2.0

4.0

6.0

8.0

10.0

industrial mill dom. mill industrial mill dom. millfactory bakery home factory bakery home

Greenhouse effect

0

200

400

600

800

g C

O2-

eqiv.

/kg

brea

dfarming milling baking transport

conventional farming organic farming

industrial mill dom. mill industrial mill dom. millfactory bakery home factory bakery home

Ozone depletion

0.00

0.10

0.20

0.30

0.40

0.50

0.60

g N 2

O/k

g br

ead

farming milling baking transportconventional farming organic farming

industrial mill dom. mill industrial mill dom. millfactory bakery home factory bakery home

Acidification

0.00

0.50

1.00

1.50

2.00

2.50

3.00

g S

O2 -e

quiv

./kg

brea

dfarming milling baking transport

conventional farming organic farming

industrial mill dom. mill industrial mill dom. millfactory bakery home factory bakery home

Land use

0,0

0,5

1,0

1,5

2,0

m2 /k

g br

ead

0.0

0.5

1.0

1.5

2.0 conventional farming organic farming

Ozone depletion Acidification0.0

2.0

4.0

6.0

8.0

10.0M

J/kg

bre

ad

0

200

400

600

800

g C

O 2-e

qiv.

/kg

brea

d

0.00

0.10

0.20

0.30

0.40

0.50

0.60

g N 2

O/k

g br

ead

0.00

0.10

0.20

0.30

0.40

g P

O4-

equi

v./k

g br

ead

0.00

0.50

1.00

1.50

2.00

2.50

3.00

g S

O2-

equi

v./k

g br

ead

LCIA results

Energy demand Greenhouse effect

Eutrophication

0.00

0.50

1.00

1.50

2.00

con org

m2

/kg

brea

d

crop production milling baking transport

Land use

Results

Organically produced grain has to be preferred to grain that was produced conventionally regarding all impact categories except land use.

Flour may be produced preferably in an industrial mill rather than in a domestic mill.

Ranking the bread baking process from the most to least advantageous option results in the order: factory, local bakery and domestic bread maker.

Sensitivity analysis for transportation

bakery

Transport by the consumer

industrial mill

conventional crop production

homefactory

home

organic crop production

home

domesticmill

retailer

retailer

home

retailer

industrial mill

homefactory

home

home

domesticmill

retailer

retailer

home

retailer

bakery

Assumptions

Basic scenario• Transport of bread from the bakery: by bicycle.

• Transport of grain, flour or bread from the supermarket: by car without driving detours (on the way from / to work etc.).

Extreme scenario

• Transport of 1 kg of bread, flour or grain by car (4 km round trip).

0.0

5.0

10.0

15.0

20.0

25.0

30.0

MJ/

kg b

read

Sensitivity analysis: transport

farming milling baking transport

basic scenario

industrial mill domestic mill

factory bakery home

band-width

extreme scenario

Ozone depletion Acidification

0.0

5.0

10.0

15.0

20.0

25.0

30.0

MJ/

kg b

read

0

200

400

600

800

1000

1200

1400

1600

g C

O 2-e

qiv.

/kg

brea

d

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

g N 2

O/k

g br

ead

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

g P

O4-

equi

v./k

g br

ead

0.00

1.00

2.00

3.00

4.00

5.00

6.00

g S

O2-

equi

v./k

g br

ead

Sensitivity analysis: transport

Energy demand Greenhouse effect

Eutrophication

extreme scenario

bandwidth

farming milling baking transport transport home

basic scenario

0

5

10

15

20

25

MJ/

kg b

read

Transportation: Break even points

home bakery factory

0.9 km0.5 km

farming milling baking transport transport home

– Energy demand –

4 km

band-width

extreme scenario

basic scenario

factory

Transportation: Break even points

farming milling baking transport transport home– Energy demand –

conv. farming organic farming 0

5

10

15

20

25

MJ/

kg b

read

0,2 km 4 kmband-width

extreme scenario

basic scenario

Transportation: Break even points

farming milling baking transport transport home

0

5

10

15

20

25

MJ/

kg b

read

0

1

2

3

4

g SO

2 -eq

uiv.

/kg

bred

– Energy demand – – Acidification –

4 km3 km4 km0,2 km

conv. farming organic farming conv. farming organic farming

Results

Advantages and Disadvantages of each processing step:

Organic

Industrial mill

Bread factory bakery

Conventional

Domestic mill

Domest. bread maker

Farming:

Milling:

Baking:

For the ultimate appraisal the transport of grains, flour or bread respectively, by the consumer is of evident importance.

Organic

Industrial mill

Bread factory bakery

Conventional

Domestic mill

Domest. bread maker

Recommendations

If land use is more important than all the other environmental impact categories:

grain from conventional farming has to be preferred to grain that was produced organically

If land use is of minor relevance compared to saving of resources, greenhouse effect, ozone depletion, acidification and eutrophication:

grain from organic farming has to be preferred to grain that was produced conventionally

Recommendations

Bread factories / Supermarkets

• Use cereals from organic production.

• Mount campaigns, that customers buy as much as possibleat once and if possible without driving detours (buy on the wayfrom / to work etc.).

Bakeries

• Use cereals from organic production.

• Optimise the energy demand.

• Mount campaigns, that customers don`t use the car to buy bread.

RecommendationsConsumer

• Buy bread from organically grown cereals in a supermarket.

- If bread from organic grain is not available in the supermarket, customers have to ask for it to increase the demand and ...

- ... buy it in a bakery.

• If baking at home, cereals from organic production and flour from industrial mills have least environmental implications.

- Use a domestic bread maker instead of an oven.- If an oven is used, increase the degree of utilisation.

• Don’t use a car to transport bakery products. If a car is used, buy also other groceries and without driving detours (on the way from/to work etc.).

Thank you – mange tak !

Dr. Jörg Braschkat

Dr. Andreas Patyk

Dr. Markus Quirin