Anaerobic Digestion

What is Anaerobic Digestion?

Anaerobic digestion is a process where plant and food waste, called biomass, is converted into useful products by micro-organisms in the absence of air. Biomass is placed into the digesters (giant sealed units) where the natural micro-organisms decompose the biomass.

This process releases biogas which is a mixture of predominantly methane and carbon dioxide that is used to produce clean renewable energy.

The resulting products are:

Biogas – a methane rich gas that typically contains:

  • 60% CH4
  • 39% CO2
  • other trace gases

Digestate  –  a bio-fertiliser that contains a range of plant nutrients and can be recycled back to land as a fertiliser/soil conditioner.

It is a liquid based system that uses 4-8% dry matter. Cannington Bio Energy uses food waste in the process of anaerobic digestion.

Anaerobic Digestion

To date, the waste used at Cannington Bio Energy is converted into enough energy to supply the equivalent of 1,477 houses. It currently also runs the Farm, Cold Stores and all our electrical needs.

The aim in the forthcoming years is to create enough energy to supply the surrounding villages of Nether Stowey, Spaxton, Cannington, Fiddington, Stogursey and Wembdon – a total of 4,400 homes!

At Cannington Bio Energy we have laboratories on site which analyses the various combinations of waste products to see which will produce the greatest volume of quality gas. This is allowing us to optimise the fuel production from the digesters and make the process even more efficient.