Lohne — After just six months of construction, the first biogas plant with a gas upgrading facility from Lower Saxony’s EnviTec Biogas AG is on the grid near Ipsden, Oxfordshire, England. Project developer David Bermingham and his funders from London’s Ingenious Renewable Energy group just started of the construction of the biomethane plant, with an initial 350 cubic meter capacity together with a 360 kW combined heat and power plant, in June. „We are really proud to have completed the work in such a short timeframe despite the difficulties caused by the weather“, said David Bermingham. Since its commissioning on 12th December, Icknield Gas Ltd. has been feeding green energy into the existing grid of Southern Gas Networks.
The biogas plant is operated using a combination of pig slurry, farm by-products and energy crop. Up to 10,000 tonnes of pig slurry can be used annually. Great Britain’s goal is to create a situation in which a total of 15 percent of its energy would come from renewable energies such as biogas. „With our EnviThan biogas upgrading plant, Icknield Gas Ltd. will be able to deliver an annual energy value of about 35 million kilowatt-hours of biomethane“, says Roel Slotman, EnviTec’s chief commercial officer.
Gas for about 2,150 homes
The delivery pressure of the EnviThan system is sufficiently high to inject gas directly into the public gas grid. Slotman further explains „an additional compression procession was hence not necessary“. The public gas pipeline is located right next to the plant boundary so that only short gas pipelines have to be laid beyond it.
A British home consumes an average of about 16,500 kWh of gas per annum. „Consequently, our new plant currently enables us to deliver enough gas for the annual needs of about 2,150 homes“, continues David Bermingham. Furthermore, the subsequent use of the fermentation residue as fertiliser will lead to a reduction in the use of chemical fertilisers in the neighbouring agricultural area.
Methane content up to 98 percent by volume
The gas upgrading process developed by EnviTec Biogas with the cooperation of Evonik Industries impresses with its high efficiency, which is above all a result of the membrane technology used. By utilising highly selective polymer membranes, the methane content can be increased to up to 98 percent by volume. The innovative technology exploits the different sizes of gas molecules: Since carbon dioxide molecules are smaller than methane molecules, they can migrate through the membrane much more quickly. As a result, the methane remains on the high-pressure side, while the CO2 molecules in the biogas pass through. Thus, the gas treatment needs neither chemicals nor water nor any other resources. „I was attracted to the EnviThan system because it is simple, cost-effective and environmentally-friendly as compared with other technologies“, said project developer Bermingham.
Through its branch office, EnviTec Biogas UK remains in charge of the construction of the plant until the turnkey delivery phase is executed on-site. With a total of five employees, the biogas all-rounder has a presence in Rugeley, Staffordshire. Here, the biogas plant manufacturer that is headquartered in Lohne offers consulting, sales, as well as service and maintenance on behalf of Envitec Biogas Service UK ltd.
Source: EnviTec Biogas AG