Comparison of novel ionic liquids and pure water for CO₂ separation through membrane contactor: CFD simulation and thermal analysis

Industrial application of novel, green and effective liquid absorbents for improving the separation yield of CO₂ greenhouse pollutant is an important milestone to reduce its emission to the atmosphere. In this research, the separation performance of three novel and green ionic liquids (ILs) including [bmim][PF₆], [bmim][BF₄] and [emim][etSO₄] are compared with pure water to evaluate the feasibility of their employment to enhance the removal potency of CO₂ through the membrane contactor. With the aim of reaching this goal, a finite element-based model and a numerical simulation are developed to solve the momentum/mass transfer equations and predict the results. Based on the modeling/simulation outcomes, the addition of the abovementioned ILs could substantially increase the separation of CO₂ molecules compared to pure water. Based on the results, [bmim][BF₄] is introduced as the most efficient IL with the separation efficiency of 100 % (100 % [bmim][BF₄]> 99 % [bmim][PF₆]> 97.5 % [emim][etSO₄]> 55 % pure water). Furthermore, the effects of different operational/functional parameters (i.e., gas flow rate, porosity, fibers’ number and packing density) on the CO₂ separation efficacy is comprehensively discussed.