(144a) Molecular Simulation and Experimental Study for the Separation of Azeotropic Hydrofluorocarbon Refrigerant Mixtures Using Silicalite.

Hydrofluorocarbons (HFCs) are a type of fluorinated refrigerant used extensively in residential and industrial refrigeration systems. These substances were developed to replace chlorofluorocarbons due to their high ozone depletion potential (ODP). While HFCs have a zero ODP, they have a high global warming potential (GWP). Various government regulations targeting global warming effects have increased the interest to find new technologies to reduce fluorinated greenhouse gas emissions from refrigeration systems. Among HFCs, R-410A is a widely used refrigerant that is composed of 50.0% mass HFC-32 and 50.0 % mass HFC-125. There is a pressing need to find a sustainable separation process for this mixture that allows for its future recycling. This study examines the zeolite silicalite as a separation agent of R-410A using grand canonical Monte Carlo molecular simulations and experiments using a Xemis gravimetric microbalance. Thermodynamic properties such as isosteric heats, selectivities and adsorption isotherms are presented for HFC-32 and HFC-125 and compared with experimental data. Additionally, simulations provide molecular insights on the adsorption mechanism. Mixed-gas adsorption isotherms are presented and compared to ideal adsorbed solution theory.