Panorama of sustainable solvents using the COSMO-RS approach

Recent regulations have banned numerous common organic solvents that have been recognized as hazardous to human health and environment. There is thus a pressing need for alternatives, often called green or sustainable solvents, which have a good HSE (Health Safety Environment) profile and are preferably obtained from the biomass feedstock. A number of such green solvents are already on the market or under advanced development and have been listed in this work. To use this set of solvents as effective alternatives, a tool is needed to compare their physico-chemical properties to the ones of the solvents they are supposed to replace. The COnductor-like Screening MOdel for Real Solvents (COSMO-RS) approach was used to model the solvents, which were located in a pseudo 3D-space thanks to Principal Components Analysis and clustering procedures. This approach had already been successfully applied to the classification of classical organic solvents into ten families in which the green solvents have been positioned. This pseudo 3D-representation of green solvents helps in the search of potential alternatives to a questionable solvent. It also sheds light on paucity or even a complete lack of green solvents in some families (e.g. strong electron pair donor bases). There is thus a need to develop new green solvents with the prerequisite properties. As the COSMO-RS approach can be applied to almost any potential candidate, it could be a powerful tool for the design in silico of new sustainable solvents.