The topic of green and sustainable solvents is of growing interest to industry, which recognizes the need to reduce solvent usage and to minimize the use of certain solvents of toxicological concern. This up-to-date review from the group of Hallett in the Chemical Engineering Dept at Imperial College, London has almost 500 references focusing on renewable solvents, deep eutectic solvents, ionic liquids, liquid polymers (such as PEGs) and CO2-tunable solvents, both for synthesis and for extractions.
The authors discuss economic viability as part of the review. Thus in the section on ionic liquids the high cost and expensive recovery of ionic liquids are examined and they conclude that “the efficient recycling of ionic liquids is a major challenge and a significant barrier for their industrial adoption”
Clarke et al, Chem Rev, 2018, DOI 10-1021/acs.chemrev/7b00571