Patent ID: 6504074
Filing Date: 2003-01-07
Classification: B01J,C07C,C10G,Y02P

Abstract:
A process for the disproportionation of toluene comprising contacting a toluene stream under toluene disproportionation conditions with a coated zeolite catalyst, said zeolite catalyst being selected from the group consisting of:(I) A zeolite catalyst comprising: (a) first crystals of a first intermediate pore size acidic zeolite having catalytic activity; (b) a discontinuous layer of second crystals of a second zeolite having less acidity than said first zeolite and a structure type that is the same as said first zeolite and said second crystals have an average particle size less than the average particle size of said first crystals covering at least a portion of the external surface of said first crystals; (c) non-zeolitic binder present in an amount of at least about 15 weight percent based on the weight of the zeolite catalyst; (II) A zeolite catalyst comprising: (a) first crystals of a first intermediate pore size acidic zeolite having catalytic activity; and, (b) a discontinuous layer of second crystals of a second zeolite and a third zeolite said second crystals having an average particle size less than the average particle size of said first crystals and covering at least a portion of the external surface of said first crystals, and said third zeolite has a structure type, composition, or both that is different from said second zeolite; (III) A zeolite catalyst comprising: (a) first crystals of a first intermediate pore size acidic zeolite having catalytic activity; (b) a discontinuous layer of second crystals of a second zeolite having a structure type that is different from said first zeolite and said second crystals have an average particle size less than the average particle size of said first crystals covering at least a portion of the external surface of said first crystals; (c) non-zeolitic binder present in an amount of at least about 15 weight percent based on the weight of the zeolite catalyst; and, (IV) Mixtures of (I), (II), and (III).