Absorption of CO 2 , NO and SO 2 from flue gas using a packed tower by aqueous ammonia and Fe( II ) EDTA

Abstract Traditional independent removal technologies for CO 2 , NO and SO 2 from coal‐fired flue gas require multiple sets of equipment and high capital investment, which severely restricts the low‐cost collaborative purification of flue gas pollutants. Aqueous ammonia exhibits high capacity for capturing CO 2 and SO 2 , while Fe(II)EDTA can selectively chelate gaseous NO. The combination of these two absorbents enables simultaneous removal of three pollutants within a single packed reactor. Based on conventional wet ammonia desulfurization, a composite absorption system incorporated with Fe(II)EDTA was constructed herein. The effects of key operational parameters on the removal efficiencies of CO 2 , SO 2 and NO were systematically investigated. Experimental results demonstrated that the steady‐state removal efficiencies of CO 2 , SO 2 and NO reached 85%, 95% and 47%, respectively. Furthermore, a macroscopic mass transfer kinetic model for CO 2 absorption was established, and the intrinsic reaction mechanisms governing CO 2 and NO uptake during multi‐pollutant co‐absorption were elucidated.