Scale effect of anaerobic digestion tests in fed-batch and semi-continuous mode for the technical and economic feasibility of a full scale digester. (April 2015) - Ruffino, Barbara
Highlights: CH4 production capacity of vegetable waste was assessed on different scales and modes. CH4 yield from the pilot scale test was about 80% of that from the smaller scale test. Produced net electricity was from 30% to 50% of the food industry plant consumption. Available thermal energy can cover from 10% to near 100% of the plant requirement. Abstract: Methane production capacity in mesophilic conditions of waste from two food industry plants was assessed in a semi-pilot (6 L, fed-batch) and pilot (300 L, semi-continuous) scale. This was carried out in order to evaluate the convenience of producing heat and electricity in a full scale anaerobic digester. The pilot test was performed in order to obtain more reliable results for the design of the digester. Methane yield, returned from the pilot scale test, was approximately 80% of that from the smaller scale test. This outcome was in line with those from other studies performed in different scales and modes and indicates the success of the pilot scale test. The net electricity produced from the digester accounted for 30–50% of the food industry plants' consumption. The available thermal energy could cover from 10% to 100% of the plant requirements, depending on the energy demand of the processes performed.