METHOD FOR CONCENTRATING GAS PRODUCING LOW CONCENTRATED GAS WITH HIGH FLUX

摘要

PURPOSE: Provided is a method for concentrating gas which is able to effectively produce low concentrated gas with high flux based on vacuum swing adsorption. CONSTITUTION: The method for preparing concentrated enriched gas from mixed gas by pressure difference with using adsorbents having adsorption ability on specific gas comprises steps of (a) a desorption step which applies vacuum pressure to the inside of an adsorption bed (1) containing adsorbents by using a vacuum pump means (2); (b) an adsorption step which cuts off the adsorption bed from the vacuum pump means by a flow path conversion valve (4) and allows mixed gas to be flown in the adsorption bed by the pressure difference between the mixed gas passed through a filter (3) and the vacuum pressure of the inside of the adsorption bed to adsorb specific gas on the adsorbent; and (c) a production step which discharges concentrated produced gas to the outside by applying vacuum pressure to the upper end of the adsorption bed, when the concentration of the produced gas becomes increased, with a gas supplying means (6), able to generate low pressure of vacuum pressure, wherein the desorption step starts before the production step is completed, the production of gas is proceeded with the desorption step for a certain period of time and the gas supplying means shortens the desorption step so that the pressure of the inside of the adsorption bed is dropped off within a short period of time by the vacuum pump means and the gas supplying means.