Provided is a method for reusing an adsorbent which can stably exhibit purification ability by regenerating a used absorbent, in order to keep the composition of a purified syngas constant.
The present invention concerns a method for regenerating a zeolite adsorbent which adsorbs a carbon dioxide gas from a syngas comprising the carbon dioxide gas and reduces the concentration of the carbon dioxide gas in the syngas, comprising: a step of recovering a used zeolite adsorbent; a step of calcining the used zeolite adsorbent at a temperature of 300° C. to 600° C. in an oxygen atmosphere to produce a regenerated zeolite adsorbent; and a step of reusing the regenerated zeolite adsorbent.