METHOD OF PRODUCING BIOGAS BY ANAEROBIC CO-FERMENTATION Russian patent published in 2024 - IPC C12P5/02 C02F11/04 C05F17/50 B09B3/40 B09B3/65 

FIELD: environmental technologies.

SUBSTANCE: invention relates to a novel method of producing biogas by anaerobic combined fermentation of organic wastes. Method includes obtaining hydrolysed biomass from solid organic wastes selected from a group, including an organic fraction of solid household wastes and digestible wastes, organic wastes formed as a result of selective collection of solid household wastes and any combination thereof. Said step, in turn, includes a first sub-step, including thermal hydrolysis treatment of solid organic wastes, which is preferably carried out at a pressure in range of 1.5 to 4.5 bar and a temperature in range of 120 to 160 °C, as a result of which crude biomass is formed. Said step also includes a second sub-step, which is then carried out for subsequent processing of the raw biomass with separation of foreign materials, resulting in a pure hydrolysed biomass, in which percentage of organic substance is at least 90 wt.%, ratio of mass of volatile solids to total mass of solids is at least 0.6, and total solids content is at least 5 wt.%. Method involves mixing pure hydrolysed biomass obtained at the previous step in amount of 5 to 65 wt.% with a residue from a waste water treatment plant in amount of 35 to 95 wt.%, as a result of which a mixture with a concentration of solid substances of less than 30 wt.% is obtained. Said mixture is then subjected to a conditioning process to bring concentration of solid substances to a value of less than 20 wt.%. Method also involves wet anaerobic fermentation of the mixture obtained at the previous stage in at least one fermentation plant, as a result of which biogas and digestate are formed. Anaerobic fermentation is carried out in a mesophilic mode at a temperature in range of 25 to 40 °C or in a thermophilic mode at a temperature in range of 50 to 60 °C and for a hydraulic retention time of 12 to 30 days.

EFFECT: invention provides higher efficiency of anaerobic fermentation process.

4 cl, 1 dwg, 8 tbl