And Substantially Complete Oxidation Of Carbon Monoxide To Carbon Dioxide Within Regeneration Zone Patents (Class 502/42)
  • Patent number: 5110775
    Abstract: A two-stage process and apparatus for the regeneration of fluidized catalytic cracking (FCC) catalyst is disclosed. A primary regenerator, a single dense bed with a spent catalyst inlet, a source of oxygen-containing gas, a flue gas outlet and a regenerated catalyst outlet, is supplemented with a secondary regenerator. The secondary regenerator has its own source of air for combustion and takes particles from a lower portion of the dense bed in the primary regenerator. Combustion gases, and some solids, are discharged from the secondary regenerator into the primary regenerator. Hot, decoked material is withdrawn from the base of the secondary regenerator for use in the catalytic cracking reaction. Preferably, a dense, fast settling additive is used with a conventionally sized FCC catalyst. These two materials can be added together to the primary regenerator and separated by elutriation therein into two catalyst phases.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: May 5, 1992
    Assignee: Mobil Oil Corporation
    Inventor: Hartley Owen
  • Patent number: 5106799
    Abstract: A process and apparatus for fluidized bed combustion using a dense phase combustion zone over a dilute phase combustion zone. When used to regenerate FCC catalyst containing coke with relatively large amounts of NO.sub.x precursors, the catalyst is added to and partially regenerated in the dense phase zone and then falls down into the dilute phase zone. Most of the combustion air is added to the dilute phase and rises into and fluidizes the dense phase zone. NO.sub.x formed in the dilute phase is reduced to N.sub.2 in the dense phase.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: April 21, 1992
    Assignee: Mobil Oil Corporation
    Inventors: Gary J. Green, Tsoung Y. Yan
  • Patent number: 5077251
    Abstract: A process for controlled, multi-stage regeneration of FCC catalyst is disclosed. A modified high efficiency catalyst regenerator, with a fast fluidized bed coke combustor, dilute phase transport riser, and second fluidized bed regenerates the catalyst in at least two stages. The primary stage of regeneration is in the coke combustor. Second stage catalyst regeneration occurs in the second fluidized bed. The amount of combustion air added to, and conditions in, the coke combustor are controlled to limit CO combustion, while the second stage of regeneration, in the second fluidized bed, achieves complete CO combustion. Controlled multi-stage regeneration reduces steaming or deactivation of catalyst during regeneration, increase coke burning capacity, and reduces NOx emissions.
    Type: Grant
    Filed: July 17, 1990
    Date of Patent: December 31, 1991
    Assignee: Mobil Oil Corporation
    Inventors: Hartley Owen, Paul H. Schipper
  • Patent number: 5043517
    Abstract: Process for the continuous conversion of light olefin gas feed containing ethene, propene and butene to produce heavier hydrocarbons by contacting the light olefin feed in a fluidized bed reaction zone with a medium pore molecular sieve zeolite catalyst under oligomerization conditions to convert the light olefin feed to heavier hydrocarbons. The catalytic reaction causes the conversion of the light olefins to heavier hydrocarbons, the deposition of coke by-product on the catalyst and the absorption of hydrocarbon product on the catalyst. The deposited coke causes the partial deactivation of the catalyst. A portion of the partially deactivated catalyst containing deposited coke and absorbed hydrocarbon product is continuously withdrawn from the reaction zone and transferred to a catalyst stripping zone in which the catalyst is contacted with an inert stripping gas to remove the absorbed hydrocarbons from the catalyst.
    Type: Grant
    Filed: October 30, 1989
    Date of Patent: August 27, 1991
    Assignee: Mobil Oil Corporation
    Inventors: James H. Haddad, Mohsen N. Harandi, Hartley Owen
  • Patent number: 5037538
    Abstract: Oxides of nitrogen (NO.sub.x) emissions from an FCC regenerator are reduced by adding a DeNO.sub.x catalyst to the FCC regenerator in a form whereby the DeNO.sub.x catalyst remains segregated within the FCC regenerator. This permits use of a DeNO.sub.x catalyst without regard to the effect of the DeNO.sub.x catalyst on the catalytic cracking reaction. Floating hollow spheres, or catalyst fines, containing the DeNO.sub.x catalyst are preferred.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: August 6, 1991
    Assignee: Mobil Oil Corporation
    Inventors: Arthur A. Chin, Jonathan E. Child, Paul H. Schipper
  • Patent number: 5013425
    Abstract: A method of converting a side by side FCC arrangement adds a new reactor vessel and uses the regenerator vessel and reactor vessel to provide a regeneration section having at least three stages of regeneration that is used as part of an enlarged FCC process. In simplest form, the conversion method calls for the use of the regeneration vessel as a first-stage regeneration zone, the use of the reactor vessel as a second-stage regeneration zone, and the use of the spent catalyst stripper as a third stage of regeneration. This arrangement provides a second stage of regeneration that is positioned to facilitate the addition of partially regenerated catalyst to the stripping zone to facilitate the operation of a hot catalyst stripping section.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: May 7, 1991
    Assignee: UOP
    Inventor: Ismail B. Cetinkaya
  • Patent number: 5011592
    Abstract: A process for controlled, multi-stage regeneration of FCC catalyst is disclosed. A modified high efficiency catalyst regenerator, with a fast fluidized bed coke combustor, dilute phase transport riser, and second fluidized bed regenerates the catalyst in at least two stages. The primary stage of regeneration is in the coke combustor, at full CO oxidation conditions. The second stage of catalyst regeneration occurs in the second fluidized bed, at partial CO combustion conditions. The process permits regeneration of spent FCC catalyst while minimizing NOx exmissions and achieving significant reduction of SOx.
    Type: Grant
    Filed: July 17, 1990
    Date of Patent: April 30, 1991
    Assignee: Mobil Oil Corporation
    Inventors: Hartley Owen, Paul H. Schipper
  • Patent number: 5006495
    Abstract: An FCC catalyst regeneration technique in which the catalyst is regenerated in a dense bed regenerator. Regenerator effluent gases are collected from different parts of the regenerator vessel in a common collection zone and passed through the catalyst separation cyclones from the common collection zone. Removal of nitrogen oxides from the regeneration effluent gases is enhanced by passing spent cracking catalyst through the effluent gases from a secondary spent catalyst inlet in the upper part of the regeneration vessel. Coke on the spent catalyst effects a reduction of nitrogen oxide (NOx) species in the effluent gases to nitrogen.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: April 9, 1991
    Assignee: Mobil Oil Corporation
    Inventors: David A. Pappal, Michael S. Sarli
  • Patent number: 5002654
    Abstract: A process for regeneration of cracking catalyst while minimizing NO.sub.x emissions is disclosed. A zinc-based DeNO.sub.x catalyst is present in an amount and in a form which reduces NO.sub.x emissions. Relatively small amounts of zinc oxides impregnated on a separate support having little or no cracking activity are preferred. The zinc NO.sub.x reduction catalyst can be a separate particle additive, or can be made in situ by adding a solution or dispersion of zinc or a compound thereof to the cracking unit, or to the hydrocarbon feed to the cracking unit.
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: March 26, 1991
    Assignee: Mobil Oil Corporation
    Inventor: Arthur A. Chin
  • Patent number: 4997800
    Abstract: A process for fluidized bed catalyst regeneration while minimizing emissions of NOx. The process uses a single, dense phase fluidized bed of particles wherein a combustible substance is burned to produce heat and a flue gas containing CO, CO2, O2 and NOx. A CO combustion promoter, present in an amount sufficient to increase the combustion of CO to CO2 in the dense bed, is disposed on particles having a settling velocity which is smaller than the settling velocity of the particles in the dense phase fluidized bed. CO combustion promoter segregates in the dense phase fluidized bed so that a majority of the combustion promoter is present in an upper one half of the dense bed. Maintaining a reducing atmosphere in the lower one half of the dense bed converts at least a portion of the NOx produced during combustion to nitrogen in the reducing atmosphere. Preferably an external means is provided to recover entrained CO combustion promoter from fines generated in the fluidized bed.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: March 5, 1991
    Assignee: Mobil Oil Corporation
    Inventor: Jonathan E. Child
  • Patent number: 4994424
    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.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: February 19, 1991
    Assignee: Mobil Oil Corporation
    Inventors: Tiberiu M. Leib, Ajit V. Sapre
  • Patent number: 4988432
    Abstract: A process for regeneration of cracking catalyst while minimizing NO.sub.x emissions is disclosed. A DeNOx additive is present in an amount and in a form which reduces NO.sub.x emissions, but does not passivate metals (such as Ni and V) deposited on the catalyst during the cracking reaction nor CO combustion promoter which may be present. Relatively small amounts of antimony oxides impregnated on a separate support having little or no cracking activity are preferred.
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: January 29, 1991
    Assignee: Mobil Oil Corporation
    Inventor: Arthur A. Chin
  • Patent number: 4980052
    Abstract: Emission of noxious nitrogen oxides with the flue gas from the regenerator of a fluid catalytic cracking plant are reduced by incorporating into the circulating inventory of cracking catalyst separate additive particles that contain a copper-loaded zeolite. A particularly effective additive is provided by ion-exchanging ZSM-5 zeolite with cupric ion. With such preferred additive, CO emissions also are reduced, and the recovered gasoline has enhanced octane number.
    Type: Grant
    Filed: November 3, 1989
    Date of Patent: December 25, 1990
    Assignee: Mobil Oil Corporation
    Inventors: Gary J. Green, David S. Shihabi, Tsoung Y. Yan
  • Patent number: 4968404
    Abstract: In a fluid catalytic cracking process, coke is burned from spent catalyst at elevated temperature in a vertically arranged regenerator vessel. The regenerator vessel contains a lower, dense phase oxidation zone to which spent catalyst is introduced and an upper, dilute phase oxidation zone. Catalyst is fluidized and oxidized by means of air which is introduced in an amount of 5 vol % to 15 vol % to a lower air distributor at the bottom of the dense phase zone. Spent catalyst is discharged above the lower air distributor. The balance of the air is distributed in a horizontal plane in the dense phase above the catalyst discharge. As a result, a substantial proportion of the coke and carbon monoxide is burned in the dense phase zone at a lower temperature. A reduced amount of carbon monoxide is carried over to the dilute phase where higher temperature oxidation occurs.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: November 6, 1990
    Assignee: Texaco Inc.
    Inventors: Henry C. Chan, Gary E. Collier
  • Patent number: 4965232
    Abstract: A catalyst regeneration process effected in an apparatus which comprises two regeneration chambers, a heat exchanger, means for withdrawing from the second chamber a controlled fraction of hot catalyst for the purpose of maintaining the temperature in that chamber substantially at a first desirable value of less than 950.degree. C., and preferably at 910.degree. C., means for transferring this fraction of hot catalyst to the heat exchanger for the purpose of cooling it, means for the discharge of the cooled catalyst from the heat exchanger and the reinjection of the cooled catalyst into the first chamber, and means, controlled by the means for measuring the temperature in the first chamber, for regulating the supply of combustion fluid to the first chamber for the purpose of maintaining said temperature substantially at a second desired value lower than 730.degree. C. and preferably ranging from 650.degree. to 710.degree. C.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: October 23, 1990
    Assignees: Compagnie de Raffinage et de Distribution Total France, Institut Francais du Petrole
    Inventors: Jean-Louis Mauleon, Jean-Bernard Siguad, Renaud Pontier, Frederic Hoffmann
  • Patent number: 4959334
    Abstract: A process for the regeneration of a catalyst by combustion of the coke deposited thereon during a hydrocarbon conversion reaction in which process more than 50 percent of the coke is burned in at least one regeneration chamber operating with a fluidized bed, wherein the upper portion of the fluidized bed the suspension of catalyst particles in said chamber is slowed down due to a substantial increase in the diameter of the regeneration chamber so that the superficial velocity of the rising fluids which no longer contain any oxygen is reduced to a value ranging from 0.5 to 1.5 meters/second, that is, to a value corresponding to the fluidization conditions in a dense fluidized bed.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: September 25, 1990
    Assignee: C. Compagnie de Raffinage et de Distribution
    Inventors: Jean-Louis Mauleon, Jean-Bernard Sigaud
  • Patent number: 4904372
    Abstract: An improved fluidized catalytic cracking-catalyst regeneration process for catalytically cracking heavy hydrocarbon feedstocks is provided which comprises first and second, relatively lower and higher temperature, catalyst regeneration zones, wherein CO-rich effluent flue gas from the first regeneration zone is combusted in a CO-incinerator/combustor means to substantially convert all CO present therein to CO.sub.2. The effluent gas from the CO-incinerator/combustor is then combined with the effluent flue gas from the second regeneration zone, with the combined streams thereafter being sent to an expansion turbine-compressor means to recover the work energy therefrom and to provide at least all the compressed air requirements of the first and second regeneration zones, and preferably in addition the compressed air requirements of the CO-incinerator/combustor means.
    Type: Grant
    Filed: November 18, 1988
    Date of Patent: February 27, 1990
    Assignee: Stone & Webster Engineering Corporation
    Inventor: Alan R. Goelzer
  • Patent number: 4851374
    Abstract: A continuous regenerator for the two-stage regeneration of hot coked fluid catalytic cracking catalyst, and a method for regenerating coked catalyst by combustion with air and with reduced emissions of nitrogen oxides, or with reduced emissions of any two or more of the pollutants which include nitrogen oxides, sulfur oxides and carbon monoxide.
    Type: Grant
    Filed: May 29, 1987
    Date of Patent: July 25, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Tsoung Y. Yan, Gary J. Green
  • Patent number: 4843050
    Abstract: Catalytic regenerators, nozzle designs and processes suitable for introducing regeneration air into a catalytic cracking unit which substantially reduce erosion induced nozzle failures include at least one nozzle which has at least one planar surface generally parallel to the nozzle's longitudinal axis.
    Type: Grant
    Filed: November 24, 1987
    Date of Patent: June 27, 1989
    Assignee: Phillips Petroleum Company
    Inventors: William C. Rahlwes, Kelly G. Knopp
  • Patent number: 4843051
    Abstract: An FCC catalyst regeneration technique in which the catalyst is regenerated in a dense bed regenerator. Regeneration effluent gases are collected from different parts of the regenerator vessel in a common collection zone and passed through the catalyst separation cyclones from the common collection zone. The cyclones may be arranged with their inlet horns adajcent one another in the common collection zone or a cyclone inlet manifold with a common inlet may be connected to the cyclone inlets. The inlet port to the manifold may be extended to form an elongated vertical duct through which regeneration effluent gases and entrained catalyst pass from the dilute phase of the dense bed to the cyclone so that mixing of the effluent gases is promoted to ensure combustion in residual quantities of oxygen present in the effluent gases before the gases enter the cyclones. Improved operating flexibility is obtained together with a reduced likelihood of cyclone damage as a result of localized high temperature excursions.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: June 27, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Richard C. Kovacs, Frederick J. Krambeck, Michael S. Sarli
  • Patent number: 4822761
    Abstract: A process for upgrading residual portions of crude oils comprising metal contaminants and Conradson Carbon contributing components by the combination of thermal visbreaking with fluid inert solids and catalytic upgrading of naphtha and higher boiling components of thermal visbreaking in separate systems of riser conversion and solids regeneration is discussed. Heat management of the regeneration systems is restricted in substantial measure by a novel external solids heat exchange apparatus arrangement utilized to partially cool hot regenerated solids utilized in the solids regeneration systems.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: April 18, 1989
    Assignee: Ashland Oil, Inc.
    Inventors: Paul W. Walters, Lloyd E. Busch, Oliver J. Zandona
  • Patent number: 4812431
    Abstract: Coke is removed from particulate catalyst by passing the coke-containing catalyst into a regenerator containing a fluidized dense bed of catalyst. An oxygen containing gas is added to the regenerator to burn coke from catalyst. The dense bed has a reducing atmosphere in its lower half because most of the CO promoter catalyst present in the regenerator is in the upper half of the dense bed. Nitrogen oxides formed during coke combustion are at least partially reacted to form free nitrogen in the CO-rich atmosphere within the lower-half of the regenerator dense bed. A CO combustion promotor, e.g., platinum on alumina, having a low density, or small size is preferred as it concentrates near the upper portion of the regenerator dense bed. The process is especially useful in FCC regenerators for minimizing the NO.sub.x content of the flue gas, however, it is applicable to any fluidized bed combustion process.
    Type: Grant
    Filed: August 12, 1987
    Date of Patent: March 14, 1989
    Assignee: Mobil Oil Corporation
    Inventor: Jonathan E. Child
  • Patent number: 4812430
    Abstract: An FCC regenerator comprising a first dense bed coke combuster, a dilute phase transport riser, and a second dense bed operates with selective addition of CO combustion catalyst downstream of the coke combustor and preferably into the dilute phase transport riser. The process and apparatus permits maintenance of a reducing atmosphere in the first dense bed, which promotes conversion of NO.sub.x compounds to nitrogen within the FCC regenerator. Coke can be burned in the first dense bed, the transport riser, or the second dense bed, so that the average catalyst temperature and steaming severity is reduced.
    Type: Grant
    Filed: August 12, 1987
    Date of Patent: March 14, 1989
    Assignee: Mobil Oil Corporation
    Inventor: Jonathan E. Child
  • Patent number: 4753907
    Abstract: Solids e.g. catalysts are separated from suspensions in gases e.g. products from catalytic cracking of crude oil fractions a discharging of suspensions against a surface positioned above the outlet of a riser conduit through which the suspensions are flowing and collecting the displaced gases for passage to cyclones.
    Type: Grant
    Filed: September 20, 1985
    Date of Patent: June 28, 1988
    Assignee: Ashland Oil, Inc.
    Inventors: Oliver J. Zandona, Paul W. Walters, Roger M. Benslay
  • Patent number: 4614726
    Abstract: In a process apparatus for the regeneration of fluid cracking catalyst, the catalyst is cooled in an exchanger mounted to the lower side of the regenerator and cool catalyst is returned to the regenerator by means of gas lift.
    Type: Grant
    Filed: June 21, 1985
    Date of Patent: September 30, 1986
    Assignee: Ashland Oil, Inc.
    Inventors: Paul W. Walters, H. Anthony Raiche, Ronald L. Harness, Genaro M. Quodala
  • Patent number: 4542114
    Abstract: A unique process arrangement is disclosed wherein the effluent flue gas from the removal of hydrocarbonaceous coke from particulate matter by combustion in a mixture of pure oxygen diluted with carbon dioxide is processed to provide a carbon dioxide-rich recycle gas stream to be mixed with oxygen as regenerator feed gas; and a net combustion product stream from which are recovered SO.sub.x and NO.sub.x to eliminate atmospheric emissions, and a pure CO.sub.2 product for export. An alternate embodiment also produces hydrogen or synthesis gas for export.
    Type: Grant
    Filed: April 13, 1984
    Date of Patent: September 17, 1985
    Assignee: Air Products and Chemicals, Inc.
    Inventor: William P. Hegarty
  • Patent number: 4539303
    Abstract: An improved process for recovering energy via an expander turbine axial flow gas compressor set which utilizes hot regeneration gas recovered from the regeneration of fluidized catalytic cracking catalyst, and during turndown conditions when the output of the gas compressor is required to be increased by an excess amount to prevent surge and the excess amount is normally vented to the atmosphere prior to entering the regenerator to prevent afterburn, the process including the steps of:(1) adjusting air compressor air rate set point to at least 10% above surge; thereby(2) increasing air rate to an amount in excess of regeneration requirement;(3) flowing all air compressed to the regenerator;(4) by use of complete combustion catalyst, oxidizing essentially all coke to carbon dioxide,(5) driving the expander with all the hot flue gas produced and thereby;(6) driving the motor-generator thereby generating electricity.
    Type: Grant
    Filed: December 7, 1983
    Date of Patent: September 3, 1985
    Assignee: Texaco Inc.
    Inventors: John P. MacLean, Joel S. Bittensky, James H. Colvert
  • Patent number: 4521389
    Abstract: NO.sub.x in flue gas from a regenerator in which an SO.sub.2 oxidation promoter is present is controlled by mixing ammonia with flue gas and passing the mixture through a combustion zone.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: June 4, 1985
    Assignee: Chevron Research Company
    Inventors: William A. Blanton, Jr., William L. Dimpel
  • Patent number: 4458022
    Abstract: A process for manufacturing molecular sieving carbon is disclosed, wherein pelletized charcoal made of coconut shell charcoal powder and coal tar is washed with dilute mineral acid solution, then a specified amount of coal tar is added, penetrated therein, followed by heat treatment under a particular range of temperature, and cooling in inert gas.
    Type: Grant
    Filed: May 17, 1983
    Date of Patent: July 3, 1984
    Assignee: Kuraray Chemical Co., Ltd.
    Inventors: Takushi Ohsaki, Susumu Abe
  • Patent number: 4453323
    Abstract: Disclosed is a method, a system and an improved butterfly valve usable therein for recovering energy from a continuous supply of hot pressurized particulate-laden flue gas. This gas is conducted to the atmosphere via a selected one of a plurality of ducts equipped with separate purgable butterfly cut-off valves each located upstream both from the point of gas disposal to the atmosphere and from separate energy recovery devices. Each duct has provision downstream from an associated cut-off valve for insertion of a slip blind crosswise of that duct after closure of the cut-off valve thereby permitting servicing operations on the energy recovery device deactivated by the closed valve or valves. One or more of the recovery devices is usable to supply operating power for components of the system or to other equipment.
    Type: Grant
    Filed: October 26, 1981
    Date of Patent: June 12, 1984
    Inventor: Nicholas Nassir
  • Patent number: 4436613
    Abstract: A two-stage cascade flow fluid catalytic cracking process capable of converting high molecular weight hydrocarbons containing catalyst poisons into products of lower molecular weight with high activity cracking catalyst susceptible to catalyst poisons, the cascade flow process resulting in higher yields of desired motor fuel fractions than those obtainable with conventional riser flow fluid catalytic cracking processes. Catalyst poisons, e.g.
    Type: Grant
    Filed: December 3, 1982
    Date of Patent: March 13, 1984
    Assignee: Texaco Inc.
    Inventors: Scott M. Sayles, Leonce F. Castagnos, Jr., Charles H. Schrader, Edward W. Dillingham, Richard P. Scott, deceased
  • Patent number: 4435282
    Abstract: An improved fluid catalytic cracking process comprises a method for the regeneration of the fluidizable hydrocarbon conversion catalyst, particularly of the molecular sieve type, which has been deactivated with coke deposits while employed in a hydrocarbon catalytic cracking process, in which the coke-containing hydrocarbon conversion catalyst is contacted with an oxygen-containing gas to burn the coke from the catalyst under conditions providing substantially complete combustion of carbon monoxide and substantially complete combustion of the coke on the catalyst. In the regenerator, particles of the hydrocarbon conversion catalyst are in association with particles of a platinum group metal or rhenium oxidation catalyst which promotes the combustion of carbon monoxide to carbon dioxide. The catalyst composite contains a mixture of cracking catalyst particles and particles having the platinum group metal or rhenium oxidation catalyst supported on a substrate.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: March 6, 1984
    Assignee: Standard Oil Company, (Indiana)
    Inventors: Ralph J. Bertolacini, William L. Forsythe, Jr.
  • Patent number: 4434147
    Abstract: Sulfur oxide and nitrogen oxide control by use of a sulfur sorbent and sulfur dioxide oxidation promoter in the regenerator and downstream removal of nitrogen oxides by selective catalytic reduction using ammonia injection and trapped cracking catalyst fines.
    Type: Grant
    Filed: June 10, 1982
    Date of Patent: February 28, 1984
    Assignee: Chevron Research Company
    Inventors: William L. Dimpfl, William A. Blanton