A review of advances in production and separation of xylene isomers

The global p-xylene market has demonstrated positive growth thanks to increasing demand for polyester fibers in the textile industry. Additionally, the chemical process becomes a target for energy efficiency; thus, process improvement and intensification have increasingly gained the attention of the scientific community. This article summarizes the advances in the production and separation of xylene isomers. An overview of the aromatics complex is displayed followed by a detailed description of the p-xylene production and separation processes. It summarizes the improvement of the catalysts, adsorbents, advanced materials; processes that strengthen the performance of the existing units, membrane-based processes, and alternative sources in past years. Special attention is given to the Simulated Moving Bed technology for separation; the flushing strategies and model development studies are also addressed. Attention has also been given to the process intensification and the unit combination with other aromatic technologies. A brief review of the latest results of Simulated Moving Bed Reactor and heat integration is also included. In summary, process intensification and integration are promising to save energy and costs, and it also allows flexibility within the feeds and intermediate products, maximizing the advantages of each process.