Transcript Slide 1

Biomethane Review of UK
activity
Wardell Armstong LLP
Alan Midwinter
SGN Project Manager
29th September 2011
Who are SGN?
• Scotia Gas Networks –
Formed in June 2005 following
the acquisition of two gas
distribution networks from
National Grid (Scotland and
South of England)
• Owns and operates the second
largest gas distribution network
in the UK.
• Serving over 5.8 million
customers
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Why gas networks here?
DECC 2050 Pathways Study
Demonstrated that substantial electrification of heat and transport is
required in order to meet 2050 Targets (80% GHG emission reduction)
What is the future for the gas networks ?
ENA Gas Futures Group commissioned Redpoint to develop future gas
scenarios to 2050 and beyond :•
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Retaining gas infrastructure could be up to £700bn cheaper to UK plc
than a complete electrification solution
Require low carbon renewable gas (BIOGAS) for Bio-methane
Potential for Bio-methane injection - 50% of UK domestic heating load
DECC output targets for bio-methane are 7TWh p.a. by 2020
and could extend to 150-210 TWh per annum of renewable
gas by 2050
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Gas Futures Redpoint
Pathways
involving
significant
Biomethane to
Grid Injection
•Green Gas
•Gas Versatility
‘Green Gas’ Incentive
Low Carbon Energy Biogas
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UK produces 16 million tonnes of food waste (8 million tonnes from
households) and 90 million tonnes of animal waste annually with the majority
going to landfill.
•
Organic material degrades producing methane gas, 23 times more damaging
to the environment as a greenhouse gas than carbon dioxide.
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EU landfill directive obliges local authorities to send less biodegradable
waste to landfill, generating requirement to recycle or reprocess.
•
Anaerobic Digestion (AD) is a waste treatment process for organic waste,
recovering energy from waste in the form of biogas (50% to 65% methane)
•
Biogas traditionally has been used for Electricity generation but can be
cleaned for Biomethane injection or used as CNG for vehicle fuel.
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Government Incentives
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UK Government is committed to meet Greenhouse Gas Emission targets
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Landfill taxes – increasing to £80 per tonne.
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Energy recovery potential for AD could support 2,100 AD plants (50,000 t) will be required.
The Government has incentive schemes for the use of Biogas as a low carbon
energy
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15% reduction by 2020
80% reduction by 2050
Existing incentives FIT’s & ROC’s for electricity generation
RTFO’s for vehicle fuels
Government has now incentivised a scheme that will for the first time provide
long-term guaranteed financial support for renewable heat installations
•
Renewable Heat Incentive (RHI)
RHI & Bio-methane Injection
• Introduction of the RHI (July 2011) provides a sound economic
pathway for gas injection into the grid, financially attractive above
500 m3/h bio-gas (300 m3/h biomethane).
• Bio-methane RHI tariff is currently 6.8p / kWh
• 20 year tariff to include capital cost for all plant
• Degression of RHI tariff will feature once target volume is reached
• Bio-methane injection is 50% more efficient than electricity only
applications
• Important contribution to a stable and reliable energy supply
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Comparative Income
£/m
Biogas Plant Capacity m /hr
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Didcot - The Objectives
Project time-line
• SGN commissioned Feasibility
study in April 2009
• Project Approval April 2010
• 3 October 2010 SGN, working with
our partners, Thames Water and
Centrica, delivered the first Biomethane gas to Grid in the UK
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Key Objectives
• SGN used Innovation Funding to deliver a number of
important objectives:
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Understand Legislative and Regulatory issues
Improve understanding in relation into gas quality (Oxygen and
siloxanes in particular)
Understand the impacts of bio-methane on the operation and
configuration of the local gas network
Prove biogas clean-up and upgrading technology in the UK
Provide a ‘base-line’ for gas quality monitoring and associated
equipment from which lower cost options could be developed
Share Project learning and improve efficiency to the benefit of future
schemes
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Regulatory Requirements
• Safety (HSE)
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Transporters may only Transport gas that complies with
provisions of Gas Safety Management Regulations (GS(M)R)
Gas Transporters are obliged (by the Regulations) to take
sufficient measures to confirm that gas is compliant or must
not allow gas to flow
• Commercial (Ofgem and the Uniform Network Code)
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The bio-methane must have its energy measured in
compliance with Gas Thermal Energy Regulations
The processes must comply with appropriate UNC
arrangements
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Gas Quality Baseline
• Establish Biogas composition and available flow-rate
• Ensure the local SGN Network could accept the
volume of gas that will be produced on a 24/7 basis
• Establish biomethane gas quality requirement,
specifically around :
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Oxygen
Siloxanes
Calorific value
• Identify appropriate biogas clean-up and upgrading
technology for Didcot
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Key Objective Outputs
• Oxygen content could potentially be up to 2%
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HSE derogation would be required for >0.2%
• Siloxanes were likely to be present in the biogas
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Additional filtration equipment would be required
• The calorific value from the bio-methane would be lower
than the existing network values
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Enrichment with propane would be required
• Costs were likely to be high – SGN IFI Funding used
• The project could be implemented in 2010 and would
therefore provide valuable learning ahead of RHI
introduction in 2011
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How can AD Biogas become
Bio-methane
• Bio-gas from an anaerobic digester contains typically
Methane = 55 – 65%
CO2 = 35 – 40%
O2 = 0.1 – 0.5%
N2 = 0.5 – 2%
H2S = 200 – 2,000 ppm
Siloxanes (sewage only)
• Natural gas contains around 90% methane, with ethane, propane,
butane, CO2 and nitrogen making up the rest.
• To inject Biogas into the gas grid it is necessary to clean it and
upgrade it to biomethane
• Bio- methane is around 98% methane content
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The Didcot Project
Didcot Project – Before
injection (April 2010)
Digester
Gas Bag
Flare
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Why Didcot ?
• Existing Sewage Treatment Works with 2 Digesters
producing sufficient waste biogas
• Thames Water interested in the SGN proposition to
clean up the biogas, upgrade and inject into
the local SGN grid
• Practical details:
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Resilient local Network within 400m of site
Available space
Unlikely to have issues with planning authorities
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Didcot – The ‘GREEN’ Gas
process
Biomethane
Biogas
Biogas Clean-up and
upgrading Plant
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Site Location
Connection
to Gas
Network
Residential Area
that will use new
gas supply
Location of
New Plant
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Biomethane – The Process
Electricity
Output
Typical Bio-gas
AD
60-65% CH4
34-36% CO2
1%
O2
Gas
Storage
Gas Engines
Flare
CO2
Filters
Bio-gas Clean
Up Plant
(Water Wash)
Out of Spec
Bio-methane
Bio-methane
97-98% BioCH4
0.3%
O2
Propane
Upgrade
Network Entry
Valve (ESD)
Bio-methane to Grid
Entry Equipment
(Network Entry Assets)
Existing Gas
Network
Network Connection
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Filters for Siloxanes
and H2S
Site Layout
Water Wash
Process
Plant
Propane Storage
and Blending Plant
Gas Analysis
equipment
Biomethane
to Grid Plant
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Didcot Project (Apr – Oct 2010)
First Biomethane to grid plant in UK
DIGESTERS
GAS
STORAGE
UPGRADE
PLANT PROPANE
TELEMETRY
CLEAN UP
PLANT
CUSTODY TRANSFER
STN
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Biogas Clean-up and
Upgrading Equipment
• Established Water scrubbing
technology
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Removes CO2
Removes H2S
Removes most siloxanes
Dries the biogas
• Additional filtration to ensure
no siloxanes enter network
• H2S captured when it is
removed from the water and
not vented to atmosphere
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Propane Enrichment
Propane
Storage Tanks
Mixing
Vessel
Propane Tanks refilled by Tanker
every 3 to 4 weeks
Industry Review Group (GDNs, shippers, REA, Ofgem)
Sept-Oct 2010 agreed that adding propane to meet FWACV was necessary to
ensure customers were not being disadvantaged by bio-methane injection
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Biomethane Injection –
Equipment and Regulations
Gas Transporter must ensure :-
Regulation Requirement
Gas Quality Measurement
GS(M)R Reg 8 Schedule 3 pt 1
Pressure Control of gas delivery into network
GS(M)R & PSSR
Stenching Agent injection
GS(M)R Reg 8 Schedule 3 pt 1
Volume Flow Measurement
to enable calculation of gas quality
GS(M)R & Gas (Calculation of Thermal
Energy ) Regs
Gas Flow weighted average CV to
measure/record the energy of the gas
OFGEM Direction under the 1996 Gas
(Calculation of Thermal Energy ) Regs
COMPLIANCE -Telemetry to monitor & record to Gas Control Centre
SHUTDOWN - Emergency Shutdown System (ESD)
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Gas Network Considerations
• Key considerations that the project had to recognise •
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Charge to Consumers
Consumer Safety
Network Integrity
CV
H2S & Wobbe Number
Water dewpoint & Oxygen
(internal corrosion)
• Existing Constraints
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Currently only one OFGEM approved device (Danalyser)
Siemens Microbox (FWACV hardware – supervisory software)
Total sulphur & H2S measurement (MAXUM)
Hydrocarbon dewpoint measurement
High Pressure Metering Information System (HPMIS)
HSE - GAS SAFETY – GS(M)R
Fast Acting and Shut Off ( ESD)
Fast acting gas quality
sampling equipment
(H2O, H2S, S, CV, H2, O2 , etc)
Emergency Shut Down System
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GAS SAFETY – Stenching
Agent
Odorant injection system
GAS SAFETY - Pressure
Control & Metering
Accurate flow
measurement
Pressure control – entry into 2 bar MP
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OFGEM - Thermal Energy
SGN as the gas transporter were Directed
by OFGEM to use an approved type
Danalyser ( Gas chromatograph) that
enables highly accurate sampling.
Accurate to around 0.14 MJ/M3 (less than
0.4% error)
Accepted that this is an expensive solution
but there was no alternative for Didcot 2010
700 Series Danalyser
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Completed Project (1)
Digesters
Propane
Storage
Propane mixing
and injection
H2S and
Siloxane
filters
Biogas clean-up and
upgrading plant
Gas bag
Thames
Water control
room
Energy and quality Measurement,
odorant addition, telemetry to Gas
Control Centre
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Project at Completion
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Project at Completion (2)
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Project at Completion (3)
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Project Learning
Successes – All in it
together!!
Co-operation of
Regulatory Bodies
Single Party Delivery
of Project
Modular Construction
HSE
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OFGEM -
Positive support for 2% Oxygen
exemption
Timely Letter of Direction
Expedited verification of Danalyser
and other directed equipment
• SGN lead project delivery as principle contractor
supported by our technical partner CNG Services Ltd
• Excellent H&S record on congested site
• Significantly reduced construction period
Output of the Technology •
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Bio-methane quality of clean up plant established
Propane requirement less than anticipated
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Learning
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Location of Anaerobic Digestion - near gas grid
Capacity of the gas grid must be able to support facility
Operating pressure (IP or MP best)
Clean up technology and AD must be designed together to meet gas
and energy quality requirements – retrofit process performance
difficulties
Income balance between CHP (Fit’s) and grid injection (RHI) is
attractive
Network Entry Agreements – Must be appropriate
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Measurement
Telemetry
Nominations – link to gas sales
Communication
Design and Build Agreements – need industry standard
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Maintenance
Ownership and Responsibility for Plant
Plant Redundancy / Availability
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Future Challenges for
Bio-methane Injection
Technical Challenges for
Biomethane Injection
Technical barriers to Biomethane growth in UK
• Oxygen content / specification - GS(M)R – is it appropriate at 0.2%?
• CV enrichment with propane – not seen as green
• Cost - Gas Quality / Thermal Energy equipment
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Regulations and systems are designed for large volumes of gas.
GSMR data duplication - clean-up and network entry plant.
Increase diversity of suppliers for network entry systems
• Network Entry Agreement
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Historically designed for large facilities, need to be reflective of smaller
biomethane sources.
• Network Capacity Constraints
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Capacity re-engineering and suitable models to facilitate biomethane
entry
• Gas Transporters Licence exemption
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Class Exemption from section 6A of Gas Act for Biomethane
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Future Challenges for
Biomethane Injection
Socio-economic barriers to Biomethane growth in UK
 Clarity on ownership and funding for network entry equipment.
 Incentives for GDN’s within next Price Control Period?
 RHI degression from 2012 ?
 Feedstock suitability – varied feedstock contaminants / landfill gas 2012 ?
 Project Funding – (Energy from Waste AD facilities)
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Conclusions
Bio-methane could supply up to 50 % of domestic gas load here
in the UK.
Bio-methane into the Gas Grid is far more efficient than into the
electricity grid providing a sustainable gas supply
2020 UK Government target - generate 15% of national energy
requirement from renewable sources
The Gas networks currently have the infrastructure to deliver
this energy supply to the majority of our consumers .
Bio-methane injection is the best way to supply this low Carbon
energy into millions of homes and businesses
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The potential is huge…..
Thank you
Alan Midwinter
[email protected]
www.sgn.co.uk
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