(569d) Integrated Solvent and Process Design Exemplified for a Diels-Alder Reaction

The purpose of this work is to develop practical and systematic methods for (1) reaction solvent design and (2) integrated reaction solvent and process design. Firstly, a new kind of solvent theoretical descriptor that is generated from quantum chemical COSMO calculations is introduced. Group contributions to each solvent descriptor are regressed for 71 UNIFAC groups. A reaction model is built by correlating a small set of experimental reaction rate constants in various solvents with the corresponding solvent theoretical descriptors. Based on the reaction kinetic model and the developed group contribution method, a computer-aided molecular design (CAMD) problem is formulated. Optimal reaction solvents with highest reaction rates are identified from the solution of the CAMD problem. On the other hand, considering the strong interdependence between solvent molecular characteristics and the process performance, an integrated reaction solvent and process design is performed. Solvent molecular structures and process operations are simultaneously optimized by the formulation and solution of an MINLP-based (mixed integer nonlinear program) optimization problem where process-wide objectives instead of a single reaction performance criterion are used. The implementation of the proposed design methodologies is exemplified, step by step, through an application to a Diels-Alder reaction.