Abstract: Modified ZSM-5 type zeolite catalyst is prepared by controlled aging in a moving bed catalytic cracking unit. The modified catalyst exhibits significant olefin isomerization activity and reduced paraffin cracking activity. Hydrocarbons are cracked to products boiling in the motor fuel range, e.g., gasoline, by using the modified catalyst mixture comprising a ZSM-5 type zeolite and a conventional cracking catalyst. The ZSM-5 type zeolite is treated with partial pressure steam under conditions which increase the gasoline octane number of the product fuel without decreasing gasoline plus distillate yield. A process for changing a catalytic cracking unit's inventory from a conventional catalyst to a modified ZSM-5 type containing catalyst is also disclosed.

Abstract: Octane and total yield improvement in catalytic cracking of petroleum fractions under cracking conditions can be obtained by adding to conventional cracking catalysts small amounts of an additive catalyst comprising a class of zeolites characterized by a silica to alumina mole ratio greater than 12 and a constraint index of 1 to 12 wherein the zeolite additive catalyst has a crystal size of between 0.2 to 10 microns.

Abstract: Octane and total yield improvement in catalytic cracking processes can be attained by the addition to conventional cracking catalysts of very small amounts of additive catalyst comprising a class of zeolites characterized by a silica to alumina mole ratio greater than about 12 and a constraint index of about 1 to 12. The additive catalyst is added to the conventional cracking catalyst in the cracking process in an amount which provides the zeolite component of the additive catalyst at from about 0.01 weight percent to about 1.0 weight percent of the conventional cracking catalyst in the cracking process.

Abstract: Preparation of the silica and alumina matrix components of a zeolite cracking catalyst while intimately mixing at a pH of 3.0 to about 4.5 results in a selective catalyst of high density and low pore volume. The coke produced during cracking emits lower amounts of sulfur during regeneration of tha catalyst translating to reduced sulfur oxide stack emissions.

Abstract: Cracking catalysts or catalyst supports prepared from mixtures comprising colloidal alumina, colloidal silica, a particulate weighting agent, and/or an active catalytic component possess excellent catalytic and physical properties. The catalysts in accordance with the invention also show excellent resistance to metal poisoning, and are also highly useful in non-cracking and/or hydroconversion processes.

Abstract: A cracking catalyst composition co-impregnated with a combination of a rare earth oxide and with either chromium, manganese, cobalt, nickel or platinum group metals. Such catalyst compositions, when used in fluidized catalytic cracking processes, result in significant reductions of sulfur content in the coke produced thereby, in turn significantly reducing sulfur oxide (SO.sub.x) emission in the regeneration stack gases.

Abstract: Octane and overall product quality improvement in catalytic cracking processes utilizing an essentially entirely amorphous cracking catalyst can be attained by using instead a catalyst comprising a minor amount, e.g. from about 0.01 to about 25 weight percent, of a class of crystalline zeolites characterized by a silica to alumina mole ratio greater than about 12 and a constraint index of about 1 to 12. The crystalline zeolites may be added to the conventional amorphous cracking catalyst in the cracking process by way of adding a separate additive composition in an amount which provides the zeolite component of the additive composition in said minor amount of the total catalyst in the cracking process.

Abstract: Octane and total yield improvement in catalytic cracking processes can be attained by the addition to conventional cracking catalysts of very small amounts of additive catalyst comprising a class of zeolites characterized by a silica to alumina mole ratio greater than about 12 and a constraint index of about 1 to 12. The additive catalyst is added to the conventional cracking catalyst in the cracking process in an amount which provides the zeolite component of the additive catalyst at from about 0.01 weight percent to about 1.0 weight percent of the conventional cracking catalyst in the cracking process.

Abstract: Cracking catalysts or catalyst supports prepared from mixtures comprising colloidal alumina, colloidal silica, a particulate weighting agent, and/or an active catalytic component possess excellent catalytic and physical properties. The catalysts in accordance with the invention also show excellent resistance to metal poisoning, and are also highly useful in non-cracking and/or hydroconversion processes.

Abstract: Octane and total yield improvement in catalytic cracking processes can be attained by the addition to conventional cracking catalysts of very small amounts of additive catalyst comprising a class of zeolites characterized by a silica to alumina mole ratio greater than 12 and a constraint index of about 1 to 12. The weight ratio of said zeolite of the additive catalyst to the amount of active component, e.g. faujasite zeolite, in the conventional cracking catalyst ranges from between about 1:400 and about 1:15.

Abstract: A method of passivating metal contaminants on cracking catalysts which comprises contacting said catalysts with steam for limited periods of time and at moderate temperatures.

Abstract: Amorphous (e.g., silica-alumina) and/or crystalline (e.g. aluminosilicate zeolite) cracking catalysts having improved resistance to metal poisoning are provided when colloidal dispersions, such as silica and/or alumina are added thereto.

Abstract: A catalytic process is provided for cracking a hydrocarbon charge stock containing aromatic nuclei components and non-aromatic nuclei components which involves contacting such chargestock with a catalyst composition having an alkali metal content less than about 1.5 weight percent and containing a mixture of faujasite and mordenite in which contacting takes place under catalytic cracking conditions of such severity that the conversion level exceeds that attributable to conversion of the non-aromatic nuclei portion of the chargestock. Under such conditions, the coke yield is substantially lower than would be obtained with the same catalyst in the absence of mordenite at the same level of conversion.