MANUFACTURE OF METHANE-CONTAINING GAS

PURPOSE:To efficiently remove CO2 gas under a low thermal load by a process in which the CO2 gas in a reaction product gas obtained through a reaction of an alcohol with steam is absorbed by a liquid phase alcohol. CONSTITUTION:After moisture removal, a reaction product gas obtained through a reaction of an alcohol with steam is introduced through a pipe 1 into a CO2 gas separation step. On the other hand, the gas dissolved in a liquid phase alcohol is separated from the alcohol under reduced pressure in a flush tank F; the pressure of the gas is raised by a circulator K; and the gas passing through a pipe 6 and mixed with the reaction product gas is introduced into a CO2 gas absorption tower T. A supply alcohol from the upper part and a circulating alcohol from the middle part are fed into the tower T to remove the CO2 gas in the reaction product gas, so that a methane-containing gas is obtained through a pipe 3. The circulating alcohol containing an absorbed CO2 gas passes through the flush tank F and is fed into a CO2 gas diffusion tower D, where the CO2 gas is removed by the air introduced therein through a pipe 8 with a blower B. Part of the alcohol is then sent through a pipe 12, a cooler E, and a pipe 13 to the absorption tower T for reuse.