# US 5,348,642 A · Catalytic cracking process with circulation of hot, regenerated catalyst to the stripping zone > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,348,642 A - Document ID: US5348642A - Status: Granted - Kind: A - Application number: 08/016,398 - Filed: 1993-02-11 - Granted: 1994-09-20 - Earliest claimed: 1991-05-02 - Assignees: Exxon Research & Engineering Co. - Inventors: Willibald Serrand; Philip Holmes; Todd R. Steffens; Patrick H. Terry; Paul E. Eberly - Web page: https://patentgrep.com/patent/US5348642A ## CPC - C10G 11/18: according to the "fluidised-bed" technique - C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES ## Abstract A catalytic cracking process and apparatus wherein particles of cracking catalyst circulate continuously between a reaction zone and a regeneration zone and hot regenerated catalyst from the regeneration zone contacts hydrocarbon feed in the reaction zone to produce cracked hydrocarbon products and spent catalyst. The spent catalyst is recovered and subjected to stripping in a stripping zone to remove strippable material therefrom. The stripped spent catalyst is circulated to the regeneration zone for oxidative exothermic regeneration. Some hot regenerated catalyst is passed directly from the regenerator to the stripping zone via a conduit provided for this purpose. Another hydrocarbon stream is passed into contact with the hot regenerated catalyst in this conduit. The said other hydrocarbon stream is converted to products of enhanced value (e.g., olefins) during contact with catalyst in the conduit, and the said products are recovered. The heat for the conversion is abstracted from the catalyst particles passing via the pipe to the stripping zone. The hot catalyst particles entering the stripping zone from the pipe increase the temperature in the stripping zone, thereby improving the stripping in the stripping zone. ## Claims ### Claim 1 In a catalytic cracking process comprising contacting a hydrocarbon feedstock in a reactor with particles of hot regenerated cracking catalyst under fluid catalytic cracking conditions to form vaporous cracked products and used catalyst particles having hydrocarbonaceous material and coke deposited thereon; stripping the used catalyst particles with a stripping fluid in a stripping zone to remove some hydrocarbonaceous material therefrom; recovering stripped hydrocarbonaceous material from the stripping zone and circulating stripped used catalyst particles to a regeneration zone; contacting stripped used catalyst particles in the regeneration zone with an oxygen-containing gas to remove unstripped hydrocarbonaceous material and coke therefrom by oxidation thereby raising the temperature of the catalyst particles; and circulating hot regenerated catalyst particles to the reactor for contact with further amounts of hydrocarbon feedstock; the improvement which comprises (a) separately circulating hot regenerated catalyst particles from the regenerator into the stripping zone whereby the hot regenerated particles mix with and raise the temperature of used catalyst particles in the stripping zone, (b) passing into contact with the separately circulating hot regenerated catalyst particles in step (a) a hydrocarbon-containing stream, said hydrocarbon-containing stream being contacted with the separately circulating hot regenerated particles before they enter the stripping zone and said hydrocarbon-containing stream containing an amount of hydrocarbon in excess of that required to effect aeration of the separately circulating hot regenerated catalyst and to combust all the oxygen present therewith so that the hydrocarbons are catalytically and thermally cracked into more desirable products and (c) recovering the cracked hydrocarbon products produced in step (b). ### Claim 2 (depends on 1) In the catalytic cracking process of claim 1, the improvement wherein the hydrocarbons in the hydrocarbon-containing stream in step (b) are selected from alkanes, cycloalkanes, alkenes, cycloalkenes and alkylaromatics and any combination of one or more of the said hydrocarbons. ### Claim 3 (depends on 1) In the catalytic cracking process of claim 1, the improvement wherein said hydrocarbon-containing stream of step (b) comprises a C.sub.4 to C.sub.5 olefin in combination with a hydrocarbon selected from the group consisting of alkanes, cycloalkanes, cycloalkenes, alkylaromatics and mixtures thereof. ### Claim 4 (depends on 1) In the process of claim 1, the improvement comprising passing a catalyst-conditioning gas and/or vapor stream into contact with the separately-circulating particles in step (a) before the separately-circulating particles are contacted with the hydrocarbon-containing stream, said catalyst conditioning stream containing a catalyst-conditioning agent selected from the group consisting of hydrogen, steam, methane, ammonia, nitrogen, an aromatic-containing stream, an amine-containing stream and a combination of at least two of the foregoing. ### Claim 5 (depends on 1) In the process of claim 1, the improvement comprising the step of separating vapor-phase materials from the regenerated catalyst particles passing to the stripper before the regenerated particles enter the stripper. ### Claim 6 (depends on 5) In the process of claim 5, the improvement wherein the separated vapor-phase materials are recovered separately. ### Claim 7 (depends on 1) In the process of claim 1, the improvement comprising incorporating a paraffins-dehydrogenation component in or with the cracking catalyst to promote or enhance the dehydrogenation of paraffinic hydrocarbons in the said hydrocarbon-containing stream. ### Claim 8 In a catalytic cracking process comprising contacting a hydrocarbon feedstock in a reactor with particles of hot regenerated cracking catalyst under fluid catalytic cracking conditions to form vaporous cracked products and used catalyst particles having hydrocarbonaceous material and coke deposited thereon; stripping the used catalyst particles with a stripping fluid in a stripping zone to remove some hydrocarbonaceous material therefrom; recovering stripped hydrocarbonaceous material from the stripping zone and circulating stripped used catalyst particles to a regeneration zone; contacting stripped used catalyst particles in the regeneration zone with an oxygen-containing gas to remove unstripped hydrocarbonaceous material and coke therefrom by oxidation thereby raising the temperature of the catalyst particles; and circulating hot regenerated catalyst particles to the reactor for contact with further amounts of hydrocarbon feedstock; the improvement which comprises (a) separately circulating hot regenerated catalyst particles from the regenerator into the stripping zone whereby the hot regenerated particles mix with and raise the temperature of used catalyst particles in the stripping zone, (b) passing into contact with the separately circulating hot regenerated catalyst particles in step (a) a hydrocarbon-containing stream, said hydrocarbon-containing stream being contacted with the separately circulating hot regenerated particles before they enter the stripping zone and said hydrocarbon-containing stream containing an amount of hydrocarbon in excess of that required to effect aeration of the separately circulating hot regenerated catalyst and to combust all the oxygen present therewith so that the hydrocarbons are catalytically and thermally cracked into more desirable products and (c) separating the cracked hydrocarbon products from the regenerated catalyst particles passing to the stripper before the regenerated particles enter the stripper.