Life cycle analysis of bread production a comparison of eight different options

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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

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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 ecological optimisations or to reduce environmental implications, and what are the corresponding recommendations ?

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Goal definition

Functional unit:

1 kg bread ready for consumption at home.

Others:

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

System boundaries:

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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

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Life Cycle of the bread production

fuel

seed pesticide fertiliser

fuel oil drying T

flour-production T baking process retailer electricity natural gas fuel oil electricity grain flour bread transport grain cultivation T T home

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baking process: = factory flour production: = industrial mill crop production: = 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 bread seed harvest

Energy demand

transport to the farm potassium phosphorus pesticide application fertilizer application seed application plowing harrowing bread transport baking: factory process heat gas boiler process heat oil-boiler electricity supply flour transport industrial mill Electricity supply grain transport drying, stocking pesticide nitrogen

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Differentiation of important processes

Crop production:

conventional Ù organic

Baking technologies:

large bread factory Ù bakery Ù domestic bread maker

Flour production:

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1 2 3 4 5 6 7 8

8 scenarios to produce bread

organic conventional industrial mill industrial mill

factory bakery home home home home bakery factory

domestic mill

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0,0 2,0 4,0 6,0 8,0 10,0 M J/ kg br ead

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

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0,0 2,0 4,0 6,0 8,0 10,0 M J/ kg br ead

Energy demand

farming milling baking transport

conventional farming organic farming

0.0 2.0 4.0 6.0 8.0 10.0

industrial mill dom. mill industrial mill dom. mill

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Greenhouse effect

0 200 400 600 800 g C O2 -eqi v. /k g br ead

farming milling baking transport

conventional farming organic farming

industrial mill dom. mill industrial mill dom. mill

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Ozone depletion

0.00 0.10 0.20 0.30 0.40 0.50 0.60 g N 2 O/kg bread

farming milling baking transport

conventional farming organic farming

industrial mill dom. mill industrial mill dom. mill

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Acidification

0.00 0.50 1.00 1.50 2.00 2.50 3.00 g SO 2-equiv./kg bread

farming milling baking transport

conventional farming organic farming

industrial mill dom. mill industrial mill dom. mill

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Land use

0,0 0,5 1,0 1,5 2,0 m 2 /k g br ead 0.0 0.5 1.0 1.5

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Ozone depletion Acidification 0.0 2.0 4.0 6.0 8.0 10.0 MJ/kg bread 0 200 400 600 800 g CO 2 -eqiv ./kg bread 0.00 0.10 0.20 0.30 0.40 0.50 0.60 g N 2 O/kg bread 0.00 0.10 0.20 0.30 0.40 g PO 4 -equ iv ./kg bread 0.00 0.50 1.00 1.50 2.00 2.50 3.00 g SO 2 -equ iv ./kg bread

LCIA results

Energy demand Greenhouse effect

Eutrophication 0.00 0.50 1.00 1.50 2.00 con org m 2 /kg br ead

crop production milling baking transport

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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.

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bakery

Transport by the consumer

industrial mill

conventional crop production

home factory

home

organic crop production

home domestic mill retailer retailer home retailer industrial mill home factory home home domestic mill retailer retailer home retailer bakery

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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

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0.0 5.0 10.0 15.0 20.0 25.0 30.0 MJ/kg bread

Sensitivity analysis: transport

farming milling baking transport

basic scenario

industrial mill domestic mill

factory bakery

home

band-width extreme scenario

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Ozone depletion Acidification 0.0 5.0 10.0 15.0 20.0 25.0 30.0 MJ/kg bread 0 200 400 600 800 1000 1200 1400 1600 g CO 2 -eqiv ./kg bread 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 g N 2 O/kg bread 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 g PO 4 -equ iv ./kg bread 0.00 1.00 2.00 3.00 4.00 5.00 6.00 g SO 2 -equ iv ./kg bread

Sensitivity analysis: transport

Energy demand Greenhouse effect

Eutrophication

extreme scenario bandwidth

farming milling baking transport transport home

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0 5 10 15 20 25 MJ/kg bread

Transportation: Break even points

home bakery factory

0.9 km 0.5 km

farming milling baking transport transport home

– Energy demand – 4 km band-width extreme scenario basic scenario

factory

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Transportation: Break even points

farming milling baking transport transport home

– Energy demand –

conv. farming

organic farming

0 5 10 15 20 25 MJ/kg bread 0,2 km 4 km band-width extreme scenario basic scenario

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Transportation: Break even points

farming milling baking transport transport home

0 5 10 15 20 25 M J/ kg br ead 0 1 2 3 4 g SO 2-equiv./kg bred

– Energy demand – – Acidification –

4 km 3 km

4 km 0,2 km

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Results

Advantages and Disadvantages of each processing step:

Organic Industrial mill Bread factory Ù Ù Ù bakery Ù 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 Ù Ù Ù bakery Ù Conventional Domestic mill

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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

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Recommendations

Bread factories / Supermarkets

• Use cereals from organic production.

• Mount campaigns, that customers buy as much as possible

at once and if possible without driving detours (buy on the way from / to work etc.).

Bakeries

• Use cereals from organic production. • Optimise the energy demand.

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Recommendations

Consumer

• 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.).

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Thank you – mange tak !

Dr. Jörg Braschkat

Dr. Andreas Patyk

Figure

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References

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