The plant, located at a former landfill site at Barkip, North Ayrshire, will have the capacity to process 75-80,000t of organic waste and produce 2.5MW of renewable electricity annually, Xergi UK manager Colin Steel told FoodManufacture.co.uk.
“Under the deal, we’ll commission and build it and SSE will own and operate it. The inputs will come from a firm called William Tracey, which has signed a 25-year contract to supply the plant with food waste, agricultural waste, catering waste, some domestic waste and so on.”
If everything goes to plan, it should be operational early next year, and will convert organic waste into renewable energy in the form of methane gas and nitrogenous organic fertiliser, said SSE chief executive Ian Marchant.
“We believe this offers opportunities beyond on-site electricity generation to include connections to the gas distribution network in the future.”
How it works
Anaerobic digestion uses bacterial cultures within enclosed silo tanks to generate methane-rich biogas from waste organic materials and energy crops such as grass silage.
The Barkip plant will use a high-temperature thermophilic two-stage digestion process supplied by Xergi.
The biogas will be captured and used to fuel engines, which will generate renewable electricity. It will also incorporate a novel digestate processing stage, which will capture heat from the generation process and use it to concentrate the liquid fraction of the digestate into liquid fertiliser, said Steel.
Xergi, which has commissioned AD plants in Denmark, Germany, Holland, Belgium and the US, has also designed a 1.4MW AD plant in Lincolnshire for Staples Vegetables to convert out-of-specification vegetables into energy.
AD facilities in the UK
The SSE plant is one of several AD facilities being built in the UK this year offering food manufacturers an alternative to landfill for their waste.
Scottish Water Waste Services is developing plants in Cumbernauld, Renfrewshire and Ayreshire, while Prosper De Mulder Group is developing sites in Doncaster, Widnes, Exeter, Nuneaton and London.
Rising landfill taxes and the pressure on businesses to reduce or eliminate waste sent to landfill makes anaerobic digestion an increasingly attractive solution for food manufacturers,
The standard rate of landfill tax increased by £8/t to £48/t on April 1 this year and will increase by £8/t annually thereafter until 2014.