Isomerization of aromatic compounds over ZSM-22 zeolite
AssigneeMobil Oil Corporation
InventorsDavid H. Olson, Ernest W. Valyocsik, R. Bruce Calvert
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Abstract
A mixture of aromatic hydrocarbons, comprising xylenes, is isomerized in the presence of ZSM-22 zeolite to produce a product stream wherein the proportion of para-xylene is substantially equal to the equilibrium ratio of the para-isomer. The process is conducted at about 500.degree. F. to about 1100.degree. F., at about 0 to about 3000 psig, optionally in the presence of hydrogen, and also optionally with the catalyst comprising about 0.005% to about 5.0% of a metal, e.g., platinum, palladium or cobalt, based on total catalyst weight.
Claims15
In a process for isomerizing xylenes from a hydrocarbon mixture to produce a product stream comprising substantially an equilibrium mixture of xylene isomers, said process comprising contacting the hydrocarbon mixture with a catalyst comprising a zeolite, the improvement for selectively isomerizing said xylenes by minimizing xylene loss due to undesired side reactions, said improvement comprising selecting as said zeolite a ZSM-22 zeolite having a silica:alumina mole ratio of at least about 20 and having the X-ray diffraction pattern of Table I.
Dependencies are inferred from the claim text.