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Anaerobic Digestion

Harnessing energy from food

Anaerobic digestion (AD) is a biological process where food waste and other organic materials are broken down by micro-organisms in the absence of light and oxygen. The result, a nutrient-rich biofertiliser.

Natural methane is harnessed to fuel engines, generating green power and heat.

Another output from AD is biogas, a fossil fuel substitute; used either as upgraded biomethane in vehicle fuel or into the national gas grid for heating, or as an engine fuel to generate electricity.



  • Eco has recycled over 478,357 tonnes of food waste.
  • Our AD plant has generated over 70,000 MWh’s of green electricity - that is enough to power 22,000 houses!
  • Every tonne of food waste recycled by AD saves 0.5-1 tonne of CO2 entering the atmosphere.

Pioneering Processes

Eco’s AD facility is based just outside of Dorchester, strategically located to minimise waste miles whilst, at the same time, maximising the outputs of the process in supplying heat and power to a neighbouring animal feed factory.

Our unique ‘front-end’ processing equipment allows customers to deposit waste directly and safety into the bunker before the intelligent depackaging equipment gets involved. The waste is cleaned and cultivated into a soup ready to be pumped into large tanks where the bugs can do their thing.

Our AD facility alone has prevented over 147,925 tonnes of CO2 from being emitted into the planet’s atmosphere.

Stringent Quality Control

The bugs are constantly being fed with fresh food waste. Spent material is pumped out through a fine channel screen before the pasteurisation process, ensuring full environmental integrity.

An on-site lab analyses daily samples by trained technicians to ensure conditions within the system are consistently optimum for the best end result.

The biofertiliser, also known as digestate, is analysed, both on site and through external laboratories, to fully conform with the stringent PAS:110 accreditation.

1. Dorset's Food Waste Collected

Across most of Dorset, kitchens have food caddies that are used to store all food waste. This waste is then collected once a week and delivered to Eco.

2. Maceration & Anaerobic Digestion

We then macerate the food waste into a soup and pump it into our digestion tanks. In these, it's like a human stomach; in the absence of oxygen, bugs breakdown the food and emit methane. This methane is capture, cleaned and used to generate energy, which is used to power the local community.

3. Eco AgriFert production

Another product of this process is a bio-fertiliser. The digestate from the digestion tanks is a fantastic fertiliser, especially across local farmers' fields.

Quality Output

The AD process produces a nutrient rich organic fertiliser, known as Digestate. Our Eco digestate, marketed as AgriFert and PAS110 accredited, is extremely high quality and sought after by farmers to help reduce cost, improve sustainability and increase crop growth yields.

Digestate substitutes the need for nitrates used from fossil fuel sources, such as urea. Therefore, the use of digestate can contribute in reducing GHG emissions from fertiliser production.

The GHG contribution of digestate is in the substitution of fossil fuel-based fertilisers, and according to a World Biogas Association (WBA) report from 2019, digestate has the potential to substitute seven per cent of fossil fuel produced nitrogen globally – a significant amount!

Digestate offers farmers a fantastic alternative to petrochemical fertilisers by providing vital organic nutrients to restore our depleted soils. Our product helps farmers mitigate the fluctuations of global commodity prices and to decarbonise farming. Eco helps keep farmers farming by making them more competitive and so helping them create more rural jobs.

Membership and Accreditations

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