During the concerned period from Dec. 20th to Dec. 30th, the average daily biogas outputs were 3.175 m3 and 3.785 m3, and the average daily net production were 1.754 m3 and 2.477 m3 respectively in D2 and D3, while this value of D1 was 0.930 m3. For D2, about 44.75% of the produced biogas was combusted in the boiler, and about 34.55% was consumed in D3.