With Condensation Of Second Stage Vapors Patents (Class 208/105)
  • Patent number: 9683182
    Abstract: A process for making high cetane diesel. The process includes contacting a distillate feedstock in a hydrodenitrogenation and polyaromatics saturation zone and passing the resulting treated effluent to a high pressure stripping zone. The stripped liquid fraction from the high pressure stripping zone is contacted with a base metal catalyst under monoaromatics saturation conditions to yield a reactor product. The reactor product undergoes a separation to provide a hydrogen portion and a dearomatized distillate portion with the hydrogen portion being recycled and introduced into the high pressure stripping zone.
    Type: Grant
    Filed: May 19, 2014
    Date of Patent: June 20, 2017
    Assignee: SHELL OIL COMPANY
    Inventors: John Anthony Smegal, Aristides Macris, Yvonne Johanna Lucas
  • Patent number: 8568584
    Abstract: A method is described for controlling instability of operation in a de-ethanizer tower (13) in the gas recovery unit in fluid catalytic cracking units and delayed coking units. The method comprises the step of intervening in the de-ethanizer tower (13) when instability occurs in it, and adjusting the material balance of water in such a way that the excess of water in the feed load stream (9) is removed only as an azeotrope. The intervention is performed by introducing into the feed load stream (9) of the de-ethanizer tower (13) a volume fraction (18) of a flow of hydrocarbon, which may be either dry hydrocarbons or hydrocarbons with a low level of water content.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: October 29, 2013
    Assignee: Petroleo Brasileiro S.A.-Petrobras
    Inventors: Mario de Sousa Almeida, Neyde Alexandra Fraga Marques, Francisco Carlos da Costa Barros, Claudine Toledo Alvares da Silva Costa
  • Patent number: 7858834
    Abstract: A method for utilizing a feed comprising condensate and crude oil for an olefin production plant is disclosed. The feed is subjected to vaporization and separated into vaporous hydrocarbons and liquid hydrocarbons. The vaporous hydrocarbons stream is thermally cracked in the plant. The liquid hydrocarbons are recovered.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: December 28, 2010
    Assignee: Equistar Chemicals, LP
    Inventor: Donald H. Powers
  • Patent number: 7591940
    Abstract: A catalytic hydrocracking process for the production of ultra low sulfur diesel wherein a hydrocarbonaceous feedstock is hydrocracked at elevated temperature and pressure to obtain conversion to diesel boiling range hydrocarbons. The resulting hydrocracking zone effluent is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the hydrocracking zone to produce a first gaseous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. The first gaseous hydrocarbonaceous stream containing diesel boiling range hydrocarbons is introduced into a desulfurization zone and subsequently partially condensed to produce a hydrogen-rich gaseous stream and a second liquid hydrocarbonaceous stream containing diesel boiling range hydrocarbons. At least a portion of the first liquid stream is thermal cracked to produce diesel boiling range hydrocarbons. An ultra low sulfur diesel product stream is recovered.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: September 22, 2009
    Assignee: UOP LLC
    Inventor: Tom N. Kalnes
  • Patent number: 7479217
    Abstract: The invention concerns a process for treating a hydrocarbon feed comprising a series of a first upstream process for hydrocarbon hydroconversion comprising at least one reaction chamber, the reaction or reactions occurring inside said chambers and employing at least one solid phase, at least one liquid phase and at least one gas phase, and a second downstream steam reforming process comprising at least one reaction chamber, characterized in that the said upstream process is carried out in a “slurry” and/or an ebullated bed mode and in that the downstream process comprises a first step for at least partial conversion of hydrocarbons heavier than methane into methane, termed the pre-reforming step, and in that the reaction or reactions occurring inside the chambers of the downstream stream reforming process enables the production of a reagent, namely hydrogen, which is necessary for the reactions in the first upstream process.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: January 20, 2009
    Assignee: Institut Francais du Petrole
    Inventors: Mathieu Pinault, Thierry Gauthier, Stéphane Kressmann, Arnault Selmen
  • Patent number: 7452458
    Abstract: Process for treatment of a hydrocarbon feedstock that comprises a hydrocarbon-containing liquid phase and hydrogen, in which the feedstock is separated under a pressure P1 into a liquid L1 and a gas G1, that is compressed and brought into contact with a portion of L1 under a pressure P2>2×P1 to recover a liquid L2 and a hydrogen-rich gas G2; L2 is fractionated to obtain a stabilized liquid L4a that is free of LPG and lighter products, a liquid stream of LPG, and a gas stream G4 that is recycled, and in which one of gas streams: recompressed G1 and G4 is in counter-current contact with an unstabilized liquid AL that is obtained from or extracted from L1 or L2, whereby this unstabilized liquid is supercooled by at least 10° C. below its bubble point at pressure P2.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: November 18, 2008
    Assignee: Institute Francais du Petrole
    Inventors: Eric Sanchez, Béatrice Fischer
  • Patent number: 7396449
    Abstract: A method for utilizing natural gas condensate as a feedstock for an olefin production plant wherein the feedstock is subjected to vaporization and separation conditions that remove light hydrocarbons from the condensate for thermal cracking in the plant, and leave liquid distillate for separate recovery.
    Type: Grant
    Filed: March 1, 2006
    Date of Patent: July 8, 2008
    Assignee: Equistar Chemicals, LP
    Inventor: Donald H. Powers
  • Patent number: 7285697
    Abstract: A process for cracking hydrocarbon feedstock comprising at least one sulfur-containing compound comprising: heating the feedstock and a peroxide-containing compound, mixing the heated feedstock and peroxide-containing compound with a fluid and/or a primary dilution steam stream to form a mixture, flashing the mixture to form a vapor phase and a liquid phase which collect as bottoms and removing the liquid phase, separating and cracking the vapor phase, and cooling the product effluent, wherein the oxidized sulfur-containing species are removed as bottoms
    Type: Grant
    Filed: July 16, 2004
    Date of Patent: October 23, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventor: Paul F. Keusenkothen
  • Patent number: 7132044
    Abstract: A device comprising at least one absorber, at least one cold separator from which is extracted a gaseous phase that feeds the absorber, at least one recycling to said cold separator of at least a portion of liquid effluent that is obtained from the absorber and which is mixed with the feedstock, at least one heat exchanger for cooling the mixture prior to the recycling, at least one conduit for recovering a light hydrocarbon-enriched liquid fraction obtained from the cold separator and at least one conduit for evacuating gases from the absorber, said device being useable for the treatment of a hydrogen-rich gas or for the recovery of a hydrocarbon-enriched liquid.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: November 7, 2006
    Assignee: Institut Francais du Petrole
    Inventors: Larry Mank, Laurent Watripont, Bruno Domergue
  • Patent number: 7087153
    Abstract: A catalytic hydrocracking process for the production of ultra low sulfur diesel wherein a hydrocarbonaceous feedstock is hydrocracked at elevated temperature and pressure to obtain conversion to diesel boiling range hydrocarbons. The resulting hydrocracking zone effluent is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the hydrocracking zone to produce a first gaseous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. The first gaseous hydrocarbonaceous stream containing diesel boiling range hydrocarbons is introduced into a desulfurization zone and subsequently partially condensed to produce a hydrogen-rich gaseous stream and a second liquid hydrocarbonaceous stream containing diesel boiling range hydrocarbons. At least a portion of the first liquid stream is thermal cracked to produce diesel boiling range hydrocarbons. An ultra low sulfur diesel product stream is recovered.
    Type: Grant
    Filed: February 4, 2003
    Date of Patent: August 8, 2006
    Assignee: UOP LLC
    Inventor: Tom N. Kalnes
  • Patent number: 7074321
    Abstract: An integrated hydrocarbon conversion process for the production of low sulfur fuels utilizing a hydrocracking zone, a diesel hydrodesulfurization zone, a fluid catalytic cracking zone and a gasoline hydrodesulfurization zone. The hydrocracking zone is used to convert at least a portion of the feedstock into diesel boiling range hydrocarbons which are desulfurized in the first hydrodesulfurization zone. The unconverted feedstock is introduced into a fluid catalytic cracking zone to produce gasoline boiling range hydrocarbons which are desulfurized in a second hydrodesulfurization zone.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: July 11, 2006
    Assignee: UOP LLC
    Inventor: Tom N. Kalnes
  • Patent number: 7005057
    Abstract: A catalytic hydrocracking process for the production of ultra low sulfur diesel wherein a hydrocarbonaceous feedstock is hydrocracked at elevated temperature and pressure to obtain conversion to diesel boiling range hydrocarbons. The resulting hydrocracking zone effluent is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the hydrocracking zone to produce a first gaseous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. The first gaseous hydrocarbonaceous stream containing diesel boiling range hydrocarbons is introduced into a desulfurization zone and subsequently partially condensed to produce a hydrogen-rich gaseous stream and a second liquid hydrocarbonaceous stream containing diesel boiling range hydrocarbons. At least a portion of the first liquid stream is separated in a dividing wall column to produce a liquid hydrocarbonaceous stream containing diesel boiling range hydrocarbons which is also introduced into the desulfurization zone.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: February 28, 2006
    Assignee: UOP LLC
    Inventor: Tom N. Kalnes
  • Patent number: 6787026
    Abstract: This invention is directed to a process for hydroprocessing vacuum gas oils and other feeds in order to produce unconverted oil suitable for use as base oil feed for white oils, Group III oils, and BMCI (Bureau of Mines Correlation Index) ethylene plant feed. Ammonia, hydrogen sulfide, and light products are removed from the first stage at high pressure in order to produce a higher quality of unconverted oil that is suitable for Group III base oils.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: September 7, 2004
    Assignee: Chevron U.S.A. Inc.
    Inventor: Darush Farshid
  • Patent number: 6787025
    Abstract: In the refining of crude oil, vacuum gas oil hydrotreaters and hydrocrackers are used to remove impurities such as sulfur, nitrogen, and metals from the crude oil. Typically, the middle distillate boiling material (boiling in the range from 250° F.-735° F.) from VGO hydrotreating or moderate severity hydrocrackers does not meet the smoke point, the cetane number or the aromatic specification. In most cases, this middle distillate is separately upgraded by a middle distillate hydrotreater or, alternatively, the middle distillate is blended into the general fuel oil pool or used as home heating oil. With this invention, the middle distillate is hydrotreated in the same high pressure loop as the vacuum gas oil hydrotreating reactor or the moderate severity hydrocracking reactor.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: September 7, 2004
    Assignee: Chevron U.S.A. Inc.
    Inventors: Ujjal Kumar Mukherjee, Wai Seung W. Louie, Arthur J. Dahlberg
  • Publication number: 20030111387
    Abstract: In the refining of crude oil, vacuum gas oil hydrotreaters and hydrocrackers are used to remove impurities such as sulfur, nitrogen, and metals from the crude oil. Typically, the middle distillate boiling material (boiling in the range from 250° F.-735° F.) from VGO hydrotreating or moderate severity hydrocrackers does not meet the smoke point, the cetane number or the aromatic specification. In most cases, this middle distillate is separately upgraded by a middle distillate hydrotreater or, alternatively, the middle distillate is blended into the general fuel oil pool or used as home heating oil. With this invention, the middle distillate is hydrotreated in the same high pressure loop as the vacuum gas oil hydrotreating reactor or the moderate severity hydrocracking reactor.
    Type: Application
    Filed: December 17, 2001
    Publication date: June 19, 2003
    Inventors: Ujjal Kumar Mukherjee, Wai Seung W. Louie, Arthur J. Dahlberg
  • Patent number: 6517705
    Abstract: A catalytic hydrocracking process for the production of lube base oil wherein a hydrocarbonaceous feedstock is contacted with hydrogen and a metal promoted hydrocracking catalyst in a hydrocracking reaction zone at elevated temperature and pressure to obtain conversion to higher hydrogen-content hydrocarbons including lube base oil. The resulting hot, uncooled effluent from the hydrocracking reaction zone is hydrogen stripped in a hot, high pressure stripping zone maintained at essentially the same pressure as the hydrocracking zone to produce a first gaseous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. At least a portion of the first gaseous hydrocarbonaceous stream is condensed to produce a second liquid hydrocarbonaceous stream and a second hydrogen-rich gaseous stream. The first liquid hydrocarbonaceous stream is preferably separated at a pressure greater than atmospheric pressure to provide at least one lube base oil product stream.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: February 11, 2003
    Assignee: UOP LLC
    Inventors: Tom N. Kalnes, Vasant P. Thakkar
  • Patent number: 6296758
    Abstract: A hydrocracking process wherein a hydrocarbonaceous feedstock and a hot hydrocracking zone effluent containing hydrogen is passed to a denitrification and desulfurization reaction zone to produce hydrogen sulfide and ammonia to thereby clean up the fresh feedstock. The resulting hot, uncooled effluent from the denitrification and desulfurization zone is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the preceding reaction zone with a hydrogen-rich gaseous stream to produce a vapor stream comprising hydrogen, hydrocarbonaceous compounds boiling at a temperature below the boiling range of the fresh feedstock, hydrogen sulfide and ammonia, and a liquid hydrocarbonaceous stream.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: October 2, 2001
    Assignee: UOP LLC
    Inventors: Tom N. Kalnes, Vasant P. Thakkar
  • Patent number: 6190536
    Abstract: Processes and apparatus for providing improved catalytic cracking, specifically improved recovery of olefins, LPG or hydrogen from catalytic crackers. The improvement is achieved by passing part of the wet gas stream across membranes selective in favor of light hydrocarbons over hydrogen.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: February 20, 2001
    Assignee: Membrane Technology and Research, Inc.
    Inventors: Kaaeid A. Lokhandwala, Richard W. Baker
  • Patent number: 6096191
    Abstract: A catalytic hydrocracking process wherein a hydrocarbonaceous feedstock and a liquid recycle stream having a temperature greater than about 500.degree. F. and saturated with hydrogen is contacted with hydrogen and a metal promoted hydrocracking catalyst in a hydrocracking reaction zone at elevated temperature and pressure to obtain conversion to lower boiling hydrocarbons. The resulting hot, uncooled effluent from the hydrocracking reaction zone is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the hydrocracking zone to produce a first gaseous hydrocarbonaceous stream and a first liquid hydrocarbonaceous stream. At least a portion of the first gaseous hydrocarbonaceous stream is condensed to produce a second liquid hydrocarbonaceous stream and a second hydrogen-rich gaseous stream. At least a portion of the first liquid hydrocarbonaceous stream is recycled to the hydrocracking reaction zone.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: August 1, 2000
    Assignee: UOP LLC
    Inventor: Tom N. Kalnes
  • Patent number: 5980729
    Abstract: A hydrocracking process wherein a hydrocarbonaceous feedstock and a hot hydrocracking zone effluent containing hydrogen is passed to a denitrification and desulfurization reaction zone to produce hydrogen sulfide and ammonia to thereby clean up the fresh feedstock. The resulting hot, uncooled effluent from the denitrification and desulfurization zone is hydrogen stripped in a stripping zone maintained at essentially the same pressure as the preceding reaction zone with a hydrogen-rich gaseous stream to produce a vapor stream comprising hydrogen, hydrocarbonaceous compounds boiling at a temperature below the boiling range of the fresh feedstock, hydrogen sulfide and ammonia, and a liquid hydrocarbonaceous stream.
    Type: Grant
    Filed: September 29, 1998
    Date of Patent: November 9, 1999
    Assignee: UOP LLC
    Inventors: Tom N. Kalnes, Vasant P. Thakkar
  • Patent number: 5647972
    Abstract: A method of processing a cracked gas feedstream containing hydrogen and C.sub.1 to C.sub.6 and heavier hydrocarbons is described using a relatively low pressure as compared to conventional cryogenic separation processes. At pressures below 27 bars, the feedstream is dried and cooled in a series of steps to initially separate out essentially all of the C.sub.6 and heavier hydrocarbons forming a vapor stream containing the hydrogen, the C.sub.1 to C.sub.3 hydrocarbons and at least some of the C.sub.4 and C.sub.5 hydrocarbons. The C.sub.4 and C.sub.5 components act as an absorption liquid to lower the light ends partial pressure permitting the condensation of C.sub.2 and C.sub.3 components at higher temperature levels and permitting the operation at lower pressures. The vapor stream is then further cooled and separated in another series of steps and processed in a demethanizer column in a manner to provide a high pressure hydrogen and methane overhead product and a high recovery of C.sub.2 and C.sub.
    Type: Grant
    Filed: January 5, 1995
    Date of Patent: July 15, 1997
    Assignee: ABB Lummus Global Inc.
    Inventors: Steven I. Kantorowicz, Stephen J. Stanley, David M. Wadsworth, Rene C. L. Warner
  • Patent number: 5558767
    Abstract: A method of converting a hydrocarbon feed with a catalyst and regenerating the catalyst by contact with an oxygen-containing stream is disclosed. The hydrocarbon conversion process employs a purification zone that purifies a net gas stream and that also removes water from a circulating regeneration gas stream. This method is useful for the regeneration of reforming catalysts comprising L-zeolite.
    Type: Grant
    Filed: December 29, 1994
    Date of Patent: September 24, 1996
    Assignee: UOP
    Inventor: Charles T. Ressl
  • Patent number: 5453177
    Abstract: An integrated three-column process for recovering hydrocarbon distillate products from a hydroprocessing or hydrocracking reactor effluent stream and a hydrocarbon distillate product recovery train are disclosed. According to the present recovery process, an effluent stream from the cracking reactor is cooled and separated into light and heavy phase streams. The heavy phase stream is depressurized and stripped of light end components in a steam stripping column. The light phase stream is further cooled to separate a liquid stream which is combined with the light ends from the stripper and fed to a debutanizer. A C.sub.4 -rich light end stream taken overhead from the debutanizer is condensed to produce LPG product stream(s). A C.sub.4 -lean heavy end stream removed from the bottoms of the debutanizer is combined with a heavy end bottoms stream from the stripper and fed to a fractionator for fractionation into product distillate streams such as light and heavy naphtha, jet fuel, diesel oil, and the like.
    Type: Grant
    Filed: January 27, 1994
    Date of Patent: September 26, 1995
    Assignee: The M. W. Kellogg Company
    Inventors: Kenneth W. Goebel, Michael G. Hunter
  • Patent number: 5360533
    Abstract: A FCC product recovery section operates at greater efficiency by recovering separate riser product streams and reactor product streams and quenching and absorbing lighter, more valuable hydrocarbon products from the reactor product stream in separate quench and absorption vessels. The quench and absorbtion vessels are intergrated with a main fractionator and gas concentration section of a typical FCC product recovery section. Heavy hydrocarbons, clarified oil and/or cycle oil absorb hydrocarbons from the reactor product stream in the quench and absorption vessels and return the absorbed products to the main fractionator while net gasoline product from the reactor product stream enter the primary absorber of the gas concentration section. This arrangement is particularly useful in increasing the product recovery capacity of an existing FCC product separation section.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: November 1, 1994
    Assignee: UOP
    Inventors: Constante P. Tagamolila, Edward C. Haun, David A. Lomas, Joseph E. Zimmermann
  • Patent number: 5360535
    Abstract: In an ebullated bed process reactor effluent is subjected to high pressure followed by intermediate flash separation. An ebullation liquid is formed by educting high pressure flash separation liquid into an intermediate flash separation liquid. The ebullation liquid is recycled to the reactor to expand the catalyst bed to 110 vol % to 200 vol % of a settled catalyst bed volume. As a result of recycle pressure balance is advantageously maintained. Carry over catalyst and catalyst fines are recycled to the reactor and kept out of downstream equipment.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: November 1, 1994
    Assignee: Texaco Inc.
    Inventors: Edward K. Liu, Doyun Kim, Ting Y. Chan
  • Patent number: 4931165
    Abstract: A catalytic hydrocracking process which comprises: (a) contacting a hydrocarbonaceous feedstock having a propensity to form heavy polynuclear aromatic compounds and a liquid recycle stream in a hydrocracking zone to convert a substantial portion of the hydrocarbonaceous components in the feedstock to lower boiling products; (b) recovering a hydrocarbon effluent from the hydrocracking zone and partially condensing the hydrocarbon effluent from the hydrocracking zone and separating the same into a lower boiling hydrocarbon product stream and an unconverted hydrocarbon stream having at least a portion boiling above about 400.degree. F. (204.degree. C.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: June 5, 1990
    Assignee: UOP
    Inventor: Tom N. Kalnes
  • Patent number: 4925573
    Abstract: Process for separating a mixed-phase hydrocarbonaceous effluent originating from the conversion of a hydrocarbonaceous feedstock in the presence of hydrogen at elevated temperature and pressure in a multiple separator system, which effluent contains hydrogen, normally liquid hydrocarbonaceous components and normally gaseous hydrocarbonaceous components by(i) separating in a first separation zone the effluent into a first liquid phase (L1) and a first vapor phase (V1),(ii) cooling the first vapor phase obtained to a temperature in the range between 25.degree. and 85.degree. C.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: May 15, 1990
    Assignee: Shell Internationale Research Maatschappij, B.V.
    Inventor: Sotiris Vorlow
  • Patent number: 4058449
    Abstract: Process for hydrocracking a petroleum hydrocarbon charge contaminated with nitrogenous compounds, comprising the hydrogenation of said charge in a first reaction zone followed with a separation in two phases, gaseous and liquid, of the resulting hydrogenated product, adding to said liquid phase the effluent from a subsequent prefractionation zone, treating the resulting mixture in a second reaction zone, adding to the effluent of said second reaction zone the above-mentioned gaseous phase, treating the resulting effluent in said prefractionation zone and separating therefrom a liquid fraction, at least one portion of which is recycled to said second reaction zone and a gaseous fraction which, after cooling is separated into a gas of high hydrogen content and a liquid effluent containing products converted in at least one reaction zone, said products being separated by fractionation.
    Type: Grant
    Filed: May 21, 1976
    Date of Patent: November 15, 1977
    Assignees: Institut Francais du Petrole, BASF Aktiengesellschaft
    Inventors: Ortwin Reitz, Jean-Pierre Retoret
  • Patent number: 4003822
    Abstract: Separation of the catalyst-containing product effluent from a fluid catalytic cracking unit is effected in the main column by a technique which involves removing a light naphtha fraction as the single overhead stream and separately withdrawing a heavy naphtha fraction as a lower side-cut. The latter is stripped of light naphtha (for recycle to the main column) and recovered as a product stream. Preferably a portion of the heavy naphtha fraction (as withdrawn) is cooled and combined with the light naphtha overhead reflux stream.
    Type: Grant
    Filed: January 26, 1976
    Date of Patent: January 18, 1977
    Assignee: UOP Inc.
    Inventor: Hong-Kyu Jo
  • Patent number: 3996129
    Abstract: A reaction product effluent, containing hydrogen, normally gaseous hydrocarbons and normally liquid hydrocarbons, is separated into desired component streams in a system which incorporates a low-pressure flash zone, a debutanizer and a deethanizer. The net overhead vaporous product from the deethanizer is introduced into the flash zone, the liquid phase from which serves as a portion of the feed to the debutanizer. Preferably, the net overhead vaporous product from the debutanizer is also introduced into the flash zone.
    Type: Grant
    Filed: May 12, 1975
    Date of Patent: December 7, 1976
    Assignee: Universal Oil Products Company
    Inventor: James D. Weith