The invention belongs to the technical field of
biomass energy utilization, and particularly relates to a
biogas fermentation system and method. The
biogas fermentation system comprises a pretreatment section, a desulfurization section, a
hydrolysis section, an
acid production section and a
methane production section which are sequentially arranged from top to bottom. A
discharge pipe at the bottom of the pretreatment section penetrates through the liquid
distributor to reach the middle part of the desulfurization section; the return
pipe is connected with the liquid
distributor through the pump; gas in the
hydrolysis section enters the desulfurization section for desulfurization through a gas guide
pipe and a floating valve group in the desulfurization section; gas in the
acid production section enters the
hydrolysis section through a gas guide pipe and a floating valve group in the hydrolysis section to be hydrolyzed; and gas in the
methane production section enters the
acid production section through a gas guide pipe and a floating valve group in the acid production section to be subjected to acid production treatment. According to the invention, CO2 removal, H2S removal,
oxygen removal,
ammonia removal, mercaptan removal, halogenated
hydrocarbon removal and
siloxane removal are carried out on the
fermentation system through a plurality of strengthening means, so that high-quality
biogas and functionalized biogas
slurry are obtained.