| 摘要 |
Provided is a method whereby, using an inexpensive PSA apparatus, highly pure nitrogen gas can be obtained from a mixed gas of methane and nitrogen, and methane for use in power generation can be recovered at a high recovery rate. Provided is a method for separating methane and nitrogen employing a pressure swing adsorption process using two or more adsorption columns (A, B), to separate methane and nitrogen from a source gas which is a mixed gas of primarily methane and nitrogen, wherein the method for separation of methane and nitrogen is characterized in that the adsorption columns (A, B) are packed with gas separation adsorbents (21, 22)having greater equilibrium absorption of methane than of nitrogen, the duration of the pressure equalization step performed by the adsorption column (A) after completion of the adsorption step and by the adsorption column (B) after completion of the regeneration step is 25-35 seconds, inclusive, and methane is recovered at a concentration of 70% or greater and at a recovery rate of 95% or above, while recovering nitrogen at a concentration of 95% or greater. |
