Utilizing waste heat of the flue gas for post-combustion CO2 capture—A comparative study for different process layouts

Abstract

ABSTRACTThe inlet flue gas entering the absorber column must be ~40°C and hence needs cooling. In this article, it is proposed that waste heat be recovered from the flue gas using a condensing heat exchanger. This recovered heat is utilized as partial supplement to subsequent heating in stripper during CO2 capture. System layouts—one for base case and two others—have been conceptualized. ASPEN Plus® simulation results for the other two layouts are discussed for energy savings with respect to the base case. Results show that, for the other two layouts, reboiler heat duty decreases though carbon capture efficiency also decreases.