Para-Xylene Manufacturing Catalytic Reactions and Processes

Institut Frangais du Petrole, 1 et 4 Avenue de Bois Preau, 

Laboratoire de Catalyse en Chimie Organique, UFR Sciences, 40, Avenue du Recteur Pineau, 86022 Poitiers Cedex, France 

The most valuable isomer among the four C8 aromatics (ethylbenzene -EB-, para-xylene -pX-, ortho-xylene -oX- and meta-xylene -mX-) is pX, which is a chemical intermediate for the production of polyethyleneterephtalate (PET) fibers, resins and films. pX production is then driven by PET fiber and resin markets, which are growing at an estimated 4-6% per year for the next decade. The highest growth rates are observed in emerging countries, mainly in Asia, where most of the latest large capacity plants have been constructed. 

The main source of pX is the mixed xylenes cut, containing the four C8 aromatics including EB. The mixed xylenes are produced by catalytic reforming (82%), steam cracking (9%) and toluene disproportionation or toluene-heavy aromatics transalkylation (9%). The xylenes distribution is generally close to thermodynamic equilibrium values, while EB content depends on the origin of the cut (Table 9.1). 

There are two types of isomerization processes depending on EB transformation (xylene isomerization occurs in every industrial process)  

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PARA-XYLENE MANUFACTURING CATALYTIC REACTIONS AND PROCESSES... 

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