GHG emissions of biomass: Consequence of modelling choices

Dr. Heinz StichnotheJohann Heinrich von Thünen-Institut

Institute of Agricultural Technology and Biosystems Engineering

Braunschweig, Germany

Outline

• Methodological approaches

• Basis of comparison and allocation

• Indirect Emissionen (default values)

• Lack of knowledge

• Bio-based economy - limited resource

• Limits

• Conclusions

Life cycle of biofuelsRM

Transp.

Field

Transp.

Convers.

Transp.

Land use change

Use

Waste management

Co-products

Methodological approaches

• Attributional LCAdirect impacts due to diesel, fertiliser and pesticide usestandardised procedure (system boundaries, allocation, etc.)used for product declaration and certification systems

Advantage: comparable Disadvantage: blind spots

• Consequentional LCAstudies the consequences of changeactivities in- and outside the LC effected by changes are investigatedincludes alternative uses of constrained production factors

Advantage: more complete Disadvantage: less precise

Basis of comparison• Carbon intensity per energy output• Annual emissions

Not suitable for material useCascade use (all burdens to first life) Catch crops, crop rotation shift of emissions

• Energy content• Exclusion of agricultural co-products

Allocation

Specialities of palm oil

• Used as food, raw material and energy source

• Yield (PO 3.7, rapeseed 0.6; soja 0.4 t/ha)

• World production 45-50 Mt

• 86% occurs in Malaysia and Indonesia

• Export (approx. 80%)

• 250.000 ha/a 3. GHG-emitter

Agricultural residuesEU-RED Annex 5 (18) Exclusion of nut shells, husk, etc

Compostplant

FFB

Input Process

Diesel

Water

Biogasplant

EFB POME

Power plant

Fibre Shells Electr .

Biogas

Compost Ash

Plantation 1000 kg

92 kg

650 kg230 kg

Output

CPO

Kernel

AirWaterSoil

Energycarrier

Products

By-Products

Emissions

Oil mill

Diesel

Fertilizer22 kg

Pesticides

Diesel

0.07 L

Steam

8.7 m ³ CH 4

Compost

Compostplant

FFB

Input Process

DieselDiesel

WaterWater

Biogasplant

EFB POME

Power plant

FibreFibre ShellsShells Electr .Electr .

Biogas

Compost Ash

Plantation 1000 kg

92 kg

650 kg230 kg

Output

CPO

Kernel

AirWaterSoil

Shells

Products

By-Products

Emissions

Oil mill

DieselDiesel

Fertilizer22 kg FertilizerFertilizer22 kg

PesticidesPesticides

DieselDiesel

0.07 L

SteamSteam

8.7 m ³ CH 4

CompostCompostCompost

CH4 from POME

• Default value 27 g/MJ (1.5 times higher)

• CH4 capture - Yes or no

• No difference between flaring and utilisation• Use of biogas hampered by exclusion of by-

products (nut shells)• Efficiency of biogas capture is not

considered (THREAT: leackage can outbalance the benefits)

Biowaste managementBiowaste “treatment” on palm oil plantations

0

50

100

150

200

250

300

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Anaerobic condition in the pileG

WP

fro

m E

FB

[C

O2e

q/

t F

FB

]

1 t FFB = 0.2 t palm oil; 150 – 1125 kg CO2eq. per t Palm oil 4 – 30 g CO2eq/MJ Biodiesel: 37 g CO2eq/MJ

50% reduction

35% GHG reduction

Currently not specified in palm oil production systems according to EU-RED

Indirect emissions

• Nitrogen fertiliser production18 g N2O per kg N (average without N2O removal)

• After implementation of catalytic N2O reduction measures in Western Europe9 g N2O per kg N (current average)

• Technically possible 3 g N2O per kg N (future average in Western Europe)

In comparison approx. 10 g N2O is formed per kg N applied

Emission intensive fertiliser production is treated preferentially if Global default values are used; consequently GHG reduction from imported biomass might be overestimated

Direct emissions

• Organic Nitrogen is currently excluded in GHG calculations(examples in Annex V)

• IPCC 2006 Guidelines (table 11.1), the default emission factor is 1% of applied (inorganic and organic) N.

Example total N demand per t palm oil: 25 kg N, thereof 3,7 kg „returned“15% N input is not considered and consequently nitrous oxide from this input is also not taken into account

Advantage: Nutrient recycling is fostered; simplified approachDisadvantage: GHG emission savings are overestimated

Land use change - Indonesia

Mit 100 t CO2e/ha = 25 Mt CO2e = 50% THG LW in D.

0,7

1,2

2,5

3,0

3,33,4

3,73,9

4,4

4,9

0

1

2

3

4

5

1990 1995 2000 2001 2002 2003 2004 2005 2006 2007

Are

a [M

ha]

Assuming 100 t CO2e/ha = 25 Mt CO2e = 50% GHG German agriculture

Context

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

Pa

lm o

il [1

00

0*t]

18075 16100 14150 5400 2988 2100 312

Indonesia MalaysiaIndia/China

EU-27 EU-FoodEU-

IndustryEU-Energy

16% 9% 6% 1%

55%38%

6%

Limited resource - Oil

Limited resource - P

Limits

• National versus international responsibilitywho is contributing what to which extent

• Influence sphere• Default values versus „real values“,

management practise• Lack of knowledge – organic nitrogen, soil

carbon• Focus on GHG blind spots• Crude oil and phosphorous are limited

Conclusions

• Do we want to be accurate or comparable?Indirect land use change, soil carbon storage

• Technology - European average values for developing countries?

• Right incentives for imported biomass?• Simplification - overestimation of savings• For imported biomass

Learning curve yes, but GHG savings?