| abstract |
The recovery rate of the final gas after treatment in the gas purification device using the PSA system is higher, and at the same time high purity and recovery rate with good energy efficiency are obtained. The present invention relates to a gas purification method using pressure swing adsorption (PSA) in which a carbon molecular sieve with a pore volume of (V0.38) and a pore diameter of 0.38 nm or more, not exceeding 0.05 cm3/g, is used as the adsorbent, and pore volume (V0.34), with a pore diameter of 0.34 nm, of 0.15 cc/g or greater with a pore diameter distribution as measured by the MP method. In the adsorption step, other gas is adsorbed from the source gas by contacting the source gas with the adsorbent for 10 to 6000 seconds to obtain concentrated methane. |