Slurry

Animal slurry is an important feedstock in anaerobic digestion (AD) and is worthy of a closer look.

First of all, animal slurry is particularly important to farmers, as it is often in plentiful supply at farms keeping animals such as cattle or pigs.

Secondly, it contains large amounts of the bacteria required in the AD process.

An AD plant therefore has the potential to be easily integrated into a farm of any size.

A dairy cow might be expected to produce between 15 and 20 tonnes of slurry each year, while a pig should produce closer to the lower end of that range.

Advantages

Processing animal slurry through an anaerobic digester reduces (and often eliminates) certain harmful bacteria such as E coli and Salmonella. The use of slurry in AD can therefore help to reduce a farm’s potential pathogen release into the environment. It should also reduce the risks to animal health.

Another advantage of the use of slurry is that is does not require the addition of water that most other feedstocks do.

Although the biogas yield of slurry is the lowest of all feedstocks, the avoidance of waste management and fertilizer costs, plus any electricity and/or heat production, should be considered.

Page Last Updated: 29 May 2020