Bernhard Gutsche

Design and control of a reaction distillation column including the recovery system

Abstract A complex dynamic model for reactive distillation, which includes control systems and the capability of coupling additional columns is derived. On this basis, a typical reactive distillation column coupled with a recovery column is investigated and optimized. In this paper, the esterification of myristic acid in a reaction column as a typical example is optimized through simulations. To guarantee an almost complete conversion of the acid and a high purity of the reaction by product water, the reaction column is coupled with a recovery column. Both columns are designed based on steady state simulations. To develop a control structure, the reaction columns steady state and dynamic sensitivity of possible disturbances and manipulated variables are analyzed. It is shown, that in this reaction column there is no direct relationship between temperature and purity as is usual in common distillation columns. The influence of the reaction on the temperature profile within the reaction column has to be known, when the temperature is used as a reference variable for the purity. The recovery does not lead to an instability of the system. With this knowledge an efficient control structure is presented for this strongly non-linear coupled system. The purities of the product streams can be guaranteed

Transesterification of methyl myristate in a continuous reactive distillation column: simulation and experiment

The transesterification of methyl myristate with isopropanol to methanol and isopropyl myristate is presented. This reactive system is suitable for reactive distillation and is used for the investigation carried out in this paper. A simulation model for the steady state and dynamic simulation of the reactive distillation processes was developed. For the validation of this model experiments were carried out. Based on dimensioning calculations, a 6 meter high reactive distillation column (0.1 m i.d.) with 22 bubble cap trays and a total liquid holdup of about 10 litres was constructed and built up. The stationary results obtained from the column show a good comparison between the simulated and the experimental concentration and temperature profiles. The experimentally determined dynamic time constants and sensitivities of the temperature profile of the column could be reproduced very well by the simulation tool developed. n n n nUntersuchung zur Methylmyristat-Synthese in einer Reaktivkolonne: Simulation und Experimente n n n nDie Umesterung von Methylmyristat mit Isopropanol zu Methanol und Isopropylmyristat wird vorgestellt. Es handelt sich dabei um eine Reaktion, die fur die Reaktivrektifikation geeignet ist und die bei den hier durchgefuhrten Untersuchungen eingesetzt wird. Ein Simulationsmodell zur stationaren und dynamischen Simulation der Reaktivrektifikation wurde entwickelt. Zur Validierung dieses Modells wurden Experimente durchgefuhrt. Auf der Grundlage der Dimensionierungsrechnungen wurde eine ca. 6 Meter hohe Reaktionskolonne mit 22 Glockenboden und einem flussigen Gesamtholdup von ca. 10 Litern konstruiert. Stationar stellten sich gute Ubereinstimmungen zwischen dem simulierten und dem experimentellen Temperatur- und Konzentrationsprofil ein. Auch dynamisch konnten die Zeitkonstanten und Sensitivitaten der Temperaturen in der Kolonne nach einem Sprung im Rucklauf in die Kolonne gut abgebildet werden.