(372p) Phase Equilibria for HFC-32, HFC-125, and Binary Mixtures (R-410A) with a Variety of Ionic Liquids

Hydrofluorocarbons (HFCs), the current generation of refrigerants, are being phased out due to high global warming potential (GWP) while hydrofluoroolefins (HFOs), the new generation of more environmentally friendly refrigerants, are being commercialized. Thus, millions of tons of HFC mixtures will need to utilize new technology to be efficiently recycled and repurposed. Project EARTH (Environmentally Applied Research Toward Hydrofluorocarbons) is focused on developing selective and efficient separation processes for HFC mixtures for this purpose. One approach is to use ionic liquids (ILs) as entrainers to selectively separate azeotropic HFC mixtures like R-410A, which is composed of 50 wt.% HFC-32 (CH₂F₂) and 50 wt.% HFC-125 (CHF₂CF₃). HFC-32 can then be blended with new HFOs to produce products and HFC-125 can be repurposed as a high-value fluorinated feedstock for production of new materials with a low-GWP.

This presentation will compare the phase equilibria data for a variety of novel ILs with HFC-32, HFC-125, and mixtures (e.g., R-410A). This presentation will discuss ILs that are both solid and liquid at 25 °C as well supporting data from a high-pressure view cell and a Calvet calorimeter. Phase equilibria data for HFC-32 and HFC-125 were measured using a Hiden Isochema IGA gravimetric balance to compare differences in gas solubility for a variety of ILs.