Machine learning for predicting the solubility of high-GWP fluorinated refrigerants in ionic liquids

The development of technology to reduce the environmental impact of fluorinated refrigerant gases (F-gases) is currently of outmost importance. The capture of F-gases in ionic liquids (ILs) is envisaged as solution to avoid emissions of F-gases to the atmosphere, and many studies have been devoted to the experimental determination of the vapor-liquid equilibrium of F-gas/IL mixtures. However, this is an expensive and time-consuming task, so finding prescreening options that can reduce the experimental load would pose a significant advantage in the development of new industrial-scale processes. Here, we develop a prescreening tool based on the use of artificial neural networks (ANNs) to predict the solubility of F-gases in ILs from easily accessible properties of the pure compounds, such as the critical properties of the gases or the molar mass and volume of the IL. We have used the UC-RAIL database with more than 4300 solubility data of 24 F-gases in 52 ILs. The ANN resulting from this study is capable to predict the fed dataset with an average absolute relative deviation (AARD) and mean absolute error (MAE) of 10.93% and 0.014, respectively, and we further demonstrate its predictive capabilities showing the very accurate prediction of a system including R-1243zf, an F-gas that was not present in the training set because it had not been previously studied. Finally, the developed ANN is implemented in an easy-to-use spreadsheet that will allow to extend its use in the prescreening of ILs towards the abatement and recovery of high environmental impact refrigerant gases.This publication is a result of project PID2019-105827RB-I00 funded by MCIN/AEI/10.1039/501100011033. S. A.-D. acknowledges the FPU18/03939 grant and F.P. acknowledges the post-doctoral fellowship (FJCI-2017-32884 Juan de la Cierva Formación) awarded by the Spanish Ministry of Science and Innovation (MCIN/AEI/10.1039/501100011033)