Modeling of the Isomerization and Separation Process of para‐Xylene in a Moving Bed Reactor

Abstract

Simulated moving bed reactors (SMBRs) are hybrid reactors that perform reaction and separation processes simultaneously in a single unit. Their high separation performance and ability to overcome equilibrium constraints on the reaction make them effective in a wide range of equilibrium reactions. This study investigated an SMBR for xylene isomerization and separation of p-xylene from other xylene isomers (free of ethylbenzene) in the liquid phase. The effects of operating variables including temperature, switching time, and columns arrangement on the performance parameters and optimal conditions were determined. Due to the removal of products from the reaction site, the SMBR drives the chemical equilibrium toward producing more product than a conventional reactor under the same conditions.

Mathematical simulation and optimization of xylene isomerization reactor to enhance p‐xylene production

“…in 2021, used a new SMBR for the isomerization and separation of p‐xylene from other xylene isomers (without ethylbenzene) in the liquid phase that effects of operating variables including; Temperature, switch time, and arrangement of columns were studied on the performance parameters and the optimal conditions were obtained, which was the best switching time range of 1.10–1.15 min. In this range of switching time and 453 K, 98% purity, 96% recovery, minimum adsorbent consumption, and maximum deviation from equilibrium value (DE) of 1.08 were obtained 11 …”

“…In this range of switching time and 453 K, 98% purity, 96% recovery, minimum adsorbent consumption, and maximum deviation from equilibrium value (DE) of 1.08 were obtained. 11 P-xylene is one of the most widely used aromatic compounds, accounting for approximately 86% of the total mixed xylene demand, which was equal to the global demand for benzene in 2021. 17 As a result, this research aims to explore an accurate and exact mathematical model to simulate the xylene isomerization process and optimize the process condition to maximize p-xylene production.…”

Improving the Performance of a Simulated Moving Bed Reactor for the Synthesis of Solketal by Implementing Multifeed Strategy

“…The design and optimization of the SMBR, which basically consists in the definition of the number of columns per section, the flow rate in each of those sections, and the solid phase velocity, has been the focus of several works reported in the open literature. − Since there are many variables that can influence the process, the optimization is rather challenging. The most common approaches include the determination of the so-called reactive separation regions or reactive separation volumes (representing a region of the γ 3 –γ 2 plane that fulfills predefined purity and/or conversion requirements, for a specified pair of γ 1 and γ 4 values or several combinations of both, respectively), and multiobjective optimization using genetic algorithms − or particle swarm optimization, , for instance. In the present work, an extensive simulation study was performed, aiming the optimization of these decision variables for the conventional and multifeed SMBR.…”