METHOD FOR RECOVERING CO2 FROM GAS CONTAINING THIN CO2 BY PSA PROCESS

摘要

PURPOSE:To recover CO2 gas efficiently by using synthetic zeolite as adsorbents and purging adsorbed CO2 using CO2 having been preheated to specific temperature. CONSTITUTION:Part of gas containing thin CO2 produced at a boiler 1 etc., is passed through a line 3 and heat-exchanged at a purge gas preheater 5 and thereafter stored in a cushion tank 7. The combustion gas from the tank 7 is successively cooled and dehumidified at an air fin cooler 9 and dehumidifier 11, pressurized to a predetermined adsorption pressure by means of a booster blower 13 and fed via a valve 15 to an adsorption column 19 loaded with adsorbents 17, where most of the CO2 in the combustion gas and a small quantity of N2 and O2 are adsorbed. Thereafter, CO2 of high purity in a product tank 37 is sent to the column 19, where CO2 is further adsorbed and substituted by M2 and O2. As a result, CO2 recovery efficiency can be improved.