Initiator Or Promoter Used With Catalyst Patents (Class 562/417)
  • Patent number: 5132450
    Abstract: A process for producing isophthalic acid by oxidation of m-xylene with an oxygen-containing gas in a hydrous acetic acid solvent in the presence of a cobalt/manganese/bromine system catalyst, the process being capable of industrially advantageously producing high-purity isophthalic acid having excellent whiteness, the process comprising (1) a step of carrying out an oxidation reaction in a main oxidation reactor under specified ranges of a catalyst concentration, a reaction temperature and an oxygen concentration in a discharge gas such that the concentration of 3-carboxybenzaldehyde becomes 500 to 10,000 ppm, (2) a step of further carrying out an oxidation reaction in a post oxidation reactor such that the concentration of 3-carboxybenzaldehyde becomes 100 to 800 ppm, separating crude isophthalic acid, evaporating remaining mother liquor and recovering acetic acid, and (3) mixing the crude isophthalic acid with purified acetic acid, stirring the resultant mixture at 100.degree. C.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: July 21, 1992
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Kazuo Tanaka, Terumasa Yoshida, Fumio Okoshi, Ichihei Motoyama, Tazuo Ohta, Toshiaki Abe
  • Patent number: 5118838
    Abstract: Substantial proportions of methyl acetate and unreacted polymethylbenzene are recovered from the waste gas produced during the oxidation of a polymethylbenzene to its corresponding polycarboxylic acid by passing the waste gas, after being cooled for removal of water vapor, through at least one bed of activated carbon and subsequently desorbing the methyl acetate and polymethylbenzene from the bed by passing a desorbing medium, such as steam, through the bed. Preferably, the cooled stream is heated to a temperature of at least 21.degree. C. (70.degree. F.) prior to being passed into the bed of activated carbon.There is also disclosed an improved process for the oxidation of a polymethylbenzene to its corresponding aromatic polycarboxylic acid, which process comprises producing the polycarboxylic acid and waste gas comprising methyl acetate, water vapor, and unreacted polymethylbenzene and treating the waste gas according to the above method.
    Type: Grant
    Filed: June 27, 1991
    Date of Patent: June 2, 1992
    Assignee: Amoco Corporation
    Inventors: Martin A. Zeitlin, David S. Hacker, Kristi A. Fjare, Diane J. Graziano, Stacey L. Kissinger
  • Patent number: 5112992
    Abstract: The addition of hafnium to oxidation catalysts provided by a heavy transition metal-bromine ion catalyst combination containing cobalt-manganese-bromine or manganese-bromine or cobalt-bromine and a soluble source of hafnium uniquely increases catalytic activity of the said catalyst combination for converting methyl groups on the benzene nucleus. The presence of hafnium in the total reactor contents is equal to or less than 250 parts per million by weight of the total reactor mother liquor. The solubility of the hafnium in the reactor solvent is such that reactor product cake contains less than 0.3 ppm by weight. Bromine emissions can be reduced.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: May 12, 1992
    Assignee: Amoco Corporation
    Inventors: Frank G. Belmonte, Kristi A. Fjare, Walter Partenheimer
  • Patent number: 5107020
    Abstract: A method is disclosed for producing trimesic acid of improved quality and at an improved yield by a process involving the liquid-phase oxidation of mesitylene in a solvent.
    Type: Grant
    Filed: December 4, 1986
    Date of Patent: April 21, 1992
    Assignee: Amoco Corporation
    Inventor: Aubrey C. Reeve
  • Patent number: 5095143
    Abstract: A method to oxidize an oxidizable component in a liquid phase with an oxygen-containing gas is disclosed. The method comprises mixing the liquid phase and gas phase in a reactor with a rotating agitator element operated at constant power.
    Type: Grant
    Filed: June 13, 1990
    Date of Patent: March 10, 1992
    Assignee: Amoco Corporation
    Inventors: Daniel L. Heberer, Paul R. Schiller, Virginia R. Seemann, Michael J. Yerkes
  • Patent number: 5091564
    Abstract: Disclosed is a process for preparing a diphenyl sulfonetetracarboxylic acid, the process comprising oxidizing a tetramethyldiphenyl sulfone with oxygen or an oxygen-containing gas in an aliphatic monocarboxylic acid having 2 to 10 carbon atoms in the presence of a catalyst consisting essentially of a cobalt component, a manganese component and a bromine compound wherein the weight ratio of manganese metal to cobalt metal is in the range of approximately 0.01 to 0.5.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: February 25, 1992
    Assignee: New Japan Chemical Co., Ltd.
    Inventors: Hiroshi Manami, Mikio Nakazawa, Shigeo Miki, Akihiro Nishiuchi
  • Patent number: 5081290
    Abstract: There is provided a process for the partial oxidation of a polymethylbenzene to the corresponding aromatic polycarboxylic acid, which process comprises contacting in a reaction zone said polymethylbenzene with molecular oxygen in the presence of an oxidation catalyst comprising at least one heavy-metal compound, said heavy-metal compound being acetate free, a source of bromine, and a non-metal acetate compound, the concentration of acetate in the reaction zone being employed to control the rate of oxidation and the selectivity of oxidation.There is also provided the catalyst that is employed in the process.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: January 14, 1992
    Assignee: Amoco Corporation
    Inventors: Walter Partenheimer, Diane J. Graziano
  • Patent number: 5068406
    Abstract: An apparatus and a method for continuously oxidizing an aromatic alkyl in the liquid phase and under oxidation reaction conditions, for the purpose of producing a desired aromatic carboxylic acid product, is disclosed. A seriatim arranged array of reactor compartments, each of which is adapted to accommodate a gaseous phase as well as a liquid phase is contemplated. Means for separately adjusting the reaction mixture composition of each reaction compartment is provided.
    Type: Grant
    Filed: August 1, 1990
    Date of Patent: November 26, 1991
    Assignee: Amoco Corporation
    Inventors: Juergen K. Holzhauer, Albert P. Brown, Aubrey C. Reeve
  • Patent number: 5068407
    Abstract: A process for the production of para-oriented dicarboxylic aromatic acids is disclosed in which an aromatic compound, having a tertiary alkyl group, is oxidized with molecular oxygen in the presence of a catalytic composition comprising a cobalt salt, a minor amount of a manganese salt, and a source of chloride in the presence of a solvent.
    Type: Grant
    Filed: January 31, 1990
    Date of Patent: November 26, 1991
    Assignee: Monsanto Company
    Inventors: Roy A. Periana, George F. Schaefer
  • Patent number: 5055612
    Abstract: A process for the preparation of naphthalene mono or polycarboxylic acids, such as 2,6-naphthalene dicarboxylic acid, is disclosed which includes oxidizing a naphthalene compound such as 2,6-diisopropylnaphthalene in a specific solvent with molecular oxygen in the presence of a catalyst containing a heavy metal compound and a bromine compound. The solvent is an aliphatic monocarboxylic acid and may further contain benzene and/or water. By controlling the ratio of the amount of catalyst metal to the feed rate of the raw material naphthalene compound, the yield of desired product can be controlled.
    Type: Grant
    Filed: December 19, 1989
    Date of Patent: October 8, 1991
    Assignees: NKK Corporation, Chiyoda Corporation
    Inventors: Yakudo Tachibana, Kazuhiko Tate, Masami Ono, Nobuhiro Takei, Jun Miki, Hiroaki Taniguchi, Yoshimi Shiroto, Misunori Shimura, Yoshio Fukui
  • Patent number: 5028737
    Abstract: An oxidation process is provided for converting dixylylpropane to isopropylidene bis(phthalic acid) in good yields with minimal by-product production, especially trimellitic acid production. The oxidation process employs an oxidation catalyst that includes zirconium as well as cobalt, manganese, and bromine.
    Type: Grant
    Filed: February 22, 1990
    Date of Patent: July 2, 1991
    Assignee: Amoco Corporation
    Inventor: Paul A. Sanchez
  • Patent number: 5008450
    Abstract: A process for exchanging a dispersing medium of a terephthalic acid slurry by introducing an aliphatic carboxylic acid slurry of terephthalic acid into a multi-stage column at the upper part thereof and introducing water at the lower part thereof to form an upflowing stream of water in the multi-stage column, while a sedimentation of terephthalic acid particles is effected, and withdrawing an aqueous aliphatic carboxylic acid solution from the upper part of the multi-stage column and an aqueous slurry of terephthalic acid from the lower part of the multi-stage column.
    Type: Grant
    Filed: December 14, 1989
    Date of Patent: April 16, 1991
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Ryoichi Yamamoto, Hiroshi Suzuki
  • Patent number: 5004830
    Abstract: A process is disclosed for liquid phase oxidation of alkyl aromatic hydrocarbons to aromatic carboxylic acids in presence of a multivalent catalyst promoted by a source of bromine. The oxidation is conducted in at least two oxidation reactions. Exothermic heat of reaction is controlled by means of a liquid phase heat exchanger to control temperature and pressure. Oxygen partial pressure in each stage is at least 1.5 psia to minimize oxygen starvation and improve selectivity. Low reactor temperature, high reactor pressure and improved selectivity improve product yield and product quality.
    Type: Grant
    Filed: November 29, 1989
    Date of Patent: April 2, 1991
    Assignee: Amoco Corporation
    Inventors: Chang M. Park, Wayne P. Schammel
  • Patent number: 4996353
    Abstract: A process for the preparation of polyphenyl dicarboxylic acids is disclosed. The process comprises contacting para,para'-diisoalkyl or dialkyl-polyphenyl or an oxidation intermediate thereof with oxygen under reaction conditions sufficient to form para,para'-polyphenyldicarboxylic acid. The process is optionally carried out in the presence of cobalt, manganese, and bromine compounds.
    Type: Grant
    Filed: May 16, 1989
    Date of Patent: February 26, 1991
    Assignee: The Dow Chemical Company
    Inventors: Guo-shuh J. Lee, Kenneth A. Burdett, Joseph J. Maj
  • Patent number: 4992579
    Abstract: A process for the manufacture of trimelitic acid from pseudocumene is disclosed. The pseudocumene is oxidized in the presence of a cerium, cobalt, manganese, and optionally zirconium, bromine catalyst wherein all of the cerium is added in the second stage of the oxidation, and wherein most of the bromine is also added during the second oxidation stage. Trimellitic acid is useful in the manufacture of polyester and polyamide-imides.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: February 12, 1991
    Assignee: Amoco Corporation
    Inventor: Wayne P. Schammel
  • Patent number: 4990659
    Abstract: A process for the manufacture of benzoic acid derivatives is described. The process is based on the reaction of a toluene derivative in a liquid phase oxidation with an oxygen containing gas in the presence of a phase-transfer catalyst (a), a transition metal salt (b) and traces of a polar solvent, such as water, the molar ratio between (a) and (b) being in the range of between 0.25:1 to 1.5:1. The phase-transfer catalyst is selected from quaternary ammonium and phosphonium salts having a total carbon atoms in the range of 17 to 58, the anion bound thereto being selected from Br.sup.-, F.sup.-, Cl.sup.-, OH.sup.-, CH.sub.3 COO.sup.- or HSO.sub.4.sup.31 . The benzoic acid derivatives produced are characterized by their very high purity and high conversion reaching generally values of above 95%.
    Type: Grant
    Filed: July 20, 1989
    Date of Patent: February 5, 1991
    Assignees: Gadot Petrochemical Industries Ltd., Yissum Research Development Company of the Hebrew University
    Inventors: Dakka Jihad, Zoran Amikam, Yoel Sasson
  • Patent number: 4952721
    Abstract: A process is disclosed for the oxidation of esters of para- and meta-methyl-substituted phenols to the corresponding aromatic carboxylic acid in the presence of a promoter comprising an anhydride of a lower aliphatic carboxylic acid and a heavy metal catalyst with or without the presence of bromine. The resulting carboxylic acids are useful in liquid crystal polymers and polymers useful in engineering plastics.
    Type: Grant
    Filed: March 8, 1989
    Date of Patent: August 28, 1990
    Assignee: Amoco Corporation
    Inventor: Kristi A. Fjare
  • Patent number: 4950786
    Abstract: A method for making 2,6-naphthalene dicarboxylic acid by the oxidation of 2,6-diisopropylnaphthalene or its oxidation derivatives in the presence of a catalyst comprising cobalt, manganese, cerium and bromine components is disclosed.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: August 21, 1990
    Assignee: Amoco Corporation
    Inventors: Paul A. Sanchez, David A. Young, George E. Kuhlmann, Walter Partenheimer, Wayne P. Schammel
  • Patent number: 4933491
    Abstract: A method for purifying a naphthalene dicarboxylic acid produced by the liquid phase oxidation of a kialkylnaphthalene or partially oxidized derivative thereof in the presence of a catalyst comprising a bromine-containing component and at least one of a cobalt- or manganese-containing component.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: June 12, 1990
    Assignee: Amoco Corporation
    Inventors: Rusins Albertins, Stephen J. Pietsch, Juergen K. Holzhauer, Hobe Schroeder
  • Patent number: 4925977
    Abstract: An improved method for the preparation of a naphthalene dicarboxylic acid by liquid-phase catalytic oxidation of a diisopropylnaphthalene in a lower fatty acid-based solvent is disclosed wherein a catalyst system comprising bromine and the heavy metals cerium, cobalt, and manganese is used. The cerium compound used as a cerium source for the catalyst can be recovered from crystals of the naphthalene dicarboxylic acid product by dissolving the crystals in an alkali solution and separating the cerium compound as insolubles from the solution.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: May 15, 1990
    Assignee: Sumikin Chemical Co., Ltd.
    Inventors: Teruaki Yamada, Yoshiji Doko, Kazuki Sugiura
  • Patent number: 4906772
    Abstract: A process is disclosed for the co-production of aliphatic monocarboxylic acids and polycarboxylic aromatic acids in high selectivity, conversion and yield. The aliphatic monocarboxylic acid can serve as a component of the solvent for the process.
    Type: Grant
    Filed: December 2, 1988
    Date of Patent: March 6, 1990
    Assignee: Amoco Corporation
    Inventors: Calvin T. Chew, Rosemary F. McMahon, Kristi A. Fjare, Wayne P. Schammel
  • Patent number: 4886906
    Abstract: A process for producing 2,6-naphthalene dicarboxylic acid which comprises oxidizing a 2-alkyl-6-acyl naphthalene with molecular oxygen-containing gas in the presence of a catalyst containing cobalt, manganese, bromine and at least one metal selected from the group consisting of iron, copper and mixtures thereof in an acetic acid solvent is disclosed.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: December 12, 1989
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Toru Tanaka, Masato Inari
  • Patent number: 4885116
    Abstract: Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.
    Type: Grant
    Filed: February 23, 1988
    Date of Patent: December 5, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: William B. Alston, Roy F. Gratz
  • Patent number: 4873366
    Abstract: Disclosed in the present invention is a process for producing 2,6-naphthalenedicarboxylic acid comprising oxidizing 2,6-diisopropylnaphthalene or its partially oxidized intermediate with molecular oxygen in a solvent containing at least 50% by weight of an aliphatic monocarboxylic acid, having not more than three carbon atoms, in the presence of a catalyst composed of (i) a heavy metal comprising cobalt and/or manganese and (ii) bromine, and a salt of an inorganic acid having an acid dissociation constant Ka smaller than 1.34.times.10.sup.-5 (at 25.degree. C.) and a vapor pressure lower than that of the aliphatic monocarboxylic acid used as the solvent. According to the process of this invention, 2,6-naphthalenedicarboxylic acid of high bulk density can be obtained in a high yield and with high purity.
    Type: Grant
    Filed: April 5, 1988
    Date of Patent: October 10, 1989
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Toshiharu Matsuda, Atsushi Sasakawa, Shoichiro Hayashi, Yutaka Konai
  • Patent number: 4855492
    Abstract: A continuous process for producing a polycarboxylic acid product is disclosed. The process comprises combining a methyl substituted aromatic hydrocarbon, an oxidation catalyst, and an oxygen-containing gaseous stream in a reaction zone to produce a reaction mixture. The oxygen-containing gaseous stream includes non-condensible gases. The reaction mixture in the reaction zone is subjected to a predetermined temperature and pressure for a predetermined residence time to produce an admixture of reactants and reaction products. The reaction products include a vapor phase and a product-containing liquid phase. Heat is removed from the product-containing liquid phase by withdrawing a portion of such liquid stream from the reaction zone and passing such reaction zone-removed portion to a heat-removal/separation zone.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: August 8, 1989
    Assignee: Amoco Corporation
    Inventor: John G. Hundley
  • Patent number: 4853479
    Abstract: An improved process for the manufacture of aromatic dicarboxylic acids and derivatives thereof is described. The process is based on the reaction of a corresponding aromatic hydrocarbon in a liquid phase oxidation with an oxygen-containing gas in the presence of a phase-transfer catalyst (a) a transition metal salt (b) and traces of a polar solvent, such as water, the molar ratio between (a) and (b) being in the range of between 0.25:1 to 1.5:1. The phase-transfer catalyst is selected from the quaternary ammonium and phosphonium salts having a total carbon atoms in the range of 17 to 58, the anion bound thereto being selected from Br.sup.-, F.sup.-, Cl.sup.-, OH.sup.-, CH.sub.3 COO.sup.- and HSO.sub.4. Among the aromatic dicarboxylic acids and derivatives thereof the following are mentioned: terephthalic acid; isophthalic acid and methyl terephthalate. The process is characterized by the very high conversion of the respective aromatic hydrocarbon reaching even 100%.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: August 1, 1989
    Assignees: Gadot Petrochemical Industries, Ltd., Yissum R & D Company of the Hebrew University of Jerusalem
    Inventors: Jihad Dakka, Amikam Zoran, Yoel Sasson
  • Patent number: 4845275
    Abstract: An improved process for the manufacture of trimellitic acid from pseudocumene feedstock is disclosed. In this process, lead (IV) is used as a catalyst component in addition to the cobalt, manganese, and zirconium catalyst. The use of lead (IV) reduces higher boiling impurities and improves the yield. In our novel process, pseudocumene is converted to trimellitic acid which is used to manufacture plasticizers and polyamide-imide polymers used as molding compounds for replacement of metals.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: July 4, 1989
    Assignee: Amoco Corporation
    Inventors: Wayne P. Schammel, Michael R. Green
  • Patent number: 4845274
    Abstract: A process for the manufacture of polycarboxylic acids is disclosed. In this novel process, antimony is used to improve the selectivity of cobalt-manganese-bromine or zirconium-cobalt-manganese-bromine oxidation system. Polymethylbenzenes such as pseudocumene are converted to their corresponding polycarboxylic acids which are used to manufacture plasticizers and polyamide-imide polymers used as molding compounds for replacement of metals.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: July 4, 1989
    Assignee: Amoco Corporation
    Inventors: Wayne P. Schammel, Michael R. Green
  • Patent number: 4827026
    Abstract: A method is disclosed for producing purified 5-t-butylisophthalic acid by the liquid-phase oxidation of 5-t-butyl-m-xylene in a solvent and in the presence of a catalyst comprising cobalt, manganese and bromine components.
    Type: Grant
    Filed: November 24, 1987
    Date of Patent: May 2, 1989
    Assignee: Amoco Corporation
    Inventors: Stephen P. Brugge, Jon J. Harper, Larry W. Autry
  • Patent number: 4794195
    Abstract: Disclosed herein is a process for producing a highly pure produce of 2,6-naphthalenedicarboxylic acid in a large quantity at a moderate price by oxidizing 2,6-diisopropylnaphthalene while using a water-soluble salt of cobalt, a water-soluble salt of maganese or a mixture thereof, a water-soluble salt of cerium and a bromine compound as the catalyst of the oxidation.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: December 27, 1988
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Shoichiro Hayashi, Toshiharu Matsuda, Atsushi Sasakawa, Yutaka Konai
  • Patent number: 4786621
    Abstract: A process is disclosed for recovery of cobalt and manganese, and other metals, in the form of their acetate salts, directly from mixed metal oxides present in oxidation residue incinerator ash comprising fly ash and clinkers from incineration of a residue from manufacture of benzene di- and tricarboxylic acids by catalytic means. These acetate salts are recycled directly for manufacture of benzene di- and tricarboxylic acids after recovery.
    Type: Grant
    Filed: June 17, 1987
    Date of Patent: November 22, 1988
    Assignee: Amoco Corporation
    Inventors: Juergen K. Holzhauer, Dennis J. Michalak, Wayne P. Schammel
  • Patent number: 4786753
    Abstract: A novel method of oxidizing di- and trimethylbenzenes with molecular oxygen to the corresponding di- or tricarboxylic acid under liquid-phase conditions is disclosed. The process is conducted at a temperature of about 100.degree. C. to 260.degree. C. This process comprises conducting the oxidation in the presence of a catalyst system comprising a source of bromine with nickel, manganese and zirconium. The benzene di- and tricarboxylic acids have wide industrial application, including the manufacture of polyesters, polyamides, and fibers and films.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: November 22, 1988
    Assignee: Amoco Corporation
    Inventors: Walter Partenheimer, Wayne P. Schammel
  • Patent number: 4716245
    Abstract: A process for producing 2,6-naphthalenedicarboxylic acid which comprises oxidizing 2,6-diisopropylnaphthalene or its oxidation derivative with molecular oxygen in a reaction medium containing at least 70% by weight of an aliphatic monocarboxylic acid selected from actic acid, propionic acid and a mixture of these in the presence of an oxidation catalyst comprising (A) at least one compound of a heavy metal element selected from cobalt and manganese and (B) bromine or a bromine compound; characterized in that said oxidation is carried out in the presence of 1.1 to 15 gram-atoms, per gram-atom of bromine, of an alkali metal.
    Type: Grant
    Filed: April 18, 1986
    Date of Patent: December 29, 1987
    Assignee: Teijin Petrochemical Industries, Ltd.
    Inventor: Isao Hirose
  • Patent number: 4625056
    Abstract: This invention relates to a method of producing benzene carboxylic acids from an aromatic material, especially coal, by the oxidation of the aromatic material in an aqueous alkaline mixture containing an aliphatic organic acid promoter agent with a source of gaseous oxygen. Use of the aliphatic organic acid promoter agent results in a surprising and unexpected increase in the benzene carboxylic acid yield which is higher than that obtained without the promoter agent.A finely divided coal, potassium carbonate, water, and aliphatic carboxylic acid promoter agent are charged to a feed tank (10) where they are mixed with an agitator (14). A slurry pump (18) pumps the mixture through a preheater (20) to an autoclave (30). Air is continuously fed to the autoclave (30) by a gas compressor (34). The coal slurry is oxidized in the autoclave (30) while being agitated by a mixer (36). Gaseous products, and in particular carbon dioxide, is continuously removed from the autoclave (30) through a vent conduit (42).
    Type: Grant
    Filed: December 19, 1979
    Date of Patent: November 25, 1986
    Assignee: Occidental Research Corporation
    Inventors: James R. Graham, John G. Huntington
  • Patent number: 4490554
    Abstract: In crystallizing and separating trimellitic acid obtained by the oxidation of dimethylbenzaldehyde or its oxidation derivative with a molecular oxygen-containing gas in an aqueous solvent in the presence of a bromine ion or a bromine ion and a heavy metallic ion catalyst, a process for crystallizing trimellitic acid wherein the crystallization is carried out with at least two crystallization vessels connected in series, of which the first vessel is kept at a temperature of 40.degree. to 130.degree. C. and at a concentration of trimellitic acid of 20 to 60 wt. %.
    Type: Grant
    Filed: December 30, 1982
    Date of Patent: December 25, 1984
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Toru Tanaka, Masanori Hataya, Kazuo Tanaka
  • Patent number: 4485247
    Abstract: A method is described for autoxidizing particular ortho-dialkyl substituted aromatic compounds using a particular type of solvent which gives rise to the formation of 3-alkanoyloxyphthalide compounds, some of which are novel.The phthalides in turn are ionically oxidized to their corresponding aromatic polycarboxylic acids.Combination of the two methods provides a means for converting ortho dialkyl substituted aromatic compounds directly to the corresponding polycarboxylic acids in higher yields and at generally lower overall temperatures and reaction conditions compared to prior art methods.Polycarboxylic acids so obtained are known to be useful in the preparation of alkyds, polyesters, and the like, and, particularly, in the formation of the corresponding acid anhydrides which are used in the preparation of organic high temperature polymers such as polyamides, polyamideimides, and polyimides.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: November 27, 1984
    Assignee: The Upjohn Company
    Inventor: Visweswara R. Durvasula
  • Patent number: 4447646
    Abstract: The present invention provides an improved process for the purification of crude terephthalic acid which has been produced by the oxidation of para-xylene. The process comprises contacting the crude terephthalic acid with oxygen-containing gas at a temperature of about 190.degree. to 230.degree. C. and a pressure of about 1,850 to 3,600 kPa in the presence of a solvent comprising an alkanoic acid which is preferably acetic acid. The process further comprises the use of a novel and surprisingly effective catalyst system. The catalyst system comprises cobalt, a bromide compound, and samarium, with the samarium being employed at a concentration of about 0.005 to 500 ppm.
    Type: Grant
    Filed: January 28, 1983
    Date of Patent: May 8, 1984
    Assignee: Eastman Kodak Company
    Inventors: Griffin I. Johnson, Judy E. Kiefer
  • Patent number: 4398037
    Abstract: Disclosed is an improvement in the process for making an aromatic carboxylic acid or its methyl ester from an aromatic compound having at least one methyl or formyl group bonded directly to a nuclear carbon atom of the aromatic ring. The process comprises effecting oxidation of said compound in the liquid phase with molecular oxygen or a gas containing the same with a catalyst comprising a heavy metal compound, and in the substantial absence of an aliphatic carboxylic acid as a solvent, whereby a reaction mixture comprising the acid is formed. If the ester is desired, the acid then is esterified with methanol. The improvement comprises carrying out the oxidation in the co-presence of a lithium compound at a concentration of 0.1-10 moles per mole of heavy metal compound. The lithium compound is at least partly soluble in the reaction mixture or reacts with an acid component of the reaction mixture to form a lithium compound soluble in the reaction mixture.
    Type: Grant
    Filed: November 9, 1981
    Date of Patent: August 9, 1983
    Assignee: Hercofina
    Inventors: Shinichi Takeda, Masao Nonobe, Kenji Ishida, Yorihiko Omoto, Tatsuro Anno
  • Patent number: 4314073
    Abstract: A substituted aromatic compound e.g. p-xylene is oxidized to an aromatic dicarboxylic acid e.g. terephthalic acid using a Co/Mn/Br catalyst in acetic acid and the slurry product is purified by treating with molecular oxygen and diluting with fresh acetic acid before separation of the terephthalic acid and mother liquor.
    Type: Grant
    Filed: June 20, 1980
    Date of Patent: February 2, 1982
    Assignee: Imperial Chemical Industries Limited
    Inventor: Graham R. Crooks
  • Patent number: 4189603
    Abstract: A process for producing terephthalic acid of high quality suitable for use in direct polymerization comprising oxidizing a para-dialkylbenzene and/or an oxidized intermediate thereof in the liquid phase with molecular oxygen or a molecular oxygen-containing gas in the presence of an oxidation catalyst containing a heavy metal in a lower aliphatic carboxylic acid solvent, the reaction being carried out in the presence of a specified amount of a phenol. Polyesters prepared from the resulting terephthalic acid have good color.
    Type: Grant
    Filed: September 20, 1978
    Date of Patent: February 19, 1980
    Assignees: Matsuyama Petrochemicals Inc., Maruzen Oil Co., Ltd.
    Inventors: Motoo Shigeyasu, Hatsutaro Yamazaki, Takehiko Kitamura