Ionic Liquid as a Selective Capture Method of CO₂ from Different Sources: Comparison with MEA

Ionic liquids (ILs) have received growing consideration as a prospective decarbonization solvent. Nevertheless, most studies have focused on flue gases with specific compositions and flow rates, which makes it a challenging task to use ILs with divergent CO₂ emission scenarios for the comprehensive carbon management. In this work, complete conceptual designs for absorption processes 1-butyl-3-methylimidazolium acetate ([bmim][Ac]) are developed for separating at least 90% of CO₂ from the feed before pressurizing it to 150 bar to the sequestration sites over a broad range of CO₂ flue gas compositions and flow rates. Each scenario is rigorously modeled, simulated, optimized, heat integrated, and compared with the conventional process by MEA. The simulation results show that compared to conventional processes, IL-based processes are only quite economical at high flue gas flow rates and CO₂ contents. Also, a quantitative method toward technology comparison and scaling up is presented, which helps in selecting the suitable technology when input conditions change. Finally, a cost model for investment and operating costs of various emission sources is proposed as a tool to design an energy-saving and cost-efficient CO₂ supply chain network for the future.