Solvent Recovery

Recycling and recovery of solvents is an important downstream issue that should be considered. Solvent recovery can have a positive effect on the environmental impact and hence the metrics of a given process. Studies have been carried out to determine whether solvent recovery is viable depending upon factors such as the energy required to achieve this.[1] ETH Zurich has also developed an LCA-based tool that quantifies the environmental impact of waste-solvent treatment. 

The incineration of spent solvents, as opposed to their recovery, has been shown to considerably increase life cycle impacts.[2] However, this depends on the complexity of the production of the solvent itself and its boiling point; for solvents such as diethyl ether, incineration is a preferable option than distillation in terms of Total Cumulative Energy Demand (CED).[3]

Where solvent recovery is deemed to be uneconomical, other options include downcycling the solvent for example for heat recovery or use in other industrial applications.[4]

Other approaches could include solvent ‘leasing’ whereby used solvent is collected by supplier and cleaned up for reuse.