Iain Ward BSc. C. Eng. MIGEM

CNG Services Ltd

www.cngservices.co.uk

29th Sept 2011

RESCO

Biomethane for Grid Injection

supply chain workshop

‘The energy view’

Summary

• CNG Services Ltd• Making biogas• Biogas clean up and upgrading• Biomethane to grid plant• BtG Projects• Biomethane Utilisation

• Efficiency• CO2• Value

• Summary

CNG Services Ltd

• Supporting development of the BtG and CBM markets in the UK:

• Cleaning bio-gas and injecting biomethane into the gas grid (BtG)• Creator of the UU Davyhulme BtG and CBM Project• Developing the Didcot project for Thames Water, SGN and Centrica• Supporting a further 15 potential BtG Projects in the UK for Water

Companies and AD developers• Supporting introduction of compressed biomethane (CBM) fuelled

vehicles in the UK• VW Caddy Ecofuel• MB Sprinter NGT and Econic NGT• Iveco Daily and Eurocargo• MB and Volvo dual fuel tractors

We are independent from all makers of CHP plant, vehicles, clean-up, compression etc. Our aim is to support biogas producers in exploiting the biomethane to grid and compressed biomethane for vehicle opportunities

What is Biomethane?

• Bio-gas from an anaerobic digester contains typically 65% methane, 35% CO2

– Lager shandy

• Natural gas contains around 90% methane, with ethane, propane, butane, CO2 and nitrogen making up the rest

– Blended whisky - made from dinosaur poo in a prehistoric AD, contaminated over the millenia

• Biomethane is bio-gas without the CO2, containing around 98% methane

– Malt whisky, the elixir of life, we all want to drink it

So, we can make biomethane from organic material in an AD (waste food etc) or from wood in a gasification plant – better than landfill

Anaerobic Digester and Uses for Biogas

Drawing courtesy of the German Renewable Energy Agencyhttp://www.unendlich-viel-energie.de/en/bioenergie/biogas.html

Gasification and Methanation

Schematic courtesy of the International Gas Union - British Gas used to do this from coal (plant closed in 1985 when it was clear that UK had a lot of gas)

UK Biomethane Potential

UK gas – sold at 20 p/therm for power generation…..by 2025, UK gas production from North Sea and from organic matter will be similar

UK gas productionNetherlands

Biomethane to Grid (BtG)

Widespread consensus that gas grid injection is attractive because of absence of uses for waste heat where renewable methane is made. Take the gas to the customers along existing pipelines and have high efficiency utilisation….

Making Biomethane

Lots of ways of cleaning up raw biogas to make

Biomethane with the technology shown as

a ‘black box’

This shows biomethane going into the gas grid, with addition of propane (to increase the calorific value) and odorant (to give a smell)

Gas Grid

FromAnaerobicDigester

Water Wash

• 99% of biomethane to grid, 1% methane vented• Can recover heat from larger plants (from cooling water)• 12 m high – can have planning issues• Removes H2S and siloxanes• Likely to be lowest cost option• Didcot 2010 (Chesterfield Biogas)

Chemical Absorption

• 99.5% of biomethane to grid, <0.5% methane vented• Needs significant heat to regenerate the chemicals (15 –

20% of biogas)• Ideal if waste heat already available

Pressure Swing Adsorption

• 92% of biomethane to grid, 8% of methane goes with the CO2• This gas can be flared or burnt in CHP or boiler (but needs to be

brought back to 33% methane)• No methane vented• Small footprint• Likely for UU Davyhulme 2011

• Few membrane plants• Contamination of the membranes is an issue• May be a good technology – similar to PSA in that gives a

waste CO2/CH$ stream that should be used to generate electricity or make heat

Membrane Separation

BtG Plant

BtG Plant – Biomethane to Grid plant comprises the

following:• Propane storage and injection

• Odorant storage and injection

• Gas quality monitoring

• Gas CV measurement

• Gas flow measurement

• Pressure control

• Telemetry

The BtG plant is located after the Clean-up and Upgrading

Plant and before the gas grid

Propane Enrichment Plant

• Gas Thermal Energy Regs set a Flow Weighted Average CV for gas networks, max 1 MJ difference between grid inputs

• Typically around 39.5 MJ/m3

• Pure CH4 has a CV of around 36 MJ/m3

• Accepted that propane addition is the technically best resolution

• Accuracy of dosing paramount to meet CV and WI limits

• Incurs substantial Opex; “methane value loss”, energy deducted from RHI entitlement

• Control system required to manage

• On-site storage, contracts for supply

BtG Plant – Ownership Options

• DN funds the plant, owns it, receives a return and takes appropriate liabilities

• Customer funds, DN owns and maintains, no return to DN, DN takes liabilities for plant performance• 350 m3/hr plant = 1 million th/annum = approx £5k per day gas value

• Customer funds and owns, having to meet DN’s specification• This is the National Grid NTS Model

• Customer has GT Licence, they fund, own, operate BtG plant and pipeline with the DN network a connected system

No consensus on which of these, may be that each DN will adopt a different approach related to their appetite for investment and risk

Network Entry Agreement

• Needs to address capacity (NTS NEA has no relevance to capacity which is covered in UNC)• May need to address liabilities if the DNO provides some services such as odorant addition or

gas quality monitoring• ie from Options 1 and 2

• NTS NEA has concept of Daily Flow Notifications were NTS informed continuously of flow forecasts• For biomethane likely to be unmanned sites• Key is that the DNO network is not impacted if biomethane flows stop• The biomethane system flows must be monitored by computer with no need for manual intervention

• Links to Biomethane Sales - the gas purchaser also requires forecasts to allow them to stay in balance• Materiality point as flows very low

Didcot Project

CNG Services as designer and project manager

Gas Analysis

Odorant

Safety shut off valve

Pressure control

New plant to remove impurities

in BioGas

New plant to remove impurities

in BioGas

Dedicated plant toapply safety controls at

gas network entry

Dedicated plant toapply safety controls at

gas network entry

Initial separation

Fertiliser Cake

Clean Water

Anaerobic Digesters

BioGas is

currently wasted

BioGas is

currently wasted

From Summer 2010 gas is saved

for treatment

and beneficial

use

From Summer 2010 gas is saved

for treatment

and beneficial

use

Clean Biomethane

to consumers via existing

network

Clean Biomethane

to consumers via existing

network

Sludge

Up to 7 days Up to 18 days

Efficiency - Converting Sunlight Falling On A Hectare Of Land Into Vehicle Fuel

Biomethane always wins……..graph courtesy of German Energy Agency (dena) “Biogas Partnership,” initiative http://www.biogaspartner.de/

Carbon Trust Shows Best Use is Transportation

CBM is environmentally very attractive but the worst in terms of economics for the biogas producer

CBM Vehicles

Vehicle use makes sense for depot based vehicles

Electricity Feed In Tariff

• Biogas that generates electricity can an electricity Feed In Tariff (FIT)

• FIT worth 9 p/kwh on top of the normal electricity price

UK makes a lot of biogas at present, water companies, it all goes to make electricity, limited use for waste heat....in long term, post 2020,

this will not be a good idea as the UK electricity grid is being de-carbonised (wind, nuclear, CCS)

Renewable Heat Incentive (RHI)

• Worth approx £1.96/therm in 2011, indexed• Earned on the net energy exported to grid, heat raised by

non-renewable sources is deducted• Paid to the Biomethane producer• Economically comparable to CHP with advantage in favour

unless CHP has very high efficiency• Particularly good if Biogas plant already exists e.g. Water

Co. • Gas Transporters keen to facilitate, Ofgem may allow

incentive return to stimulate further

Injection into gas grid strongly supported by UK gas grid owners

Green Gas Certificates

• Enables injection of Biomethane in one place and by displacement usage at another, regardless of relative locations.

• Supports all BtG projects and also gas a transport fuel.• Scheme arranged by REA and now active

At the present time, more value from making electricity or injecting gas into the gas grid. UK CBM is highest taxed CBM in EU – in most places it is duty free – UK CBM tax is more than double the tax on Fossil CNG in

Germany...

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 is declining and 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 (it is just processing gas on a small scale)

• We have commercial vehicles made by OEMs such as VW, MB and Iveco – new dual fuel diesel-CBM tractors very good

• Put all this together and we can create a thriving domestic BtG and CBM industry that is able to make a very material contribution towards the UK’s 2020 targets

There are no material technical issues or barriers, the BtG premium has been set at an appropriate level so that we can get on with it. We also need promotion of CBM as a vehicle fuel for depot based commercial

vehicles (and lower CBM fuel duty please)