Abstract: An improved process and apparatus are disclosed for fluidized catalytic cracking of hydrocarbons using a cross-flow or swirl type catalyst regenerator. Instead of a single catalyst withdrawal outlet for regenerated catalyst, multiple catalyst withdrawal points are provided. Use of multiple catalyst outlets, or a continuous radial catalyst outlet, greatly reduces stagnant regions in the bed.

Abstract: Catalyst stripping in the fluid catalytic cracking process is improved by cooling the spent catalyst to quench catalytic condensation reactions, then stripping the cooled catalyst in a primary stripper, followed by heating and a stage of hot stripping. Quenched stripping reduces coke make by reducing conversion of light olefins, made during the FCC process, into coke.

Abstract: A process for thermally and catalytically upgrading a heavy feed in a single riser reactor FCC unit is disclosed. A heavy feed is added to a blast zone in the base of the riser, and sufficient hot regenerated FCC catalyst is added to induce both thermal and catalytic cracking of the heavy feed. A reactive quench material, which cools the material discharged from the blast zone is added to a quench zone downstream of the blast zone, to reduce temperature at least in part by undergoing endothermic reactions in the riser. Quench liquids can be distillable FCC feeds such as gas oil, slack wax, or alcohols or ethers. The quench material is added in an amount equal to 100 to 1000 wt % of the non-distillable material in the heavy feed. A preferred catalyst, with a high zeolite content, is used which retains activity in the quench despite initial contact with the heavy feed, which tends to overwhelm conventional FCC catalysts.

Abstract: Coke formation/deposition within and downstream of catalytic cracking reactors is suppressed by adding a coke suppressing additive to the cracking reactor and/or cracked product vapor. Free radical inhibitors, such as oxygenates, are preferred. The additive addition rate is preferably controlled based on temperature of regenerated catalyst, or a direct or indirect measurement of coke accumulation on the transfer line between the cracking reactor and the main fractionator.

Abstract: Operational flexibility of a fluid catalytic cracking process is improved by indirectly cooling catalyst in an endothermic catalyst cooler. Catalyst withdrawn from the FCC unit is cooled by driving an endothermic chemical reaction, which may be either thermal or catalytic. Dehydrogenation of, e.g., light aliphatics, produced by the cracking reactor in the endothermic cooler allows the FCC unit to adapt to heavier feeds. A preferred endothermic cooler, comprising a base heat exchanger section, transport riser, and solids collection and recycle vessel is disclosed.

Abstract: An process and apparatus are disclosed for fluidized bed catalyst regeneration in a cross-flow type regenerator. A baffled coked catalyst inlet located within the dense bed of catalyst disperses and distributes coked catalyst flow in a direction generally normal to the direction of flow in the catalyst inlet. The baffle significantly reduces the stagnant regions in the bed.

Abstract: A flue gas that contains small amounts of both HCN and NO.sub.x, produced, for example, by catalyst regeneration in the fluid catalytic cracking of a petroleum gas oil, is readily denitrified by the catalyzed reaction that proceeds approximately according to:HCN+NO.fwdarw.N.sub.2 (gas)+CO+CO.sub.2 +H.sub.2 OIf the molar ratio of HCN to NO in the flue gas is about 1.0, e.g. in the range of about 0.8 to 1.2, effective denitrification is achieved without first changing the composition of the flue gas by contacting it with catalyst under conversion conditions including elevated temperature. If the molar ratio of HCN to NO exceeds 1.2, the ratio may be adjusted to about 1.0 to 1.1 by thermal or catalytic oxidation in the presence of oxygen gas, followed by catalytic denitrification. If the molar ratio is less than about 0.8, the effective molar ratio is adjusted to about 1.0 to 1.1 by adding NH.sub.3 gas, followed by denitirification.

Abstract: An improved process for regeneration of catalyst used in fluidized catalytic cracking of hydrocarbons using a cross-flow or swirl type catalyst regenerator is disclosed. Instead of a single catalyst withdrawal outlet for regenerated catalyst, multiple catalyst withdrawal points are provided. Use of multiple catalyst outlets, or a continuous radial catalyst outlet, greatly reduces stagnant regions in the bed. The process is useful in FCC units having inventories of from 10 to 100 tons of catalyst.

Abstract: A process for reducing the benzene content of a reformate stream in a conventional catalytic cracking reactor wherein a heavy hydrocarbon feed is cracked to lighter products by contact with a supply of hot regenerated cracking catalyst is disclosed. The reformate can be mixed with the heavy feed to the cracking reactor, but preferably reformate contacts hot regenerated cracking catalyst before the heavy feed is added. Benzene content is reduced by alkylation with reactive fragments created in the cracking reactor, or by transalkylation with alkyl aromatics. Benzene removal can be enhanced by adding a light reactive gas such as ethylene to the cracking reactor, by adding heavier aromatics, such as a light cycle oil, or both. The reaction is preferably conducted in an FCC riser reactor, but may be conducted in a moving bed cracking reactor.

Abstract: A catalytic cracking process operates with enhanced stripper efficiency by subjecting spent catalyst to microwave radiation before catalyst regeneration. Preferably the microwave frequency is one which ignores the catalytic cracking catalyst and preferentially excites the hydrocarbon or coke on the spent catalyst, the stripping steam conventionally used, or both the stripping steam and the hydrocarbonaceous coke. In preferred embodiments, microwave frequencies are used which are selective for various impurities in the coke, such as sulfur and/or nitrogen impurities. Additives, such as ferrous materials, may be added to augment the efficiency of desulfurization during stripping. The process is applicable to fluidized catalytic cracking and moving bed catalytic cracking units.

Abstract: An improved process and apparatus are disclosed for fluidized catalytic cracking of hydrocarbons using a cross-flow or swirl type catalyst regenerator. Instead of a single catalyst withdrawal outlet for regenerated catalyst, multiple catalyst withdrawal points are provided. Use of multiple catalyst outlets, or a continuous radial catalyst outlet, greatly reduces stagnant regions in the bed.

Abstract: Operational flexibility of a fluid catalytic cracking process is improved by directly cooling regenerated catalyst in an external catalyst cooler/stripper (ECCS). Regenerated catalyst withdrawn from the catalytic cracking unit regenerator is mixed with spent catalyst from the reactor stripper to effect desorption of cracked products from the spent catalyst at elevated temperature. The catalyst mixture is then contacted with an alkane-containing feedstream in a fluid bed maintained within a central section of the external catalyst cooler/stripper (ECCS). The mixture of spent and regenerated catalyst, cooled by the endothermic dehydrogenation of the alkanes, then flows downward through the ECCS to a lower section of the ECCS where the catalyst is countercurrently stripped with steam to remove remaining entrained hydrocarbons. Steam is withdrawn from an upper section of the steam stripping zone and bypassed around the dehydrogenation/stripping and mixing stages to avoid steam deactivation of the catalyst.

Abstract: A catalytic cracking process especially useful for the catalytic cracking of high metals content feeds including resids in which the feed is cracked in the presence of a catalyst additive comprising an alkaline earth metal oxide and an alkaline earth metal spinel, preferably a magnesium aluminate spinel which acts as a trap for vanadium as well as an agent for reducing the content of sulfur oxides in the regenerator flue gas. The additive is used in the form of a separate additive from the cracking catalyst particles in order to keep the vanadium away from the cracking catalyst and so preserve the activity of the catalyst; in addition, use of separate additive particles permits the makeup rate for the additive to be varied relative to that of the cracking catalyst in order to deal with variations in the metals and sulfur content of the cracking feed.

Abstract: Conversion of benzene to heavier aromatics by contact with alkyl polynucleararomatics, preferably FCC heavy cycle oil, in the presence of an alkylation/transalkylation catalyst is disclosed. Efficient conversion of relatively dilute benzene in reformate is possible. Use of alkyl polynucleararomatics as a source of alkyl groups, with reduced use of monocyclic alkyl aromatics, permits robust reaction conditions to be used without a net formation of benzene by dealkylation. The process preferably uses a solid zeolite based acidic catalyst disposed in a fixed, moving or fluid bed reactor. Preferred catalysts comprise MCM-22 or ZSM-5.

Abstract: An improved process and apparatus are disclosed for fluidized catalytic cracking of hydrocarbons using a swirl type catalyst regenerator. Multiple, symmetrically spaced spent catalyst inlets are provided for addition of coked catalyst to the regenerator. Preferable a single catalyst outlet, for withdrawal of regenerated catalyst, is provided in the center of the regenerator. Use of multiple symmetrical inlets and a central catalyst outlet greatly reduce stagnant regions in the bed.

Abstract: A fluidized catalytic cracking process using a riser reactor to crack a mixture of high and low nitrogen content fresh feeds is operated to reduce NO.sub.x emissions in the regenerator flue gas. Segregation of the feed into high and low nitrogen content streams, and addition of the high nitrogen content feed to the base of the riser, followed by separate addition of the low nitrogen content feed higher up in the riser, reduces NO.sub.x emissions and reduces production of low value products from the FCC unit.

Abstract: An improved process and apparatus are disclosed for fluidized bed catalyst regeneration in a cross-flow type regenerator. A baffled coked catalyst inlet located within the dense bed of catalyst disperses and distributes coked catalyst flow in a direction generally normal to the direction of flow in the catalyst inlet. The baffle significantly reduces the stagnant regions in the bed.

Abstract: A catalytic cracking process operates with enhanced stripper efficiency by subjecting spent catalyst to microwave radiation before catalyst regeneration. Preferably the microwave frequency is one which ignores the catalytic cracking catalyst and preferentially excites the hydrocarbon or coke on the spent catalyst, the stripping steam conventionally used, or both the stripping steam and the hydrocarbonaceous coke. In preferred embodiments, microwave frequencies are used which are selective for various impurities in the coke, such as sulfur and/or nitrogen impurities. Additives, such as ferrous materials, may be added to augment the efficiency of desulfurization during stripping. The process is applicable to fluidized catalytic cracking and moving bed catalytic cracking units.

Abstract: A system is provided for passivating metals, such as vanadium, deposited on a catalyst during a conversion reaction. Spent catalyst particles containing the metal deposits are introduced into a regenerator, and passivating particles containing the passivating materials are also introduced into the regenerator. The passivating particles and the catalyst particles are separated after they have exited from the regenerator. At least a portion of the separated passivating particles are recycled to the regenerator, and the regenerated, separated catalyst particles are reintroduced into a reaction zone, such as a riser conversion zone.

Abstract: A method for measuring local fluid flow rates in a vessel, e.g., a packed bed two-phase flow catalytic reactor, is disclosed which comprises:(a) arranging a plurality of heated thermocouple probes in the vessel at predetermined locations in the path of the fluid flow therethrough;(b) obtaining a first set of temperature readings with the probe heaters off to provide the local reactor temperature;(c) obtaining a second set of temperature readings with the probe heaters on to provide the skin temperature of the heater well;(d) using the difference between readings (b) and (c) to calculate the fluid flow rates.