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Harnessing the energy of biogas

Dr Leonid ItskovichEnergy Manager

Energy Awareness Week, Christchurch, May 2010

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Harnessing the energy of biogas

1980s: Christchurch Wastewater Treatment Plant 2007: QEII 2010: Christchurch Art Gallery 2010: WWTP Biosolids Dryer 2010: New Civic Building

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Biogas utilisation efficiency

gas escaping to atmosphere flareflare heating fuel co-generation (electricity+heat) tri-generation (electricity+heat+refrigeration)tri-generation (electricity+heat+refrigeration) city-wide bio-energy system!city-wide bio-energy system!

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Digester Gas: Christchurch Wastewater Treatment Plant

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Digester Gas utilisation

730 m3 of gas per hour 63% methane compressed gas - fuel for Council’s

vehicles (1983-1994) electricity and heat generation since

1996 11,000,000 kWh per annum of electricity

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Burwood Landfill• 90 hectares• Up to 25 m deep• Up to 264,000 tonnes of refuse per year• 60% organic waste• Operated 1984 – 2005

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Landfill Gas

1000 m3 of gas per hour 50-60% methane Methane - a powerful greenhouse gas

with 22 times more impact on climate change than carbon dioxide.

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Biogas and the City

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Biogas and the City

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Biogas and the City

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Directional drilling for 18-kilometre gas pipeline Burwood Landfill - QEII – WWTP – New Civic – Art Gallery

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Burwood Landfill• 90 hectares• Up to 25 m deep• Up to 264,000 tonnes of refuse per year• 60% organic waste• Operated 1984 – 2005

Gas pipeline Treatment plant & flare

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Landfill gas utilisation at QEII

Landfill

15 gas collection wells

Flare

Condensatecollected& returnedto landfill

Gaschiller & condensatecollection

Cogeneration

Underground gas pipeline3.7 km

Burwood Landfill

QEII

Fan

Boiler 2

Boiler 1 Heat and electricityused in QEII sports centre

Gas Collection Gas Treatment Gas Transport Gas Combustion

Pipeline to WWTP

Pipeline

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Gas collection well-head on Burwood Landfill

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Burwood Landfill Gas Treatment Plant

Chillers

Flare

Inwardgas pipe

Condensate collectors

Compressors

Controls

Blast chiller

Controls

Fan

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Landfill gas boilers at QEII Sports Centre

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Landfill gas co-generationengine at QEII

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Under construction: biogas boiler for biosolids dryer at WWTP

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Under construction: Biogas and wood chip boilers for biosolids dryer at WWTP

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Absorption chiller – part of Tri-generation plant at

New Civic building

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Biogas projects: benefits

replaces 2.1 million litres of LPG each year (fossil fuel)

replaces 16 million kWh of electricity from grid pa

saves city ratepayers $3M each year in energy costs

carbon credits sold to British Gas ($4M) better environment the landfill can more easily be re-vegetated

because the landfill gas that damages plant roots is captured.

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Acknowledgement of expertise and assistance

• BECA• Powell Fenwick Consultants• Rockgas (Contact Energy)• Energy For Industry (Meridian Energy)• EECA• Contractors and equipment Suppliers

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Harnessing the energy of biogas

Further information:

http://www.ccc.govt.nz/EnergyEfficiency/Projects/WasteToRenewableEnergy.asp

http://www.energie-cites.eu/db/christchurch2_575_en.pdf

http://www.energie-cites.eu/db/christchurch_113_fr.pdf

Energy Awareness Week, Christchurch, May 2010