(28a) PX Recovery by Crystallization

Paraxylene (PX) is one of the fastest growing major petrochemical products in the world.  PX is used as a feedstock for terephthalic acid (PTA), which in turn is used to make polyester film, fiber, and chips. Demand for paraxylene and PTA is growing rapidly, especially in the developing regions of the world.  This brings attention to new manufacturing methods, which can produce paraxylene at lower cost and which can be brought on stream more quickly to match the market cycles in demand.  While historical crystallization technologies have been denigrated as obsolete and not competitive, recent technology improvements have proven the notion that crystallization is not competitive untrue.

Today’s paraxylene crystallization technologies include numerous innovations that improve the operation of crystallization processes and reduce the production cost. This paper will present details of the outlining the benefits of crystallization technologies for paraxylene production.

Fundamentals and recent innovations in crystallization will be highlighted.  Special insight will be given from the operator’s perspective, and the strong relevance and application possibilities of crystallization in modern aromatics complexes will be shown.