US 5,206,194 A · Process for reactivating a deactivated crystalline molecular sieve group VIII metal catalyst

Abstract

A reactivated catalyst having optimum activity for hydrocracking and other acid catalyzed chemical conversion processes is prepared by contacting its deactivated counterpart, which contains a crystalline molecular sieve, a Group VIII noble metal hydrogenation component and carbonaceous deposits, with a gas containing molecular oxygen, preferably air, at a temperature between 950.degree. and 1200.degree. F., preferably between about 1050.degree. and 1150.degree. F., for a time sufficient to remove at least a portion of the carbonaceous deposits. When the reactivated catalyst contains a dealuminated Y zeolite that has been ion-exchanged with both noble metal and rare earth metal cations, its activity for hydrocracking in an ammonia-deficient atmosphere can be further increased by a rejuvenation procedure in which the reactivated catalyst is contacted with an aqueous ammonia solution in which an ammonium salt has been dissolved.

Claims43

Dependent claims

A process for reactivating a deactivated hydrocracking catalyst produced by subjecting a fresh catalyst to hydrocracking conditions in the presence of a hydrocarbon feedstock wherein said deactivated catalyst comprises (1) a crystalline, dealuminated Y zeolite having an overall silica-to-alumina mole ratio above about 6.0, said zeolite having been ion-exchanged with rare earth-containing cations and Group VIII noble metal-containing cations, (2) a porous, inorganic refractory oxide and (3) carbonaceous deposits, which process comprises:

(a) contacting said deactivated catalyst with a flowing gas containing between about 20 and about 25 volume percent molecular oxygen in a combustion zone at a temperature between about 1025.degree. F. and 1175.degree. F. for a time sufficient to remove at least a portion of said carbonaceous deposits via combustion;
and
(b) recovering a reactivated catalyst from said combustion zone, said reactivated catalyst having an activity temperature for hydrocracking less than about 48.degree. F. above the activity temperature of said fresh catalyst.

A process for reactivating a deactivated hydrocracking catalyst produced by subjecting a fresh hydrocracking catalyst to hydrocracking conditions in the presence of a hydrocarbon feedstock, wherein said deactivated catalyst comprises (1) a crystalline dealuminated Y zeolite having an overall silica-to-alumina mole ratio above about 6.0, said zeolite having been ion-exchanged with rare earth-containing cations and Group VIII noble metal-containing cations, (2) a porous, inorganic refractory oxide and (3) carbonaceous deposits, which process comprises:

(a) contacting said deactivated catalyst with a flowing gas containing between about 20 and about 25 volume percent molecular oxygen in a combustion zone at a temperature between about 1025.degree. F. and 1175.degree. F. for a time sufficient to remove at least a portion of said carbonaceous deposits via combustion and thereby produce a regenerated catalyst;
(b) contacting said regenerated catalyst with an aqueous ammonia solution containing a dissolved ammonium salt while correlating the contacting time with the temperature and reagent strength so as to effect a substantial improvement in activity of said catalyst, thereby producing a rejuvenated catalyst;
(c) separating said rejuvenated catalyst from said aqueous ammonia solution;
and
(d) drying and calcining said separated catalyst to produce a reactivated catalyst having an activity temperature for hydrocracking less than about 5.degree. F. above the activity temperature of said fresh catalyst.

2 more elements

Dependencies are inferred from the claim text.

Process for reactivating a deactivated crystalline molecular sieve group VIII metal catalyst

Life of this patent

Process for reactivating a deactivated crystalline molecular sieve group VIII metal catalyst

Life of this patent

Abstract

Claims43