One of the UK’s largest water and waste water treatment companies, Severn Trent, is building a third food waste and green gas plant at its Spondon waste water treatment works in Derby.
Severn Trent is investing around £20 million in a anaerobic digestion and biogas treatment facility that will turn 50,000 tonnes of food waste a year into renewable gas for heating and cooking in local homes.
The company, which serves eight million people across the Midlands and mid-Wales, has previously built a similar food waste processing plant at its sewage treatment site in Coleshill near Birmingham, and is soon to complete another at Roundhill near Stourbridge.
Peter Ravenscroft, who is leading the project, said: “We’ve got more than 60 years of experience of turning sewage into clean energy, and we’re now putting that to good use in our food waste plants.”
The new plant will take waste food from local businesses and waste management companies in the Derby area and process it to produce biomethane gas which can be used in homes and businesses across the area.
“The process makes sure that the food waste doesn’t end up going to landfill and any packaging that we remove at the plant will be sent for recycling,” added Ravenscroft.
The biomethane gas is processed for domestic use by first ‘washing’ it at high pressure, then compressing it to the same pressure as natural gas. The gas is then tested for quality and energy composition. Finally, an odour is added so it smells like normal gas, before ‘injecting’ the engineered biomethane into the local distribution network.
Ravenscroft explained: “We currently generate the equivalent of more than a third of the energy we use through renewable sources, and we’re aiming to increase that to 50 per cent by 2020. If everything goes to plan we expect the new food waste plant in Spondon to be in use by the middle of 2018 and it will have a big impact on helping us reach that ambitious target.”