Anaerobic digestion

Anaerobic digestion

Anaerobic digestion is where organic materials (food and garden waste) are converted into methane or 'biogas' and compost in the absence of oxygen. These processes take place in an enclosed building and involve the breakdown of organic material in a sealed vessel called a digester. This allows the biogas to be generated.

Any odours from the digester or composting is removed using a filter. Liquid left over at the end of the digestion process is recycled back into the digester.

Advantages of anaerobic digestion

Reduces greenhouse gas emissions and waste going to landfill
Produces marketable products (energy and/or compost)
Low risk of air and water pollution
Low risk of odours
Recovery of packaging materials
Proven technology
Minimal risk of health consequences
Some Australian technical expertise

Disadvantages of anaerobic digestion

Markets for compost derived from municipal solid waste in Western Australia are still being developed
Restricted to treating organic materials - other materials are removed for recycling or disposal
Exhaust gas from gas engines may need treatment
Contamination of the organic material affects digester performance
Biogas cleaning to avoid corrosion and odour can be problematic

Examples of anaerobic digestion facilities

Anaerobic facilities are operating successfully in Australia and overseas, particularly throughout Europe and the US. Click on the links below for examples of anaerobic digestion in Australia:

ArrowBio anaerobic digestion facility at Macarthur Resource Recovery Park in Jack's Gully NSW
WSN Environmental
AnaeCo anaerobic digestion facility at Western Metropolitan Regional Council in Shenton Park, WA