The ReFood AD plant at Schwallungen, Germany.

Anaerobic Digestion

Anaerobic digestion (AD) is the term applied to the process of the biological breakdown of organic material in the absence of oxygen.

 

During the process organic matter such as food waste is broken down biologically and this generates large amounts of biogas; a combination of methane and carbon dioxide.

 

The process is similar to that which takes place during composting, with AD it is carried out in the absence of oxygen and the methane generated is captured and utilised as a biogas rather than being lost to the atmosphere.

 

According to a recent Defra report, "Anaerobic Digestion, Shared Goals" the UK Government believes there is tremendous potential for the generation of renewable energy using AD, as has already been proven in Germany. This will not only help the UK reduce its dependence on landfill, but also find alternatives to fossil-fuelled energy production.  

 

According to Defra, the UK produces over 100 million tonnes of organic material per year that could be used to produce biogas. This breaks down as follows:

 

• 12-20 million tonnes of food waste (approximately half of which is municipal waste collected by local authorities, the rest being hotel or food manufacturing waste);  
• 90 million tonnes of agricultural material such as manure and slurry;  
• 1.73 million tonnes of sewage sludge

 

   

ReFood AD network – helping the UK foodchain to deliver a sustainable future