At a dairy and arable farm in Den Bommel (NL), owned by firm J. Ras and Sons, gas is produced and delivered to the natural gas network. In a Microferm digestion plant built by HoSt, 8.000 tonnes of cattle manure is digested annually. The produced biogas is upgraded to natural gas quality and then fed into the natural gas network. The amount of produced natural gas is 200,000 m3 annually, which is equivalent to the consumption of 125 households.
Unique to this project is the valorization of the biogas. After the upgrading process, the gas is fed directly into the gas network, whereas before the biogas was primarily used to produce electricity and heat. It is the first plant where 100% manure is digested in combination with the production of gas on this small scale. For the upgrading of biogas on such small scale, HoSt is awarded with the Jan Terlouw Award, a Dutch innovation award, in 2012.
The Microferm concept focuses on the digestion of 100% manure on farm-scale, without adding co-flows. Meanwhile, HoSt has built several Microferm digesters in The Netherlands, Fance, and Germany. The plant at the farm in Den Bommel consists of a digestion tank, gas tight after-storage, and a container containing the upgrading unit, control system and a heat pump. The advantage of the production of gas of natural gas quality is the maximum energetic efficiency, which is considerably higher than when producing electricity.