Provision of waste heat and CO2 from sewage works Thermal Hydrolysis AD plant and CHP to urban farm

This project seeks to prove the viability and subsequently to deliver a project which utilises the waste heat and CO2 from Combined Heat and Power (CHP) and Thermal Hydrolysis (TH) plants associated with advanced anaerobic digestion at Northumbrian Water’s sewage treatment works. These two locally derived streams will be used to promote the growth of salad crops under glass for local delivery.
In conventional anaerobic digestion, most of the biogas fuelling a CHP plant is required to heat the digester itself. Only plants that manage their energy balance with a TH plant produce a significant amount of additional heat. However, the waste heat output from just these plants has been calculated as being up to 24.5 MW. It is inevitable that many more new anaerobic digestion plants will be built over the next few years, treating a variety of organic waste material. TH will form an integral part of many of these, as well as being retrofitted onto existing anaerobic digesters. There is thus great potential for gaining even greater benefit from anaerobic digestion in the future by utilising waste heat in this way.
Much of Europe’s greenhouse crop production is supplied with power and heat from dedicated CHP plants. This project is unique in that it proposes to utilise the energy from a fully sustainable product, sewage sludge.