Roadmap for Solvent Recovery, Reuse and Recycling in Industries

Solvents are commonly used in both fine chemicals and pharmaceutical industries to aid chemical reactions and purification of products. In pharmaceutical industries, active pharmaceutical ingredients (APIs) are often formulated in batch organic reactions that utilize solvents as a reaction medium. The combined contribution of current solvent usage rate and disposal method such as incineration can release toxic chemicals to the environment. The US EPA has predicted that solvent emissions are expected to double by 2030 and reach 10 million metric tons of carbon dioxide equivalent. The potential detrimental effects on the environment and safety considerations required the implementation and optimization of existing solvent recovery technologies to improve the greenness and overall sustainability of a given chemical process. To assess the feasible recovery pathways, General Algebraic Modeling Systems (GAMS) was employed to develop the mathematical models that focus on the material and energy balance, utility requirements, equipment design, and costing around common separation and recovery technologies such as distillation, ultrafiltration, membranes, evaporation, and extraction. This work is part of the United States Environmental Protection Agency (US EPA) funded pollution prevention project where the goal is to consult with industries and perform typical case-by-case analysis to develop a roadmap for selecting the best pathway for solvent recovery that minimizes cost, reduces the environmental impact, limits waste, and maintains safe operation. In this work, we reanalyzed a case study conducted by Pfizer and Rowan University to recover and purify isopropanol (IPA) while minimizing waste from the celecoxib process. The waste stream following the final purification stage contained a significant amount of recoverable IPA and we identified the most economical recovery pathway using our optimization methodology. In the next step, we will evaluate the sustainability of the pathway by comparing the environmental impacts with the traditional solvent disposal methods such as incineration.