In a process for converting C.sub.9+ aromatic hydrocarbons to lighter aromatic products a feed comprising C.sub.9+ aromatic hydrocarbons is contacted under transalkylation reaction conditions with a catalyst composition comprising (i) a first molecular sieve selected from the group consisting of ZSM-12, mordenite and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including d-spacing maxima at 12.4.+-.0.25, 6.9.+-.0.15, 3.57.+-.0.07 and 3.42.+-.0.07; and (ii) a second molecular sieve having a constraint index ranging from 3 to 12. At least the first molecular sieve has a hydrogenation component associated therewith and the first and second molecular sieves are contained in the same catalyst bed. The C.sub.9+ aromatic hydrocarbons are converted under the transalkylation reaction conditions to a reaction product containing xylene.
Processes for making xylene employ catalysts containing rhenium and a molecular sieve component comprising an acidic MFI molecular sieve having a Si/Al.sub.2 molar ratio of less than about 80 and mordenite to provide a transalkylation product with a low content of benzene co-boilers. The invention encompasses the use of sulfided catalyst embodiments in xylene production processes.
Transalkylation catalysts containing rhenium and a molecular sieve component comprising an acidic MFI molecular sieve having a Si/Al.sub.2 molar ratio of less than about 80 and mordenite provide a transalkylation product with a low content of benzene co-boilers. The invention encompasses sulfided catalyst embodiments and methods of making the catalysts.
A catalyst composition, a process for producing the composition and a process for the conversion of a feedstock containing C.sub.9+ aromatic hydrocarbons to produce a resulting product containing lighter aromatic products and less than about 0.5 wt % of ethylbenzene based on the weight of C.sub.8 aromatics fraction of the resulting product. The C.sub.9+ aromatic hydrocarbons are converted under the transalkylation reaction conditions to a reaction product containing xylene. The catalyst composition comprises (i) an acidity component having an alpha value of at least 300; and (ii) a hydrogenation component having hydrogenation activity of at least 300. The composition can be produced by to incorporating at least one hydrogenation component into an acidity component having an alpha value of at least 300.
