Methane emissions from biogas plants are measured and reported through a Swedish voluntary agreement system. The system involves plants conducting monthly leak detection and external parties quantifying emissions every 3 years. Results from 2007-2012 show average methane losses of 1.5% at biogas production plants and 1.6% at gas upgrading plants. The voluntary agreement has helped plants improve, with some reducing losses significantly. However, the system has had limited impact on researchers and policymakers. Sustainability criteria for biogas as a vehicle fuel in Sweden are based on EU directives and involve meeting greenhouse gas savings thresholds. Default loss values from the voluntary agreement are used in calculations to meet these criteria.

1. Methane emissions from biogas plants
The Swedish voluntary agreement system and
sustainability criteria
Magnus Andreas Holmgren
SP Energy Technology
magnus.andreas.holmgren@sp.se
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2. BACKGROUND
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3. The origins 2004/2005
Media
• Article in Svenska Dagbladet
2004 “Biogas as vehicle fuel has
no environmental advantage”
• Losses in production and
distribution of biogas
• Losses during filling
Research & Development
• Program for evaluation of
biological treatment (BUS) in
Sweden and Norway 2004-2005
covered methane emissions
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4. 4 reasons to act on methane emissions
• Environment
– Methane is a strong GHG (CO2 x 23)
– Odour
• Economy
– Reduced leaks and emissions = higher yield
• Safety
• Goodwill
– To show that the biogas sector acts responsibly
– To be pro-active on this issue (in relation to authorities)
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5. The Swedish voluntary agreement system
launched in January 2007
• Methane only
• Waste Treatment plant focus
• All work reported to Avfall Sverige
• First round of measurements 2007-2009
• Second round of measurements is on-going 2010-2012
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6. Biogas production plants Biogas upgrading plants
• Boden • Boden • Uppsala
• Borås • Borås • Västerås
• Eskilstuna • Eskilstuna • Wrams Gunnarstorp
• Falköping • Falköping • Östersund (WWT)
• Helsingborg • Göteborg (WWT)
• Jönköping • Helsingborg (x2)
• Kalmar • Jönköping (x2)
• Kristianstad • Kalmar
• Laholm • Kristianstad
• Linköping • Laholm
• Linköping (WWT) • Linköping
• Norrköping • Malmö (WWT)
• Skellefteå • Norrköping
• Skövde • Norrköping (WWT)
• Uppsala • Skellefteå
• Vänersborg • Skövde
• Västerås • Stockholm, Bromma (WWT)
• Wrams Gunnarstorp • Stockholm, Henriksdal (WWT)
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7. DESCRIPTION OF THE SYSTEM
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8. How the system is set up
• System for leak detection at plant
– Recommended monthly
• Systematic emission sources are identified
– Classification plans
• Quantification every 3 years by external resource
– Measurements of methane concentration and flow
– Calculations of mass emission and percentage loss
• Plant sets targets and measures to reach targets
• Plant reports to Avfall Sverige
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9. System boundaries, Gas production plant
Solid waste Bolier/Gas motor/ Digestate
Upgrading plant
Biogas plant
Pretreatment Torch
Digestate
unit
storage
Mixing
tank Dewatering
Recieving Hygienisation Digester Digestate
tank tank
Liquid waste
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10. System boundaries, Gas upgrading plant
Upgrading plant
Biogas
pipeline
Compression
Odorising
Hydrogen
sulphide Drying Gas grid
removal
Off gas Propane addition
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11. Typical measurement points for quantification
• Ventilation from process parts
• Ventilation from buildings
• Ventilation from rooms with gas equipment
• Digestion residue (digestate) storage
• Digestion residue (digestate) treatment (centrifuge etc.)
• Gas analysis instruments
• CO2 emission from gas upgrading plants (off-gas, e.g. stripper air)
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12. Measurement methods
• International and European Standard Methods (ISO/CEN)
– Methane concentration
– Gas flow
– Leak detection  mass flow estimations
• Methane measurements handbook
– SGC report no 227, February 2011
– Aimed at measurement personnel
– Section on strategies for leak detection
– Calculation spreadsheets (Excel)
– Default values
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13. Theory vs Reality
Measurement section:
5 diameters upstream
2 diameters downstream
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14. RESULTS
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15. Biogas production plants
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16. Biogas production plants
• Round 1: 2007-2009
Category Mean value Median
WWT 1,4 % 1,5 %
Household waste 2,0 % 1,1 %
Industrial waste 1,2 % 0,2 %
1,6 % 0,7 %
• Rolling average: 2007-2012
Category Mean value Median
WWT 1,5 % 1,8 %
Household waste 2,1 % 1,0 %
Industrial waste 0,8 % 0,3 %
1,5 % 0,3 %
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17. Gas upgrading plants
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18. Gas upgrading plants
• Round 1: 2007-2009
Technique Mean value Median
Chemical scrubber 0,4 % 0,4 %
End-of-pipe 1,7 % 1,7 %
PSA 2,5 % 1,8 %
Water scrubber 3,2 % 2,1 %
2,7 % 2,1 %
• Rolling average: 2007-2012
Technique Mean value Median
Chemical scrubber 0,2 % 0,2 %
End-of-pipe 1,0 % 0,7 %
PSA 2,5 % 1,8 %
Water scrubber 2,1 % 2,0 %
1,6 % 1,1 %
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19. IMPACT
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20. Improvements in industry
• Gas production plant, example
– 2007: Loss 7,5 %
– 2010: Loss <0,1 %
• Gas upgrading plant, example
– 2008: Loss 12 %
– 2010: Loss 7 %
– 2011: Loss 2 %
• Focus on methane losses during design and in permits
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21. Poor impact on researchers and policy makers
• Scientific article: Anaerobic digestion and digestate use: accounting
of GHG and global warming contribution
– Losses from gas upgrading are estimated at 0,2 % (without
reference to anything)
• University study on GHG emissions from biogas, on assignment from
Swedish Government
– No reference to Voluntary Agreement
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22. Waste Water Treatment plants
• Aprox. 130 plants with biogas production in Sweden
• A few plants take part in the voluntary agreement
• Measurements (outside the system) have been performed at a few
large plants
• In general there is poor knowledge of the size of methane emissions
from WWT biogas plants
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23. SUSTAINABILITY CRITERIA
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24. Sustainability criteria for biofuels and bioliquids
• A given set of sustainability criteria that cover the entire production
chain of a biofuel or bioliquid, from feedstock production to end use,
shall be fulfilled for it to be considered sustainable
• The Swedish legislative framework concerning biofuels and bioliquids
is based on the European Directive 2009/28/EC on the promotion of
the use of energy from renewable sources (RED), and is aimed at
suppliers and users of biofuels and bioliquids
• Covers biogas for vehicle use
– Not heat and power!
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25. Sustainability Criteria for biogas as vehicle fuel
• GHG emission savings (LCA)
– XX % better than the fossil reference case
– Same reference case for all vehicle fuels!
”average emissions from the fossil part of petrol
and diesel”
– All plants from April 2013: 35 %
– All plants from January 2017: 50 %
– New plants from 2018: 60 %
• RED default value for biogas from municipal organic waste: 73 %
– 1 % loss in production, 1 % loss in gas upgrading
– Included: Household waste, WWT sludge
– Not included: Industrial waste
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26. Voluntary Agreement and sustainability criteria
• Excel spreadsheet developed for the Swedish gas industries
– In co-operation with Swedish Energy Agency
• Need for default methane loss values when measurements have not
been performed
• Upper quartile of rolling average
– 2,5 % production
– 2,1 % upgrading
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27. Voluntary Agreement and sustainability criteria
• Using the default methane loss values:
– 2,5 % loss in production, 2,1 % loss in gas upgrading
– GHG emission savings: 56 % (prel.)
• Add to this the actual values for:
– Transportations of substrate (zero in RED default value!)
– Transportations of produced biogas
– Process energy use
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28. Sustainability criteria for biogas used in heat&power
• Legislation/recommendations that would cover gaseuous fuels for
heat and power (+ solid fuels)
• According to yesterday’s presentation by Mr Kuepker, DG Energy:
– Not yet decided if they will present directive or recommendations
• The reference case for GHG emission savings calculations might be
different to the present directive!!
– Natural gas for heat and power would be the natural reference!
• Tough times ahead…?
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