Abstract: In a method of desulfurization used at a geothermal power plant, stem removed from a production well, after being used for power generation, is condensed and separated into condensed water and hydrogen sulfide-containing gas, and the hydrogen sulfide-containing gas is treated at biochemical treatment tank. The initial cell density of the reactor liquid of the biochemical treatment tanks is adjusted by cell culture liquid obtained from a cell breeding culture tank provided independently of the biochemical treatment tanks and water or a part of hot water returning to a reduction well, hydrogen sulfide-containing gas is supplied thereinto and desulfurized thereat. With lowering of activation at the biochemical treatment tanks and with lowering of desulfurization ability there, the acidified reaction liquid is removed and is added to the hot water returning to the reduction well. Accordingly, addition of inorganic nutritive salt for cell breeding becomes unnecessary.

Abstract: In a method of desulfurization used at a geothermal power plant, stem removed from a production well, after being used for power generation, is condensed and separated into condensed water and hydrogen sulfide-containing gas, and the hydrogen sulfide-containing gas is treated at biochemical treatment tank. The initial cell density of the reactor liquid of the biochemical treatment tanks is adjusted by cell culture liquid obtained from a cell breeding culture tank provided independently of the biochemical treatment tanks and water or a part of hot water returning to a reduction well, hydrogen sulfide-containing gas is supplied thereinto and desulfurized thereat. With lowering of activation at the biochemical treatment tanks and with lowering of desulfurization ability there, the acidified reaction liquid is removed and is added to the hot water returning to the reduction well. Accordingly, addition of inorganic nutritive salt for cell breeding becomes unnecessary.