Promotion of cracking catalyst octane yield performance

Claim 2

In an improved process for increasing gasoline octane number in catalytic cracking of a hydrocarbon chargestock in the presence of a cracking catalyst comprising an active component and a matrix and under cracking conditions, the improvement which comprises addition to said catalyst of a shape selective additive promoter characterized by a particle size of less than 5 microns, a silica to alumina mole ratio greater than about 12 and a constraint index within the approximate range of 1 to 12, said additive promoter not being intimately combined with a substantial amount of other solid prior to contact thereof with said cracking catalyst and wherein the weight ratio of said additive promoter to the said cracking catalyst is in the range between about 1:10000 and about 1:100.

Claim 3

The process of claim 1 wherein said weight ratio is in the range of between about 1:5000 and about 1:300.

Claim 4

The process of claim 1 wherein said additive promoter is at least one zeolite selected from the group consisting of ZSM-5, ZSM-11, ZSM-23, ZSM-35 and ZSM-38.

Claim 5

The process of claim 1 wherein said additive promoter is ZSM-5.

Claim 6

The process of claim 1 wherein said additive promoter contains essentially no alumina.

Claim 7

The process of claim 1 wherein said active component is selected from the group consisting of zeolite X and zeolite Y.

Claim 8

The process of claim 6 wherein said active component is zeolite Y.

Claim 9

The process of claim 1 wherein said catalytic cracking of hydrocarbon chargestock takes place in a fluid catalytic cracking operation.

Claim 10

The process of claim 1 wherein said catalytic cracking of hydrocarbon chargestock takes place in a compact moving bed catalytic cracking operation.

Claim 11

The process of claim 1 wherein said additive promoter is contacted in the form of dry powder in sufficient amount to at least partially surface coat particles of said cracking catalyst.

Claim 12

The process of claim 1 wherein said additive promoter is dispersed in said hydrocarbon chargestock prior to contact of the latter with said cracking catalyst.

Claim 13

The process of claim 1 wherein said additive promoter is added to the catalyst inventory.

Claim 14

The process of claim 12 wherein said additive promoter is introduced into said catalyst inventory in the form of an aqueous slurry.

Claim 15

The process of claim 12 wherein said additive promoter is introduced into said catalyst inventory as a suspension in an organic medium, other than the cracking chargestock.

Claim 16

The process of claim 12 wherein said additive powder is introduced into said catalyst inventory with recycle feed.

Claim 17

The process of claim 11 wherein said additive promoter is present in sufficient amount and under conditions such as to prereact with said hydrocarbon chargestock.

Claim 18

The process of claim 1 wherein said additive promoter is ZSM-5 and said active component is zeolite Y.

Claim 19

The process of claim 17 wherein the ZSM-5 additive promoter is dispersed in said hydrocarbon chargestock prior to contact of the latter with said cracking catalyst containing zeolite Y as an active component.

Claim 20

The process of claim 17 wherein the ZSM-5 additive promoter is introduced into the regenerator of the cracking unit wherein it contacts cracking catalyst containing zeolite Y as an active component.

Claim 21

In an improved process for increasing gasoline octane number in catalytic cracking of a hydrocarbon chargestock in the presence of a cracking catalyst comprising an active component and a matrix and under cracking conditions, the improvement which comprises addition to said catalyst of a shape selective additive promoter, characterized by a particle size of less than 5 microns made up of crystals in which atoms constituting at least those of silicon or germanium are tetrahydrally coordinated to oxygen atoms to provide structures of definite configuration having an X-ray diffraction pattern substantially as shown in Table 1, said additive promoter not being intimately combined with a substantial amount of other solid prior to contact thereof with said cracking catalyst and wherein the concentration of said additive promoter is between about 0.01 and about 1.0 weight percent based on the total quantity of cracking catalyst.

Claim 22

In an improved process for increasing gasoline octane number in catalytic cracking of a hydrocarbon chargestock in the presence of a cracking catalyst comprising an active component and a matrix and under cracking conditions, the improvement which comprises addition to said catalyst of a shape selective additive promoter, characterized by a particle size of less than 5 microns made up of crystals in which atoms constituting at least those of silicon or germanium are tetrahydrally coordinated to oxygen atoms to provide structures of definite configuration having an X-ray diffraction pattern substantially as shown in Table 1, said additive promoter not being intimately combined with a substantial amount of other solid prior to contact thereof with said cracking catalyst and wherein the concentration of said additive promoter is between about 0.01 and about 1.0 weight percent based on the total quantity of cracking catalyst.

Claim 23

The process of claim 20 wherein said concentration is between about 0.02 and about 0.5 weight percent.

Claim 24

The process of claim 20 wherein said additive promoter is a crystalline aluminosilicate.

Claim 25

The process of claim 20 wherein said additive promoter is at least one zeolite selected from the group consisting of ZSM-5 and ZSM-11.

Claim 26

The process of claim 20 wherein said additive promoter is ZSM-5.

Claim 27

The process of claim 20 wherein said additive promoter contains essentially no alumina.