Xylene isomerization side reactions over Beta zeolite: Disproportionation and transalkylation of C<inf>8</inf> aromatics and toluene

An experimental and parametric behavior study of disproportionation and transalkylation between C8 aromatics and toluene were carried out over mono-functional acid Beta zeolite with a SiO2/Al2O3 ratio of 35 (BEA35). The experiments were performed in liquid phase under the following conditions: 453,...

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Bibliographic Details
Authors: Shi, Qian, Gonçalves, Jonathan C., Ferreira, Alexandre F.P., González Plaza, Marta, Rodrigues, Alírio Egídio
Format: article
Status:Versión aceptada para publicación
Publication Date:2018
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/290381
Online Access:http://hdl.handle.net/10261/290381
https://api.elsevier.com/content/abstract/scopus_id/85048304962
Access Level:Open access
Keyword:Disproportionation
Ethylbenzene
Kinetics
Toluene
Transalkylation
Description
Summary:An experimental and parametric behavior study of disproportionation and transalkylation between C8 aromatics and toluene were carried out over mono-functional acid Beta zeolite with a SiO2/Al2O3 ratio of 35 (BEA35). The experiments were performed in liquid phase under the following conditions: 453, 473, and 493 K and 2.1 MPa. Ethylbenzene disproportionation and ethylbenzene-toluene transalkylation were identified as the main side reactions; therefore, the kinetics of both reactions were estimated. Both reactions were verified to be second-order with no signs of competition for the adsorption sites under the studied conditions. Additionally, ethylbenzene disproportionation and ethylbenzene-toluene transalkylation, undergo through a deethylation-ethylation mechanism, the activation energies were 66 and 57 kJ/mol respectively. Furthermore, the existence of parallel reactions, as well as the feed concentration, showed no effect on the p-diethylbenzene selectivity. Selectivity towards the para-isomer was observed only at very low conversions. Finally, an analytical solution was developed for the system showing excellent agreement with the experimental data.