MOLECULAR SIEVING CARBON FOR SEPARATING METHANE FROM MIXED GAS OF METHANE AND NITROGEN

摘要

PROBLEM TO BE SOLVED: To selectively absorb and separate a non-combustible gas such as nitrogen or carbon dioxide from a mixed gas composed mainly of methane and thereby, efficiently recover a high-purity methane by using a molecular sieving carbon. SOLUTION: The molecular sieving carbon is used for industrially separating a mixed gas containing methane and nitrogen into the methane and the nitrogen. Alternatively the molecular sieving carbon is used for selectively adsorbing and removing the nitrogen from the mixed gas containing the methane and the nitrogen and upgrading the purity of the methane to separate/refine the methane. The molecular sieving carbon to be favorably used shows such a property that the average pore diameter is 0.3-0.5 nm and the equilibrium adsorption (value at 0.1 MPa and 25 deg.C) is 3.0-15.0 Nl/kg for nitrogen; 10.0-40.0 Nl/kg for methane; 30.0-90.0 Nl/kg for carbon dioxide; and 30.0-90.0 Nl/kg for ethylene.