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ChemInform Abstract: Dynamic Operation of a Three-Phase Upflow Reactor for the Hydrogenation of Phenylacetylene

Authors :
Giancarlo Baldi
J. B. M. Visser
Luigi Manna
Andrzej Stankiewicz
L.L. van Dierendonck
Silvio Sicardi
Source :
ChemInform. 26
Publication Year :
2010
Publisher :
Wiley, 2010.

Abstract

The selective catalytic hydrogenation of phenylacetylene to styrene presents an attractive and interesting process both from scientific and industrial viewpoints. The process mechanism consists of two consecutive reaction steps in which a high selectivity towards the intermediate product is desired. There have been many papers published so far, that report an increase in the selectivity of adsorption-desorption-based gas-phase processes performed on solid catalysts, due to a periodic (pulsing) operation of the reactor system. Pulsing the gas feed is believed to create more preferential adsorption conditions for the required reactant (transient conditions). This paper presents the results of a theoretical and experimental study concerning the influence of forced periodic oscillations of the gas-phase component on the performance of a three-phase reactor. The theoretical results are based on a heterogeneous mathematical reactor model considering both the transient mass balance over the reactor length as well as accumulation inside the catalyst pellets. Numerical dynamic reactor simulations with a simplified model neglecting accumulation of components within the catalyst pellet showed little improvement in conversion and selectivity when compared to results of the steady-state model. These results were supported by dynamic experiments in a bench scale reactor. It is shown that due to mass transfer limitations, the original square wave shape of the oscillation in the gas-phase concentration was almost completely faded into a smooth and rather flat oscillation at the catalyst surface. Simulations with a model in which accumulation of the relevant components inside the particles was considered showed no further improvement in performance at transient conditions, but demonstrated the impact of accumulation capacity of the pellets on the shape of oscillation present at the catalyst surface. The study is a result of direct cooperation between Politecnico di Torino, where the modelling and calculations were performed, and DSM Research. Its aim was to offer an attractive alternative to the conventional approach.

Details

ISSN :
09317597
Volume :
26
Database :
OpenAIRE
Journal :
ChemInform
Accession number :
edsair.doi...........fc144e11777f1fae03d32ab0a6696c96
Full Text :
https://doi.org/10.1002/chin.199502058