Kinetic Study of Xylene Isomerization on De-Ethylation Catalyst

The kinetics of xylene isomerization on SKI-210 de-ethylation C8aromatics isomerization catalyst (SKI-210 catalyst for short) was studied in a micro fixed bed reactor. The reaction network consists of the primary isomerization reaction between three xylene isomers and the second disproportionation reaction of xylene. The reaction rate was simulated using Langmuir-Hinshelwood-Hougen-Watson(LHHW) equation, reaction kinetic parameters were obtained through fitting by use of gPROMS software, and a first-order kinetic model was established, and also tested. The results show that the reaction network for the interconversion of three xylenes on SKI-210 catalyst is in line with experimental data; the model can predict the distribution of xylene isomerization products, and the standard deviation for the molar fraction of products predicted by the model is 0.0002—0.0152, from which it can be found that the predicted value of model agrees well with the measured value. In this work, the model was used for simulation analysis and to investigate the impact of reaction conditions on the yield and selectivity of xylene (PX). It is found that PX yield can reach 24.6% at the reaction temperature of 380 ℃, reaction pressure of 0.6 MPa and MHSV of 15 h-1, providing a kinetic model as the support for the operation optimization of industrial reactors. © 2023 Science Press. All rights reserved.