Development of an Interactive Software Tool for Designing Solvent Recovery Processes

Solvents are used in chemical and pharmaceutical industries as a reaction medium, selective dissolution and extraction media, and dilution agents. Thus, a sizable amount of solvent waste is generated due to process inefficiencies. Most common ways of handling solvent waste are on-site, off-site disposal, and incineration, which have a considerable negative environmental impact. Solvent recovery is typically not used because of potential difficulties in achieving required purity guidelines, as well as additional infrastructure and investments that are needed. To this end, this problem must be studied carefully by involving aspects from capital needs, environmental benefits, and comparison with traditional disposal methods, while achieving the required purity. Thus, we have developed a user-friendly software tool that allows engineers to easily access solvent recovery options and predict an economical and environmentally favorable strategy, given a solvent-containing waste stream. This consists of a maximal process flow diagram that encompasses multiple stages of separations and technologies within those stages. This process flow diagram develops the superstructure that provides multiple technology pathway options for any solvent waste stream. Separation technologies are placed in different stages; depending on the component, they can separate in terms of their physical and chemical properties. A comprehensive chemical database is created to store all relevant chemical and physical properties. The pathway prediction is modeled as an economic optimization problem in General Algebraic Modeling Systems (GAMS). With GAMS code as the backend, a Graphical User Interface (GUI) is created in Matlab App Designer to provide a user-friendly tool to the chemical industry. This tool can act as a guidance system to assist professional engineers and provide an easy comparative estimate in the early stages of process design.