COSMO-RS guided screening of ionic liquids for the separation of fluorinated greenhouse gases R-410A: Delving into anion, cation effects, and hydrogen bond dynamics

被引：3

作者：

Ye, Gongran ^{[1
]}

Wu, Xilei ^{[1
]}

Gao, Neng ^{[2
]}

Xu, Yingjie ^{[3
]}

Guo, Zhikai ^{[4
]}

Han, Xiaohong ^{[1
,5
]}

机构：

[1] Zhejiang Univ, Inst Refrigerat & Cryogen, Key Lab Refrigerat & Cryogen Technol Zhejiang Prov, Hangzhou 310027, Peoples R China

[2] Zhejiang Univ, Ningbo Inst Technol, Ningbo 315100, Peoples R China

[3] Zhejiang Univ Technol, Inst Proc Equipment & Control Engn, Hangzhou 310014, Peoples R China

[4] Zhejiang Res Inst Chem Ind, State Key Lab Fluorine Greenhouse Gases Replacemen, Hangzhou 310023, Peoples R China

[5] Zhejiang Univ, Inst Refrigerat & Cryogen, Dept Energy Engn, Hangzhou 310027, Peoples R China

来源：

ENVIRONMENTAL RESEARCH | 2023年 / 239卷

关键词：

COSMO-RS; Ionic liquids; Solubility; Refrigerant reclamation; R-410A; VAPOR-LIQUID; THERMODYNAMIC PROPERTIES; HFC-125; COEFFICIENTS; EQUILIBRIUM; SOLUBILITY;

D O I：

10.1016/j.envres.2023.117386

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Reclamation of high-GWP near-azeotropic refrigerant R-410A (50 wt% R-32 (difluoromethane) + 50 wt% R-125 (pentafluoroethane)) can be an effective way to mitigate the greenhouse effect and achieve a circular economy. Efficient ionic liquids (ILs) as extractants needed to be found for the extractive distillation (ED) separation process of R-410A. Given the numerous combinations of cations and anions in ILs, the discovery of an efficient IL via experimental methods proves to be an exceedingly complex task. In this work, the solubilities of R-32, and R125 in 840 conventional ILs (comprised of 20 cations and 42 anions) were analyzed based on infinite dilution activity coefficient. The absorption mechanisms of R-32 and R-125 in ILs were elucidated by analyzing excess enthalpy (HE), excess Gibbs free energy (GE)) and surface charge density distribution through COSMO-RS (Conductor-like Screening Model for Real Solvents). Results revealed that HE and GE of the mixture formed by R-125 and most ILs surpassed those of R-32, resulting in higher solubility of R-32 in most ILs compared to R-125. Structural changes of anions and cations had a greater effect on the solubility of R-125 in ILs. It is found for the first time that the existence of a strong hydrogen bond donor region in cations/anions generated intense repulsion with the hydrogen atom in R-125. Furthermore, a large area of weak polarity on the surface of cations/ anions was difficult to form an effective charge shield with fluorine atoms in R-125, thus inhibiting the dissolution of R-125. Finally based on the identified interaction sites, combined with melting point and viscosity, some novel functional ILs with high selectivity for R-32 + R-125 were designed and determined for actual separation process. These findings significantly enrich the understanding of the solubility mechanism and provide theoretical guidance for designing new ILs for R-410A reclamation.

引用

页数：13