(198f) Green Solvent Selection Using End-of-Life Metrics

Solvents are an often overlooked yet indispensable aspect of chemical reactions and processing. Improving solvent consumption and reuse/recycle has the opportunity to greatly decrease overall process waste production. Current green solvent selection guides either completely ignore solvent process impacts or lack a comprehensive metric for determining the role of solvent end-of-life options in their solvent ranking. End-of-life options include solvent recycle using separations to purify and reuse the solvent or disposal/incineration. In previous works the determination of solvent end-of-life impacts are either overly simplified or require rigorous computational analysis and/or significant process and thermophysical property data. The goal of this work is to provide a comprehensive yet simple way to compare solvent end-of-life options solely relying on basic chemical properties.

The end-of-life options that are compared in this work include recycling via distillation and membrane separations as well as incineration. For each option, the minimum energy of separation is determined and compared to the energy recovered via incineration as well as energy demand for solvent manufacture. This approach is used across a large range of solvents and solvent mixtures in order to help determine the lowest impact options for each solvent and help to evaluate green solvents for various process considerations.