Ionic liquids for highly efficient capture C4 alcohol aldehyde isomer VOCs: experimental and molecular mechanisms

Imidazolium-based ionic liquids (ILs) were explored for the first time to capture C4 alcohol aldehyde isomer VOCs. The suitable IL was screened with viscosity, solubility, and selectivity as indicators by COSMO-SAC model. The absorption experiment showed that [BMIM][TFO] had excellent absorption capacity compared with [EMIM][TFO], and the average absorption rate was increased by 3.51 %. Quantum chemical analysis and molecular dynamics simulations have clarified the dual interaction mechanism of the process, that is, the cation binds to the alcohol/aldehyde through van der Waals force and hydrogen bond, while the anion interacts with the aldehyde through van der Waals force. The process simulation shows that using [BMIM][TFO] can reduce the amount of absorbent by 26.26 % compared with [EMIM][TFO] absorbent. This work provides a theoretical basis for the design and process optimization of C4 alcohol and aldehyde isomers VOCs capture absorbents and expands the application range of ILs in chemical waste gas treatment.