Patent ID: 9732297
Date: 2017-08-15
CPC Classifications: B01D,B01J,C01B,C10L

Claim:
1. A gas purification method comprising: providing an adsorption tower filled with an adsorbent that adsorbs a miscellaneous gas comprising at least nitrogen and oxygen from a source gas containing methane; providing a source gas supply line for supplying the source gas to the adsorption tower; providing a product gas recovery line for discharging methane that has not been adsorbed on the adsorbent as a product gas; providing a miscellaneous gas discharge line for discharging desorbed miscellaneous gas that has been adsorbed on the adsorbent; and alternately performing, with the adsorption tower, the source gas supply line, the product gas recovery line, and the miscellaneous gas discharge line, an adsorption step of receiving the source gas into the adsorption tower from the source gas supply line, adsorbing the miscellaneous gas onto the adsorbent, and recovering the product gas into the product gas recovery line, and a desorption step of depressurizing-desorbing the miscellaneous gas adsorbed on the adsorbent and discharging said miscellaneous gas from the miscellaneous gas discharge line in a state in which the source gas supply line and the product gas recovery line are closed, wherein a carbon molecular sieve having a pore volume (V a pore volume (V in the adsorption step, the miscellaneous gas is adsorbed from the 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.