Computer-Aided Design (CAMD) of Deep Eutectic Solvent (DES) based Processes for the Separation of Natural Components from Liquid Mixtures

• Applicant: Professor Dr.-Ing. Kai Sundmacher
• Subject Area: Chemical and Thermal Process Engineering
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411446655

In the last 10 years, deep eutectic solvents (DES) have been discovered that are very suitable agents for the mild separation of natural product mixtures. DES have a low melting point, negligible vapor pressure and molecularly tunable physico-chemical properties. So far, the research activities on DES-based separation processes for natural product mixtures were mainly focused on the experimental investigation of different combinations of hydrogen bond donors (HBD) and hydrogen bond acceptors (HBA) to form DES systems. The systematic selection and the molecular design of DES components as well as their process-level performance evaluation were rarely investigated. For closing these knowledge gaps, the proposed project is aiming at the development of a model-based methodology to combine the design of DES systems with the synthesis of optimal processes for the efficient separation of natural product mixtures. The separation of tocopherol (vitamin E) from methyllinoleate is taken as a practically relevant example. First, potential HAB-candidates for the formation of DES systems with the target product tocopherol (acting as HBD) are identified by a computer-aided screening approach. Second, the solid-liquid equilibria (SLE) of the binary tocopherol/HBA-mixtures are investigated experimentally. In this way, the DES systems are identified that show the predicted eutectic behavior also in reality. For these validated DES systems, the liquid-liquid equilibria (LLE) of the ternary HBA/tocopherol/methyllinoleate-mixtures and further process-relevant properties (e.g. viscosity, heat capacity) are measured. Third, based on the experimental SLE and LLE data, the PC-SAFT equation of state is used for modelling the DES phase behavior. Fourth, for each modelled DES system, the optimal separation process consisting of extraction and crystallization stages is determined by means of a superstructure approach. Moreover, a a group contribution method (GC-PC-SAFT) is used to perform the synthesis of the optimal separation process and the optimization of the molecular structure of the DES components simultaneously. By use of this design methodology, innovative eutetic solvent systems and highly efficient extraction-crystallization processes are to be identified. Selected model-based predictions are validated experimentally in a modular miniplant.

• DFG Programme: Research Grants
• International Connection: China
• Partner Organisation: National Natural Science Foundation of China
• Cooperation Partner: Professor Dr. Zhiwen Qi