Design of absorption process for CO2 capture using cyano based anion ionic liquid

Abstract

Ionic liquids are regarded as potential candidate for CO2 absorption because of their tunable properties, wide liquid range, negligible vapor pressure and their high CO2 solubility. This work aimed to study the feasibility of CO2 separation from gas containing methane and carbon dioxide using a cyano based anion ionic liquid “1-hexyl-3-methylimidazolium tetracyanoborate” [hmim][TCB] as physical absorbent due to its high CO2 capacity and its low viscosity comparing to the organic solvent DEPG called Selexol. A comparative study among different proposed case studies for CO2 absorption in the both cases of solvent has been carried out to improve the performance of the separation process. Results show that for feed gas containing between 20 and 40mol.% of CO2, it is well favorable to use the IL instead of DEPG. At 5mol.% of CO2 in feed gas it was found that lower solvent flow rate is required for the absorption with [hmim][TCB] than DEPG and the solvent can be regenerated by combining both the pressure and temperature swing process.