In order to increase the use of biogas plants in Korea, a farm-scale biogas plant with a working
volume of 200 m3 was
constructed at the pig farm in Sung Hwan, Korea as a demonstration project supported by the Korean
government. This plant mainly consists of an anaerobic digester processing daily 10 m3 pig manure
and a dual-fuel engine-generator to produce heat and electricity. Digestion takes place in a
semi-continuous, single stage, completely stirred anaerobic
digester under mesophilic temperatures with maximum 0.8℃ deviation per day from the setting
temperature of 35℃.
The digester was constructed as cylindrical flat-bottomed tanks instead of general conical bottoms.
But it did not cause any serious mixing trouble. The results of solids profiles and temperature
profiles inside the digester showed very small variations, which mean adequate mixing
performances. During anaerobic digestion, 55% of volatile solids (VS) reduction in average
was stably achieved. However no further VS reduction was occurred due to its inherent non- readily
biodegradable materials. The average biogas yield was 0.70 m3 per kg of added volatile solids. The
biogas composition was relatively constant for the entire run with the 68-73% methane(V/V) and
27-30% carbon dioxide(V/V).
The produced biogas was effectively used in a dual-fuel engine-generator to produce heat and
electricity.