Ionic liquids for highly efficient methyl chloride capture and dehydration

Abstract A new methyl chloride (CH 3 Cl) capture and dehydration process using two ionic liquids (ILs) was designed and systematically studied. ILs [EMIM][Ac] and [EMIM][BF 4 ] were screened out as CH 3 Cl capture and drying absorbents through the COSMO‐RS model. The result of solubility experiment suggests [EMIM][Ac] has an excellent solvent capacity for CH 3 Cl at mild operation conditions. The bench‐scale CH 3 Cl absorption experiments further confirmed the outstanding CH 3 Cl capture ability of [EMIM][Ac]. Besides, the water content of outlet gas can be decreased to 452 ppm (mass fraction) using [EMIM][BF 4 ] in the dehydration experiment. The industrial‐scale CH 3 Cl capture and dehydration process was simulated and optimized. Compared to the benchmarked triethylene glycol process, IL process has higher product purity (99.99 wt%), and lower energy consumption. The quantum chemical calculations clearly revealed the relationship between hydrogen bond and separation performance. This study provides a decision‐making basis for designing green process associated with volatile organic compounds.