Patent ID: 8168149

Claim:
A method of reducing power consumed by a system for capturing CO 2 from flue gas, the method comprising: contacting in a contacting step a flue gas stream containing CO 2 with an ammoniated solution lean in CO 2 to provide an ammoniated solution rich in CO 2 ; regenerating in a regenerating step the ammoniated solution rich in CO 2 to release CO 2 from the ammoniated solution, thereby producing the ammoniated solution lean in CO 2 ; recycling the ammoniated solution lean in CO 2 from the regenerating step to the contacting step; adding a promoter to the ammoniated solution lean in CO 2 , the promoter being effective to enhance the formation of ammonium bicarbonate within the ammoniated solution lean in CO 2 , thereby increasing the CO 2 absorption capacity of the ammoniated solution lean in CO 2 ; and reducing the amount of ammoniated solution lean in CO 2 that is recycled from the regenerating step to the contacting step, thereby reducing the power consumed by the system.