methane emissions from biogas plants - the swedish voluntary agreement system and sustainability...
DESCRIPTION
Presentation held at the Nordic Biogas Conference 2012TRANSCRIPT
Methane emissions from biogas plants
The Swedish voluntary agreement system and sustainability criteria
Magnus Andreas Holmgren
SP Energy Technology
1Nordic Biogas Conference 2012
BACKGROUND
2Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
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)
Nordic Biogas Conference 2012
5
The Swedish voluntary agreement systemlaunched 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
Nordic Biogas Conference 2012
6
Biogas upgrading plants• Boden• Borås• Eskilstuna• Falköping• Göteborg (WWT)• Helsingborg (x2)• Jönköping (x2)• Kalmar• Kristianstad• Laholm• Linköping• Malmö (WWT)• Norrköping• Norrköping (WWT)• Skellefteå• Skövde• Stockholm, Bromma (WWT)• Stockholm, Henriksdal (WWT)
Biogas production plants• Boden• Borås• Eskilstuna• Falköping• Helsingborg• Jönköping• Kalmar• Kristianstad• Laholm• Linköping• Linköping (WWT)• Norrköping• Skellefteå• Skövde• Uppsala• Vänersborg• Västerås• Wrams Gunnarstorp
Nordic Biogas Conference 2012
• Uppsala• Västerås• Wrams Gunnarstorp• Östersund (WWT)
DESCRIPTION OF THE SYSTEM
7Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
9
System boundaries, Gas production plant
Nordic Biogas Conference 2012
Biogas plant
Liquid waste
Digestate
Recieving tank
Hygienisation
Mixing tank
Digester
Torch
Bolier/Gas motor/ Upgrading plant
Pretreatment unit
Digestate tank
Dewatering
Digestate storage
Solid waste
10
System boundaries, Gas upgrading plant
Nordic Biogas Conference 2012
Biogas pipeline
Propane addition
Compression
Hydrogen sulphide removal
Drying
Odorising
Upgrading plant
Gas grid
Off gas
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)
Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
Theory vs Reality
13Nordic Biogas Conference 2012
Measurement section:5 diameters upstream2 diameters downstream
RESULTS
14Nordic Biogas Conference 2012
15
Biogas production plants
Nordic Biogas Conference 2012
16
Biogas production plants
• Round 1: 2007-2009
• Rolling average: 2007-2012
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 %
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 %
Nordic Biogas Conference 2012
17
Gas upgrading plants
Nordic Biogas Conference 2012
18
Gas upgrading plants
• Round 1: 2007-2009
• Rolling average: 2007-2012
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 %
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 %Nordic Biogas Conference 2012
IMPACT
19Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
SUSTAINABILITY CRITERIA
23Nordic Biogas Conference 2012
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!
24Nordic Biogas Conference 2012
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 petroland 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
Nordic Biogas Conference 2012
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
Nordic Biogas Conference 2012
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
27Nordic Biogas Conference 2012
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…?
28Nordic Biogas Conference 2012