When GENeco commissioned the anaerobic digestion (AD) plant at its parent company Wessex Water’s Bristol sewerage works in 2014, it became the first company in the UK to inject gas generated from food waste and sewage sludge into the national gas grid. The plant is now treating around 657,000m3 of sewage sludge and 35,000 tonnes of food waste from local homes, food manufacturers and supermarkets each year – producing as much as 34,000m3 of biomethane per day in the process.
Anaerobic digestion plant
Renewable Energy Generation Manager, GENeco
Biomethane produced from anaerobic digestion cannot be introduced directly into the mains gas network in its raw state. As well as going through a water-wash system to remove impurities, its calorific value must be altered to bring it up to the required standard – which is achieved by injecting the biomethane with propane. As a leading provider of propane and a specialist in biomethane enrichment, GENeco appointed Flogas as the plant’s propane supplier.
Wayne Boakes, Renewable Energy Generation Manager at GENeco, says: “The success of the gas-to-grid process relies heavily on having a dependable propane supply. Due to the plant’s scale and the large volume of waste it treats, the quantities of propane required are significant. Flogas’ role is to supply us with all that propane, which enables us to alter the calorific value of our biomethane ready for injection into the grid.”
Flogas’ propane enrichment experts specified, designed and installed a tailor-made propane injection solution for the GENeco plant – consisting of a 25-tonne underground LPG tank and pump system, with a bespoke liquid propane injection kit. Because of the site’s size and layout, the team also needed to lay 230 metres of pipework to connect the LPG tank to the grid injection point.
"We at Flogas feel privileged to be involved in such a pioneering project. The plant is – quite literally – giving back to the people of the South West, by taking what they don’t need and turning it into something they do need."
National Account Manager, Flogas