Method for concentrating methane from sewage sludge and methane storage equipment

摘要

The invention provides a method for concentrating methane from sewage sludge capable of economically concentrating methane after simply removing carbon dioxide gas contained in a digestion gas, and methane storage equipment. The digestion gas containing methane generated from sewage sludge is preferably pressurized at 0.5 to 3.5 MPa with a pressurizing device 3, and is supplied to a DDR zeolite membrane 5. Carbon dioxide gas in the digestion gas is separated and removed by allowing the gas to pass through the DDR zeolite membrane 5 to concentrate methane gas. Concentrated methane gas is introduced into a methane adsorption storage tank 9 without re-pressurizing the gas, and methane is stored by allowing it to adsorb on an adsorbing agent. Since the DDR zeolite membrane 5 is superior to organic membranes in moisture resistance, it is suitable for use for treating the digestion gas containing moisture, and methane storage efficiency is enhanced by increasing the concentration of methane, because the membrane can be used under a high pressure.