Energy Analysis of Physical Absorption and Chemical Absorption of CO2 in Ionic Liquids

Abstract

CO2 solubility in ionic liquids (ILs) is measured extensively to develop IL‐based technology for CO2 capture. Herein, the choline‐ and acetate‐based ILs are selected as the studied physical and chemical absorbents for CO2 capture, respectively. The CO2 solubilities in choline‐ and acetate‐based ILs are thermodynamically modeled. The ILs consumed for CO2 absorption and the energy demands for the ILs regeneration are calculated and compared with those of the conventional imidazolium‐based ILs. The results show that the three choline‐based ILs are not energy saving in the pressure‐swing process. In the temperature‐swing process, the energy demand for CO2 absorption by using acetate‐based ILs reveals that the chemical absorption‐based ILs are the absorbent with lower energy demands compared with the physical absorption‐based ILs.