Invited Talk: The Integration of Safety, Health and environmental Indexes in Solvent Design Using Process Systems Engineering Tools

Computer-Aided Molecular Design (CAMD) is a powerful tool for designing solvents with targeted properties. The benefit of CAMD tools in solvent design is its ability to search for a vast number of conventional or novel potential solvents that exhibit the best performance based on the properties of interest. In most of the CAMD problems, the molecular physical and thermodynamic properties are often selected as the target properties during the design stage since they can be estimated through property prediction models. The generated set of molecules will then undergo performance analysis in order to determine the optimal solvent. The performance of the molecules is usually assessed using economic, safety and environmental indicators. While designing solvent molecules, it is important to incorporate safety, health and environmental (SHE) aspects along with target properties to ensure that the solvents do not cause hazardous conditions. The measurement of SHE parameters are based on the molecular properties that have impact on both of these aspects. The property involved in each parameter is assigned with an index score to represent the degree of potential hazards. These properties can be estimated through various property prediction methods. In an integrated design approach, SHE indexes can be estimated during the early stage of solvent design. A higher index value represents a higher hazard and impact level for the potential solvent. Hence, a solvent that satisfies the target properties and has the lowest penalty value may be a reasonable choice. However, the solvents with the best functionality may not necessarily exhibit a low penalty score. Therefore, a decision making must be made on the trade-off between the functionality of the solvent and its inherent safety and health level and potential environmental impacts. Various process systems engineering tools have been developed to incorporate the functionality and SHE targets simultaneously for solvent design.