Experiences in Designing Solvents for the Environment

Solvents used throughout industry are chosen to meet specific technological requirements such as solute solubility, cleaning and degreasing ability, or utility as a medium for paints and coatings. With the increasing awareness of the human health effects and environmental risks of solvent use, the replacement of current solvents with more benign alternatives has become a necessity. In this paper, we initially outline the elements of a solvent design theory, and on the basis of this theory, we then discuss the PARIS II (Program for Assisting the Replacement of Industrial Solvents) solvent design algorithms and software. The PARIS II software designs technologically effective and environmentally benign substitute solvents. We finally present and discuss several cases of solvent substitutes developed using PARIS II. These cases include substitutes for pure chemicals and mixtures involving components from a wide range of chemical families, including normal hydrocarbons, ketones, alcohols, aromatics, and organic and aqueous mixtures. These case studies show that replacement solvents can be found with consistently lower potential environmental impacts while maintaining similar levels of technical performance.