And Return Of Distillation Product To A Previous Distillation Zone Patents (Class 203/75)
  • Patent number: 4305790
    Abstract: The recovery of alcohol from fermentation liquors is accomplished by the evaporation of the liquor feed and simultaneous rectification of the volatile component. Evaporation of the liquor feed can be accomplished by a single flash evaporation or multiple effect evaporation combined with the flash evaporation in which the flash evaporator is one effect of the multiple effect evaporator. A concentrated alcohol component is recovered along with a concentrated residue useful as a fertilizer or animal feed supplement.
    Type: Grant
    Filed: January 31, 1980
    Date of Patent: December 15, 1981
    Inventor: Edward F. Kramer, Sr.
  • Patent number: 4302298
    Abstract: Process for isolating methyl tert-butyl ether contained in the reaction product of methanol with a C.sub.4 hydrocarbon cut containing isobutene, comprising fractionating said reaction product by introducing it at an intermediate point of a distillation zone, recovering methyl tert-butyl ether at the bottom thereof and, at the top thereof, a mixture of C.sub.4 hydrocarbons with methanol which is washed with water and condensed and wherefrom is separated a condensed C.sub.4 hydrocarbon fraction, a portion of which is fed back as reflux to the top of the distillation zone and another portion discharged, and separating the remaining water-methanol mixture by distillation.
    Type: Grant
    Filed: February 22, 1980
    Date of Patent: November 24, 1981
    Assignee: Institut Francais du Petrole
    Inventors: Paul Mikitenko, Lionel Asselineau
  • Patent number: 4299667
    Abstract: A process for recovering pure benzene from hydrocarbon mixtures containing the same and non-aromatic compounds which are gaseous and difficultly condensible is described in which the feedstock is fed to an initial distillation column operated at atmospheric or sub-atmospheric pressure. Overhead comprising benzene and non-aromatics is obtained and a portion thereof condensed. The condensible material is in part returned to the distillation column and in part subjected to extractive distillation to recover pure benzene. Those components which did not condense, i.e. the non-condensible and difficultly condensible components and entrained aromatics are fed to a reflux vessel such as a scrubber, stripper, or the like for recovery of any benzene or other valuable components which might be soluble in a selective solvent and used for such recovery. The selective solvent can be the same solvent used for the extractive distillation.
    Type: Grant
    Filed: July 28, 1980
    Date of Patent: November 10, 1981
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Helmut Klein, Kamar P. John
  • Patent number: 4294666
    Abstract: A process for the manufacture of 4,4'-diphenylmethane diisocyanate and a mixture of diphenylmethane diisocyanate isomers containing a controllable amount of uretdione and hydrolizable chlorine which comprises feeding crude MDI to an evaporator, condensing a head fraction in two stages in the presence of an inert gas, feeding the first stage condensate to a distillation column, producing a mixture of diphenylmethane diisocyanate isomers as an overhead, producing 4,4'-diphenylmethane diisocyanate as a side draw, and condensing each of the overhead and side draw in two stages in the presence of an inert gas.
    Type: Grant
    Filed: August 15, 1980
    Date of Patent: October 13, 1981
    Assignee: BASF Aktiengesellschaft
    Inventors: Hans J. Astheimer, Horst Brandtstaedter, Rainer Ohlinger, Willy Van Pee, Jaak Van Steen, Friedrich Sauer, Rudolf Schmidt, Siegfried Krueger
  • Patent number: 4282389
    Abstract: A process for the simultaneous manufacture of pure methyl tertiary butyl ether (MTBE) and a substantially isotubene-free mixture of C.sub.4 -hydrocarbons, by reacting the isobutene contained in the mixture of C.sub.4 -hydrocarbons with excess methanol in the liquid phase at elevated temperatures on strongly acid, macroporous, organic ion exchange resins.The process has the following steps:(a) methanol and isobutene are reacted in a molar ratio of 2:1 to 5:1 at temperatures between and C.;(b) the unconverted hydrocarbons are then removed as the top product under a pressure of 2 to 10 bars from a first rectification column;(c) the bottom product from this first column is rectified in a second column under normal pressure or under a slight excess pressure of up to 2 bars at the top of the column, the bottom product of this rectification is recycled to reaction zone (a), if necessary, after separating off a portion of the tertiary butanol formed and the C.sub.
    Type: Grant
    Filed: December 4, 1979
    Date of Patent: August 4, 1981
    Assignee: Chemische Werke Huls A.G.
    Inventors: Wilhelm Droste, Fritz Obenaus
  • Patent number: 4278505
    Abstract: A process of recovering an n-hexane product which is free from aromatic compounds by extractive distillation from a mixture of aromatic and non-aromatic compounds. The mixture is fed to and distilled in a first distillation column, from which a benzene-containing sump product and the overhead product consisting of non-aromatic compounds are withdrawn. The distillate is laterally withdrawn above the feeding point of the feed mixture and transferred to the upper portion of a second distillation column. The hexane cut is withdrawn as sump product from the second distillation column and fed to an extractive distillation column approximately in the middle thereof and is extracted in the extractive distillation column with a selective solvent which is fed above the feeding point of the hexane cut consisting of the sump product of the second distillation column. The sump product containing the selective solvent is withdrawn from the extractive distillation column and the overhead thereof vapors are condensed.
    Type: Grant
    Filed: October 10, 1978
    Date of Patent: July 14, 1981
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Hans F. Danulat, Kamar P. John, Helmut Klein, Stephen Lukatsch
  • Patent number: 4257850
    Abstract: The invention relates to a process for purifying 1,2-dichloroethane which is recovered during incomplete thermal cracking to vinyl chloride and contains contaminants boiling at a temperature lower than C. under a pressure of 1011 millibars, briefly termed low boilers, and contaminants boiling at a temperature higher than C. under a pressure of 1011 millibars, briefly termed high boilers. More particularly, low boilers are distilled off overhead from contaminated 1,2-dichloroethane, in a first distilling zone; a portion of low boiler concentrate is continuously treated at to C.
    Type: Grant
    Filed: January 25, 1980
    Date of Patent: March 24, 1981
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gerhard Rechmeier, Ulrich Roesnik, Harald Scholz
  • Patent number: 4239926
    Abstract: Isobutane is oxidized to provide a debutanized oxidate comprising tertiary butyl alcohol, acetone, water and other byproducts including high boiling products. Water is removed by extractive distillation using a combination of water and xylene as the extractant. The molar amount of recycled water is greater than the amount of water to be removed from the oxidate. By thus recirculating water through the decantation zone the acetone is satisfactorily coextracted from the butyl alcohol in such a manner that a stream of acetone and a stream of water, as well as the desired dry stream of tertiary butyl alcohol can be withdrawn. If the water is not recycled, the acetone will concentrate in the upper section of the distillation zone and reduce the volatility of water, thereby inhibiting the water removal from the tertiary butyl alcohol.
    Type: Grant
    Filed: June 25, 1979
    Date of Patent: December 16, 1980
    Assignee: Atlantic Richfield Company
    Inventors: Henry R. Grane, John C. Jubin, Jr., G. Richard Worrell
  • Patent number: 4234391
    Abstract: A continuous distillation apparatus and method, the apparatus including separate stripping and rectifying sections in tandem, each of which are segregated into a plurality of vapor/liquid contact stages. The rectifying section is operated at a higher temperature than the stripping section by compressing vapor from the stripping section prior to introducing the vapor into the rectifying section. Thermal energy is conserved during the distillation process by transferring thermal energy from the rectifying section to the stripping section with a plurality of heat pipes.
    Type: Grant
    Filed: October 13, 1978
    Date of Patent: November 18, 1980
    Assignee: University of Utah
    Inventor: Junior D. Seader
  • Patent number: 4219389
    Abstract: Acrylic acid is separated from its solutions in tri-n-butyl phosphate by establishing from such a solution a vapor phase comprising substantially all of the acrylic acid and a portion of the solvent, at a temperature below the degradation point of the acrylic acid; next partially or totally condensing said vapor phase; and then distilling the acrylic acid from such condensation product, while maintaining an amount of acrylic acid at the base of the distillation column, and conducting the distillation under conditions such that neither solvent degradation nor acrylic acid crystallization results.
    Type: Grant
    Filed: June 12, 1978
    Date of Patent: August 26, 1980
    Assignee: Rhone-Poulenc Industries
    Inventors: Georges Biola, Yves Komorn, Gerard Schneider
  • Patent number: 4166774
    Abstract: The separation of acrylic acid from a mixture of acrylic acid and acetic acid found in the reaction product stream obtained in the process of producing acrylic acid by the oxidation of propylene or acrolein is improved by removing a vapor sidestream from the solvent recovery column found in the process. Acetic acid is then separated from this stream without the addition of external heat.
    Type: Grant
    Filed: December 5, 1977
    Date of Patent: September 4, 1979
    Assignee: The Standard Oil Company
    Inventor: David R. Wagner
  • Patent number: 4134797
    Abstract: A process for the recovery of ethylene oxide containing low levels of aldehydic impurities from an impure aqueous ethylene oxide solution containing the same is provided in which the impure solution is treated in a novel multi-stage, countercurrent distillation zone for improved separation of said aldehydic impurities and recovery of an ethylene oxide-containing product stream having the desired low concentration of aldehydic impurities.
    Type: Grant
    Filed: February 21, 1978
    Date of Patent: January 16, 1979
    Assignee: Halcon Research & Development Corporation
    Inventor: Brian J. Ozero
  • Patent number: 4110087
    Abstract: Anhydrous liquid sulfur dioxide is recovered from environmentally unsuitable vapor or liquid streams comprising water, sulfur dioxide and carbon dioxide. The vapor streams are fed into an absorption zone and contacted with a lean liquid water stream. A resulting sulfur dioxide rich water stream is passed into a first fractionation column utilized in part as the stripper column which produces the lean water stream. A sidecut stream removed above the feed point is passed into a second fractionation column, and the overhead vapor of the first column is subjected to two stages of partial condensation to aid carbon dioxide rejection. Anhydrous sulfur dioxide is removed as a liquid sidecut of the second column, and the net overhead vapor of the second column is preferably passed into the overhead system of the first column after a partial condensation.
    Type: Grant
    Filed: September 12, 1977
    Date of Patent: August 29, 1978
    Assignee: UOP Inc.
    Inventor: John P. Nolley, Jr.
  • Patent number: 4107002
    Abstract: A process for the purification of crude acetic anhydride by continuous fractional distillation, which comprises first introducing the anhydride into an evaporator, thereafter removing from the evaporator the non-distillable components contained in the crude anhydride, then introducing the distillable components of the anhydride in vapor form into about the central section of a fractionating column, withdrawing from the top of the column the low boiling components together with acetic acid, withdrawing near the bottom of the column a high-percentage of pure acetic anhydride, and separating from the sump of the column up to about 8% by weight based on the initial amount of crude acetic anhydride and returning the same to the evaporator.
    Type: Grant
    Filed: February 2, 1976
    Date of Patent: August 15, 1978
    Assignee: Wacker-Chemie GmbH
    Inventors: Herbert Eck, Elmar Bethe, Hans Schwarzbauer, Hellmuth Spes, Klaus Kaiser
  • Patent number: 4070253
    Abstract: Process for separating a solution, which essentially contains propylene oxide, propylene, a carboxylic acid containing 1 to 4 carbon atoms and benzene, by distillation. The solution is fed to a first distillation stage in which propylene, propylene oxide and an amount of the benzene contained in the solution such that the top product from this first distillation contains 20 to 70% by weight of benzene are distilled off over the top at a pressure of 1.0 to 2.5 bars, and in which the carboxylic acid and the remaining benzene are obtained as the sump product. The top product from the first distillation is fed to a second distillation column in which propylene and possibly present small fractions of components which boil lower than propylene oxide are distilled off over the top and a sump product which essentially consists of propylene oxide and benzene is obtained and part of this is returned as reflux to the first distillation column.
    Type: Grant
    Filed: April 28, 1976
    Date of Patent: January 24, 1978
    Assignees: Bayer Aktiengesellschaft, Deutsche Gold- und Silber-Scheideanstal vormals Roessler
    Inventors: Willi Hofen, Rolf Wirthwein, Karl-Hermann Reissinger, Jorg Krekel
  • Patent number: 4043875
    Abstract: An improved technique employing first and second flash vaporization stages for purifying radioactive liquids is described. The liquid is first flash-evaporated in the first vaporization stage and the resulting vapor is conducted to a first direct condenser. Enriched liquid obtained from the second vaporization stage is applied via a circulating pump to the first direct condenser to condense by contact the vapor from the first vaporization stage and to form a mixture with this condensate. The resulting mixture is thus flash-evaporated in the second vaporization stage. A portion of the enriched liquid obtained from the second vaporization stage is withdrawn from the loop formed by said second vaporization stage, said circulating pump, said first direct condenser, and the connecting conduits therebetween for further processing, e.g., recycling to the first vaporization stage, or for discharging.
    Type: Grant
    Filed: December 17, 1975
    Date of Patent: August 23, 1977
    Assignee: Vereinigte Delstahlwerke AG. (VEW)
    Inventors: Gundolf E. Rajakovics, Heinz Gabernig, Guenter Peter Klein
  • Patent number: 4038156
    Abstract: An improvement is described on a process for recovery of butadiene from a C.sub.4 hydrocarbon mixture additionally containing minor amounts of C.sub.5 saturated and unsaturated hydrocarbons, said hydrocarbon mixture being obtained as the overhead product of an initial hydrocarbon fractionation employed to separate larger quantities of C.sub.5 and heavier hydrocarbons from the hydrocarbon mixture, wherein the hydrocarbon mixture is subject to extractive distillation in the presence of a polar solvent e.g. acetonitrile, in which butadiene is separated from the fat solvent bottoms of extractive distillation by sequential low pressure flashing and stripping, followed by compression of the combined vapors of flashing and stripping with part of the compressed vapors being recycled as reboiled vapor to the extractive distillation and the remainder being again stripped at a higher pressure to recover butadiene therefrom. In this improved process, butadiene purification problems associated with carry over of C.sub.
    Type: Grant
    Filed: September 21, 1976
    Date of Patent: July 26, 1977
    Assignee: Shell Oil Company
    Inventors: Robert F. Knott, Arthur E. Handlos
  • Patent number: 4033617
    Abstract: Crude ethylene oxide present in the dilute aqueous solution resulting from the extraction with an aqueous solvent of ethylene oxide from the gaseous stream obtained by catalytic oxidation of ethylene is purified by desorption, liquefaction, distillation in a fractionating column and final desorption treatment to remove absorbed non-condensable gases. The fractionating column is heated by condensation of the water vapor evolved during desorption and a liquid stream of ethylene oxide rich in acetaldehyde is discharged from the bottom, treated to convert a fraction of said acetaldehyde into high-boiling products, distilled to remove the latter as bottoms and returned to the fractionating column.
    Type: Grant
    Filed: July 8, 1976
    Date of Patent: July 5, 1977
    Assignee: Societa' Italiana Resine S.I.R. S.p.A.
    Inventors: Gioacchino Cocuzza, Gianni Torreggiani, Michele Sfregola
  • Patent number: 4014752
    Abstract: A process and installation for vaporizing liquids and in particular radioactive liquids. A two-step flash vaporization is carried out. The vapor exiting from a first vaporizing stage is condensed by means of liquid taken from a second vaporizing stage, the latter liquid being injected into a condenser into which the vapor steam from the first vaporizing stage is being conducted. The thus formed mixture is conducted into the second vaporizing stage.
    Type: Grant
    Filed: January 30, 1973
    Date of Patent: March 29, 1977
    Assignee: Vereinigte Edelstahlwerke AG
    Inventors: Gundolf Rajakovics, Heinz Gabernig, Gunter Peter Klein
  • Patent number: 3954566
    Abstract: An improved arrangement is described for self-controlling the evaporation rate in the first stage of a two-stage expansion type evaporation installation for radio-active liquid purification, as described e.g. in the U.S. patent application Ser. No. 328065 filed on Jan. 30, 1973, in case of failure of the main circulating pump of the second stage. Such failure causes a pressure drop at the mixing condenser between first and second stage and normally, thus, a pressure drop in the first stage too. Such pressure drop leads to unwanted evaporation in the first stage and transfer to the second stage of excessive and insufficiently purified fluid from the first stage. A flow throttle element such as a diaphragm or a necked-down section of steam conduit is interposed between the vapor exit of the first stage and the mixing condenser in which the vapor is condensed by contact with a portion of the liquid from the second stage circulated therethrough by the pump.
    Type: Grant
    Filed: January 23, 1975
    Date of Patent: May 4, 1976
    Assignee: Vereinigte Edelstahlwerke AG
    Inventor: Gundolf E. Rajakovics
  • Patent number: 3953301
    Abstract: A process is provided for recovering hexane from the mixed recycle stream from a plurality of ethylene polymerization reactors. The recycle stream containing hexane and periodically vinyl acetate and/or an alkyl acrylate admixed with vinyl acetate to provide a mixed feed stream containing at least 45% by weight vinyl acetate. This feed stream is distilled at atmospheric pressure and all of the hexane is recovered as an overhead azeotrope containing about 57% hexane. The overhead fraction is redistilled at a superatmospheric pressure of at least 4 atmospheres in a second column. The overhead fraction of the second column will be enriched in vinyl acetate and pure hexane is recovered as a bottoms fraction from the second column. The vinyl acetate and/or alkyl acrylate contained in the bottoms fraction of the first column is recovered by atmospheric distillation in a third column.
    Type: Grant
    Filed: September 5, 1974
    Date of Patent: April 27, 1976
    Assignee: Gulf Oil Corporation
    Inventors: Tomas Mendez, Guy Van Cleve, Jr.
  • Patent number: 3936360
    Abstract: Substantial capital and operating cost savings and improved recovery of acrylonitrile and methacrylonitrile are realized by the recycle of the product column bottoms to the quench liquid of the reactor effluent quench system.
    Type: Grant
    Filed: February 9, 1973
    Date of Patent: February 3, 1976
    Assignee: The Standard Oil Company
    Inventor: Hsin Chih Wu