Process modifications for a hot potassium carbonate‐based CO2capture system: a comparative study

Abstract Chemical absorption using hot potassium carbonate (K 2 CO 3 ) is believed to be a more energy‐efficient post‐combustion CO 2 capture technology as compared to conventional amine‐based absorption processes. That notwithstanding, literature information on how process modifications could render this technology more appealing are limited. In this study, seven different modified process configurations have been investigated to observe their impacts on the system performances of a typical hot K 2 CO 3 ‐based capture system. The results demonstrate that flue gas precooling is capable of improving the carbon removal level in the K 2 CO 3 ‐based capture system by 11.46% over the base case value. This was achieved by precooling the flue gas stream from 110 to 70°C before feeding into the absorber column. Other modified process systems such as the rich solvent pre‐heating and lean vapour compression were equally observed to decrease the specific stripper reboiler duty by 24.28% and 21.38%, respectively. The findings from this research prove that process modifications are capable of enhancing the system performances of the hot K 2 CO 3 ‐based post‐combustion CO 2 capture technology. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.