Patent ID: 6388159
Filing Date: 2002-05-14
Classification: B01J,C01B,C07C,Y02P

Abstract:
A process for the isomerization of a non-equilibrium feed mixture comprising xylenes and ethylbenzene comprising contacting the feed mixture in the presence of hydrogen in an isomerization zone with a catalyst composite comprising an effective amount of at least one platinum-group metal component and a crystalline aluminosilicate zeolite at isomerization conditions to obtain an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, the zeolite characterized in that it is a microporous crystalline zeolite having a composition in the as synthesized form on an anhydrous basis in terms of mole ratios of the elements of:Mmn+Rrp+Al(1âˆ’x)ExSiyOz where M is at least one exchangeable cation selected from the group consisting of alkali and alkaline earth metals, â€œmâ€  is the mole ratio of M to (Al+E) and varies from about 0 to about 1.2, R is a nitrogen-containing organic cation selected from the group consisting of protonated amines, protonated diamines, protonated alkanolamines, quaternary ammonium ions, diquaternaryammonium ions, quaternized alkanolamines and mixtures thereof, â€œrâ€  is the mole ratio of R to (Al+E) and has a value of about 0.25 to about 3.0, E is at least one element selected from the group consisting of Ga, Fe, Cr, In and B, â€œXâ€  is the mole fraction of E and varies from 0 to 0.5, â€œnâ€  is the weighted average valence of M and has a value of about +1 to about +2, â€œpâ€  is the weighted average valence of R and has a value of +1 to about +2, â€œyâ€  is the mole ratio of Si to (Al+E) and varies from about 5 to about 12 and â€œzâ€  is the mole ratio of O to (Al+E) and has a value determined by the equation:z=(mÂ·n+rÂ·p+3+4Â·y)/2 the material characterized in that it has at least two x-ray diffraction peaks, one at a d-spacing of 3.9Â±0.12 Ã¥ and one at 8.6Â±0.20 Ã¥.