Integrated Molecular Screening and Process Optimization To Identify Ionic Liquids for Energy-Efficient Refrigerant Separation

Hydrofluorocarbon (HFC)-based mixed refrigerants are widely used in commercial cooling and manufacturing processes. HFCs have a high global warming potential (GWP), which makes their reclamation particularly important. End-of-life recovery of HFCs that form azeotropes requires advanced separation technologies. Solvent-based extractive distillation can break azeotropes and recover high-purity constituents, but solvent selection critically affects the separation performance. In this work, we present a computer-aided molecular and process design (CAMPD) framework that integrates molecular simulation and solubility-based screening with rigorous process optimization to identify promising ionic liquid solvents for HFC separation. This approach addresses the complex multiscale interplay between solvent choice and the operating conditions of the extractive distillation process, offering a holistic solution to the HFC separation challenge. We apply the framework for the separation of R-410A, a 50/50 wt % blend of HFC-32 and HFC-125. We screen 341,687 ionic liquids and salts, the largest set of solvent candidates considered for this application. We identify 285 new ionic liquids that outperform the existing solvents for the R-410A separation. Many show potential to significantly reduce the process energy consumption of HFC separation. We also analyze the molecular features of the top-performing ionic liquids to gain insights and uncover design principles for their use as effective mass separating agents.