Computer-Aided Screening and Experimental Evaluation of Conventional Molecular Solvents for R32 Absorption

Abstract

Fluorinated gases (F-gases) contribute substantially to global warming, motivating the development of efficient solvents for their recovery. Conventional molecular solvents represent a practical class of absorbents, yet their large chemical space remains insufficiently explored. Here, a computer-aided framework integrating COSMO-RS evaluation, high-throughput screening, environmental and health assessment, experimental evaluation, and molecular-level analysis was developed for difluoromethane (R32) absorption. COSMO-RS was evaluated against 996 experimental F-gas solubility data and applied to screen 2562 conventional molecular solvents based on absorption capacity and ease of desorption. Sequential screening identified dimethyl sulfoxide (DMSO) and 1-(2-hydroxyethyl)-2-pyrrolidinone (HEP) as the two highest-ranked candidates. Experiments confirmed appreciable R32 solubility in both solvents, with DMSO showing higher solubility at 303.15 K and solubility decreasing with increasing temperature. IGM and RDG analyses further identified polar O-containing groups as important interaction sites for R32. Overall, this framework enables efficient screening of conventional molecular solvents for R32 absorption and recovery.