ecoinvent: methodological issues around lca ghg emissions - the swiss approach
DESCRIPTION
ecoinvent: Methodological issues around LCA GHG emissions - the Swiss approach. Expert meeting LCA GHG methodologies for bioenergy: Beyond biofuels European Environment Agency, Copenhagen, 10 June 2008. Status in Switzerland. Full LCA is basis for tax reduction for biofuels 40% GWP reduction - PowerPoint PPT PresentationTRANSCRIPT
Niels JungbluthESU-services Ltd., Uster,
Rainer ZahEMPA and ecoinvent Centre, St. Gallen
Switzerland
ecoinvent: Methodological issues around LCA GHG emissions - the
Swiss approach
Expert meetingLCA GHG methodologies for bioenergy: Beyond biofuels
European Environment Agency, Copenhagen, 10 June 2008
www.esu-services.chPage 2
Status in Switzerland
• Full LCA is basis for tax reduction for biofuels– 40% GWP reduction– <125% of overall environmental impacts (UBP)
than fossil reference– Cradle to grave LCA one prerequisite
• Data provision by importers or producers of biofuels not from waste
• Common background database and methodology: ecoinvent v2.0
Harmonization of data collection in ecoinvent
• Collaboration of several research institutes and consultants
• Clear definition of product properties• Guidelines for methodology e.g. allocation,
land transformation• Standard assumptions, e.g. prices in
allocation, distances for biomass transports, regional storage
Allocation: Example Biogas
use, digested matter(0.71 kg)
disposal, organic waste(1 kg)
biogas(0.1 Nm3)
biogas plant
organic waste, to biogas plant(1 kg)
cleaning, filling station
agriculture
Allocation• Multi-output processes are stored in the database – BEFORE allocation• Input- and output-specific allocation factors, i.e.
individual allocation factor allowed per pollutant and input• Allocation executed after import of dataset into database
-> calculation of allocated unit processes-> matrix becomes invertible
• NO system expansion,NO creditsNO double counting of impacts
• All products included: fuel, electricity, heat, material, fertilizer, waste management, fodder, food, etc.
• Cut-off applied for outputs without economic value and wastes for recycling
Land use change:Clear cutting of primary forests
• Agricultural area is increased by clear cutting• Land transformation leads to CO2 emissions from soil
and biomass• Burning of residues with further emissions• Loss of biodiversity• CO2 from land transformation accounts for about 90%
of Brazil CO2 emissions• Particles from residue burning are an important
problem in South-East Asia
Principle of investigation• Increase in agricultural area for the production in the
reference year?• Emissions per m2 of clear cut land?• Allocation of emissions between wood production and
stubbed land• Stubbed land assumed the main driver• New elementary flow „CO2, land transformation“ as
used by IPCC for different possibilities of analysis • No indirect effects – double counting in a database!
Plant oil production
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
rape oil CH rape oil RER palm oil MY palm kernel oilMY
soybean oil BR soybean oil US Soya oil RER
fossil, non-CO2 CH4, biogenic CO2
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
rape oil CH rape oil RER palm oil MY palm kernel oilMY
soybean oil BR soybean oil US Soya oil RER
fossil, non-CO2 CH4, biogenic CO2 CO2, land trans
kg CO2-eq per kg oil at plant
Models for agricultural emissions
Indirect N2O emissions due to nitrate leaching are taken into account
www.esu-services.chPage 10
Capital goods must be included
• Share in GWP up to 10-30%• Especially important in agriculture with low usage
intensity• Exclusion would give wrong picture• Article published in the Int.J.LCA that gives further
details and recommendationsFrischknecht R, Althaus H-J, Bauer C, Doka G, et al., The environmental
relevance of capital goods in life cycle assessments of products and services. Int. J. LCA, 2007. DOI: http://dx.doi.org/10.1065/lca2007.02.309.
(Jungbluth et al. 2008: LCA of biomass-to-liquid fuels)
GWP reduction of BTL-Diesel
0 0.0002 0.0004 0.0006 0.0008 0.001
diesel
BTL
passenger car roadevaporation and tyre abrasion provision fuelcombustion, fuel
52%
65%
Neglecting parts of the life cycle leads to different conclusions concerning reduction potentials expressed as a percentage
www.esu-services.chPage 12
UBP 06
0% 100% 200% 300% 400% 500%
Eco-indicator 99
0% 100% 200% 300% 400% 500%
GWP
0% 20% 40% 60% 80% 100% 120%
Methane manure, optimizedMethane manure+cosubstrate, optimized
100% Recycled plant oil ME FREthanol whey CH
100% Recycled plant oil ME CHMethanol fixed bed CH
Methane woodMethanol fluidized bed CH
Ethanol sugar cane BREthanol grass CHEthanol wood CH
Ethanol sweet sorghum CNEthanol sugar beets CHMethane sewage sludge
Methane grass biorefinery100% Soy ME US
Methane biowaste100% P almoil ME MY
100% Rape ME CHMethane manure+cosubstrate
Methane manure100% Rape ME RER
Ethanol corn USEthanol rye RER
Ethanol potatoes CH100% Soy ME BR
BTL-fuel, miscanthus, ICFB-DBTL-fuel, short-rotation wood, CFB-DBTL-fuel, short-rotation wood, ICFB-DBTL-fuel, short-rotation wood, cEF-D
BTL-fuel, forest wood, cEF-DBTL-fuel, straw, CFB-DBTL-fuel, straw, dEF-DBTL-fuel, straw, cEF-D
BTL-fuel, straw, CH, cEF-DNatural gas, EURO3
Diesel, low sulphur EURO3P etrol, low sulphur EURO3
Comparison of biofuels
Conclusion from biofuels study
• A broad variety of investigated biofuels have a significant GWP-reducing potential
• Environmental impacts of biofuel pathways are more dependent on the raw material and its production, not on the type of product or conversion process
• Many biofuels from energy crops have higher overall impacts than fossil fuels
Conclusions (2)• Differences of biomass production to be considered:
– Natural variation: sun, soil, water, climate– Agricultural technology: Fertilization, irrigation,
pesticides use, machinery use– Specific issues: land transformation, burning
• ecoinvent data provides the best basis for such assessments: transparent, harmonized, unit processes that can be reworked, numerous background data
Niels JungbluthESU-services Ltd., Uster,
Rainer ZahEMPA and ecoinvent Centre, St. Gallen
Switzerland
Annexe
Problem setting“Ökobilanz von Energieprodukten”
• Diverging results for bioenergy and biofuels in separate studies in 2004
• ecoinvent data v1.3 covered only a part of bioenergy chains. No common database
• Aims to fully investigate the most important bioenergy chains transparent and publically available
• Main issue biofuels in Switzerland or imported• Support for energy policy (fuel tax reductions)• Examination for GHG reduction potential• Investigation of several environmental aspects of “biofuels”
supply chains
Possible classifications of fuels• Chemical classification of energy carrier
– methane, ethanol, methanol, hydrogen, oils, methyl ester, liquids (petrol, diesel), ETBE, MTBE
• Resources used– Non-renewable: crude oil, natural gas, coal, nuclear– Renewable: energy crops (edible, non-edible), algae, forest wood,
biomass residues, sun, wind• Type of conversion process
– mechanical, chemical reaction, thermal treatment, fermentation, anaerobic digestion, gasification, Fischer-Tropsch synthesis, biotechnical
• Marketing: – Sunfuel, Sundiesel, Ökodiesel, Biodiesel, Naturgas, 1st, 2nd, 3rd generation
Resources, conversion techniques and “bioenergy” products investigated
biomass ressources (crops, wood, residues)
biogas
transport devices
wood pellets
heating
combined heat and power plant
electricity
methanolBTL-fuelshydrogen
synthetic gasethanol
filling station
plant oils
fatty acid methyl ester
wood chips
Investigated biofuels
Methane 96%agriculturebiowastesludgewheygrasswood
Ethanol 99.7%woodgrasspotatoessugar beetswheysugar cane BRmaizerye DE / RER
Methanolwaste woodIndustrial wood
XMEWaste cooking oilRape seed CH/RERsoya oil US / BRpalm oil MY
BTLforest woodshort-rotation woodmiscanthusstraw
Data contributions
ESU-services•Project organisation•Methodology•Clear cutting•Gas upgrading and distribution•Validation
Carbotech•Agriculture•Biogas
ETH•Biogas•Chemicals•Agriculture•Ethanol
Infras•Transports
PSI•Transports
Data basev1.3
Doka•Waste management
Eners / LASEN•Synthetic fuels•Plant oils•Methyl ethers (XME)•Ethanol
Chudacoff•Chemicals
Raw data biogasName
Loca
tion
Uni
t biowaste, to anaerobic digestion
biogas, from biowaste, at
storage
disposal, biowaste, to anaerobic digestion
digested matter,
application in agriculture
Location 0 0 CH CH CH CH InfrastructureProcess 0 0 0 - - -
Unit 0 0 kg Nm3 kg kg biogas, from biowaste, at storage CH Nm3 1.00E-1 100.00 - - disposal, biowaste, to anaerobic digestion CH kg 1.00E+0 - 100.00 - digested matter, application in agriculture CH kg 7.12E-1 - - 100.00 heat, natural gas, at boiler condensing modulating >100kW RER MJ 5.94E-1 18.24 81.76 -
electricity, low voltage, at grid CH kWh 4.00E-2 18.24 81.76 - disposal, municipal solid waste, 22.9% water, to municipal incineration CH kg 1.00E-2 18.24 81.76 -
diesel, burned in building machine GLO MJ 1.80E-2 - - 100.00 transport, lorry 16t CH tkm 1.50E-2 - 50.00 50.00 solid manure loading and spreading, by hydraulic loader and spreader CH kg 1.00E+0 - 50.00 50.00
Carbon dioxide, in air - kg 5.95E-1 55.00 - 45.00
Carbon dioxide, biogenic - kg 7.05E-1 18.26 81.79 0.05 - Methane, biogenic - kg 8.53E-3 18.24 81.76 -
Inventory Clear CuttingName
Loca
tion
Infra
stru
ctu
reP
roce
ss
Uni
t clear-cutting, primary forest
round wood, primary forest, clear-cutting, at forest road
provision, stubbed
land
Location BR BR BRInfrastructureProcess 0 0 0
Unit ha m3 m2round wood, primary forest, clear-cutting, at forest road BR 0 m3 5.21E+1 100 -
provision, stubbed land BR 0 m2 1.00E+4 - 100 Wood, primary forest, standing - - m3 1.82E+2 29 71 Transformation, from tropical rain forest - - m2 1.00E+4 - 100 Transformation, to forest, intensive, clear-cutting
- - m2 1.00E+4 - 100
power sawing, without catalytic converter RER 0 h 1.24E+1 100 - Carbon dioxide, land transformation - - kg 1.20E+5 - 100 Carbon monoxide, fossil - - kg 7.84E+3 - 100 Methane, fossil - - kg 5.14E+2 - 100
Inventory agricultural product
Name
Loca
tion Uni
t soybeans, at farm
Location BRInfrastructureProcess 0
Unit kgOccupation, arable, non-irrigated m2a 1.97E+0Transformation, to arable, non-irrigated m2 3.93E+0Transformation, from forest, intensive, clear-cutting m2 6.22E-2Transformation, from arable, non-irrigated m2 3.77E+0Transformation, from shrub land, sclerophyllous m2 1.03E-1provision, stubbed land BR m2 6.22E-2
www.esu-services.chPage 24
Share capital goods(starting point, MJ fuel)
0%
20%
40%
60%
MJ-Eq kg Sb eq kg CO2 eq kg C2H4 kg SO2 eq kg PO4--- eq m3 m2a
cumulativeenergy demand
abioticdepletion
global warming(GWP100)
photochemicaloxidation, non-
b
acidification eutrophication water use landcompetition
BTL-fuel, miscanthus TUV BTL-fuel, straw CUTECBTL-fuel, straw FZK BTL-fuel, straw UETBTL-fuel, wood CUTEC BTL-fuel, wood TUVBTL-fuel, wood UET dimethylether, black liquor Chemrec
Questions to be answered
• Using BTL reduces the GWP by X% compared to fossil fuel
• Using a specific amount (e.g. 1 MJ or 1 kg) of BTL reduces the GWP by Y kg (or another appropriate unit) compared to fossil fuel
www.esu-services.chPage 26
Calculations of potential reduction
100%
38%
20%
15%
12%
And again: How much better are biofuels?
• If we want an answer like „the use of biofuel has ???% lower GWP than fossil fuels“ than we have to include the all parts of the life cycle, e.g. for transports also cars and streets
• Neglecting certain parts of the life cycle, even if the same for both options, will bias the results
• System boundaries must be stated correctly if comparing reduction figures, e.g. well-to-wheel should include the wheel
• See www.esu-services.ch/btl/ for background paper
0 200 400 600 800 1000
UBP [Pt/pkm]
Aggregated Environmental Impact
LCA of Biofuels: Main Results
-0.05 0.00 0.05 0.10 0.15 0.20 0.25
100% Rape ME CH
100% Rape ME RER
100% Palmoil ME MY
100% Soy ME US
100% Soy ME BR
100% Recycled plant oil ME CH
100% Recycled plant oil ME FR
Methanol fixed bed CH
Methanol fluidized bed CH
Ethanol grass CH
Ethanol potatoes CH
Ethanol sugar beets CH
Ethanol whey CH
Ethanol wood CH
Ethanol sweet sorghum CN
Ethanol rye RER
Ethanol corn US
Ethanol sugar cane BR
Methane grass biorefinery
Methane manure
Methane manure+cosubstrate
Methane manure, optimized
Methane manure+cosubstrate, optimized
Methane biowaste
Methane sewage sludge
Methane wood
Diesel, low sulphur EURO3
Petrol, low sulphur EURO3
Natural gas, EURO3
CO2-eq. [kg/pkm]
Cultivation
Production
Transport
Operation
Bio
dies
elEt
hano
lM
etha
neFo
ssil
GHG emissions
fossil benchmark
Mileage per hectare
short-rotation wood, cEF-Dshort-rotation wood, CFB-D
miscanthus, ICFB-D
short-rotation wood, ICFB-Dforest wood, cEF-D
Outlook
• Full LCA based on investigated data published in the framework of the project (http://www.esu-services.ch/bioenergy.htm)
• Life cycle inventories of BTL-fuels are published in EcoSpold format in a European project (www.esu-services.ch/renew.htm)
• Ongoing discussion on guidelines for tax exemption will further increase the need for reliable LCI data
• Shift of focus from fuel to fuel consumption