Searching for Solvents with an Increased Carbon Dioxide Solubility Using Multivariate Statistics

Ionic liquids (ILs) are used in various fields of chemistry. One of them is CO(2) capture, a process that is quite well described. The solubility of CO(2) in ILs can be used as a model to investigate gas absorption processes. The aim is to find the relationships between the solubility of CO(2) and other variables—physicochemical properties and parameters related to greenness. In this study, 12 variables are used to describe a dataset consisting of 26 ILs and 16 molecular solvents. We used a cluster analysis, a principal component analysis, and a K-means hierarchical clustering to find the patterns in the dataset and the discriminators between the clusters of compounds. The results showed that ILs and molecular solvents form two well-separated groups, and the variables were well separated into greenness-related and physicochemical properties. Such patterns suggest that the modeling of greenness properties and of the solubility of CO(2) on physicochemical properties can be difficult.