Catalytic cracking process improvement

Claim 2

IN A FLUIDIZED CATALYTIC CRACKING PROCESS IN WHICH A FEED STOCK CONTACTS A FLUIDIZED CATALYST IN A REACTION ZONE AT CONDITIONS TO EFFECT THE CRACKING OF SAID FEED STOCK INTO CRACKED PRODUCTS AND WHEREIN CATALYST IS SEPARATED FROM A VAPOROUS EFFLUENT MATERIAL FROM SAID REACTION ZONE, WHICH VAPOROUS EFFLUENT MATERIAL CONTAINS ENTRAINED CATALYST PARTICLES, THE IMPROEMENT WHICH COMPRISES PASSING SAID VAPOROUS EFFLUENT MATERIAL INTO A CATALYST DISENGAGING ZONE AND THEREIN CONTACTING THE SAME WITH A LIQUID HYDROCARBON STREAM AT CONDITIONS TO CONDENSE A PORTION OF SAID VAPOUOUS EFFLUENT MATERIAL AND TO REMOVE ENTRAINED CATALYST FROM SAID VAPOROUS EFFLUENT, RECOVERING FROM SAID CATALYST DISENGAGING ZONE A LIQUID OIL BOTTOMS STREAM COMPRISING SAID CATALYST AND AT LEAST A PORTION OF SAID LIQUID HYDROCARBON AND CONDENSED EFFLUENT MATERIAL, PASSING REMAINING CATALYST-FREE VAPOROUS EFFLUENT MATERIAL FROM SAID CATALYST DISENGAGING ZONE INTO A FRACTIONATION ZONE AND THEREIN FRACTIONALLY CONDENSING THE SAME TO FROM AN OVERHEAD GASOLINE-CONTAINING VAPOR AND A HEAVY CYCLE OIL STREAM SUBSTANTIALLY FREE OF ENTRAINED CATALYST ARTICLES AND BOILING IN THE RANGE OF FROM ABOVE ABOUT 600*F. TO ABOUT 1,000*F, SUPPLYING AT LEAST A PORTION OF SAID CATALYST-FREE HEAVY CYCLE OIL STREAM TO THE CATALYST DISENGAGING ZONE AS AT LEAST A PORTION OF SAID LIQUID HYDROCARBON STREAM, AND CONDENSING SAID GASOLINECONTAINING VAPOR.

Claim 3

The process of claim 1 wherein said liquid oil bottoms stream is passed into a settling zone which divides said liquid oil bottoms stream into a slurry oil stream and a stream of clarified oil, said slurry oil stream having a higher concentration of catalyst than said clarified oil stream.

Claim 4

The process of claim 2 wherein at least a portion of said slurry oil stream is returned to the catalyst disengaging zone.

Claim 5

The process of claim 2 wherein at least a portion of said clarified oil stream is returned to the catalyst disengaging zone.

Claim 6

In a fluidized cracking process in which a feed stock contacts a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said feed into a cracked product effluent, wherein effluent vapors which contain entrained catalyst particles are separated from said catalyst and passed into a fractionation zone to be separated into various boiling fractions including a heavy oil comprising the highest boiling components of said effluent and catalyst particles, and a heavy cycle oil, the improvement which comprises: a. passing said effluent vapors into a catalyst disengaging zone and contacting said effluent vapors with a first liquid hydrocarbon stream and with a second liquid hydrocarbon stream and thereafter with a heavy cycle oil stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; b. recovering from said disengaging zone a liquid oil bottoms material comprising catalyst particles, condensed effluent, and first and second liquid hydrocarbon stream material from said disengaging zone; c. separating said bottoms material into a slurry oil containing catalyst particles and a clarified oil substantially free of catalyst particles; d. recycling slurry oil to said disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream; e. recycling heavy cycle oil from said fractionation zone to said catalyst disengaging zone; and, f. passing effluent vapors substantially free of entrained catalyst particles from said catalyst disengaging zone into said fractionation zone, to thereby preclude the passage of catalyst particles into said fractionation zone.

Claim 7

In a fluidized cracking process in which a feed stock contacts a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said feed into a cracked product effluent, wherein effluent vapors which contain entrained catalyst particles are separated from said catalyst and passed into a fractionation zone to be separated into various boiling fractions including a heavy oil comprising the highest boiling components of said effluent and catalyst particles, and a heavy cycle oil, the improvement which comprises: a. passing said effluent vapors into a catalyst disengaging zone and contacting said effluent vapors with a first liquid hydrocarbon stream and with a second liquid hydrocarbon stream and thereafter with a heavy cycle oil stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; b. recovering from said disengaging zone a liquid oil bottoms material comprising catalyst particles, condensed effluent, and first and second liquid hydrocarbon stream material from said disengaging zone; c. separating said bottoms material into a slurry oil containing catalyst particles and a clarified oil substantially free of catalyst particles; d. recycling slurry oil to said disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream; e. recycling heavy cycle oil from said fractionation zone to said catalyst disengaging zone; and, f. passing effluent vapors substantially free of entrained catalyst particles from said catalyst disengaging zone into said fractionation zone, to thereby preclude the passage of catalyst particles into said fractionation zone.

Claim 8

A fluidized catalytic cracking process which comprises: a. contacting a feed stock with a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said feed into a cracked product effluent vapor; b. separating effluent vapors which contain entrained catalyst particles from fluidized catalyst; c. contacting said effluent vapors, in a catalyst disengaging zone, with a first liquid hydrocarbon stream and thereafter with a second liquid hydrocarbon stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; d. recovering a heavy liquid oil bottoms material comprising catalyst particles, condensed effluent and first liquid stream material from said catalyst disengaging zone; e. separating said heavy liquid oil bottoms material into a slurry oil containing catalyst particles and a clarified oil substantially free of catalyst particles; f. recycling slurry oil to said catalyst disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream; and, g. recovering effluent vapors substantially free of entrained catalyst particles from said catalyst disengaging zone.

Claim 9

A fluidized catalytic cracking process which comprises: a. contacting a feed stock with a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said feed into a cracked product effluent vapor; b. separating effluent vapors which contain entrained catalyst particles from fluidized catalyst; c. contacting said effluent vapors, in a catalyst disengaging zone, with a first liquid hydrocarbon stream and thereafter with a second liquid hydrocarbon stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; d. recovering a heavy liquid oil bottoms material comprising catalyst particles, condensed effluent and first liquid stream material from said catalyst disengaging zone; e. separating said heavy liquid oil bottoms material into a slurry oil containing catalyst particles and a clarified oil substantially free of catalyst particles; f. recycling slurry oil to said catalyst disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream; and, g. recovering effluent vapors substantially free of entrained catalyst particles from said catalyst disengaging zone.

Claim 10

The process of claim 6 wherein said effluent vapors of step (g) are passed into a fractionation zone for separation into various boiling fractions.

Claim 11

The process of claim 6 wherein said first and second liquid stream materials recycled to said disengaging zone are cooled prior to passage into that zone.

Claim 12

A fluidized catalytic cracking process which comprises: a. contacting a hydrocarbon feed stock with a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said hydrocarbon; b. separating from fluidized catalyst a stream of effluent vapors containing entrained catalyst; c. contacting said stream of effluent vapor, in a lower portion of a catalyst disengaging zone, with a first liquid hydrocarbon stream and thereafter with a second liquid hydrocarbon stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; d. recovering from said lower portion of the catalyst disengaging zone a heavy liquid oil bottoms material comprising catalyst particles, condensed reaction zone effluent and liquid hydrocarbons from said first and said second liquid hydrocarbon streams of step (c); e. passing the remaining portion of said effluent vapor into an upper portion of said catalyst disengaging zone, said upper portion of the catalyst disengaging zone being designed to promote the fractionation of the effluent vapor; f. contacting said remaining portion of said effluent vapor with a third liquid hydrocarbon stream comprising a heavy cycle oil stream in said upper portion of the catalyst disengaging zone to thereby cool said effluent vapor and cause the condensation of heavier hydrocarbons contained in the effluent vapor; g. recovering effluent vapor substantially free of entrained catalyst particles from said upper portion of the catalyst disengaging zone; h. recovering from said upper portion of the catalyst disengaging zone a bottoms stream of liquid hydrocarbons comprising condensed effluent vapor material; i. separating said heavy liquid oil bottoms material recovered from said lower portion of the catalyst disengaging zone into a slurry oil containing catalyst particles and a clarified oil having lower concentration of catalyst particles; and, j. recycling slurry oil to said lower portion of the catalyst disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream.

Claim 13

A fluidized catalytic cracking process which comprises: a. contacting a hydrocarbon feed stock with a fluidized catalyst in a reaction zone at reaction conditions to effect the cracking of said hydrocarbon; b. separating from fluidized catalyst a stream of effluent vapors containing entrained catalyst; c. contacting said stream of effluent vapor, in a lower portion of a catalyst disengaging zone, with a first liquid hydrocarbon stream and thereafter with a second liquid hydrocarbon stream at conditions to condense a portion of said effluent vapors and recover entrained catalyst particles in the condensed liquid; d. recovering from said lower portion of the catalyst disengaging zone a heavy liquid oil bottoms material comprising catalyst particles, condensed reaction zone effluent and liquid hydrocarbons from said first and said second liquid hydrocarbon streams of step (c); e. passing the remaining portion of said effluent vapor into an upper portion of said catalyst disengaging zone, said upper portion of the catalyst disengaging zone being designed to promote the fractionation of the effluent vapor; f. contacting said remaining portion of said effluent vapor with a third liquid hydrocarbon stream comprising a heavy cycle oil stream in said upper portion of the catalyst disengaging zone to thereby cool said effluent vapor and cause the condensation of heavier hydrocarbons contained in the effluent vapor; g. recovering effluent vapor substantially free of entrained catalyst particles from said upper portion of the catalyst disengaging zone; h. recovering from said upper portion of the catalyst disengaging zone a bottoms stream of liquid hydrocarbons comprising condensed effluent vapor material; i. separating said heavy liquid oil bottoms material recovered from said lower portion of the catalyst disengaging zone into a slurry oil containing catalyst particles and a clarified oil having lower concentration of catalyst particles; and, j. recycling slurry oil to said lower portion of the catalyst disengaging zone as said first liquid hydrocarbon stream and clarified oil as said second liquid hydrocarbon stream.

Claim 14

The process of claim 9 wherein a portion of said bottoms stream of liquid hydrocarbons recovered from the upper portion of the catalyst disengaging zone is recycled to the catalyst disengaging zone as at least a portion of said third liquid hydrocarbon stream.

Claim 15

The process of claim 9 wherein at least a part of the slurry oil Is charged to the reaction zone.

Claim 16

The process of claim 9 wherein said bottoms stream of liquid hydrocarbons recovered from the upper portion of the catalyst disengaging zone is a heavy cycle oil.