摘要 |
PROBLEM TO BE SOLVED: To provide a method for refining a mixed gas and a refining equipment which can inhibit a concentration of a target gas in a refined gas from becoming less than a desired concentration while improving a recovery ratio of the target gas from the mixed gas.SOLUTION: Provided is a method for refining a mixed gas whereby a mixed gas is refined by a pressure swing adsorption method to obtain a refined gas by using a refining equipment provided with at least two adsorption towers packed with an adsorbent. While an adsorption process is performed with at least one adsorption tower, a desorption process is performed with at least one of the remaining adsorption towers and, at the same time, at least a portion of a desorbed gas is circulated as a recycled gas into the adsorbing tower which is performing an adsorption process and, at the end of the adsorption, concentrations of a target gas and/or an impurity gas in the mixed gas are measured, and, using the concentrations of the gases in the mixed gas, a maximum time is determined, during which the recycled gas can be circulated into the adsorbing tower when performing the next adsorption process. Also provided is a refining apparatus suitable for the refining process. |