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

Abstract

CO 2 solubility in ionic liquids (ILs) is measured extensively to develop IL‐based technology for CO 2 capture. Herein, the choline‐ and acetate‐based ILs are selected as the studied physical and chemical absorbents for CO 2 capture, respectively. The CO 2 solubilities in choline‐ and acetate‐based ILs are thermodynamically modeled. The ILs consumed for CO 2 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 CO 2 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.