| abstract |
The rate of recovery of a purification target gas from a gas purification apparatus that uses a PSA device is improved, and both a high purity and a high recovery rate are achieved with good power efficiency. The present invention is directed to a gas purification method using the PSA method, in which a carbon molecular sieve having a pore volume, at a pore diameter of 0.38 nm or more, of not exceeding 0.05 cm 3 /g and a pore volume, at a pore diameter of 0.34 nm, of 0.15 cm 3 /g or more, in a pore diameter distribution measured by the MP method is used as an adsorbent, and, in an adsorption step, a miscellaneous gas is adsorbed from a source gas by bringing the source gas into contact with the adsorbent for 10 seconds or more and 6000 seconds or less so as to obtain a concentrated methane. |