Preparation of methane-rich biogas comprises anaerobic fermentation of biomass and/or other substrates to raw fermentation gas, biochemical desulfurization of the gas, and photo-biological carbon dioxide reduction of the desulfurized gas

摘要

Preparation of methane-rich biogas comprises: anaerobic fermentation (1) of biomass and/or other substrates to raw fermentation gas (5), where the process liquid is enriched with oxygen and at least a part of the oxygen comes from an oxygen-enriched, methane-rich fermentation gas (7); biochemical desulfurization (2) of the produced raw fermentation gas; and photo-biological carbon dioxide reduction (3) of the desulfurized fermentation gas, where oxygen-enriched, methane-rich fermentation gas and algal biomass (14) are produced. Preparation of methane-rich biogas comprises: anaerobic fermentation (1) of biomass and/or other substrates to raw fermentation gas, where the process liquid is enriched with oxygen and at least a part of the oxygen comes from an oxygen-enriched, methane-rich fermentation gas (7) that is produced in a photo bioreactor; biochemical desulfurization (2) of the produced raw fermentation gas, results in a separable methane-rich fermentation gas (8) and desulfurized fermentation gas (6);and photo-biological carbon dioxide reduction (3) of the desulfurized fermentation gas, where oxygen-enriched, methane-rich fermentation gas and algal biomass (14) are produced, after which the oxygen-enriched, methane-rich fermentation gas is led to the process of biochemical desulfurization. An independent claim is included for a plant for the production of methane-rich fermentation gas comprising at least a biogas container, a biochemical desulfurization container and a photo-bioreactor container.