METHOD FOR SEPARATING AND REMOVING CARBON DIOXIDE IN GASEOUS MIXTURE CONTAINING CARBON MONOXIDE BY USING ADSORPTION METHOD

摘要

PURPOSE:To remove CO2 from a mixed gas contg. easily adsoprtive components such as CO with a variable-pressure adsorption method by carrying out the purging with the product gas after a reduced-pressure evacuation stage during vacuum evacuation. CONSTITUTION:Adsorption towers A and B contg. an adsorbent such as zeolite are evacuated under reduced pressure by a vacuum pump 16. The waste gas from a steel making plant contg. CO is introduced into the adsorption tower A under pressure by opening a valve 2. A part of easily adsorptive components such as CO2, CO, and N2 is adsorbed, and the remainder is recovered from a valve 5 as the product gas. After finishing the adsorption stage, the valves 2 and 5 are closed, and a valve 3 is opened to release the pressure inside the adsorption tower A to the atmospheric pressure. Then the valve 3 is closed, a valve 4 is opened, and the tower is evacuated under reduced pressure by a vacuum pump to desorb remaining CO2. Then the valves 6 and 4 are opened to introduce the product gas, and the remaining CO2 is desorbed while evacuating under vacuum. After the product gas is purged, the valves 4 and 6 are closed, a valve 7 is opened to introduce the product gas, and the internal pressure of the tower A is increased to the adsorption pressure.