| 摘要 |
PROBLEM TO BE SOLVED: To provide a nitrogen separation apparatus separating nitrogen from a raw material gas essentially consisting of methane, in which the recovery rate of methane at a low cost is high, and a method therefor.SOLUTION: Provided is a nitrogen separation apparatus comprising: a membrane separation device 1 having a separation membrane 1C selectively permeated with nitrogen from methane, dividedly formed into a first chamber 1A and a second chamber 1B by the separation membrane, in which nitrogen in the raw material 11 fed into the first chamber permeates through the separation membrane, a membrane separation exhaust gas 14 increased in the nitrogen concentration is stored into the secondary chamber, and the membrane separation treatment gas 13 including residual nitrogen in which methane concentration is made higher than that in the raw material gas is stored into the first chamber; and a pressure swing adsorption device 2 provided with an adsorber selectively adsorbing nitrogen gas from methane, in which the adsorber adsorbs the residual nitrogen in the membrane separation treatment gas under pressure swing by the receiving of the membrane separation treatment gas 13 from the first chamber of the membrane separation device 1 to produce a product gas in which the methane concentration is increased from the membrane separation treatment gas and exhaust gases 16, 17 including adsorbed nitrogen, increased with the nitrogen concentration and including methane. |
