METHOD FOR REMOVING CARBON DIOXIDE FROM COMBUSTION EXHAUST GAS

摘要

PURPOSE:To sufficiency fulfill CO2 absorption performance in hindered amine aq. soln. by providing a process for heating the hindered amine aq. soln. absorbing CO2 before supplying this soln. to a regenerating tower and a process for separating a part of CO2 isolated from the soln. CONSTITUTION:CO2 in a combustion exhaust gas is removed by using such a process to bring the aq. soln. of hindered amine as the CO2 absorbing liquid into contact with the exhaust gas in a CO2-removing tower 2 to remove CO2 in the exhaust gas, and a process for supplying the absorbing liquid which absorbs CO2 to a regenerating tower 9 where CO2 is isolated and the liquid is regenerated. In this process, the absorbing liquid which absorbs CO2 is sent to at least one-step process where the liquid is heated by heat exchange with a regenerated absorbing liquid at a high temp. in a heat exchanger 5 so that a part of isolated CO2 is separated from the absorbing liquid in a separation drum 6. Then the partly regenerated absorbing liquid is heated in a heat exchanger 8 and supplied to the regenerating tower 9 where CO2 in the partly regenerated absorbing liquid is further isolated and the liquid is regenerated.