Conversion of ethyl benzene to para xylene

Claim 1

In a process for recovering para-xylene from a source mixture of eight carbon atom aromatics which contains ethyl benzene and each of the xylene isomers by extracting para xylene from a mixture of xylene isomers, isomerizing the resultant mixture lean in para xylene to convert ortho- or meta-xylene to para-xylene, recycling the resultant isomerizate to the said extraction and adding to the loop of extraction and isomerization fresh charge containing each of the xylene isomers; the improvement whereby to provide said fresh charge reduced in ethyl benzene content and enhanced in para-xylene content above the thermodynamic equilibrium value which comprises converting said source mixture at conversion conditions of temperature between about 650° F. and 1000° F., pressure of 50 to 500 pounds per square inch, in admixture with 0.1 to 15 mols of hydrogen per mol of hydrocarbon and a space velocity of 1 to 100 volumes of hydrocarbon per volume of the hereinafter recited zeolite with a catalyst composite of a strong hydrogenation/dehydrogenation metal of Group VIII of the Periodic Table and a shape selective moderate acid zeolite characterized by a silicate/alumina ratio greater than 12, a constraint index of 1 to 12, a xylene sorption capacity greater than 1 gram per 100 grams of zeolite and an ortho-xylene sorption time for 30 percent of said capacity greater than 10 minutes, said sorption capacity and sorption time being measured at 120° C. and a xylene pressure of 4.5 ± 0.8 mm. of mercury.