1st fermentation tank adopts CSTR method (completely mixed anaerobic reactor Continuous Stirred Tank Reactor, CSTR) fermentation. On top of this kind of fermentation tank has top stirring or interior dive stirring, and inside of tank have heating coil, by stirring and heating, the methane bacteria and raw material fully contacts with each other, while maintaining the optimum reaction temperature of methane bacteria, so as to greatly improve the utilization efficiency of raw material and save the reaction time. This advantage makes the CSTR biogas fermentation process has been widely used in the biogas project.

Biogas stored in the gas cabinet at the top of secondary fermentation tank is delivery to desulfurization system through roots blower, so as to remove hydrogen sulfide of biogas (H2S). Hydrogen sulfide is a corrosive gas, if not remove, it will bring the corrosion of the pipe, causing a series of problems, so need timely remove hydrogen sulfide. Hydrogen sulfide in the gas is removed, through the preliminary dewatering device, to remove saturated steam in the biogas. Thus, the biogas can be used to generate electricity.

Flow chart:

The advantages :
① The raw material of high content of suspended solid (SS) could enter into the reactor.

② Substrate uniform distribution to enhance the touch chance for substrate and microorganism.

③ The temperature distribution uniformity in reactor.

④ Any of the inhibiting substance into reactor could dispersion in a minimum level quickly.

⑤ To avoid the jams, channel flow and gas evolution.