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Item type:Publication, Access status: without files , Pilot-scale validation of enzymatic reactive distillation for butyl butyrate production(Elsevier, 2016-11-16); ; ; ; For enzyme-catalyzed reactions, batch processes using stirred tank reactors are the state-of-the-art production mode. The yield of the process may be limited by reaction equilibrium, product inhibition of the enzyme, low concentrations and possibly low reaction rates, while the recovery of the product may be limited due to thermodynamic constraints such as azeotropes. Using enzymes in an integrated reactive distillation process can overcome these limitations and provides a cost advantage over classic batch reactor processes. The aim of this paper is i) to report the successful pilot-scale experimental validation of an Enzymatic Reactive Distillation (ERD) process for the synthesis of butyl butyrate and ii) to establish a rate-based model for conceptual process design which can be quickly adapted to other systems. The main novelty is the application of a continuous RD column with enzymes as a heterogeneous catalyst provided in two different types of catalytic packing: loosely filled immobilized enzyme beads in standard packings with catalyst pockets and gauze packings with catalytic coating. Experimental pilot-scale experiments show the feasibility of ERD and allow the comparison of the different packing types based on catalytic performance as well as stability. Furthermore, these experiments are used to validate a predictive rate-based model to describe ERD which can be used to check the sensitivity of process and design parameters as well as to provide a quick adaption to other systems for quick evaluation.Publicationtype: Journal Article89 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Enzymatic reactive distillation for the transesterification of ethyl butyrate: model validation and process analysis(Elsevier, 2015-05); ; ; ; For the production of new and more sustainable products, new technologies need to be developed. Within process intensification, reactive distillation which is the integration of reaction and distillation in one apparatus is one known technology. A new concept is to integrate enzymes into the distillation column which enables new or more selective reaction routes. However, matching operating windows is difficult due to for example the temperature sensitiveness of the enzyme. Here, modeling is an important tool for design, scale-up, analysis and optimization of chemical and biochemical processing by enzymatic reactive distillation systems. The lipase-catalyzed transesterification of ethylbutyrate with n-butanol is highlighted, which is an equilibrium-limited reaction. Based on kinetic data and investigations of a surface coating to provide the enzyme into the reactive section, a detailed model of a continuous enzymatic reactive distillation is developed in Aspen Custom Modeler®, including hydrodynamic and mass transfer investigations of coated reactive packings. Subsequently, the detailed model is validated against experimental data of a pilot-scale enzymatic reactive distillation column with a diameter of 50. mm to check the agreement between experiments and modeling.Publicationtype: Conference Paper76 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Integration of enzymatic catalysts in a continuous reactive distillation column: Reaction kinetics and process simulation(2014-12-17); ; ; ; This work presents a feasibility study for an enzymatic reaction in a continuously operated reactive distillation column. As a model reaction, the transesterification of ethyl butyrate with n-butanol in the presence of lipase CALB was considered. For use in the distillation column, lipase CALB was immobilized by entrapment in a hydrophobic silica xerogel and introduced as granulate into the catalytic packing Katapak-SP-11. The reaction kinetics was experimentally determined for different concentration and temperature ranges and described by means of the Michaelis-Menten double-substrate kinetic model in combination with the Arrhenius model. With these kinetic data, process simulations were carried out with an Aspen Custom Modeler nonequilibrium-stage model validated for a DN50 pilot-scale column. The concentration of n-butanol in the reactive section was maintained low to decrease the inhibiting effects on the enzyme. For an optimized setup and operating conditions, conversion rates of more than 90% were achieved for n-butanol and 26% for ethyl butyrate. These results clearly demonstrate that lipase CALB can be applied in a continuously operated reactive distillation column.Publicationtype: Journal Article28