METHOD FOR MANUFACTURING CARBON DIOXIDE BY PRESSURE SWING ABSORPTION

摘要

PROBLEM TO BE SOLVED: To improve the recovery of a high purity carbon dioxide at the time of separating and recovering from a gaseous mixture containing CO2 by operating an adsorption column packed with an adsorbent by a pressure swing adsorption. SOLUTION: An adsorption waste gas low pressure cleaning step for replacing and desorbing a remaining CO2 in the adsorption column finished in a desorption step by counter currently introducing a waste gas low in CO2 concentration and discharged from an adsorption step of another adsorption column into an adsorption column finished in the desorption step and a CO2 adsorption low pressure cleaning waste gas adsorption step by supplying a waste gas high in CO2 concentration discharged from the adsorption waste gas low pressure cleaning step to another column finished in the adsorption step are introduced in the well-known process structure composed of a pressure elevation step-the adsorption step-a cleaning step-the desorption step. The adsorption waste gas reverse pressure accumulation step for sending an adsorption front line to the adsorption column inlet side by counter currently introducing the waste gas of the adsorption step, which is low in CO2 concentration, to a column finished in the adsorption waste gas low pressure cleaning step is supplemented to decrease the CO2 concentration in the waste gas discharged from the adsorption step performed after the adsorption waste gas reverse pressure accumulation step.