Effect of Non-Aromatic Components and Non-Ideal Feed Compositions On An Industrial Xylene Separation Process

Effect of Non-Aromatic Components and Non-Ideal Feed Compositions on an Industrial Xylene Separation Process

Kevin Wood, Yueying Yu, and Y. A. Liu, SINOPEC/AspenTech Center of Excellence in Process System Engineering, Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061

While several models of the xylene separation process have appeared in the literature, the majority focus on the 5 main chemical components: p-, m-, and o-xylene along with ethylbenzene (EB) and paradiethylbenzene (PDEB.)  Such models achieve reasonable agreement with industrial data, but they ignore various non-aromatic (NA) components as well as the simpler aromatics, toluene and benzene.  These components can be a significant portion of the feed, up to 10% by mass.  In order to improve the industrial operation and get a deeper understanding of the PX separation process, we have quantitatively simulated xylene separation performance with feeds containing these additional components.  We consider feed variations that are industrially relevant, based on full scale plant data.  Recommendations are made regarding the optimal operation of columns with these varying feed conditions.