| 초록 |
The biological methanation using autotrophic methanogen could be operated at relatively low temperature and pressure, which is easier and simpler than conventional chemical methanation process. However, gas-liquid mass transfer of CO2 and hydrogen has been pointed out as a problem in this process. Biological methanation was conductedusing an isolated thermophilic hydrogenotrophic methanogen, Methanothermobacter sp. KEPCO-1. To overcome gas-liquid mass transfer limitation, several operating factors such as reactor pressure, gas flow rate, and agitation rate in a pressurized reactor (1-L) were investigated. The continuous feeding of NH4Cl, Na2S, and trace elements solution enhanced microbial growth and methane production rate. The maximum methane production rate was observed about 450 VVD (L/L/d) at 60°, 7.5 bars. At that time, the feeding rates of NH4Cl, Na2S, and trace elements solution to the reactor were 1.5 g/L/d, 4.0 g/L/d, and 1.0 x/L/d, respectively. |
