Shell Customer Day
UK Biomethane to Grid Developments
19th October 2011 John Baldwin CNG Services Ltd john.baldwin@cngservices.co.uk www.cngservices.co.uk 07831 241217
UK Experience with Gas Grid Injection • • • • • • • • • • •
CNG Services Ltd Didcot Biomethane Project Adnams Biomethane Project Biogas clean-up and upgrading Gas Enrichment Ofgem Review Process Biogas Utilisation Economics Market Forecast Green Gas Certificates Dual fuel trucks and high pressure grid Biomethane Conclusions
CNG Services Ltd • Cleaning bio-gas and injecting biomethane into the gas grid – Developer of Didcot project for Thames Water, SGN and Centrica – Working on 8 further BtG Projects in UK
• CNG Filling Stations – Development of new high pressure supplied CNG StationsLNG for vehicles/off-grid energy consumers
• Supporting development of onshore gas and storage projects – Ryedale Gas Project – Wingas Saltfleetby – Halite Preesall
We are independent from all makers of plant, vehicles, clean-up, compression....our aim is to support developers in projects which are gas engineering based but a bit complicated.....
BG Group Kazakhstan • We commissioned in July 2010 the first CNG filling station in Kazakhstan • 200 buses ordered for Asian games • CNG is the solution to air quality
Most major cities have air quality problems and so make CNG the fuel of choice for buses.......we should have CNG buses in UK, we have very few
Crewe CNG Station • We have re-opened our Crewe CNG station in August • Filling 5 CNG dual fuel trucks for GIST/M&S • http://www.youtube.com/watch?v=orxBtoXyjos
Largest grid supplied CNG station in UK – takes gas from 4 bar grid and so uses 20% less electricity compared to 0.5 bar grid. Shell supplied gas.
Didcot – UK’s First BtG Project
Digesters
Propane Storage Gas bag Propane Injector
Telemetry
Energy & quality Measurement
CSL – Designer and Project Manager H2S and Siloxane filters
Biogas upgrader
Flow of biogas - 100 m 3/hr First gas to grid on 3rd Oct 2010
Site Location
Connection to Gas Network
Location of New Plant
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Residential Area that will use new gas supply
Adnams – BioGroup – the UK’s first BtG Food Waste Project
CNG Services is providing design and other consultancy related to the injection of gas into NTS and biomethane sales
Biogas Clean up and Upgrading Technology Summary
Biogas Composition
• • • • • •
Methane 55 - 60% CO2 35 - 40% O2 0.1 – 0.5% N2 0.5 – 2% H2S 200 – 2,000 ppm Siloxanes (sewage biogas)
H2S and O2/N2 important Aim is to remove H2S, CO2 and dry the gas
Water Wash
• • • • •
99% of biomethane to grid, 1% methane slip Can recover heat from larger plants (from compressor cooling water) 14 m high Removes H2S and siloxanes Simple plant, as Didcot, likely to be lowest cost option at <500 m3/hr
Chemical Absorption
• 99.8% of biomethane to grid, <0.2% methane vented • Needs significant heat to raise steam regenerate the chemicals (around 10% of biogas energy) – can often recover most of this • Ideal if waste heat already available • Requires less propane • Less electricity if 2 bar grid
EU Experience of Biogas Clean-up and Upgrading
• Task 37 Report: • 42 Water Wash • 36 PSA • 23 Chemical Wash
• CSL staff have visited around 10 such plants including >500 m3/hr for each technology
Propane Enrichment Propane Storage tanks
Propane Mixing Vessel
• The Gross Calorific Value (GCV) in the GB gas grid is around 39 MJ/M3 • The typical biomethane GCV is 37 MJ/M3 • Propane has to be added to bring the CV up to 39 MJ/M3 • This is because of billing for natural gas
BtG Plant • The BtG plant is located after the Clean-up and Upgrading Plant and before the connection pipeline to the gas grid • BtG Plant comprises the following: • • • • • •
Odorant storage and injection Gas quality monitoring Gas CV measurement Gas flow measurement Pressure control Telemetry
Next slides show the major components
Odorant Plant
Odorant injection system
Gas Metering & Pressure Control Equipment
Accurate flow measurement
Pressure control â&#x20AC;&#x201C; entry into 2 bar MP
Gas Quality and CV Measuring Equipment 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
Ofgem Review • Ofgem are leading an industry wide review to establish consensus in relation to a number of key issues: – GDN Connection Policy/ownership for Biomethane Projects (see next slides) – Capacity for Biomethane – Technical standards associated with Calorific Value measurement for biomethane flows – Gas Quality Analysis at Biomethane entry – Transmission of data to the GDN's agent (Xoserve)
• First meeting on 27th Sept 2011 • Aim to complete by end 2011
Oxygen • GS(M)R limit is 0.2%, the industry needs 1% (ideally 2%) • Usually no blending option (as at Didcot)
• Key issue is corrosion if there are metal mains and the grid is wet • At present HSE may grant an exemption based on individual risk assessment in each case • HSE have reviewed Oxygen content in respect to GDN networks and are believed to be content to change specification to 1% subject to some additional data from GDNs • Hopefully, move to 1% in 2012
Biogas Utilisation Economics
Renewable Heat Incentive (RHI) • 6.7 p/kWh • This is on top of value of gas – around 2 p/kWh • Energy that can claim RHI adjusted: – First remove propane energy – Next, remove energy from external sources used to heat the AD
• Tariff fixed for 20 years, increases each year with inflation • The RHI gives broadly similar project returns to the electricity option RHI is attractive if there is no local use for waste heat
Electricity Feed In Tariff or ROCs • Biogas that generates electricity can an electricity Feed In Tariff (FIT) • For plants >500 kWh , FIT worth 9 p/kWh on top of the normal electricity price (which is around 4 p/kWh) • Or biogas that generates electricity can earn double ROCs (Renewable Obligation Certificates) worth around £45/MWh for 1 ROC
Most existing ADs in UK (they are located at sewage treatment works) earn 1 x ROCs
Renewable Transport Fuel Certificates • • • •
Compressed Biomethane (CBM) earns 1 X Renewable Transport Fuel Certificates (RTFC) 1 x RTFC worth around 20 p per KG of CBM Under EU Renewable Energy Directive double RTFCs for transport fuel made from waste 40 p/kg still not as good as income from electricity or for grid injection
300 m3/hr gives around 1 MWh of electricity with FIT of around £600k
500,000 therms into grid = 1 million kg = RHI of around £700k 1 million kg of CBM has RTFC worth around £400k – so vehicles will not run directly on biomethane
Dual Fuel Trucks and use of High Pressure Gas Grid for CNG
Dual fuel trucks • •
•
A diesel-fossil CNG tractor will save around 15% CO2 compared to diesel alone 2 OEMs: • Mercedes Benz • Volvo See next slides Tenens/Warburtons
Dual fuel trucks are a game changer
Tenens – 12 Actros, 2 Axor Dual Fuel • HT carried out 6 month trial on trunking & multidrop routes from Andover resulting in investment: • 12 x Actros tractor unit converted running from Andover • 2 x Axor tractor units converted running from London • LCNG station installed at Andover • CNG station London M25/A13
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Warburtons – 6 Axor Dual Fuel
These vehicles are transformational – benefit of diesel efficiency but with natural gas – 15% lower CO2.....with the world full of abundant shale gas we can now start to shift trucks to dual fuel CNG diesel Range is 400 Miles Substitution is 60% 23/11/2011
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GIST/M&S Crewe - 5 Axor Dual Fuel
Initial feedback is good â&#x20AC;&#x201C; drivers say they are just same as diesel
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Dual Fuel Tractors â&#x20AC;&#x201C; Volvo
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Coca Cola – 12 Iveco Stralis • 12 dedicated CNG • Enfield • Stralis AD260S30Y/FS-D CNG is purpose-built on the factory-line for natural gas powered applications • Features a six cylinder 7.8 litre Cursor 8 engine which produces up to 300 hp at 2,000 rev/min and up to 1,100 Nm of torque between 1,100 and 1,650 rev/min, driven through an Allison 3500 six-speed automated gearbox.
EEV = Very good for air quality
UK gas system
LTS is ideal for CNG
UK can run most trucks on CNG from high pressure gas grid • 80% less energy for compression (see next slide) • Only 2 stages of compression not 5, so lower capex • Very high flow-rates possible – Typical CNG station flow rate is 300 m3/hr (eg Tenens, Warburtons) – LTS CNG flow-rate 2,000 – 3,000 m3/hr per compressor – This means smaller sites, much less CNG Storage
• LTS gas is very dry so no need for gas driers – Saves Capex/Opex and better CO2 outcome
• There is no gas leakage from LTS – If CNG taken from Medium Pressure/Low Pressure then approx 0.5% of the gas in these mains leaks out (hence 750 million pounds per annum pipeline replacement ) – Methane approx 20 times worse as GHG so this leakage adds around 10% to well to wheel CO2 – For LTS no leakage
Compressor Power 400
Flow-rate = 1,000 m3/hr per station
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Electricity
300
kWh
250
1000m3/hr 500m3/hr 250m3/hr 100m3/hr
200 150 100
Less than 100 kWh â&#x20AC;&#x201C; around 25% of electricity required at 0.5 bar MP
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0
10
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40
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Typical LTS site
Inlet Gas Pressure
Estimated CO2 savings from Dual Fuel supplied via LTS • This assumes normal fossil natural gas (not biomethane) • Tail-pipe saving = 15% – This is based on the Axor dual fuel operations underway and also theoretical saving – This is based on 55% CNG, 45% Diesel – On 75% CNG, 25% diesel saving 20 – 25% (Volvo OEM Product)
• Saving from LTS = 17% – No leakage of methane to get gas to the supply point = 10% – 80% less electricity for compression = 6% – No need for drier = 1%
• Total CO2 reduction from Dual Fuel trucks supplied via LTS is around 30 - 40%
Green Gas Certificates
Green Gas Certificate Scheme • Announced on 8 October 2010, system being built, formal launch was on 3rd March 2011 by Renewable Energy Assurance Ltd • Designed to allow ‘tracking of biomethane from injection point to customer” – Integrity - no ‘double counting’
• It is expected that the Green Gas Certificate will be bought by the gas purchaser and not sold separately • Allows the gas purchaser to work with the producer to market biomethane to customers
GGCS Launch Members • • • • • • • • •
National Grid British Gas Eon Thames Water (Didcot) Adnams Biogroup (Adnams) Milton Keynes City Council CNG Services Ltd System built that will allow the system to operate http://www.greengas.org.uk/
AD Developer – Gas Supplier – Gas Grid – Gas Consumer Gas can be used in CHP, in vehicles, in fuel cells, any use possible – but LTS supplied CNG is best!
Green Gas Certificate Scheme
Gas Consumer Sale of ‘green’ therms
Gas Supplier
Purchase of biomethane therms
Normal grid gas
Clean-up plant and grid injection
Gas Distribution Network Inject gas into grid
AD Developer Organic material Processing via Anaerobic Digesters
Market Forecast •
The are 5 main sectors: • Agricultural • • •
• • • •
Waste Animal manure Crops for Energy
Commercial food waste Biodegradable waste (local authority garden/food waste) Sewage sludge Landfill
It is possible that there will be 40 BtG projects in UK in period to 2014
Biomethane Conclusions • • •
• • •
Biogas should only generate electricity when all the heat can be used UK has advanced gas grid and the full support of UK gas distribution network owners and energy suppliers UK gas production declining, we need to find new gas resources to supply domestic customers and improve security of supply Biomethane injection into gas grid is widespread in Europe, no material technical issues 10% of domestic customer gas supply by 2020 is a reasonable target Green Gas Certificates offer opportunity to keep gas into new homes which has to make a lot of sense and also to fuel dual fuel CNG-diesel trucks supplied from LTS With biomethane and CNG from LTS something CAN be done to reduce CO2 emissions from trucks