Businesses create green gas from human waste

Waste and energy companies are working together to open a plant in Oxfordshire that will be able to convert human waste to biogas, which will then be inserted into the National Grid.

Energy company Centrica, owner of British Gas, is opening a plant at Didcot works sewage in South Oxfordshire, which will be the first in the UK to produce renewable gas from sewage for household use. Waste generated from households and businesses will be used to create biogas that can be used for cooking and heating.

The Didcot facility is a pilot project to demonstrate this new technology and will supply about 200 homes with renewable gas. The project is a joint venture between Thames Water, British Gas and Scotia Gas Networks.

The facility at Didcot takes waste from the sewage works and produces gas via anaerobic digestion (AD), where bacteria breaks down biodegradable material. The resulting biogas is scrubbed to remove impurities and smell, and propane is added so that it mimics natural gas and can be fed into the gas grid and used in everyday appliances. The whole process – from flushing a toilet to gas being piped to people’s homes – takes around 20 days.

A study by the National Grid believes that at least 15 per cent of all gas consumed could be made from sewage slurry, old sandwiches and other food thrown away by supermarkets, as well as organic waste created by businesses such as breweries. The project took six months to complete and cost £2.5 million, and this is only the beginning of more efforts to utilise waste.

For the full article see Greenwise