METHANE FERMENTATION GAS PURIFICATION PROCESS AND PURIFICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a methane fermentation gas purification process and purification system having a reduced energy requirement for the purification of methane fermentation gas.SOLUTION: There is provided the methane fermentation gas purification process including: a methane fermentation gas production step of obtaining a methane fermentation gas containing a methane gas and a carbon dioxide gas by subjecting organic waste to methane fermentation treatment; and a purification step of obtaining a methane gas-enriched purified gas by purifying the methane fermentation gas obtained in the methane fermentation production step. The purification step includes at least a pressure swing adsorption step of separating carbon dioxide gas from methane fermentation gas using a pressure swing adsorption process, and the pressure of the methane fermentation gas purified in the purification step is less than or equal to the pressure of the methane fermentation gas obtained in the methane fermentation gas production step and the pressure of the purified gas obtained in the purification step is less than or equal to the pressure of the methane fermentation gas purified in the purification step. There is also provided the methane fermentation gas purification system suitable for the implementation of the purification process.