Industrial digestion & MBT-ADIntegration with Gas Engines

Renewable Energy Association Bioenergy Conference8th October 2009

Alex Marshall

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Graveyard slot!

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Agenda

Clarke Energy introduction MBT-AD & industrial digestion CHP basics Gas characteristics Gas treatment Physical integration Biogas CHP GHP savings Summary

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Locations

9 Territories Globally

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ESTABLISHED 1989

1990

ISO ACCREDITATION 1991

1992

1993

1994

UK JENBACHER DISTRIBUTOR 1995

1996

1997

AUSTRALIA, NZ AND NIGERIA DISTRIBUTOR 1998

1999

2000

2001

2002

GE PURCHASE JENBACHER, CEL ACQUIRE COGEN INDIA 2003

ACQUIRED JENBACHER FRANCE 2004

IRELAND DISTRIBUTOR 2005

2006

2007

CHINA, TUNISIA DISTRIBUTOR 2008

2009

Timeline

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Clarke Energy MW Installed

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

MW

UK France ANZ India Nigeria China Tunisia

Country

Biogas Landfill gas Syngas Natural gas Mines gas Flare gas

Bioenergy

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MBT-AD and industrial digestion comparison

Landfill, RDFTo landDigestate utilisation

IntensiveLightMechanical pre-treatment

Highly variedPackaging, sandContaminants

Mixed wastesFood waste, biowaste, slurries, energy crops

Input

Gate fee, energy, sale of recyclables

Gate fee, energyRevenue

MBT-ADIndustrial ADFactor

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Food Waste & Co-Fermentation

Source: Haase Midlum, Sibstin plants

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MBT – AD

Source: Haase Goettingen MBT facility

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Gas contaminant comparison

PossibleYesMixed waste

NoYesFood

NoYesMaize

YesYesSewage

YesYesLandfill

VOSCs*Hydrogen sulphide

Biogas type

*Volatile organic silicon compounds

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H2S Reduction – Air dosing

~1% oxygen dosing Biological reduction Air allocation

important Additional air

increases corrosion Fluctuating

efficiency Lower capital

investment

M

Biogas

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H2S Reduction - Air dosing

Biological desulphurisation – the H2S will be converted into sulphur

Source: MT Energie

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H2S Reduction – Scrubber tower

air water

biogas

Biological reduction Gas saturated with water Additional air increases

corrosion Stable performance Higher investment costs

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H2S Removal – FeCl dosing

Iron chloride binds to H2S

Fast action Adjustable to substrate Industrial digestion Moderate investment costs

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GE Jenbacher gas module

Heat recovery -heat exchanger

EngineEngine control

panelGenerator

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Energy balance

HE 1 - Mixture intercooler

HE 2 - Oil exchange heater

HE 3 - Engine jacket water heat exchanger

HE 4 - Exhaust gas heat exchanger

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Typical engine integration

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Heat limits & hazards

Acid dew point22050Exhaust gas

Condensation8055Intercooler

Viscosity9070Lube oil

Overheating9557Jacket water

DangerMax. (oC)Min. (oC)Heat source

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Engine integration

EvaluateEvaluateResidential/ Industrial heating

Heat sink

YesNoReduce weight

Increase CV

Digestate drying

EvaluateYesPathogen killPasteurising

EvaluateYesEncourage microbial action

Digester heating

Exhaust gasJacket waterPurposeHeat use

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Engine integration

Exhaust heat

Jacket water, oil heat & intercooler

~400ºC

90ºC

Drier

2-300ºCAir

Heat exchanger

Pasteuriser

External heat sink

Digester

District heating Industry

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Pasteurisation unit integration

Pasteurisation

Inflow from buffer tank

Outflow to digesters

Heating water from

CHP

Fill70OC 1hr

Purge

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Biogas utilisation – GHG Savings

Source: Optimierungen fur einen nachhaltigen ausbau der biogaserzeugung und nutzung in Deutschland (Ifeu et al. 2008)

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Summary

Main biogas contaminants – H2S & VOSCs

H2S treatment – biological or chemical Heat utilised for:

Digesters Pasteurisation Drying External heating

Biogas CHP – Significant GHG savings

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Thank you

Alex MarshallClarke Energy

+44 151 546 4446alex.marshall@clarke-energy.com