Purging Patents (Class 208/150)
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Patent number: 5215653Abstract: An improved method of controlling catalyst inventory in the reactor of an ebullated bed process has been discovered. Pressure differentials are measured to calculate a catalyst inventory characterization factor. This factor is calculated by means of a new algorithm. Aged catalyst is withdrawn and fresh catalyst added in an amount to reestablish the value of the factor. The catalyst to oil ratio is maintained despite changes in bed ebullation, gas and liquid holdups, oil residence time and conversion.Type: GrantFiled: March 25, 1992Date of Patent: June 1, 1993Assignee: Texaco Inc.Inventors: Gerald V. Nelson, Govanon Nongbri
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Patent number: 5141625Abstract: The use of lift gas for FCC risers is improved by the direct use of stripping vapors from a second stage of catalyst stripping as a lift gas. Reactor vapors recovered primarily from the stripping section of an FCC reactor/regenerator section provide an excellent source for lift gas material. These reactor vapors contain high concentrations of light paraffinic materials often with an equal weight percent amount of steam. The recovery of the stripping vapors independent from the product stream allows such gaseous mixtures to be readily used as lift gas. The lift gas material is obtained from a stripping section located subadjacent to a regenerator section so that it will have adequate pressure for use as a lift gas stream. The relatively high pressure of the lift gas stream eliminates processing requirements that would otherwise be necessary for the removal of particulate material and the compression of the gas to the pressure conditions at the bottom of the riser.Type: GrantFiled: November 13, 1990Date of Patent: August 25, 1992Assignee: UOPInventor: David A. Lomas
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Patent number: 5139649Abstract: A process and apparatus for achieving turbulent or fast fluidized bed regeneration of spent FCC catalyst in a bubbling bed regenerator having a stripper mounted over the regenerator and a stripped catalyst standpipe within the regenerator. A coke combustor vessel, which may be partially or totally open to the dilute phase above the bubbling bed, is added to the existing regenerator vessel. Spent catalyst is discharged into the coke combustor, regenerated in a turbulent or fast fluidized bed, then discharged into the dilute phase region above the bubbling bed, either via a deflector or by simply overflowing the combustor. Regeneration of catalyst is completed in the bubbling dense bed, and/or an annular fast fluidized bed surrounding the coke combustor. Catalyst may be recycled from the dense bed to the coke combustor either by a flow line, or by adjusting relative heights of bubbling to fast fluidized bed.Type: GrantFiled: April 27, 1990Date of Patent: August 18, 1992Assignee: Mobil Oil CorporationInventors: Hartley Owen, Paul H. Schipper
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Patent number: 5100536Abstract: A method of processing hydrocarbon substances including coal, heavy crude oil, and bitumen by hydrogenating the hydrocarbon substance with a gas containing from 20%-100% hydrogen at a pressure in the range of from 50 bar to 700 bar and at a temperature in the range of from 250.degree. C. to 600.degree. C. to produce a hydrogenation residue which is treated in a secondary stripping operation using hydrogen gas at a pressure between about 1.2 bar and 150 bar to recover light hydrocarbon gases from the hydrogenation residue.Type: GrantFiled: April 30, 1990Date of Patent: March 31, 1992Assignee: Ruhrkohle AGInventors: Ulrich Bonisch, Claus Strecker, Wolfdieter Klein
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Patent number: 5062945Abstract: A method and apparatus are disclosed to reduce the amount of unstripped hydrocarbon flowing to the regenerator in an FCC unit. The catalyst stripper section is heated by indirect heat exchange with a mixture of hot regenerator flue gas and regenerated catalyst.Type: GrantFiled: October 16, 1989Date of Patent: November 5, 1991Assignee: Mobil Oil CorporationInventors: David A. Pappal, Paul H. Schipper
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Patent number: 5059305Abstract: 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.Type: GrantFiled: January 30, 1991Date of Patent: October 22, 1991Assignee: Mobil Oil CorporationInventor: Ajit V. Sapre
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Patent number: 5015363Abstract: This invention provides an improved method for stripping hydrocarbons from spent catalyst which has been used in effecting hydrocarbon conversion reactions prior to the regeneration of this catalyst by combustion of carbon deposits upon the catalyst. The invention is described in terms of its use in FCC processes, since such processes are the most common application of the invention. In order to better distribute stripping gas, which is normally steam, so that the gas contacts and passes through substantially all of the catalyst, distribution ports are added to the skirts of the stripper baffles which direct catalyst flow in a generally side-to-side manner as it moves downward through a stripping vessel. The ports are sized to vary penetration of the stripping gas into the stream catalyst that moves past the grids. Use of these ports increases the amount of hydrocarbons removed from the spent catalyst and/or decreases stripping gas requirements.Type: GrantFiled: December 14, 1989Date of Patent: May 14, 1991Assignee: UOPInventor: Ismail B. Cetinkaya
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Patent number: 5001095Abstract: A semi-continuous process for combusting coke from catalyst particles in a fixed bed is improved by segregating flue gas from the combustion process into a high moisture content flue gas stream which is withdrawn from the process and a relatively low moisture content flue gas stream which is combined with an oxygen-containing make-up gas and recycled to the process. When coke is combusted in a fixed bed to which catalyst is added at an inlet and withdrawn from an outlet on a semi-continuous basis, hydrogen from the coke is quickly combusted whereas less volatile coke components are more slowly combusted. As a result, flue gas passing through the catalyst that has just entered the bed will have the highest water concentration. By separately recovering the flue gas stream having this high moisture content, the overall equilibrium level of water in a flue gas/recycle gas that circulates through the process is lowered.Type: GrantFiled: November 16, 1989Date of Patent: March 19, 1991Assignee: UOPInventor: Paul A. Sechrist
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Patent number: 5000841Abstract: A fluidized catalytic cracking process operates with a hot stripper to improve stripping of spent catalyst from the FCC process. The catalyst from the hot stripper is cooled by direct contact heat exchange with a source or cooled regenerated catalyst. Cooled catalyst may contact hot, stripped catalyst in the base of the stripper or downstream of the stripper. The cooled, stripped catalyst has reduced hydrogen, sulfur and coke content, improves regeneration efficiency, and reduces hydrothermal degradation of catalyst.Type: GrantFiled: April 10, 1989Date of Patent: March 19, 1991Assignee: Mobil Oil CorporationInventor: Hartley Owen
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Patent number: 4988430Abstract: The use of lift gas for FCC risers is improved by the direct use of reactor vapors as the source of the lift gas. Reactor vapors recovered primarily from the stripping section of an FCC reactor/regenerator section provide an excellent source for lift gas material. These reactor vapors contain high concentrations of light paraffinic materials often with an equal weight percent amount of steam. The recovery of the stripping vapors independent from the product stream allows such gaseous mixtures to be readily processed for use as lift gas. The only processing requirements are the removal of particulate material and the compression of the gas to pressure conditions at the bottom of the riser. Compression of the gas requires a reduction in its temperature to suitable compressor inlet conditions. This invention is readily practiced in the most recent FCC reactor designs that separate the majority of product vapors from the catalyst in a closed riser cyclone arrangement.Type: GrantFiled: December 27, 1989Date of Patent: January 29, 1991Assignee: UOPInventors: Paul A. Sechrist, David A. Lomas, Daniel N. Myers
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Patent number: 4976755Abstract: An apparatus and method for stripping and depressurizing fine particulates mixed with gas discharged from a vessel operated at elevated temperature and pressure conditions to a low pressure vessel using a purge gas injected into a conduit designed for significant frictional pressure loss per unit length of conduit while maintaining a substantially constant velocity of the mixture conveyed.Type: GrantFiled: October 19, 1989Date of Patent: December 11, 1990Assignee: Shell Oil CompanyInventor: Thomas S. Dewitz
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Patent number: 4973398Abstract: A method and apparatus are disclosed to reduce the amount of coke and unstripped hydrocarbon flowing to the regenerator in an FCC unit. The catalyst stripper section is heated by indirect heat exchange with hot regenerator flue gas.Type: GrantFiled: May 25, 1988Date of Patent: November 27, 1990Assignee: Mobil Oil Corp.Inventors: David A. Pappal, Paul H. Schipper
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Patent number: 4971681Abstract: A method and apparatus are disclosed to reduce the amount of unstripped hydrocarbon flowing to the regenerator in a riser reactor FCC unit. The catalyst stripper section is heated by indirect heat exchange with a mixture of hot regenerator flue gas and regenerated catalyst. In the preferred embodiment, the regenerator is operated under partial combustion conditions and the resulting carbon monoxide-containing flue gas is burned in a catalyst stripper heat exchanger.Type: GrantFiled: September 13, 1989Date of Patent: November 20, 1990Assignee: Mobil Oil Corp.Inventors: Mohsen N. Harandi, Hartley Owen, David A. Pappal, Paul H. Schipper
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Patent number: 4971682Abstract: In the purification of light hydrocarbons to remove carbonyl sulfide impurity by selective adsorption thereof on molecular sieve adsorbents, significant losses of the hydrocarbon are incurred by its coadsorption on the adsorbent with the COS impurity. Conventional desorption procedures produce a desorbate which is a non-commercial mixture of COS and hydrocarbon. The purge desorption method of the present invention utilizing a mixture of CO.sub.2 and a non-sorbable purge gas permits recovery of the coadsorbed hydrocarbon in a pure and commercially useful form.Type: GrantFiled: June 27, 1989Date of Patent: November 20, 1990Assignee: UOPInventor: Keith R. Clark
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Patent number: 4968403Abstract: 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.Type: GrantFiled: December 21, 1989Date of Patent: November 6, 1990Assignee: Mobil Oil CorporationInventors: Joseph A. Herbst, Catherine L. Markham, Ajit V. Sapre, Gerald J. Teitman
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Patent number: 4935400Abstract: Molecular sieves are used to remove sulfur compounds (e.g., COS and H.sub.2 S) from liquid hydrocarbon streams, particularly liquid propane. During regeneration of the sieves, some of the liquid hydrocarbons remains on the sieves and is lost by vaporization during the purge step and the liquid fill step. This invention reduces the loss by recovery and recycle of the vaporized hydrocarbons in the liquid recovery process.Type: GrantFiled: October 12, 1988Date of Patent: June 19, 1990Assignee: Amoco CorporationInventors: Glen A. Blackburn, Richard B. Macon
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Patent number: 4935399Abstract: Molecular sieves are used to remove sulfur compounds (e.g., COS and H.sub.2 S) from liquid hydrocarbon streams, particularly liquid propane. During regeneration of the sieves, some of the liquid hydrocarbons remains on the sieves and is lost be vaporization during the purge step and the liquid fill step. This invention reduces the loss by recovery and recycle of the vaporized hydrocarbons in the liquid recovery process.Type: GrantFiled: October 12, 1988Date of Patent: June 19, 1990Assignee: Amoco CorporationInventors: Glen A. Blackburn, Richard B. Macon
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Patent number: 4752377Abstract: In a fluid catalytic cracking unit where oil and steam are mixed with regenerated catalyst the individual and combined improvements: (1) extending the oil-steam line into the riser reactor at least to a point where the axis of the riser is intersected by an imaginery extension of the inside diameter of the catalyst standpipe and (2) installation of a plurality of purge gas points beneath the regenerator slide valve in the catalyst standpipe.Type: GrantFiled: April 16, 1986Date of Patent: June 21, 1988Assignee: Phillips Petroleum CompanyInventors: Randal E. York, Dwain R. Parker, Frank W. Skraba
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Patent number: 4574044Abstract: A method for increasing the overall efficiency of fluidized catalytic cracking (FCC) with crystalline zeolitic catalysts is disclosed. Separated or spend cracking catalyst after reaction with hydrocarbonaceous material is first stripped and then subjected to an additional period of time in the presence of steam in the dense phase before the catalyst is returned to a regenerator. In a preferred form the spent catalyst after normal steam stripping is subjected to an additional period from 1/2 to 30 minutes at elevated temperature. This time is from 6 to 900 times the reaction time of the catalyst and hydrocarbonaceous mixture in an FCC reactor riser pipe. Such additional steam exposure allows the stripped spent catalyst to react with the steam to produce one or more significant benefits in FCC operations.Type: GrantFiled: May 8, 1984Date of Patent: March 4, 1986Assignee: Chevron Research CompanyInventor: Russell R. Krug
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Patent number: 4464250Abstract: A process for economically converting carbo-metallic oils to lighter products. The carbo-metallic oils contain 650.degree. F. and material which is characterized by a carbon residue on pyrolysis of at least about 1 and a Nickel Equivalents of heavy metals content of at least about 4 parts per million. This process comprises flowing the carbo-metallic oil together with particulate cracking catalyst through a progressive flow type reactor having an elongated reaction chamber, which is at least in part vertical or inclined, for a predetermined vapor riser residence time in the range of about 0.5 to about 10 seconds, at a temperature of about 900.degree. to about 1400.degree. F., and under a pressure of about 10 to about 50 pounds per square inch absolute sufficient for causing a conversion per pass in the range of about 50% to 90% while producing coke in amounts in the range of about 6 to about 14% by weight based on fresh feed, and laying down coke on the catalyst in amounts in the range of about 0.Type: GrantFiled: July 30, 1981Date of Patent: August 7, 1984Assignee: Ashland Oil, Inc.Inventors: Virginia K. Myers, Bill E. McKay, Jr., Lloyd E. Busch
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Patent number: 4289605Abstract: Metal contaminated heavy oils such as residual fractions from petroleum distillation are economically converted to gasoline and other light products in catalytic cracking by practice of a novel catalyst makeup policy of adding controlled proportions of both an active cracking catalyst and a substantially inert, large pore solid to replace the amount of catalyst withdrawn from the inventory of a continuous cracking unit wherein catalyst inventory is continuously circulated between a reactor for cracking charge hydrocarbons and a regenerator for burning off the carbonaceous deposit laid down on catalyst in the cracking reaction.Type: GrantFiled: February 19, 1980Date of Patent: September 15, 1981Assignee: Engelhard Minerals & Chemicals CorporationInventor: David B. Bartholic
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Patent number: 4274942Abstract: Process and system are described for control of sulfur oxide in emissions to the atmosphere from regenerators of Fluid Catalytic Cracking Units (FCC) in a manner which improves the operation of the regenerator and/or the reactor. Spent FCC cracking catalyst containing sulfur-bearing inactivating carbonaceous deposit is partially oxidized, preferably in the presence of steam, thereby producing a mixture of CO and CO.sub.2 and releasing sulfur in the resulting reducing atmosphere as vaporous hydrogen sulfide before the catalyst is regenerated, whereby the amount of sulfur convertible to noxious SOx in the regenerator flue gas is reduced. By the disclosed process and system, the quantity of oxygen introduced is predetermined and controlled in response to hydrogen content of the coke on the partially oxidized catalyst or an SOx analyzer associated with the regenerator can be used as a control tool.Type: GrantFiled: April 4, 1979Date of Patent: June 23, 1981Assignee: Engelhard Minerals & Chemicals CorporationInventors: David B. Bartholic, Don S. Chin
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Patent number: 4239599Abstract: A mixture of a high density particulate inorganic heat source and a low density particulate carbon containing residue formed in the pyrolysis of a solid waste is passed along with some entrained pyrolytic oil to a fluidized bed of particles, where a gas is injected to strip the entrained pyrolytic oil from the particles, and a mixture of a high density particulate heat source and low density particulate carbon containing solid residue of pyrolysis are separated from an intermediate point of the fluidized bed and passed to a decarbonization zone, where the carbon containing solid residue of pyrolysis is decarbonized to form a high density particulate inorganic solid heat source for use as the source of heat in the pyrolysis of organic solid waste.Type: GrantFiled: August 23, 1978Date of Patent: December 16, 1980Assignee: Occidental Petroleum CorporationInventor: Charles K. Choi
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Patent number: 4206038Abstract: A fluidized catalytic cracking process wherein regenerated catalyst is stripped with an acid gas for displacing nitrogen, carbon monoxide, and other combustion gases from said regenerated catalysts, and wherein a hydrogen product of high purity and substantially free of nitrogen, carbon monoxide and other non-condensible gases is recovered from cracked vapors from said cracking process.Type: GrantFiled: June 26, 1978Date of Patent: June 3, 1980Assignee: Texaco Inc.Inventors: Randlow Smith, Henry B. Jones
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Patent number: 4176083Abstract: A stripper arrangement is provided in a regenerated catalyst standpipe for removing or displacing combustion flue gas products with fuel gas products of hydrocarbon conversion freed of hydrogen sulfide.Type: GrantFiled: August 25, 1978Date of Patent: November 27, 1979Assignee: Mobil Oil CorporationInventors: Stephen J. McGovern, Klaus W. Schatz, Fred S. Zrinscak, Sr.
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Patent number: 4149963Abstract: By manipulating the degree of stripping of the used or spent catalyst leaving the cracker, the afterburning in a regenerator is controlled both efficiently and rapidly.Type: GrantFiled: September 28, 1977Date of Patent: April 17, 1979Assignee: Phillips Petroleum CompanyInventor: Paul D. Hann
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Patent number: 4098677Abstract: A catalytic cracking process is provided in which entrained nitrogen is stripped from the regenerated cracking catalyst with a stripping gas comprising at least about 80 mole percent of carbon dioxide prior to contacting the hydrocarbonaceous feed with the regenerated catalyst.Type: GrantFiled: March 22, 1977Date of Patent: July 4, 1978Assignee: Exxon Research & Engineering Co.Inventor: Robert H. Waghorne
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Patent number: 4054509Abstract: A catalytic reactor in which feed, catalyst and diluent gas enter the bottom of a reactor which has a cross-sectional area which does not decrease substantially, preferably which has a substantially constant cross-sectional area, from the point at which catalyst and feed first come in contact to the reactor outlet. Atop the reactor is a disengagement vessel of relatively large diameter in which the product gases are separated from the catalyst. The catalyst drops through a stripper culminating in a bend which collects catalyst to provide a seal between the reactor and a regenerator. A lift line carries the catalyst to the top of the regenerator through which the catalyst moves downward to a transfer line that returns the catalyst to the reactor. Flue gases are removed from the top of the regenerator. The transfer line culminates in a bend to collect solid catalyst, providing a seal between the regenerator and the reactor.Type: GrantFiled: February 27, 1976Date of Patent: October 18, 1977Assignee: Atlantic Richfield CompanyInventor: George V. Lampadarios
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Patent number: 3992284Abstract: Methods of starting up and shutting down reactors used in hydrocracking and hydrodesulfurization of black oils. The reactor is flushed with a heavy vacuum gas oil between the circulation of the black oil feed stream and the lighter hydrocarbon stream used during the low temperature portion of the operations.Type: GrantFiled: September 17, 1975Date of Patent: November 16, 1976Assignee: UOP Inc.Inventors: Frank Stolfa, Michael D. Winfield
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Patent number: 3976433Abstract: A catalytic reactor in which feed, catalyst and diluent gas enter the bottom of a reactor which has a cross-sectional area which does not decrease substantially, preferably which has a substantially constant cross-sectional area, from the point at which catalyst and feed first come in contact to the reactor outlet. Atop the reactor is a disengagement vessel of relatively large diameter in which the product gases are separated from the catalyst. The catalyst drops through a stripper culminating in a bend which collects catalyst to provide a seal between the reactor and a regenerator. A lift line carries the catalyst to the top of the regenerator through which the catalyst moves downward to a transfer line that returns the catalyst to the reactor. Flue gases are removed from the top of the regenerator. The transfer line culminates in a bend to collect solid catalyst, providing a seal between the regenerator and the reactor.Type: GrantFiled: December 11, 1974Date of Patent: August 24, 1976Assignee: Atlantic Richfield CompanyInventor: George V. Lampadarios