GHG emissions of biomass:
Consequence of modelling choices
Dr. Heinz Stichnothe
Johann 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 biofuels
RM
Co-products
Transp.
Field
Transp.
Convers.
Transp.
Use
Waste management
Land use change
Methodological approaches
• Attributional LCA
direct impacts due to diesel, fertiliser and pesticide use
standardised procedure (system boundaries, allocation, etc.)
used for product declaration and certification systems
Advantage: comparable
Disadvantage: blind spots
• Consequentional LCA
studies the consequences of change
activities in- and outside the LC effected by changes are investigated
includes 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 use
Cascade use (all burdens to first life)
Catch crops, crop rotation  shift of emissions
Allocation
• Energy content
• Exclusion of agricultural co-products
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 residues
EU-RED Annex 5 (18) Exclusion of nut shells, husk, etc
Input
Process
Output
Diesel
Pesticides
22 kg
Plantation
Fertilizer
FFB 1000 kg
Products
Compost
CPO
Diesel
Oil mill
Water
Kernel
By-Products
230 kg
0.07 L
Diesel
EFB
Fibre Shells
POME 650 kg
Electr . Steam
Energy
Shells
carrier
Emissions
Compost
plant
Biogas
plant
Biogas
Power plant
8.7 m ³ CH 4
Compost 92 kg
Ash
Air
Water
Soil
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 management
Biowaste “treatment” on palm oil plantations
GWP from EFB [CO2eq/ t FFB]
300
250
35% GHG reduction
200
150
50% reduction
100
50
0
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Anaerobic condition in the pile
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
Currently not specified in palm oil production systems according to EU-RED
100%
Indirect emissions
• Nitrogen fertiliser production
18 g N2O per kg N (average without N2O removal)
• After implementation of catalytic N2O reduction
measures in Western Europe
9 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 approach
Disadvantage: GHG emission savings are overestimated
Land use change - Indonesia
5
4,9
Assuming
100
t CO 25/ha
252eMt= CO
Mit
100 t CO
Mt=CO
50%
2e THG LW in D.
2e/ha = 2e
= 50% GHG German agriculture
Area [M ha]
4
3,7
3,3
4,4
3,9
3,4
3,0
3
2,5
2
1,2
1
0,7
0
1990
1995
2000
2001
2002
2003
2004
2005
2006
2007
Context
20000
Palm oil [1000*t]
18000
16000
14000
12000
10000
8000
16%
9%
6%
1%
6000
4000
55%
2000
38%
6%
0
Indonesia
Malaysia
18075
16100
India/China
14150
EU-27
EU-Food
EUIndustry
EU-Energy
5400
2988
2100
312
Limited resource - Oil
Limited resource - P
Limits
• National versus international responsibility
who 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?