Anaerobic Digestion of Chicken Waste Benefits from FITs

06 July 2011 A poultry farm in Hereford, UK is installing an Anaerobic Digestion (AD) facility that will convert chicken litter into biogas for the generation of heat and electricity. Great Ynys Farm - which has 125 acres of arable land and a 90,000 broiler chicken operation - will use the electricity to power its poultry houses and the AD facility itself, with a 90% surplus sold to the National Grid. The heat will provide warmth for the chicken houses - displacing fuel oil and propane gas. The facility will have capacity to process 700 tonnes of poultry litter and 1000 tonnes of cattle slurry, mixed with 3000 tonnes of maize silage per annum. Use of maize reduces nitrogen levels in the digestion process and prevents the build up of high concentrations of ammonia that would arrest biogas production. The project, due to operational by August this year is to be delivered by UK based renewable energy specialist ENER-G, and German biogas plant manufacturer PlanET Biogastechnik. Ground works were carried out by local contractors JJ Stanley and concrete tank construction by the Yorkshire-based company Galglass. Triangle Ltd supplied the low voltage electrical Panel. According to ENER-G, the combined heat and power system will provide 250kW of electricity and 200kW of heat. The plant will also qualify for financial payments from the government's Feed in Tariff and Renewable Heat Incentive programmes - providing 14 pence per kW on all electricity generated and 6.5 pence per kW for the captured heat that is used on site. Plans are in place to convert the heating system in the farm's broiler houses within the next few months, to utilise heat from the biogas generation process. This is expected to achieve payback on investment within one year. In addition, the digestion process is expected to produces 5000 cubic metres of odourless organic liquid fertilizer that will be injected into the soil to provide an enhanced nutrient source for the maize crop. The farm currently uses its poultry litter as a fertiliser, but by digesting it, methane losses to the environment during spreading will be eliminated. A new poultry litter store has been created to protect the AD feedstock from the elements and prevent the risk of nitrate run-off and leaching into the soil. Susan Shakesheff, Director of the farm's new green power company - called Ynergy Ltd said: "We are proud to be at the forefront of the move to anaerobic digestion, and to improve our sustainability, and energy self sufficiency, while securing a new income stream. We are able to find a superior alternative for utilising our chicken litter and are helping neighbouring dairy farmers to recycle their cattle slurry. ENER-G and PlanET Biogastechnik are both providing the farm with a modem link to 24/7 monitoring operations, which they say will give full visibility of system performance and efficiency data. The farm also has an ongoing maintenance agreement with ENER-G and biological support from PlanET Biogastechnik that it says will help it maximise efficiency to achieve the fastest possible pay back on its investment. Scott Tamplin, Business Development Manager-AD for ENER-G Natural Power added: "The government claims that AD could produce 7.5 per cent of the UK's renewable power by 2020 and I would urge farmers and landowners to consider the commercial benefits, while helping to hit national targets on carbon emission reductions." Sign up for Waste Management World's Free E-Mail Newsletters