Hierarchical Ionic Liquid Screening Integrating COSMO-RS and Aspen Plus for Selective Recovery of Hydrofluorocarbons and Hydrofluoroolefins from a Refrigerant Blend

Abstract

The selective recovery of hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) from end-of-life equipment is regarded as an efficient and sustainable way for their reclamation, thereby reducing the production and emission of HFCs with high global warming potential. A R454C blend constituted of difluoromethane (R-32) and 2,3,3,3-tetrafluoropropene (R-1234yf) is a nontoxic and mildly flammable refrigerant ideally suitable for hermetically sealed refrigeration systems. This work presents a hierarchical screening of ionic liquids (ILs) for R-32 and R-1234yf recovery from R454C. First, 1093 HFC/HFO-in-IL solubility data (543 for R-32 and 550 for R-1234yf) are collected from the literature to evaluate the reliability of the COSMO-RS model for this system. Then, the solubility of R-32 and R-1234yf in 2224 ILs composed of 59 cations and 38 anions is predicted by COSMO-RS; following that, the IL structural effects on gas solubility are analyzed according to σ-profiles and excess energies. Subsequently, combining the thermodynamic performance and the melting point constraint, the top six ILs among the involved ILs are identified. Based on the retained ILs, a continuous absorption is simulated and evaluated in Aspen Plus, demonstrating that ILs n-(3sulfopropyl)pyridinium thiocyanate and n-(3-sulfopropyl)pyridinium hydrogensulfate are promising absorbents from the process point of view.

Enhancing aromatics extraction by double salt ionic liquids: Rational screening‐validation and mechanistic insights

“…The and could be rapid and simple indicators of the extractive potential of DSILs for separating o ‐xylene from n ‐octane. The COSMO‐RS model has been discussed detailedly in previous literatures on its application in calculating various thermodynamic properties 16,31,32,36–41 . It is widely recognized to be able to provide qualitatively reliable and quantitatively acceptable predictions in most cases for the thermodynamic properties of IL‐involved systems, 16,37–40 and therefore is also potentially suitable for estimating the separation performance of DSILs 31,32,41 .…”

“…The COSMO-RS model has been discussed detailedly in previous literatures on its application in calculating various thermodynamic properties. 16,31,32,[36][37][38][39][40][41] It is widely recognized to be able to provide qualitatively reliable and quantitatively acceptable predictions in most cases for the thermodynamic properties of IL-involved systems, 16,[37][38][39][40] and therefore is also potentially suitable for estimating the separation performance of DSILs. 31,32,41 In this work, all COSMO-RS calculations are performed using the COSMOthermX software package (Version 22.0) at the BP86/TZVP level under the BP_TZVP_22.ctd parameterization.…”

Condensable Gases Capture with Ionic Liquids

“…Recently, an ILs screening method based on COSMO/Aspen Plus was proposed to screen the ILs recovered from R454C for R-32 and R-1234yf. 334 The COSMO-RS model predicted the solubility of R-32 and R-1234yf in 2224 ILs (59 cations and 38 anions) at an infinite dilution. The results showed that ammonium-and phosphonium-based ILs exhibit high solubility, while imidazolium-based ILs exhibit low solubility.…”

“…According to Qin et al, 334 the separation process of a fluorinated refrigerant gas (R-1234yf and R-32) mixture using IL as an absorbent is designed as shown in Figure 21. The designed process flow can achieve the product quality purity of R-1234yf up to 99.5 wt %, and the recovery rate of R-32 will reach 99.0%.…”

“…Recently, an ILs screening method based on COSMO/Aspen Plus was proposed to screen the ILs recovered from R454C for R-32 and R-1234yf . The COSMO-RS model predicted the solubility of R-32 and R-1234yf in 2224 ILs (59 cations and 38 anions) at an infinite dilution.…”