The biogas produced at the plant, will have an energy content of 16 GW per annum. The energy could be used for either cogeneration or as fuel in vehicles. The digested sludge containing both food substance and organic material is dewatered into a high-class pasteurized fertilizer for direct application to agricultural land.

Purac will be delivering the receiver unit as well as digester equipment. Purac will also be responsible for post treatment of the digested sludge. Cambi will be delivering the main elements in the process as part of the patented thermal hydrolysis process (THP). The process involves pre-heating the sludge for a fixed period of time before the sterilized sludge is passed rapidly into the flash-tank resulting in cell destruction from the pressure drop. The sludge is then cooled before being fed into the digesters, where it is more easily digested due to cell destruction. The high temperature of the THP process eliminates all pathogens and the end product is a fertilizer suitable for use on agricultural land.

Per Lillebø CEO, Cambi, said: “This is an important contract for Cambi. Cambi’s process is based upon Thermal Hydrolysis (THP), and this is the key to securing a high production of biogas and a fertilizer of good quality. Cambi has development a compact solution for the THP which has a large international potential for treatment of sludge.”

The total contract cost is 80 million NOK, including civil work and process elements. ENOVA will support the project with 8 million NOK. The plant is scheduled to be finished in the second half of 2011.