With Chemical Reaction Patents (Class 203/28)
  • Patent number: 7425247
    Abstract: This invention relates to a method for producing an aqueous solution of free hydroxylamine (HA) by simultaneous countercurrent treatment of a HA salt with ammonia or ammonia water, then separating the HA by distillation and reconcentrating the aqueous HA solution in a countercurrent with a stripping medium. The stripping medium used according to the invention is a mixture of steam and a non-condensable inert gas and the process temperature at a defined pressure is controlled by the quantity of non-condensable inert gas at the column inlet. The preferred non-condensable inert gas is nitrogen. This results in increased safety and a reduction in losses of the method for producing aqueous solutions of free HA.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: September 16, 2008
    Assignee: Domo Caproleuna GmbH
    Inventors: Norbert Leetsch, Thomas Strecker, Manfred Kretschmar, Joachim Seidler
  • Patent number: 7182840
    Abstract: The invention relates to a method and a device for the optimal use of reaction heat resulting from the production of 1,2-dichloroethane from ethene and chlorine. The aim of the invention is achieved by extracting reaction heat liberated during the reaction of chlorine with ethene and the reaction heat contained in 1,2-dichloroethane. Extraction of said reaction heat from the reaction chamber occurs using at least one part of gaseous 1,2-dichloroethane (latent heat) and at least one part of liquid 1,2-dichloroethane (feelable heat) removed from the reaction chamber. Said reaction heat is used to heat two fractioning columns in order to purify 1,2-dichloroethane of impurities having a boiling point higher than 1,2-dichloroethane.
    Type: Grant
    Filed: October 28, 2000
    Date of Patent: February 27, 2007
    Assignee: UHDE GmbH
    Inventors: Michael Benje, Peter Porscha, Stefan Von Egelstein
  • Patent number: 7179388
    Abstract: Formic acid is at least partly removed from an aqueous solution comprising formic acid, cyclohexanone and cyclohexanol by decomposition over certain decomposition catalysts. The method is preferably used for processing reaction products from the oxidation of cyclohexane and comprises: (i) extracting a product gas mixture obtained in the oxidation of cyclohexane with an aqueous scrubbing liquid, (ii) separating the aqueous solution obtained in (i) by distillation into an aqueous solution comprising formic acid, cyclohexanone and cyclohexanol together with further minor organic components and a carboxylic acid mixture (iii) removing the formic acid at least partially from the aqueous solution obtained in (ii) by decomposition, and (iv) further processing the aqueous solution obtained in (iii) to give epsilon-caprolactam, or using the aqueous solution obtained in (iii) as scrubbing liquid in (i).
    Type: Grant
    Filed: June 10, 2002
    Date of Patent: February 20, 2007
    Assignee: BASF Aktiengesellschaft
    Inventor: Thomas Nöbel
  • Patent number: 7030277
    Abstract: A process for reacting a first component with itself or a second component to produce a third component in which a first material comprising a first component or said first component and a second component is fed to divided wall column having a catalytic distillation structure in at least one of the separate vertical sections of the divided wall column where concurrently: (1) a first component alone or with a second component is contacted with a catalytic distillation structure in a distillation reaction zone thereby catalytically reacting at least a portion of the first component with itself or with the second component to form a product and (2) a first mixture comprising the first component and the product or the first component, the second component and the product; and withdrawing the product from the distillation column reactor; while within the column concurrently with the catalytic reaction and fractionation a second mixture is fractionated, which contains the first component and the product or first a
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: April 18, 2006
    Inventors: Willibrord A. Groten, Mario J. Maraschino
  • Patent number: 7014833
    Abstract: A process for reacting a first component with itself or a second component to produce a third component in which a first material comprising a first component or said first component and a second component is fed to divided wall column having a catalytic distillation structure in at least one of the separate vertical sections of the divided wall column where concurrently: (1) a first component alone or with a second component is contacted with a catalytic distillation structure in a distillation reaction zone thereby catalytically reacting at least a portion of the first component with itself or with the second component to form a product and (2) a first mixture comprising the first component and the product or the first component, the second component and the product; and withdrawing the product from the distillation column reactor; while within the column concurrently with the catalytic reaction and fractionation a second mixture is fractionated, which contains the first component and the product or first a
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: March 21, 2006
    Assignee: Catalytic Distillation Technologies
    Inventors: Willibrord A. Groten, Mario J. Maraschino
  • Patent number: 6946068
    Abstract: A process for concurrently fractionating and hydrotreating of a full range naphtha stream. The full boiling range naphtha stream, for example which is derived from fluid catalytic cracking, is first subjected to simultaneous hydrogenation of the thiophene contained therein and thioetherification and fractionation to remove the mercaptans the light fraction and then to simultaneous hydrodesulfurization and splitting of the bottoms into an intermediate boiling range naphtha and a heavy boiling range naphtha. The three boiling range naphthas are treated separately according to the amount of sulfur in each cut and the end use of each fraction.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: September 20, 2005
    Assignee: Catalytic Distillation Technologies
    Inventor: Willibrord A. Groten
  • Patent number: 6930206
    Abstract: A process for reacting a first component with itself or a second component to produce a third component in which a first material comprising a first component or said first component and a second component is fed to divided wall column having a catalytic distillation structure in at least one of the separate vertical sections of the divided wall column where concurrently: (1) a first component alone or with a second component is contacted with a catalytic distillation structure in a distillation reaction zone thereby catalytically reacting at least a portion of the first component with itself or with the second component to form a product and (2) a first mixture comprising the first component and the product or the first component, the second component and the product; and withdrawing the product from the distillation column reactor; while within the column concurrently with the catalytic reaction and fractionation a second mixture is fractionated, which contains the first component and the product or first a
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: August 16, 2005
    Assignee: Catalytic Distillation Technologies
    Inventors: Willibrord A. Groten, Mario J. Maraschino
  • Patent number: 6767517
    Abstract: An energy efficient series of mass and energy integrated reactive distillation columns and distillation columns are used to effect the production of diaryl carbonate. Utilizing the method or apparatus of the invention facilitates high diaryl carbonate production rates, and convenient recovery of unreacted starting materials and side-reaction products for recycle within the process for making diaryl carbonates or utilization in parallel reactions such as the manufacture of dialkyl carbonates. The method makes use of three reactive distillation columns and two rectification columns which are joined by a plurality of lines for transferring reactants and/or products into and out of the columns.
    Type: Grant
    Filed: April 3, 2001
    Date of Patent: July 27, 2004
    Assignee: General Electric Company
    Inventors: Philip R. de Bruin, James S. Law, Vincentius Antonius Vriens
  • Publication number: 20040024256
    Abstract: The present invention provides a process and apparatus for selectively halogenating a ketone of the formula (I) 1
    Type: Application
    Filed: July 1, 2002
    Publication date: February 5, 2004
    Inventor: Dennis E. Jackman
  • Patent number: 6583326
    Abstract: Phenol is separated from a mixture containing hydroxyacetone, cumene, water and phenol, by fractionating the mixture in a process with a fractional distillation step and a phase separation step to provide a single phenol fraction containing less than 300 ppm of hydroxyacetone. In the work-up by distillation of cleavage product mixtures, the hydroxyacetone can be removed from the cleavage product mixture together with a phenol fraction from which the hydroxyacetone has to be removed. A process can be used for purifying cleavage product mixtures obtained in the cleavage of alkylaryl hydroperoxides such as cumene hydroperoxide. The process allows separation of phenol and acetone from mixtures obtained in the cleavage of cumene hydroperoxide.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: June 24, 2003
    Assignee: Phenolchemie GmbH & Co. KG
    Inventors: Christoph Schwarz, Markus Weber, Uwe Tanger, Hermann-Josef Korte, Jochen Ullrich
  • Publication number: 20030065215
    Abstract: An object of this invention is to provide a method for producing acrylic acid that enables to suppress adverse influence of byproducts during distillation and to accomplish long-term continuous operation of the acrylic acid production apparatus. This invention is directed to a method for producing (meth)acrylic acid comprising the step of isolating (meth)acrylic acid from a liquid containing (meth)acrylic acid by distillation wherein the liquid contains glyoxal (including its hydrate) in a concentration of 0.1 mass % or less.
    Type: Application
    Filed: September 26, 2002
    Publication date: April 3, 2003
    Inventors: Kazuhiko Sakamoto, Kazuo Ohkouchi, Tomohiro Nakae
  • Publication number: 20030065224
    Abstract: A continuous process for the preparation of monoethanolamine, diethanolamine and triethanolamine by reacting ammonia and ethylene oxide in liquid phase in the presence of water as catalyst in a pressure column is proposed, where, as a result of the heat of the reaction, some of the ammonia evaporates, condenses at the head of the column and is again charged to the column, the reaction mixture at the bottom end of the pressure column is drawn off and then separated, the pressure column is constructed as a reactive distillation column (I) with evaporator at the bottom (S) and where, by means of inputting energy via the evaporator at the bottom (S), the weight ratio of monoethanolamine to diethanolamine to triethanolamine is controlled and, via the ratio of ammonia to ethylene oxide in the feed to the reactive distillation column (I), the ammonia proportion in the bottom product from the reactive distillation column (I) is controlled.
    Type: Application
    Filed: August 27, 2002
    Publication date: April 3, 2003
    Inventors: Werner Peschel, Axel Hildebrandt, Bernd Bebetaling
  • Publication number: 20030065227
    Abstract: A process for producing methyl isobutyl ketone includes introducing acetone into a catalytic distillation. Some of the acetone is converted to mesityl alcohol (‘MSO’), water and, optionally, diacetone alcohol (‘DAA’) and/or other by-products. A product stream comprising MSO, water, and, optionally, DAA, other by-products and/or unreacted acetone is withdrawn from the catalytic distillation zone. When the product stream includes DAA, other by-products and/or unreacted acetone, it is treated in a treatment zone to remove at least some of the DAA, other by-products and/or the unreacted acetone therefrom. The product stream and hydrogen are fed into a reaction zone in which MSO present in the product stream and hydrogen react to form methyl isobutyl ketone (‘MIBK’). A MIBK rich product stream is withdrawn from this reaction zone.
    Type: Application
    Filed: November 7, 2002
    Publication date: April 3, 2003
    Applicant: CATALYTIC DISTILLATION TECHNOLOGIES
    Inventors: Nelis Saayman, Grant James Lund, Sybrandus Kindermans
  • Publication number: 20020195328
    Abstract: The present invention relates to a device and method for the production of cyanuric chloride. The device has three units for the production, purification and isolation of cyanuric chloride, the second unit having a partial condensation and being set in such a way that the quantity of gaseous pure cyanuric chloride produced is greater than that of the liquid impure cyanuric chloride discharged from it.
    Type: Application
    Filed: May 13, 2002
    Publication date: December 26, 2002
    Applicant: DE GUSSA AG
    Inventors: Kurt Puschner, Stephanie Schauhoff
  • Publication number: 20020115893
    Abstract: The present invention has an object to provide a method for purifying a fluorinated hydroxyl compound of the formula 1 safely in a high yield under industrially practical conditions. Namely, a mixture containing a fluorinated hydroxyl compound of Rf—CR1R2—OH (Formula 1, wherein Rf is a C1-20 polyfluoroalkyl group, and each of R1 and R2 is a hydrogen atom or a C1-3 alkyl group) such as 2,2,3,3-tetrafluoropropanol, and a compound having an unshared electron pair, is distilled by heating in the presence of a solid acid catalyst such as a cation exchange resin catalyst, or by adding a proton source such as water.
    Type: Application
    Filed: February 20, 2002
    Publication date: August 22, 2002
    Applicant: ASAHI GLASS COMPANY LIMITED
    Inventors: Hidekazu Okamoto, Akihiro Wada, Toshihiko Toma, Nobuyuki Yamagishi
  • Patent number: 6416659
    Abstract: A process for the hydrodesulfurization of a diesel boiling range petroleum fraction wherein the hydrodesulfurization is carried out concurrently with a fractional distillation in a distillation column reactor containing a catalyst bed. The diesel is fed above the catalyst bed and hydrogen is fed below the bed. The bottoms from the distillation column reactor is then separated by fractional distillation to remove a bottoms containing most of the unconverted sulfur.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: July 9, 2002
    Assignee: Catalytic Distillation Technologies
    Inventors: Willibrord A. Groten, Mitchell E. Loescher
  • Publication number: 20020077501
    Abstract: A process for hydrolyzing an alkyl ester to produce a carboxylic acid product and an ether product, the process includes the steps of introducing into a reaction zone of a reactive distillation column a feed containing the alkyl ester wherein the reaction zone is at a temperature and pressure to preferentially produce an ether from the ester; and recovering the ether and the carboxylic acid.
    Type: Application
    Filed: October 13, 2001
    Publication date: June 20, 2002
    Inventors: Craig Alan Hoyme, Edwin Franklin Holcombe
  • Publication number: 20020028963
    Abstract: Carboxylic esters are prepared by a process, which comprises reacting dicarboxylic or polycarboxylic acids or their anhydrides with alcohols in a liquid medium with the concomitant removal of water formed by the esterification reaction by azeotropic distillation together with the alcohol in the medium, wherein the amount of liquid removed from the reaction medium by azeotropic distillation is replaced in whole or in part with the alcohol.
    Type: Application
    Filed: September 5, 2001
    Publication date: March 7, 2002
    Applicant: OXENO OLEFINCHEMIE GMBH
    Inventors: Dietmar Gubisch, Uwe Ernst, Wilfried Bueschken
  • Patent number: 6338793
    Abstract: A process for the hydrodesulfurization of a diesel boiling range petroleum fraction wherein the hydrodesulfurization is carried out concurrently with a fractional distillation in a distillation column reactor containing a catalyst bed. The diesel is fed above the catalyst bed and hydrogen is fed below the bed. The heat for the distillation is provided by the heat of reaction of the hydrodesulfurization.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: January 15, 2002
    Assignee: Catalytic Distillation Technologies
    Inventor: Hugh M. Putman
  • Patent number: 6299734
    Abstract: An aqueous solution of free hydroxylamine is prepared by treating a hydroxylammonium salt with ammonia by the countercurrent method in a stripping column by a process in which hydroxylamine is liberated and at the same time the solution obtained is separated by distillation into an aqueous hydroxylamine solution and a salt fraction. The novel process can be carried out in a simple and gentle manner and on a large scale. The danger of decomposition is minimized owing to the low thermal load, the low concentration of hydroxylamine and the short residence time in the process.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: October 9, 2001
    Assignee: BASF Aktiengesellschaft
    Inventors: Otto Watzenberger, Peter Mauer, Eckhard Ströfer, Heiner Schelling, Hans-Michael Schneider
  • Patent number: 6137023
    Abstract: The invention relates to a process for producing high purity isobutene from a hydrocarbon cut essentially comprising olefinic hydrocarbons containing 4 carbon atoms per molecule including isobutene, also butene-1 and butene-2 compounds in a ratio which substantially corresponds to the thermodynamic equilibrium. The process comprises passing the cut into a distillation zone (3) associated with a hydroisomerisation reaction zone, the bottom product of the distillation zone comprising butene-2 compounds being passed into a skeletal isomerisation zone (2) where the linear butenes are at least partially isomerised to isobutene, at least part of the principal effluent from the skeletal isomerisation zone being recycled upstream of the reactive distillation zone (3).
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: October 24, 2000
    Assignee: Institut Francais du Petrole
    Inventors: Michel Dorbon, Jean-Alain Chodorge, Jean Cosyns, Jean-Charles Viltard, Blaise Didillon
  • Patent number: 6037489
    Abstract: A method for purifying glyoxylates includes (1) a coarse distillation process in which a crude glyoxylate in which water coexists is, in a film form, continuously subjected to coarse distillation, and (2) an azeotropic dehydration process in which the crude glyoxylate purified through the coarse distillation process is subjected to azeotropic dehydration in the presence of an azeotropic agent such as propyl acetate. By this method, high-purity glyoxylates can be efficiently and easily obtained at lower costs.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: March 14, 2000
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Hideyuki Baba, Satoru Miura, Masanori Nonoguchi, Noboru Saito
  • Patent number: 5948948
    Abstract: The invention concerns a process for isomerising a feed containing essentially hydrocarbons, preferably paraffins preferably containing 5 and/or 6 carbon atoms per molecule, in which said feed is treated in a distillation zone comprising an exhausting zone and a rectification zone associated with an isomerisation reaction zone, in the presence of an isomerisation catalyst and a gas stream containing hydrogen, characterized in that the reaction zone is at least partially internal to the distillation zone, and wherein the hydrogen-containing gas is fed by a dedicated gas distributor to the bottom of at least one catalytic bed within the isomerization reaction zone.
    Type: Grant
    Filed: February 4, 1997
    Date of Patent: September 7, 1999
    Assignee: Institut Francais du Petrole
    Inventors: Etienne Lebas, Sophie Jullian, Christine Travers, Pierre Capron, Jean-Fran.cedilla.ois Joly, Michel Thery
  • Patent number: 5847249
    Abstract: A process for selectively treating the components in a multi-component stream in a distillation column reactor. Additional catalytic distillation structures are placed as a secondary bed in the distillation column, either above or below the primary bed, and the selected component withdrawn after reaction in the primary bed to prevent its entry into the secondary bed.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: December 8, 1998
    Assignee: Catalytic Distillation Technologies
    Inventor: Mario J. Maraschino
  • Patent number: 5817906
    Abstract: The present invention relates to a process for the production of light olefins comprising olefins having from 2 to 4 carbon atoms per molecule from a crude oxygenate feedstock. The crude oxygenate feedstock comprises an alcohol, and water. The process comprises passing the crude oxygenate feedstock to catalyst to a distillation with reaction zone to convert the alcohol to an ether and produce an ether product having a reduced water relative to the crude oxygenate feedstock and a first water stream. The ether product is passed to an oxygenate conversion zone containing a metal aluminosilicate catalyst to produce a light olefin stream.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: October 6, 1998
    Assignee: UOP LLC
    Inventors: Terry L. Marker, Christopher David Gosling
  • Patent number: 5779883
    Abstract: A process for the hydrodesulfurization of petroleum streams is disclosed wherein the sulfur containing petroleum stream is contacted along with hydrogen at a partial pressure of less than 70 psig in a distillation column reactor containing a hydrodesulfurization catalyst in the form of a catalytic distillation structure.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: July 14, 1998
    Assignee: Catalytic Distillation Technologies
    Inventors: Dennis Hearn, Hugh M. Putman
  • Patent number: 5763714
    Abstract: A mixed aromatic stream is hydrotreated to remove olefins and fractionated to separate C.sub.9 + heavies in a distillation column reactor and the C.sub.8 and lighter material is fed to a selective adsorption unit where the para-xylene is removed. The para-xylene depleted raffinate therefrom may be subjected to isomerization to form additional para-xylene. The effluent from the isomerization can be fed to the distillation column reactor for hydrogenation of any olefins formed during the isomerization or directly to the adsorption unit.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: June 9, 1998
    Assignee: Catalytic Distillation Technologies
    Inventors: Thomas P. Hickey, Dennis Hearn, Hugh M. Putman
  • Patent number: 5714646
    Abstract: A process for producing isopropyl alcohol by hydrating directly propylene and water in the presence of a strong acid solid catalyst which includes feeding continuously propylene, water which is the same as or more than propylene in terms of mole, and a saturated hydrocarbon (propane, butane and the like) to a reactor in which the above solid catalyst is filled or suspended, and carrying out a hydration reaction in the conditions of 50.degree. to 200.degree. C. and 60 to 250 atm while maintaining the concentration of isopropyl alcohol contained in the reaction liquid at 6 to 30 weight %, and then drawing a vapor phase out of the reactor, liquefying a part of thereof by reducing the pressure or cooling to separate vapor components, and refining crude isopropyl alcohol contained in the liquid phase to obtain refined isopropyl alcohol.
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: February 3, 1998
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Shigeru Hirata, Shinji Ogawa
  • Patent number: 5660691
    Abstract: Disclosed is an improved process for the preparation of tocotrienol/tocopherol blend concentrates from vegetable oil distillates which are enriched in tocotrienols. Tocotrienol/tocopherol blend concentrates are obtained containing 20-80% tocotrienols/tocopherols by weight, with an overall recovery of tocotrienols/tocopherols of 72% to 97%. The process is comprised first of an esterification reaction where the more volatile alcohols are converted to their less volatile fatty acid esters, followed by a series of distillation steps where components boiling higher and lower than the tocotrienols/tocopherols are separated from tocotrienols/tocopherols and other like boiling substances. Advantages of the process are that tocotrienol/tocopherol blend concentrates are produced efficiently and economically in a minimum number of steps without the use of solvents and with a relatively small capital investment.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: August 26, 1997
    Assignee: Eastman Chemical Company
    Inventors: Scott Donald Barnicki, Charles Edwan Sumner, Jr., Hampton Loyd Chip Williams, III
  • Patent number: 5507919
    Abstract: An apparatus and method are provided for the defluorination of a liquid hydrocarbon mixture, containing organic fluorides, produced during the conversion of hydrocarbons using a fluorine-containing catalyst. In one embodiment, both a thermal means and a contacting material are used to effectuate a more complete defluorination. The liquid hydrocarbon mixture is extracted from a distillation column and heated sufficiently in the thermal means to decompose at least some of the organic fluorides. The effluent from the thermal means is separated into a vaporous and a liquid effluent. The liquid effluent is passed to the bottom of the distillation column where it undergoes further defluorination through contact with the contacting material.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: April 16, 1996
    Assignee: Phillips Petroleum Company
    Inventors: Scott D. Love, Stone P. Washer
  • Patent number: 5502249
    Abstract: Disclosed is a process for the removal of iodine, including I.sub.2, I.sup.- and iodine-containing organic compounds, from acetic acid or anhydride wherein an acetyl product stream comprising (i) acetic acid or acetic anhydride and (ii) iodine, one or more iodine-containing compounds or a mixture thereof is subjected to distillation in the presence of a packing material comprising iron, nickel, copper, or an alloy thereof.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: March 26, 1996
    Assignee: Eastman Chemical Company
    Inventors: Carl F. Fillers, Jerry A. Barron, Eric D. Middlemas
  • Patent number: 5336841
    Abstract: A process is provided to remove oxygenates from a C.sub.4 raffinate stream from an MTBE plant. A back-cracking catalyst is placed into the bottom of an oxygenate removal column which will convert any MTBE or TBA contained therein back to their original components of isobutene and methanol or water. The raffinate stream is first subjected to a water wash to remove the gross amounts of methanol and DME.
    Type: Grant
    Filed: April 5, 1993
    Date of Patent: August 9, 1994
    Assignee: Chemical Research & Licensing Company
    Inventor: John R. Adams
  • Patent number: 5294305
    Abstract: The present invention is an improved process for the recovery of ethylene glycol from spent glycol generated in the manufacture of polyethylene terephthalate. The spent glycol typically consists of metal oxide catalyst residues, low molecular weight terephthalate oligomers, diethylene glycol and other trace impurities. The improved process of the present invention is based on the principle that elevating the temperature of the spent glycol increases the solubility of the low molecular weight oligomers so that the low molecular weight oligomers can be dissolved in the ethylene glycol and further that the spent glycol at an elevated temperature may be passed through an ion exchange bed to remove metal oxide catalysts, color forming impurities and other trace impurities.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: March 15, 1994
    Assignee: Mobile Process Technology, Inc.
    Inventors: Frank S. Craft, Sr., Michael D. Kelly
  • Patent number: 5284969
    Abstract: A process for the continuous catalyst-free production of polyisocyanates by thermal decomposition of the N-substituted carbamic acid esters corresponding to the polyisocyanates, in which the carbamic acid esters to be decomposed, in the form of a 5 to 90% by weight solution in an inert high-boiling solvent, are heated to a temperature of 100.degree. to 400.degree. C. and are subsequently introduced with expansion as a sidestream into a distillation column (4), in the sump of which a pressure of 0.001 to 5 bar and a temperature of 150.degree. to 400.degree. C. are maintained so that the high boiler is kept boiling in the sump, and the decomposition products are simultaneously condensed continuously and selectively at the head of the distillation column. The high boiler, which optionally contains impurities, is continuously removed via the sump outlet in a quantity substantially corresponding to the quantity of high boiler introduced into the column as solvent for the carbamic acid ester.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: February 8, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Andreas Hauner, Hans-Joachim Hennig
  • Patent number: 5246722
    Abstract: Concentrates of natural coloring agents such as carotene are prepared from organic media, particularly from palm oil, by a process in which the oil, together with a volatile solvent, is subjected to gel permeation chromatography. The concentrated coloring agent may then be used in food products such as margarine and ice cream.
    Type: Grant
    Filed: May 1, 1991
    Date of Patent: September 21, 1993
    Assignee: Unilever Patent Holdings B.V.
    Inventors: Anthonie Kunst, Marcellinus J. J. Hakkaart
  • Patent number: 5183538
    Abstract: A method for recovering a liquid diluent having a low salt content from an organic/aqueous mixture which contains significant quantities of the diluent, an alkali metal salt, and water comprises an integrated process which joins extraction and ion exchange steps and a reaction for the conversion of an alkali metal hydroxide. In the initial step the diluent is extracted from the original mixture employing a suitable extractant material. The extract from the initial step containing diluent, extractant material, along with reduced quantities of water and salt, is passed to an ion exchange column for conversion of the alkali metal salt to its hydroxide. In a following fractional distillation dewatering column the diluent begins to react with the alkali metal hydroxide to form an alkali-metal salt of aminocarboxylic acid which can pass harmlessly through the dewatering column for removal in further following fractional distillation step.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: February 2, 1993
    Assignee: Phillips Petroleum Company
    Inventors: Lacey E. Scoggins, Fu M. Lee, Allen T. Chang, Wiley D. Perkins
  • Patent number: 5122235
    Abstract: Disclosed herein is a process for removing chloroprene by subjecting chloroprene-containing 1,2-dichloroethane to heat treatment at a temperature in the range of from the boiling point (85.degree. C.) of 1,2-dichloroethane to the thermal cracking temperature (300.degree. C.) of 1,2-dichloroethane. In particular, the process can be suitably applied to a liquid distillate from a low-boiling material separation column in a step in which 1,2-dichloroethane used as a raw material for production of vinyl chloride is purified by using a fractionation column.
    Type: Grant
    Filed: August 10, 1990
    Date of Patent: June 16, 1992
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Kenji Shirai, Seiji Nagae, Tadashi Naito, Atsushi Shirai
  • Patent number: 5108551
    Abstract: The present invention provides a method for purifying alkanolamine solutions which have lost at least a portion of their acid gas sorption capacity due to degradation of the alkanolamine into heat stable salts. Particularly, it has been found that the alkanolamine solution may be rejuvenated by charging the solution to the feed zone of a distillation column reactor at temperatures above about 160.degree. C. and pressure of less than about 2000 mm Hg.
    Type: Grant
    Filed: December 17, 1990
    Date of Patent: April 28, 1992
    Assignee: Mobil Oil Corporation
    Inventor: Tsoung Y. Yan
  • Patent number: 4973698
    Abstract: 2,3-Difluoro-5-(trifluoromethyl)pyridine is prepared by contacting a 2,3-dihalo-5-(trifluoromethyl) pyridine with an effective amount of KF or CsF in a polar aprotic solvent (diluent) at an elevated temperature under substantially anhydrous conditions with removal of the difluoropyridine products essentially as they are formed. The starting material may optionally be added as the reaction proceeds to minimize decomposition. The reaction is also optionally conducted in the presence of an acid scavenger and/or a crown ether or other phase-transfer catalyst.
    Type: Grant
    Filed: January 23, 1989
    Date of Patent: November 27, 1990
    Assignee: The Dow Chemical Company
    Inventors: John C. Little, Charles A. Wilson
  • Patent number: 4944847
    Abstract: A method of inhibiting fouling in distillation towers, overhead lines, reflux lines, and condensers operating in a process to manufacture and purify epichlorohydrin. This method resides in treating process streams entering or exiting such towers, lines and condensers, including feed streams, reflux streams, gaseous or liquid overhead streams, with an effective antifouling amount of a C.sub.3 -C.sub.9 linear or branched alkyl substituted catechol, or mixtures thereof.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: July 31, 1990
    Assignee: Nalco Chemical Company
    Inventor: Karis W. Snow
  • Patent number: 4867849
    Abstract: There is disclosed an improved process for the manufacture of glyoxylic acid obtained by oxidation of glycolic acid. For processing purposes alkyl esters of these acids are employed. Increased efficiency is obtained by recovering glycolate rich streams from one or more distillation operations and after treatment to remove acetic acid by-product the streams are recycled to the oxidation reaction.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: September 19, 1989
    Inventors: Dario R. Cova, John M. Thorman
  • Patent number: 4778882
    Abstract: An apparatus and a method for carrying out the dehydration reaction to produce a high boiling compound comprises charging a raw material and an organic solvent into a circulating system including a reactor, a preheater and an evaporator to cause the chemical dehydration reaction, drawing water, formed as a result of the dehydration reaction, together with the solvent in the form of vapor, compressing the vapor, effecting a heat exchange between the compressed vapor and the evaporator, dehydrating the compressed vapor by condensation, removing the dehydrated water out of the system, and returning the remaining solvent to the reactor.
    Type: Grant
    Filed: October 17, 1985
    Date of Patent: October 18, 1988
    Assignee: Takeda Chemical Industries, Ltd.
    Inventors: Youichi Oka, Masao Yokoyama, Toshiaki Dairaku
  • Patent number: 4765869
    Abstract: A continuous process is described for the production of a substantially acid free dialkyl maleate, for example diethyl maleate, from a feed stream containing a major amount of dialkyl maleate and a minor amount of the corresponding monoalkyl maleate. This comprises continuously distilling the feed stream in a primary distillation zone, which can comprise a single distillation column or a series of distillation columns connected in series, so as to give (i) a bottom fraction containing monoalkyl maleate and dialkyl maleate in admixture, (ii) a vaporous fraction comprising alkanol, and (iii) an intermediate fraction that is substantially free from alkanol and comprises a major proportion of diethyl maleate and a minor proportion of maleic anhydride. The intermediate fraction (iii) is redistilled in a secondary distillation zone to yield (i) an overhead fraction containing maleic anhydride and (ii) a bottom fraction containing substantially acid free dialkyl maleate.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: August 23, 1988
    Assignee: Davy McKee (London) Limited
    Inventors: Norman Harris, Colin Rathmell, Keith Turner, John Scarlett
  • Patent number: 4727161
    Abstract: A process for producing an indole which comprises reacting an aniline and a diol in the presence of a catalyst to produce a reaction mixture containing the indole, unreacted aniline and by-products, condensing the reaction mixture to obtain a liquid reaction product, recovering the unreacted aniline from the liquid reaction product, reducing the contents of specified by-products in the recovered aniline below specified levels and reutilizing the resulting recovered aniline. To reduce the contents of the specified by-products in the recovered aniline below specified levels, it is preferred to subject the liquid reaction product or an aniline fraction separated therefrom to a heat-treatment and then to distillation. In the above manner, the recovered aniline can be reutilized in the reaction without causing the activity of the catalyst to deteriorate.
    Type: Grant
    Filed: November 15, 1985
    Date of Patent: February 23, 1988
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Atsuyoshi Yamauchi, Seiya Iguchi, Yuzo Ono, Hiroshii Kimura, Satoshi Morita
  • Patent number: 4522688
    Abstract: The process gives highly pure cyclopentadiene and methylcyclopentadiene from a cracked gasoline fraction. The merit of the process is that cyclopentadiene and methylcyclopentadiene are recovered by adding a simple distillation system to a conventional cracked gasoline treating plant without altering the plant and operating conditions thereof. An internal reflux stream is withdrawn from the stripping section of a BTX column of a conventional cracked gasoline treating plant, and is sent to a depolymerization-distillation column operated at a bottom temperature of 160.degree.-230.degree. C. The overhead stream of the column is sent to a cyclopentadiene column operated at a bottom temperature of 160.degree.-230.degree. C. Cyclopentadiene is recovered from the overhead of the column, and the bottom stream is sent to methylcyclopentadiene column operated at a bottom temperature of 170.degree.-210.degree. C. Methylcyclopentadiene is recovered from the overhead of the column.
    Type: Grant
    Filed: October 26, 1983
    Date of Patent: June 11, 1985
    Assignee: Maruzen Petrochemical Co., Ltd.
    Inventors: Akira Yokogawa, Asao Takahashi, Isao Maruyama, Takao Hosaka
  • Patent number: 4519875
    Abstract: Ethylene glycol is purified, particularly for fiber-grade applications, by removal of the residual ethylene carbonate from which the glycol was derived. The effluent from a reactor in which ethylene carbonate is hydrolyzed to ethylene glycol is distilled to produce a lower-boiling fraction comprising substantially ethylene glycol and water and a higher-boiling fraction comprising substantially ethylene glycol, higher glycols, and concentrated in hydrolysis catalyst. The higher-boiling fraction is recirculated to reflux against the lower-boiling product, thereby essentially completing the hydrolysis of unreacted ethylene carbonate thereby reducing the ethylene carbonate content of the ethylene glycol to very low levels suitable for fiber-grade applications.
    Type: Grant
    Filed: May 9, 1984
    Date of Patent: May 28, 1985
    Assignee: The Halcon SD Group, Inc.
    Inventors: Mitchell Becker, Howard M. Sachs
  • Patent number: 4482775
    Abstract: A method for isomerizing isobutene or n-butene to produce a mixture of isobutene and normal butene, and polymerizing at least a portion thereof to produce isobutene/n-butene codimer, which comprieses feeding at least 80 weight % of either the isobutene or n-butene to a catalytic distillation reactor containing a fixed bed acidic cation exchange resin catalyst packing which provides both the catalyst sites and distillation sites for the reaction products, isomerizing a portion of the isobutene or n-butene to produce a mixture of isobutene and n-butene and reacting at least a portion of the isobutene and n-butene to form codimer of isobutene and n-butene, whereby an overhead fraction containing any unreacted isobutene and n-butene and a bottoms fraction containing codimer is produced. The result of the reaction is substantially the same regardless whether the feed is isobutene or n-butene. Other aspects of the invention, include combinations of procedures to produce high purity isobutene and n-butene.
    Type: Grant
    Filed: September 22, 1982
    Date of Patent: November 13, 1984
    Assignee: Chemical Research & Licensing Company
    Inventor: Lawrence A. Smith, Jr.
  • Patent number: 4454358
    Abstract: Ethanol is produced continuously via the carbonylation of methanol, by(a) carbonylating methanol, in a reactor R, in the presence of a carbonyl complex of a metal of group VIII of the periodic table and of a halogen compound,(b) separating, in a distillation column D1, the reactor discharge, into a top fraction comprising methyl acetate, methanol, dimethyl ether and an organohalogen compound, and into a bottom fraction comprising water, small quantities of acetic acid and the catalyst, if the latter is not in a fixed bed, the residence time being so adjusted that the greater part of the acetic acid reacts with the methanol present to give methyl acetate,(c) separating the top fraction from D1, in a distillation column D2, into a top fraction comprising small quantities of methyl acetate, methanol, dimethyl ether and the organo-halogen compound, and a bottom fraction comprising methyl acetate and methanol, and recycling the top fraction to reactor R,(d) distilling off, via the top of distillation column D3, th
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: June 12, 1984
    Assignee: BASF Aktiengesellschaft
    Inventors: Rudolf Kummer, Volker Taglieber, Heinz-Walter Schneider
  • Patent number: 4420376
    Abstract: An improved process for recovering high purity resorcinol produced by the rearrangement of m-diisopropylbenzene dihydroperoxide in which the rearranged product mixture is neutralized, the neutralized mixture being filtered, the filtrate being admixed with toluene, the acetone being removed by distillation and the acetone-free rearranged product/toluene mixture being steam distilled to provide an aqueous resorcinol containing phase from which the resorcinol is recovered.
    Type: Grant
    Filed: August 23, 1982
    Date of Patent: December 13, 1983
    Assignee: The Goodyear Tire & Rubber Company
    Inventor: Ward J. Burkholder
  • Patent number: 4391677
    Abstract: A process is disclosed for producing a substantially sulphur-free, butene-1 rich stream from a butene-containing C.sub.4 hydrocarbon feed stream by passage through a desulphurization zone, e.g. successive beds of active alumina and zinc oxide, and then distilling it. The desulphurization zone adsorbs, absorbs or converts to higher boiling sulphurous compounds low boiling sulphurous impurities such as H.sub.2 S, COS and CH.sub.3 SH. A sulphur-free butene-1 rich stream is recovered overhead from the distillation zone, while a butene-2 rich stream containing higher boiling sulphurous impurities originally present or produced in the desulphurization zone is recovered as a bottom product. A dechlorination zone (containing, for example, a charge of copper impregnated active carbon) can be provided upstream or downstream from the desulphurization zone but upstream from the distillation zone or can be provided in the path of the butene-1 rich stream from the distillation zone.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: July 5, 1983
    Assignee: Davy McKee (Oil & Chemicals) Limited
    Inventors: Norman Harris, John F. Flintoff, John W. Kippax