Abstract: A method for operating a fluid catalytic cracking unit comprising a regeneration zone and a reaction zone with a relatively reduced temperature in the regeneration zone while processing a hydrocarbon feedstock having a 50 volume percent distillation temperature greater than about 500.degree. F. which method comprises contacting the feedstock in a reaction zone with a mixture of regenerated fluidizable cracking catalyst and fluidizable low coke make solid particles comprising a refractory inorganic oxide in a ratio of low coke make solid particles to cracking catalyst from about 1:100 to about 10:1, the low coke made solid particles having a surface area of less than about 5 m.sup.2 /g and a coke making capability of less than about 0.

Abstract: A radial flow reactor design which allows the maintenance of a temperature profile along the height of a catalyst bed which descends through the reactor by gravity flow. Two feed inlet conduits are provided on the inlet side of the annular catalyst bed, with the inlets being divided by a porous flow control and distribution means. The inlet streams have different temperatures and the distribution means produces a changing admixture rate between the two streams along the bed. A preferred form of the distribution means is an open-topped cone located within the centerpipe of the reactor.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke contaminated fluid catalyst. The process comprises a high temperature coke combustion zone, a catalyst disengagement zone and an external heat removal zone comprising a shell and tube heat exchanger. Catalyst is cooled by passing it through the shell side of the heat exchanger with a cooling medium through the tube side. A mixture of coke contaminated catalyst, oxygen containing gas, and cool regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is passed through the heat exchanger. This rate is adjusted by adjusting the difference in catalyst head between the catalyst inlet and outlet of the heat exchanger and thus the hydraulic driving force which effects catalyst circulation through the heat exchanger.

Abstract: An apparatus for regenerating coke-contaminated fluid catalyst is disclosed which comprises a vertical combustion chamber, an inlet to said chamber for spent catalyst and regeneration gas, a heat removal chamber located superadjacent to the combustion chamber and in communication therewith, heat removal means disposed within the heat removal chamber, a catalyst withdrawal conduit connected at one end to the heat removal chamber for withdrawing regenerated fluid catalyst from the heat removal chamber, and a catalyst recycle conduit connecting the withdrawal conduit with the lower portion of the combustion chamber, such that regenerated fluid catalyst can pass from the heat removal chamber to the combustion chamber. There may also be a means and control system for manipulating the extent of immersion of the heat removal means.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke contaminated fluid catalyst. The process comprises a high temperature coke combustion zone, a catalyst disengagement zone and an external heat removal zone. A mixture of coke contaminated catalyst, oxygen containing gas, hot regenerated catalyst and cool regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled from the heat removal zone. The temperature of the catalyst-gas mixture is controlled by adjusting the rate at which hot catalyst is recycled from the disengagement zone.

Abstract: An apparatus for regenerating coke-contaminated fluid catalyst which comprises a vertical combustion chamber, an inlet to said chamber for spent catalyst and regeneration gas, a disengagement chamber above and in communication with the combustion chamber, a heat removal chamber below the combustion chamber in which may be maintained a dense phase catalyst bed, heat removal means positioned within the heat removal chamber such that it will be immersed in the catalyst bed, a recycle conduit for passing catalyst from the disengagement chamber to the heat removal chamber, a vertical cooled catalyst inlet conduit connecting the heat removal chamber with the lower portion of the combustion chamber so that catalyst can pass from the former to the latter, and a regeneration gas inlet line connecting with a lower part of the cooled catalyst inlet conduit to enable the flow of cooled catalyst up into the combustion chamber, wherein a control system senses the catalyst level in the heat removal zone, formulates an outpu

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke-contaminated fluid catalyst. The process utilizes a high temperature coke combustion zone and a catalyst disengagement zone. A mixture of coke-contaminated catalyst, and oxygen-containing gas are contacted in the combustion zone and from there, the regenerated catalyst and flue gas mixture passes to the catalyst disengagement zone. There are one or more diplegs through which regenerated catalyst flows from the disengagement zone to the combustion zone. The diplegs are sized so as to ensure a low maximum accumulation of catalyst in the disengagement zone. The temperature at a lower locus of the combustion zone may be controlled by control of the catalyst inventory in the reactor-regenerator system.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke contaminated fluid catalyst. The process comprises a high temperature coke combustion zone, a catalyst disengagement zone and an external heat removal zone. A mixture of coke contaminated catalyst, oxygen containing gas, hot regenerated catalyst and cool regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled from the heat removal zone. The temperature of the catalyst-gas mixture is controlled by adjusting the rate at which hot catalyst is recycled from the disengagement zone.

Abstract: An apparatus for regenerating coke-contaminated fluid catalyst is disclosed which comprises a vertical combustion chamber, an inlet to said chamber for spent catalyst and regeneration gas, a fluid catalyst collecting means within the upper portion of said chamber, a first catalyst withdrawal conduit in communication with said collecting means, a heat removal chamber possessing heat removal means super adjacent said chamber, a second catalyst withdrawal conduit connected to said heat removal chamber and a mixing conduit connecting said first and second withdrawal conduits, wherein a control system senses the catalyst temperature in the first withdrawal conduit downstream of the mixer conduit, formulates an output signal via a temperature control means having an adjustable set point, and regulates the flow rate of regenerated catalyst through said mixing conduit via transmission of said output signal to a flow control means responsive thereto.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke-contaminated fluid catalyst. The process comprises of high temperature coke combustion zone, a lower temperature heat removal zone and an upper disengagement zone. Coke-contaminated catalyst, oxygen-containing gas and cooled regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled to the heat removal zone. The heat removal zone contains a relatively dense-phase fluid catalyst bed in which is immersed heat removal means such as cooling coils. The level of this fluid catalyst bed, and thus the extent of immersion of the heat removal means in the bed, is maintained by controlling the quantity of regeneration gas passed into the transfer line that carries catalyst upward from the heat removal zone to the combustion zone.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke contaminated fluid catalyst. The process comprises a high temperature coke combustion zone, a catalyst disengagement zone and an external heat removal zone comprising a shell and tube heat exchanger. Catalyst is cooled by passing it through the shell side of the heat exchanger with a cooling medium through the tube side. A mixture of coke contaminated catalyst, oxygen containing gas, and cool regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is passed through the heat exchanger. This rate is adjusted by adjusting the difference in catalyst head between the catalyst inlet and outlet of the heat exchanger and thus the hydraulic driving force which effects catalyst circulation through the heat exchanger.

Abstract: A catalyst regeneration apparatus for the oxidation of coke from a spent catalyst, said coke being converted to CO, and for the conversion of the CO to CO.sub.2. Hot regenerated catalyst is recycled from a dense bed in the regeneration zone to mix with incoming spent catalyst in a mixer zone. The mixer zone operates in dense phase and is supplied with a relatively small amount of a fluidizing medium, preferably air. After the mixing of spent and fresh catalyst is substantially completed, a relatively large amount of a regenerating gas, preferably air, is admixed with the catalyst mixture, and some coke oxidation occurs. The balance of coke oxidation takes place in a downstream-situated regeneration zone of substantially conventional design. There is a transfer section connecting the mixer zone to the regeneration zone through when the relatively large amount of the regenerating gas is admitted.

Abstract: Alkylaromatic hydrocarbons are dehydrogenated in admixture with steam, with the dehydrogenation zone effluent being condensed to form a water stream which is purified in a stripping column. The stripping column is reboiled by indirect heat exchange against the effluent of the dehydrogenation zone. The steam-rich overhead vapor stream of the stripping column is mixed directly into the dehydrogenation zone feed stream without intermediate condensation or pressurization.

Abstract: Methods of control and control systems for a catalyst regeneration process and apparatus for the oxidative removal of coke from a coke-contaminated fluid catalyst. Simultaneous production of hot regenerated catalyst and a relatively-cooler flue gas is provided. The process comprises a high temperature coke combustion zone, and a lower temperature heat removal zone. Coke contaminated catalyst, oxygen containing gas and regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled from the heat removal zone. Catalyst maybe withdrawn from the top of the combustion zone and sent to the reaction zone at the controlled combustion zone temperature, the remainder of the catalyst and the hot flue gas pass to the upper heat removal zone, where both gas and catalyst are cooled, preferably by utilizing the catalyst as a heat transfer medium in a dense-phase heat exchange system.

Abstract: A catalyst regeneration apparatus for the oxidation of coke from a spent catalyst, said coke being converted to CO, and for the conversion of the CO to CO.sub.2. Hot regenerated catalyst is recycled from a dense bed in the regeneration zone to mix with incoming spent catalyst in a mixer zone. The mixer zone operates in dense phase and is supplied with a relatively small amount of a fluidizing medium, preferably air. After the mixing of spent and fresh catalyst is substantially completed, a relatively large amount of a regenerating gas, preferably air, is admixed with the catalyst mixture, and some coke oxidation occurs. The balance of coke oxidation takes place in a downstream-situated regeneration zone of substantially conventional design. There is a transfer section connecting the mixer zone to the regeneration zone through which the relatively large amount of the regenerating gas is admitted.

Abstract: A process for the separation of isobutane from an alkylation reaction zone hydrocarbon effluent stream comprising isobutane, n-butane, propane and alkylate is disclosed. The hydrocarbon effluent stream is charged to an isostripper column. An isobutane vapor stream from the column is condensed in indirect heat exchange with the lower liquid stream from said column comprising n-butane. The lower liquid stream is flashed in indirect heat exchange with said vapor stream at conditions to provide a vapor phase, said vapor phase being compressed and recycled to said column at a temperature to promote vapor formation therein.

Abstract: An improved fluid catalytic cracking process providing improved product yield and selectivity and reduced catalyst deactivation which employs a split flow of catalyst to the reactor riser.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke-contaminated fluid catalyst. Simultaneous production of hot regenerated catalyst and a relatively-cooler flue gas is provided. The process comprises a high temperature coke combustion zone, and a lower temperature heat removal zone. Coke contaminated catalyst, oxygen containing gas and regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled from the heat removal zone. Catalyst may be withdrawn from the top of the combustion zone and sent to the reaction zone at the controlled combustion zone temperature, the remainder of the catalyst and the hot flue gas pass to the upper heat removal zone, where both gas and catalyst are cooled, preferably by utilizing the catalyst as a heat transfer medium in a dense-phase heat exchange system.

Abstract: A catalyst regeneration process and apparatus for the oxidative removal of coke from a coke-contaminated fluid catalyst. Simultaneous production of hot regenerated catalyst and a relatively-cooler flue gas is provided. The process comprises a high temperature coke combustion zone, and a lower temperature heat removal zone. Coke contaminated catalyst, oxygen containing gas and regenerated catalyst from the heat removal zone are contacted in the high temperature combustion zone, the temperature of which is controlled by adjusting the rate at which catalyst is recycled from the heat removal zone. Catalyst may be withdrawn from the top of the combustion zone and sent to the reaction zone at the controlled combustion zone temperature, the remainder of the catalyst and the hot flue gas pass to the upper heat removal zone, where both gas and catalyst are cooled, preferably by utilizing the catalyst as a heat transfer medium in a dense-phase heat exchange system.

Abstract: A catalyst regeneration process and apparatus for the oxidation of coke from a spent catalyst, said coke being converted to CO, and for the conversion of the CO to CO.sub.2. Hot regenerated catalyst is recycled from a dense bed in the regeneration zone to mix with incoming spent catalyst in a riser-mixer. The riser-mixer operates in dense phase and is supplied with a relatively small amount of a fluidizing medium, preferably air. After the mixing of spent and fresh catalyst is substantially completed, a relatively large amount of a regenerating gas, preferably air, is admixed with the catalyst mixture, and some coke oxidation occurs. The balance of coke oxidation takes place in a downstream-situated regeneration zone of substantially conventional design. The regenerating gas addition is preferably made at the base of a cone-shaped combustor in order to provide a venturi effect which ensures good air-catalyst mixing.