(41o) A New Step in Process Integration: The Enzymatic Catalyzed Reactive Dividing Wall Column

Abstract to AICHE 2015

Topic :          Poster Session: General Topics on Separations

Title:             A new Step in Process Integration: The Enzymatic Catalyzed Reactive Dividing Wall Column

Abstract

Increasing global competition and environmental legislation require the chemical sector to produce more cost efficient and reduce emissions. Process integration is an efficient way to achieve both goals, by reducing the energy consumption of a process as well as the investment costs. The concepts of reactive distillation and the dividing wall column have been subject of intensive research and have already been implemented on an industrial scale. The reactive dividing wall column (RDWC) combines the two concepts, creating a whole new piece of highly integrated equipment. Reactive dividing wall columns allow the simultaneous execution of a chemical reaction and distillative separation into three or more fractions. The use of an enzymatic catalyst combines the advantages of high selectivity with low temperature levels. The high level of integration leads to a complex design process that requires suitable and reliable simulation models.

Our research aims at reducing uncertainties about designing and operating reactive dividing wall columns. By modelling, simulating and operating a reactive dividing wall column we create the basis for designing RDWCs on an industrial scale and generate valuable operational experience. The approach is based on a model system: the heterogeneously catalyzed trans-esterification of butyl acetate and hexanol. After successfully developing and validating a rigorous mathematical simulation model for chemical catalyst trans-esterification, based on the concept of equilibrium stages (using experiments with our own pilot plant scale RDWC), we take RDWC research a new step forward. The existing rigorous mathematical simulation model was extended for an enzyme catalyzed reactive dividing wall column. The model can be used for simulating reactive as well as non-reactive dividing wall columns with chemical or enzymatic catalyst. This allows an easy comparison between different types of catalyst. Additionally important input parameters for the simulation have been determined by our own extensive experiments. The calculation of the separation is based on experimental measurements of the vapor liquid equilibrium of the system for the pressure range from 30 to 900 mbar. The calculation of the reaction rates are based on measured chemical kinetics of the enzyme catalyzed reaction. For the model validation an existing pilot plant scale reactive dividing wall column will be refitted for the enzymatic catalyzed process to validate the simulation results and generate operational experience with the enzymatic catalyzed process.

The poster presentation will give a short introduction into the concept of our research on the enzyme catalyzed reactive wall column. The mathematical model will be explained to give an insight into modelling reactive dividing wall columns. Furthermore it will be shown which experimental data are necessary to model the separation process and the trans-esterification and the results of these experiments will be presented. Finally the pilot plant will be described and a choice of simulation results will be shown.