Simulation-Based Multicriteria Optimization of a Multiphasic Enzymatic Hydrolysis

In order to cope with the steadily increasing competitive pressure in chemical industry, it is necessary to research alternative and resource-conserving processing routes and process windows. The application of enzymes as biocatalysts offers a great opportunity to replace conventional processes by more efficient and environmentally friendly green ones. A widely-spread and particularly industrially relevant example of application is the hydrolysis via carrier-fixed enzymes. However, the study of such reaction systems poses a major challenge, especially because of the very complex phase behavior, since usually three different phases coexist. An enhancement in efficiency of respective industrial processes requires a broad knowledge about the regarded system as well as appropriate tools to gain and accordingly use this knowledge.

Hence, the hydrolysis of short-chain fatty acid methyl esters via immobilized lipase (Novozyme® 435) is closely studied as a reference system within a research project in close consultation with industrial companies, e.g. BASF and Evonik. The high complexity of this three-phasic reaction system is especially characterized by the strong superposition and mutual interaction of multiple mechanisms such as enzymatic kinetics, liquid-liquid equilibrium, reaction equilibrium and mass transfer phenomena. The aim of the studies is the development of a rigorous model of this three-phasic system and the application of this model to perform a multicriteria optimization of an example hydrolysis process on the basis of costs. This optimization should ultimately provide a powerful tool to drastically reduce the costs for industrial processes with three-phasic reaction systems.

The presentation first shows the methodical approach applied to develop and validate a rigorous model of the reaction system. A key aspect of this part is the experimental decomposition of the reaction system with an innovative experimental setup. In the second part, the example hydrolysis process mentioned before is depicted and the concept for the multicriteria optimization is explained. Finally, first optimization results are shown and discussed.