(372d) Process Analysis of Membrane Assisted Reactive Distillation
Highly integrated processes, which integrate either different phenomena or operations, make an essential contribution in future in the field of process intensification. Synergy effects of the integrated processes leads to a sustainable augmentation concerning economical and ecological aspects. In this work reactive distillation assisted with membrane separation is investigated for the heterogeneously catalysed n-propylpropionate synthesis, whose conversion is limited by the chemical equilibrium conversion. By means of selective removal of one product species an almost complete conversion could be preserved and a nearly azeotropic ater/alcohol mixture in the upper part of the column obtained and fed to a membrane. The reactant 1-Propanol can be recycled afterwards to the column. A lab scale vapour permeation plant equipped with a flat membrane module is used to determine the separation characteristics of the hydrophilic, organic membrane. The influence of feed composition and permeate pressure on the transmembrane flux and the selectivity is investigated experimentally. For the process analysis, a sophisticated simulation tool with the non-equilibrium stage model for reactive distillation and a semi-empirical approach based on the ?Solution-Diffusion Theory? is used. Relevant model parameters for the membrane separations are determined from the lab scale permeation experiments. To identify synergy effects, detailed theoretical studies which show the influence of decisive operational parameters like reflux ratio and mass flow on concentration profiles, membrane area and chemical conversion are presented.