PURPOSE: To reduce the temp. difference of adsorbent by providing a heat transfer promoting partition plate in an adsorption tower and flowing a mixed gas in a counter flow with the partition plate between as a boundary in the processes of adsorption and desorption and making the area of gas flow passage to be larger in the inlet of the tower and to be smaller in the outlet of the tower.

CONSTITUTION: The partition plate 3 promoting heat transfer is provided in a adsorption packing layer 2 in the pressure vessel of the adsorption tower. The mixed gas is flowed as shown by arrow 4 in a counter flow with the partition plate 3 between in the process of adsorption and desorption to carry out heat exchange so that the temp. charge in the adsorbent is restrained. The flow passage areas are made larger in the inlet of the tower and smaller in the outlet of the tower so that the flow rate per unit volume of adsorbent is equalized.