Distillation Of Initial Distillate Patents (Class 203/74)
  • Patent number: 5167775
    Abstract: The present invention provides a method for the recover of a solvent used in the production of a polyarylene sulfide according to which the deterioration of the solvent is low and the recovery rate is high, wherein a mixed liquid, mainly composed of the solvent used in the production of the polyarylene sulfide, and generated from the process of producing the polyarylene sulfide, is subjected to a flash evaporating operation to separate the mixed liquid into a flashed vapor (A) and a flashed residue (B), and then the flashed vapor is rectified (A).
    Type: Grant
    Filed: October 16, 1989
    Date of Patent: December 1, 1992
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Masao Omori, Yoshinari Koyama, Daigo Shirota
  • Patent number: 5160414
    Abstract: An extractive distillation process for separation ethers (in particular methyl t-butyl ether or ethyl t-butyl ether), aliphatic hydrocarbons (in particular isobutane and/or isobutene) and alcohols (in particular methanol or ethanol) employs as solvent sulfolane(s) and/or dialkyl sulfone(s), or N-(.beta.-mercaptoalkyl)-2-pyrrolidone(s), or a mixture of N-alkyl-2-pyrrolidone(s) and either sulfolane(s) or glycol compound(s).
    Type: Grant
    Filed: July 19, 1991
    Date of Patent: November 3, 1992
    Assignee: Phillips Petroleum Company
    Inventors: Fu-Ming Lee, Robert L. Hair, Ronald E. Brown
  • Patent number: 5139620
    Abstract: Evaporation of saline water in a desalinization process, or evaporation of other types of liquid such as black liquor from paper pulp processing, is accomplished utilizing a multiple effect evaporator. Each effect includes one or more (e.g. first and second) sets of horizontally elongated dimpled plate evaporator elements. Horizontally flowing heating fluid, such as steam, is introduced to the internal passage of at least the second set in all the effects, and a head of circulation liquid is provided to cause liquid being evaporated to flow downwardly from the head over the external surfaces of the sets of dimpled plates in a thin film. The vapor evaporated is drawn through a demistor and is used as the heating fluid for the next effect. Recirculating liquid that has not evaporated and liquid separated by the demisting process are recirculated to the head associated with each effect. Clean condensate--such as distilled water--is withdrawn from the last effect.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: August 18, 1992
    Assignee: Kamyr, Inc.
    Inventors: Carl E. Elmore, Kyle Infante
  • Patent number: 5073351
    Abstract: An oligomerization system is provided for upgrading lower olefins to distillate hydrocarbons, especially useful as high quality jet or diesel fuels. The olefinic feedstock is reacted over a shape selective acid zeolite, such as ZSM-5, to oligomerize feedstock olefins and further convert recycled hydrocarbons. Reactor effluent is fractionated to recover a light-middle distillate range product stream and to obtain gasoline and heavy hydrocarbon streams for recycle.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: December 17, 1991
    Assignee: Mobil Oil Corporation
    Inventors: James H. Beech, Jr., Hartley Owen, Michael P. Ramage, Samuel A. Tabak
  • Patent number: 5028735
    Abstract: A purification process for methyl methacrylate (MMA) and a recovery process for methanol are disclosed. A mixture, which contains water, methanol and methyl methacrylate (MMA) as principal components along with at least one of methyl acrylate, methyl propionate and methacrylic acid, is azeotropically distilled together with hexane to obtain MMA in a form substantially free of water, methanol methyl acrylate, methyl propionate and hexane and a low boiling-point fraction. The low boiling-point fraction is cooled and separated into a water phase and an oil phase. Methanol can be recovered from the water phase by adding an alkaline substance to it and then distilling the resultant mixture. A preparation process of MMA is also disclosed. MMA can be prepared by esterifying methacrylic acid or methacrylamide with methanol and then applying the above purification process.
    Type: Grant
    Filed: March 30, 1990
    Date of Patent: July 2, 1991
    Assignees: Mitsui Toatsu Chemicals, Inc., Kuraray Company, Ltd.
    Inventors: Hirozo Segawa, Norio Ishikawa, Katsuji Yoguchi, Morimasa Kuragano, Minoru Koshibe
  • Patent number: 4975156
    Abstract: 1,1-Dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane and hydrogen fluoride are separated from their liquid mixtures, such as liquid mixtures resulting from the hydrofluorination, of 1,1,1-trichloroethane or vinylidene chloride. 1,1-Dichloro-1-fluoroethane and 1-chloro-1,1-difluoroethane are first separated by distillation into their respective mixtures with hydrogen fluoride, which are thereafter subjected to parallel phase separations resulting in two hydrogen fluoride-enriched liquid phases, a 1-chloro-1,1-difluoroethane-enriched liquid phase and a 1,1-dichloro-1-fluoroethane-enriched liquid phase. 1-Chloro-1,1-difluoroethane and 1,1-dichloro-1-fluoroethane are purified from the respective halohydrocarbon-enriched liquid phases by distillation. The hydrogen fluoride-enriched stream generated from the phase separation of the hydrogen fluoride/1,1-dichloro-1-fluoroethane mixture is recycled to the hydrofluorination reaction mixture.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: December 4, 1990
    Assignee: Atochem North America, Inc.
    Inventor: John A. Wismer
  • Patent number: 4963232
    Abstract: Provided by this invention is a process for producing a purified hydrazine hydrate having a low total organic carbon concentration and which involves:a first step which includes distilling an aqueous solution of hydrazine hydrate in the presence of at least one salt selected from the group consisting of chloride, sulfate, phosphate and carbonate of (a) the metals of Group Ia and IIa of the Periodic Table of the Elements, (b) ammonium or (c) hydrazinium to concentrate the aqueous solution of hydrazine hydrate by distilling water and the majority of the total organic carbon constituents off and separating the resultant concentrate as a bottom product, anda second step which includes distilling the resultant concentrate to recover a purified aqueous solution of hydrazine hydrate as a top product and separating an aqueous solution of the above salt as a bottom product.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: October 16, 1990
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Yasuhisa Kuriyama, Shuuzabu Sakaguchi, Toshiaki Kohzaki, Syoichi Nito
  • Patent number: 4950364
    Abstract: 1,1-Dichloro-1-fluroethane and 1,1,1,3,3-pentafluorobutane are separated from their liquid mixtures, such as liquid mixtures resulting from the hydrofluorination of 1,1,1-trichloroethane or vinylidene chloride. 1,1-Dichloro-1-fluoroethane and 1,1,1,3,3-pentafluorobutane are completely separated by distillation, by adding to the mixture thereof a liquid containing at least about 3 moles of hydrogen fluoride per mole of 1,1-dichloro-1-fluoroethane in the mixture subject to separation.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: August 21, 1990
    Assignee: Pennwalt Corporation
    Inventor: John A. Wismer
  • Patent number: 4946029
    Abstract: Carboxylic esters obtained by reacting olefinically unsaturated compounds with carbon monoxide and alcohols and containing aldehydes, acetals and/or unsaturated compounds are purified by(a) treating the carboxylic ester which contains an aldehyde, acetal or unsaturated compound in a first stage at from 20.degree. to 200.degree. C. with a strongly acidic agent and(b) hydrogenating the mixture thus treated in a second stage at from 50.degree. to 200.degree. C. under a pressure of from 1 to 50 bar in the presence of one or more metals of subgroup VIII of the periodic table and(c) removing low and high boilers from the hydrogenated mixture obtained in stage b by distillation and obtaining a pure carboxylic ester.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: August 7, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Gerhard Frank, Hubert Lendle, Wilfried Seyfert, Peter Stops
  • Patent number: 4925535
    Abstract: The process for production of an aromate concentrate for use as a blending component for gasification fuel includes subjecting another feed hydrocarbon mixture to an extractive distillation using N-substituted morpholines as selective solvent in a extractive distillation column. Low-boiling non-aromates with a boiling range up to about 105.degree. C. practically completely and higher-boiling non-aromates with a boiling range between about 105.degree. and 160.degree. C. to a substantial extent are discharged as a raffinate from the top of the extractive distillation column. The extract bottoms from the extractive distillation are fed to a solvent stripping column where the solvent is at least partially recovered from other hydrocarbons. To eliminate condensation and polymerization products due to components with a boiling point over 170.degree. C.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: May 15, 1990
    Assignee: Krupp Koppers GmbH
    Inventors: Gerhard Preusser, Gerd Emmrich, Martin Schulze
  • Patent number: 4919765
    Abstract: Tetrahydrofuran is recovered by a two stage distillation procedure from a crude hydrogenation product resulting from vapor phase hydrogenation of diethyl maleate and containing water, ethanol and a minor amount of n-butanol, and possibly also dissolved hydrogen, in addition to butane-1,4-diol, gamma-butyrolactone and "heavies" such as diethyl ethoxysuccinate. In the first distillation stage, conveniently operated substantially at atmospheric pressure, ethanol, water, and tetrahydrofuran are recovered as overhead product, are condensed to separate the condensible components from a hydrogen stream which can be vented, and then redistilled in the presence of a molar excess of a hydroxylic solvent containing at least two hydroxyl groups, such as butane-1,4-diol, in a second distillation zone.
    Type: Grant
    Filed: July 22, 1988
    Date of Patent: April 24, 1990
    Assignee: Davy McKee (London) Limited
    Inventors: Peter R. Wilkes, John Scarlett, George E. Harrison
  • Patent number: 4872949
    Abstract: Used drilling muds containing substantial quantities of organic liquids and water-soluble salts are treated to render them environmentally acceptable for disposal purposes, by drying the muds to evaporate all liquids, aqueous and non-aqueous, preferably in a shell-and-tube type heat exchanger through which they are conveyed and held in suspension by screw conveyors, and preferably with the vapors thus generated flowing in a direction counter-current to the mud. Water-soluble salts are removed from the dried mud components by dissolving with water, and the vapors are condensed and phase separated for further purification and re-use if desired.
    Type: Grant
    Filed: January 18, 1989
    Date of Patent: October 10, 1989
    Inventor: Carl M. Wilwerding
  • Patent number: 4871879
    Abstract: In the hydroformylation of alkenes to aldehydes, rhodium is recovered from the stripped overhead of the hydroformylation reactor by condensing the overhead, removing the bulk of the aldehyde product from the condensed overhead, stripping the residue which remains with nitrogen gas to remove minor amounts of highly volatile aldehyde product remaining in the residue and redistilling the residue to remove components from the condensed overhead which are lower boiling than the catalyst components. The catalyst components including rhodium and phosphine ligand are returned to the hydroformylation reactor.
    Type: Grant
    Filed: October 27, 1987
    Date of Patent: October 3, 1989
    Assignee: Hoechst Celanese Corporation
    Inventor: Keith A. Laird
  • Patent number: 4849186
    Abstract: An oligomerization system is provided for upgrading lower olefins to distillate hydrocarbons, especially useful as high quality jet or diesel fuels. Thye olefinic feedstock is reacted over a shape selective acid zeolite, such as ZSM-5, to oligomerize feedstock olefins and further convert recycled hydrocarbons. Reactor effluent is fractionated to recover a light-middle distillate range product stream and to obtain gasoline and heavy hydrocarbon streams for recycle.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: July 18, 1989
    Assignee: Mobil Oil Corporation
    Inventors: James H. Beech, Jr., Hartley Owen, Michael P. Ramage, Samuel A. Tabak
  • Patent number: 4832920
    Abstract: A continuous catalytic system for converting an olefinic feedstock comprising ethylene and C.sub.3.sup.+ olefins to heavier liquid hydrocarbon product comprising apparatus for(a) prefractionating the olefinic feedstock to obtain a gaseous stream rich in ethylene and a liquid stream containing C.sub.3.sup.+ olefins;(b) vaporizing and contacting the liquid stream from the prefractionating step with hydrocarbon conversion oligomerization catalyst in a catalytic reactor system to provide a heavier hydrocarbon effluent stream comprising distillate, gasoline and lighter hydrocarbons;(c) fractionating the effluent stream to recover distillate, gasoline and lighter hydrocarbons separately;(d) recycling at least a portion of the recovered gasoline as a liquid sorption stream to prefractionating step (a); and(e) further reacting the recycled gasoline together with sorbed C.sub.3.sup.+ olefins in the catalytic reactor system of step (b).
    Type: Grant
    Filed: June 13, 1984
    Date of Patent: May 23, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Hartley Owen, Chung H. Hsia, Bernard S. Wright
  • Patent number: 4767869
    Abstract: A process is described for the production of substantially pure gamma-butyrolactone from a feed mixture containing a major amount of gamma-butyrolactone and a minor amount of diethyl succinate which comprises fractionally distilling the mixture in a fractionation zone in the presence of added diethyl maleate and recovering from the fractionation zone an overhead vaporous product comprising gamma-butyrolactone which is substantially free from diethyl succinate and a liquid bottom product comprising diethyl maleate and diethyl succinate in admixture one with another. This procedure can be used to separate a gamma-butyrolactone rich fraction obtained by distillation in one or more stages of a crude reaction product obtained by hydrogenation of a C.sub.
    Type: Grant
    Filed: July 31, 1987
    Date of Patent: August 30, 1988
    Assignee: Davy McKee Limited
    Inventors: George E. Harrison, Norman Harris
  • Patent number: 4740272
    Abstract: A method of producing substantially pure dialkyl maleate by separating monoalkyl maleate from dialkyl maleate in a short residence time distillation zone while minimizing reversion of the monoalkyl maleate to alkanol and maleic anhydride and without having to neutralize the monoalkyl maleate.
    Type: Grant
    Filed: March 31, 1987
    Date of Patent: April 26, 1988
    Assignee: Davy McKee (London) Limited
    Inventors: Ernesto Vera-Castaneda, Diane A. Montevideo, David J. Miller, John E. Logsdon, David R. Bryant
  • Patent number: 4675082
    Abstract: Preparation and recovery of 1-t-butoxy-2-propanol in a high state of purity from a crude etherification reaction product obtained by reaction of isobutylene with propylene glycol in the presence of a solid resin etherification catalyst is disclosed. The crude reaction product is distilled to obtain a 1-t-butoxy-2-propanol-containing distillate, thereby leaving propylene glycol as bottoms; the condensed distillate is then further distilled to separate 1-t-butoxy-2-propanol as an overhead product from higher boiling materials.
    Type: Grant
    Filed: September 22, 1986
    Date of Patent: June 23, 1987
    Assignee: Atlantic Richfield Company
    Inventor: Vijai P. Gupta
  • Patent number: 4647344
    Abstract: Isoprene is recovered from a C.sub.5 -hydrocarbon mixture containing isoprene, penta-1,3-diene and cyclopentadiene by separating the said mixture by liquid-liquid extraction or extractive distillation with the aid of a selective solvent, in combination with a distillation upstream or downstream from the liquid-liquid extraction or extractive distillation, by a method in which a stream containing penta-1,3-diene and cyclopentadiene is separated off in the upstream or downstream distillation and is catalytically hydrogenated, and the hydrogenated stream is fed to the upper part of the liquid-liquid extraction or extractive distillation.
    Type: Grant
    Filed: October 19, 1984
    Date of Patent: March 3, 1987
    Assignee: BASF Aktiengesellschaft
    Inventors: Alfred Lindner, Ulrich Wagner, Klaus Volkamer, Walter Rebafka
  • Patent number: 4620024
    Abstract: In a continuous alkoxidation-phosphorylation process for producing tributyl phosphate having low color utilizing excess butanol in the alkoxidation reaction which is heated by an alcohol flasher wherein the excess butanol is recovered after phosphorylation by two stage flash distillation, the bottoms product from the first stage going to the second stage, the overhead product from the second stage returning to the first stage flash distillation, and the bottoms from the second stage distillation going to final product washing and drying process while the overhead from the first stage flash distillation is fed to the process alkoxidation alcohol flasher, the improvement which comprises distilling in a distillation column the overhead product from the first stage flash distillation and then feeding the overhead from the distillation column to the alkoxidation alcohol flasher.
    Type: Grant
    Filed: October 22, 1984
    Date of Patent: October 28, 1986
    Assignee: FMC Corporation
    Inventors: Robert I. Davis, Thomas G. Seador
  • Patent number: 4615770
    Abstract: Dual interrelated distillation columns are disclosed wherein the heat from a first column is transferred by thermal conduction through a common wall or surface to a second column to increase efficiency and decrease waste of energy. In one embodiment, the first heat generating column is a cylindrical column, and the second column is an annular column concentric to the first column. This concentric arrangement permits the heat generated in the first column to flow outwardly into the second column, thereby improving its efficiency and reducing the heat loss. Typically, the inner first column is a high pressure rectifying column, and the outer concentric column is a stripping column. In an alternate embodiment, the inner column can simply be a portion of a high pressure distillation process, and the outer column is a portion of a lower pressure distillation column.
    Type: Grant
    Filed: February 26, 1985
    Date of Patent: October 7, 1986
    Inventor: Rakesh Govind
  • Patent number: 4600477
    Abstract: A method of processing fermented liquid comprising(a) feeding said fermented liquid into a vacuum vaporizer, (b) heating the feed in said vaporizer to separate it into a vapor and a concentrated liquid fraction, (c) recycling said vapor to said vaporizer by compression so as to achieve heat-exchange with said feed therein thereby generating a new vapor and a condensate fraction; said condensate being discharged as a distillate, (d) supplying the remaining compressed vapor to a multistage distilling column, (e) separating said compressed vapor into two fractions, one with a higher boiling point than the other, within said distilling column, (f) condensing said distillate with the lower boiling point to yield an alcohol-rich distillate, and (g) discharging said fraction with the higher boiling point as a bottom residue, and a processor therefor, thereby discharging to the outside the low COD-liquid alone and recovering useful substances such as drinkable alcohol, livestocks feed and antibiotic substances.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: July 15, 1986
    Assignee: Sanwa Shoji Co., Ltd.
    Inventors: Takehiro Higashi, Michio Kobori, Zenichi Yoshino, Seiichi Morimoto
  • Patent number: 4586986
    Abstract: Disclosed is a method for recovering pure aromatic substances from a mixture of hydrocarbons containing both aromatic and non-aromatic fractions. The input mixture is fed through an extractive stage provided with a preliminary distillation column. In the preliminary stage the aromatics-containing product is treated at a pressure up to 20 bar and a temperature up to 300.degree. C. The pressure is adjusted to a value at which the operational temperature of the preliminary stage is higher than the pressure and temperature in the extractive stage and the heat of the vapors discharged from the preliminary stage is used for heating the extractive stage.
    Type: Grant
    Filed: September 18, 1984
    Date of Patent: May 6, 1986
    Assignee: Krupp-Koppers GmbH
    Inventors: Gerhard Preusser, Martin Schulze, Gerd Emmrich, Hans-Christoph Schneider
  • Patent number: 4568427
    Abstract: A process for the continuous isolation of phthalic anhydride and maleic anhydride from the reaction gases obtained by catalytic oxidation of o-xylene or naphthalene with air, wherein the reaction gases are treated with a hydrocarbon of boiling range from 115.degree. to 175.degree. C. as the solvent in a column, and are then treated with an organic solvent of boiling range from 180.degree. to 290.degree. C. in a second column, the phthalic anhydride and maleic anhydride being isolated from the liquid bottom product of the first column.
    Type: Grant
    Filed: February 11, 1983
    Date of Patent: February 4, 1986
    Assignee: BASF Aktiengesellschaft
    Inventors: Eckehard Danz, Gerd Dumbgen, Ernest Miesen, Johannes E. Schmidt, Friedrich Wirth
  • Patent number: 4549937
    Abstract: The disclosure relates to a process for separating the catalyst system from reaction mixtures which are obtained by reacting methyl acetate and/or dimethylether with carbon monoxide and optionally hydrogen at elevated temperatures to acetic anhydride and optionally ethylidene diacetate in the presence of a catalyst system consisting of carbonyl complexes of noble metals belonging to group VIII of the Periodic System, acetic acid, an organophosphorus or organonitrogen compound, methyl iodide and optionally compounds of carbonyl-yielding common metals, and which issue from the reaction zone under a pressure of 25 to 150 bars at a temperature of 100.degree. to 250.degree. C. More particularly, the reaction mixture coming from the reaction zone is introduced into a separator heated to 60.degree. to 140.degree. C. and released to a pressure of 0.5 to 3.
    Type: Grant
    Filed: November 16, 1982
    Date of Patent: October 29, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Heinz Erpenbach, Klaus Gehrmann, Peter Horstermann, Hans-Klaus Kubbeler, Georg Kohl
  • Patent number: 4522920
    Abstract: A flow of fermenting liquor from a fermentor is separated into a yeast concentrate flow, which is recirculated to the fermentor, and a yeast-free flow which is separated in a simple evaporator unit into a first ethanol-enriched vapor flow and a first liquid bottom flow. The first vapor flow is treated to produce the desired ethanol while a major part of the first liquid bottom flow is recirculated to the fermentor. A minor, residual part of the latter flow is fed to a stripping unit where it is separated into a second ethanol-enriched vapor flow and a second liquid bottom flow exhausted of ethanol.
    Type: Grant
    Filed: August 16, 1982
    Date of Patent: June 11, 1985
    Assignee: Alfa-Laval AB
    Inventors: Conny R. Thorsson, Indrek J. Viira
  • Patent number: 4457807
    Abstract: A process is provided for recovering epsilon-caprolactam of a purity in excess of 99.9 wt. %, in a two-stage distillation operation. Each stage comprises an evaporator and a rectification column having a pressure drop across the theoretical trays thereof of less than about 2.5 MBAR.
    Type: Grant
    Filed: May 7, 1982
    Date of Patent: July 3, 1984
    Assignee: Stamicarbon B.V.
    Inventors: Peter F. M. Rulkens, Nicolaas F. Haasen, Otto G. Plantema
  • Patent number: 4447318
    Abstract: In a method for separating a hydrocarbon mixture into relatively difficultly soluble hydrocarbons and relatively easily soluble hydrocarbons by extractive distillation using a polar solvent comprising feeding the starting hydrocarbon mixture to at least two evaporators, an extractive distillation column, a stripping column and a rectifying column; the improvement wherein(1) the polar solvent discharged at a high temperature from the bottom of the stripping column is recycled to the extractive distillation column after it has been cooled to a suitable temperature by giving up heat to a reboiler of the extractive distillation column, a reboiler of the rectifying column and successively to the two or more evaporators, and(2) the starting hydrocarbon mixture is divided into two or more streams and heated in two or more evaporators, one stream being evaporated in a first evaporator to a pressure necessary for introduction into the extractive distillation column and then fed to the extractive distillation column, a
    Type: Grant
    Filed: March 28, 1983
    Date of Patent: May 8, 1984
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Shunichiro Ogura, Masafumi Miyamoto
  • Patent number: 4422903
    Abstract: An improved distillation method and apparatus are provided for recovering anhydrous ethanol from fermentation or synthetic feedstocks. The system includes at least one stripper-rectifier tower, a dehydrating tower, and an azeotropic agent stripping tower. Substantial energy savings are realized by operating the dehydrating tower, and preferably also the azeotropic agent stripping tower, at a higher pressure than the stripper-rectifier tower and by condensing the overhead vapors from the dehydrating tower (or dehydrating tower and azeotropic agent stripping tower) to provide the heat required in the stripper-rectifier tower. In a preferred embodiment, two stripper-rectifier towers are used, one operating at a higher pressure than the other, in which case the higher pressure tower is heated as just described and the overhead vapors from the higher pressure tower are condensed to supply the heat required in the lower pressure tower.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: December 27, 1983
    Assignee: Raphael Katzen Associates International Inc.
    Inventors: John R. Messick, William R. Ackley, George D. Moon, Jr.
  • Patent number: 4414074
    Abstract: A new process for the production of very pure 4,4'-diisocyanatodiphenylmethane is disclosed, in which diisocyanatodiphenylmethane isomers which are obtained by distillation from the phosgenation products of aniline/formaldehyde condensates are initially freed from 2,2'- and 2,4'-isomers under certain distillation conditions and are then further worked-up by distillation, in that in a first final stage, from 50 to 90%, by weight of the diisocyanate freed from 2,2'- and 2,4'-isomers is isolated as the head product in the form of pure 4,4'-diisocyanatodiphenylmethane and in a second final stage, another quantity of pure 4,4'-diisocyanatodiphenylmethane is separated as the head product from the distillation of the sump of the first final stage.
    Type: Grant
    Filed: October 25, 1982
    Date of Patent: November 8, 1983
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gunther Ellendt, Gunter Gleitsmann, Max Scheidel
  • Patent number: 4410400
    Abstract: A method for working up residues of an extractive distilling process for obtaining pure hydrocarbons. The residue from an extractive distilling column is fed to the about middle part of a distilling column. The hydrocarbons are distilled and removed at the head of the distilling column and the solvent is removed at the bottom of the distilling column. A sidestream is removed from the distilling column at a position above the feed plate for the residue from the extractive distilling column via a so-called reflux evaporator plate having an elevated level of liquid. The sidestream is heated by indirect heat exchange with the solvent flowing from the distilling column. The heated-up sidestream is fed back into the distilling column at a level at or above the reflux evaporator plate. The concentration of the solvent at the reflux evaporator plate is controlled by the amount of reflux at the head of the distilling column.
    Type: Grant
    Filed: August 3, 1981
    Date of Patent: October 18, 1983
    Assignee: Krupp-Koppers GmbH
    Inventors: Gerhard Preusser, Martin Schulze
  • Patent number: 4390398
    Abstract: Volatile reactants are heated under reflux in a reactor and form volatile reaction by-products which are continuously removed in a vapor effluent from a reflux column and partial condenser. The effluent, which entrains some of the reactants, is condensed in a first total condenser and is fed to a distillation apparatus for separation of the volatile reactants and by-products and return of the separated reactants to the reactor. Before the condensate reaches the distillation apparatus, it is temporarily stored in a receiver from which it is controllably fed to a pre-heater where it is evaporated and then fed as a vapor to the distillation column of the distillation apparatus for separation. The distillation column includes at one end a reboiler which retains the reactants. The other end of the distillation column is coupled to a second total condenser in which the volatile by-products are condensed and withdrawn through a cooler for disposal.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: June 28, 1983
    Assignee: Fiberglas Canada Limited
    Inventors: Robert J. Coker, Gary W. Bate, Henk J. Deuzeman
  • Patent number: 4358536
    Abstract: A flow of fermenting liquor from a fermentor is separated into a yeast concentrate flow, which is recirculated to the fermentor, and a yeast-free flow which is separated in a simple evaporator unit into a first ethanol-enriched vapor flow and a first liquid bottom flow. The first vapor flow is treated to produce the desired ethanol while a major part of the first liquid bottom flow is recirculated to the fermentor. A minor, residual part of the latter flow is fed to a stripping unit where it is separated into a second ethanol-enriched vapor flow and a second liquid bottom flow exhausted of ethanol.
    Type: Grant
    Filed: February 22, 1980
    Date of Patent: November 9, 1982
    Assignee: Alfa-Laval AB
    Inventors: Conny R. Thorsson, Indrek J. Viira
  • Patent number: 4340447
    Abstract: Pure acetone is recovered from a crude acetone vapor fraction removed overhead from a first column separating phenol and higher boilers as a bottom fraction from a cumene hydroperoxide cleavage reaction product by partially condensing the crude acetone fraction, returning the condensed portion of the crude acetone fraction to the first column as reflux, feeding the remaining portion as a vapor to an intermediate point in a second distillation column to which there is also fed continuously at a point above the acetone feedpoint a dilute aqueous solution of an alkali, removing from the base of the second column a residue fraction comprising compounds boiling above acetone, removing from a point in the second column intermediate; between the alkali feedpoint and the top of the column as a liquid sidedraw fraction pure acetone having a permanganate time (PT) greater than 4 hours, and removing from the top of the second column as a vapor fraction acetone having a PT less than that of the sidedraw fraction, condens
    Type: Grant
    Filed: May 27, 1981
    Date of Patent: July 20, 1982
    Assignee: BP Chemicals Limited
    Inventors: Robert G. Laverick, James M. Scotland
  • 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: 4263102
    Abstract: In recovering the multi-solvent portion of the oil solvent mixture in a solvent dewaxing process, decomposition of a thermally unstable, lower boiling solvent component is substantially avoided by recovering the solvent in a series of controlled evaporations whereby the major portion of the lower boiling solvent component is removed from the mixture prior to the removal of the remaining portion of the solvent. The solvent removal may be conducted in a high pressure evaporator having an upper section and a lower section separated by an annular tray.
    Type: Grant
    Filed: September 3, 1976
    Date of Patent: April 21, 1981
    Assignee: Edleanu GmbH
    Inventors: Victor Schorr, Gerhard Wirtz
  • Patent number: 4248672
    Abstract: In an apparatus for distilling liquids an improvement is provided wherein distillate is heated within an auxiliary reboiler for further removal of volatile impurities, with the operating environment of the auxiliary reboiler being isolated from the main ambient atmosphere of the apparatus so that evaporated impurities can be vented without recontaminating the distillate or impairing the efficiency of the apparatus. Countercurrent flow of distillate and vapors within the auxiliary reboiler produces enhanced purity of the distillate.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: February 3, 1981
    Assignee: Vaponics Inc.
    Inventor: Verity C. Smith
  • 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: 4233281
    Abstract: Anhydrous hydrogen fluoride of high purity can be recovered from metallic fluoride salts containing phosphate values by digesting the metallic salts in an aqueous solution in a humid atmosphere at a sufficiently high temperature to release a gas containing hydrogen fluoride and negligible amount of P.sub.2 O.sub.5. The released gas is rectified in a rectification operation which includes a rectification zone in which the rectification occurs in the presence of sulfuric acid.
    Type: Grant
    Filed: June 9, 1978
    Date of Patent: November 11, 1980
    Assignee: Occidental Chemical Company
    Inventors: Ronald J. Hirko, Harold E. Mills
  • Patent number: 4233267
    Abstract: Volatile reactants are heated under reflux in a reactor and form volatile reaction by-products which are continuously removed in a vapor effluent from a reflux column and partial condenser. The effluent, which entrains some of the reactants, is condensed in a first total condenser and is fed to a distillation apparatus for separation of the volatile reactants and by-products and return of the separated reactants to the reactor. Before the condensate reaches the distillation apparatus, it is temporarily stored in a receiver from which it is controllably fed to a pre-heater where it is evaporated and then fed as a vapor to the distillation column of the distillation apparatus for separation. The distillation column includes at one end a reboiler which retains the reactants. The other end of the distillation column is coupled to a second total condenser in which the volatile by-products are condensed and withdrawn through a cooler for disposal.
    Type: Grant
    Filed: January 18, 1978
    Date of Patent: November 11, 1980
    Assignee: Fiberglas Canada Limited
    Inventors: Robert J. Coker, Gary W. Bate, Henk J. Deuzeman
  • Patent number: 4197168
    Abstract: Tall oil containing anthraquinone is fractionally distilled for producing the tall oil heads cut enriched in said anthraquinone.
    Type: Grant
    Filed: June 7, 1978
    Date of Patent: April 8, 1980
    Assignee: SCM Corporation
    Inventor: James M. Evans
  • 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: 4159925
    Abstract: Process for isolating propylene glycol diacarboxylates in the preparation of propylene oxide by reaction of propylene with a solution of percarboxylic acid in an organic solvent, the boiling point of which is lower than that of the carboxylic acid which corresponds to the percarboxylic acid used as the epoxidizing agent, and higher than that of propylene oxide, separation, by distillation, of the reaction mixture which essentially contains propylene oxide, the carboxylic acid corresponding to the percarboxylic acid used as the epoxidizing agent and one or more of the by-products propyleneglycol, propylene glycol monocarboxylate and propylene glycol dicarboxylate as well as propylene and the organic solvent, into a fraction containing propylene oxide and propylene and a fraction containing the carboxylic acid, the by-products mentioned and the organic solvent and further separation of the fractions into the individual components by distillation.
    Type: Grant
    Filed: December 9, 1977
    Date of Patent: July 3, 1979
    Assignees: Bayer Aktiengesellschaft, Deutsche Gold- und Silber-Scheideanstalt vormals Roessler
    Inventors: Gerd Schreyer, Rolf Wirthwein, Karl-Hermann Reissinger, Jorg Krekel
  • Patent number: 4152219
    Abstract: Mono ethylamine and diethylamine are separated together by distillation from mixtures comprising mono-, di- and tri- ethylamine and water, and the mono ethylamine is separated from the diethylamine by a subsequent distillation.
    Type: Grant
    Filed: May 11, 1977
    Date of Patent: May 1, 1979
    Assignee: Imperial Chemical Industries Limited
    Inventors: Archie Newton, William Featherstone, Geoffrey K. Hobson
  • Patent number: 4147721
    Abstract: In an oxidation process for converting methacrolein to methacrylic acid, methacrylic acid is recovered by cooling and condensing the effluent from the oxidation, followed by azeotropic distillation of the condensate with a suitable solvent, such as methyl n-propyl ketone. The condensed effluent contains methacrylic acid and water as the major components along with by-product acetic acid, a minor amount of unreacted methacrolein and impurities. Substantially dry crude methacrylic acid is separated as a bottom product from the azeotropic distillation and an azeotrope of water and the solvent is taken overhead and condensed. After condensation, solvent-rich and water-rich phases form and are separated. The solvent-rich phase is returned to the distillation column as a reflux, while the water-rich phase is sent to a stripping column for recovery of residual solvent. Water is withdrawn from the bottom of the stripping column and recycled or discarded, as desired.
    Type: Grant
    Filed: April 6, 1978
    Date of Patent: April 3, 1979
    Assignee: Halcon Research and Development Corporation
    Inventor: James Leacock
  • Patent number: 4128457
    Abstract: Butadiene is recovered from a hydrocarbon fraction containing it together with butenes and acetylene hydrocarbons by introducing said fraction into a first extractive distillation column, feeding aqueous acetonitrile into said column above the introduction point of said fraction and extracting a vapor stream containing butadiene below said introduction point; feeding said vapor stream into a second extractive distillation column, feeding aqueous acetonitrile above the introduction point of said vapor stream and recovering a vapor stream consisting essentially of butadiene at the top of said second column; and rectifying this last vapor stream to recover pure butadiene.
    Type: Grant
    Filed: March 9, 1977
    Date of Patent: December 5, 1978
    Assignee: Societa' Italiana Resine S.I.R. S.p.A.
    Inventors: Diego Barba, Candido D'Agostini, Aldo Pasquinelli
  • 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: 4099936
    Abstract: A process for the purification of a mixture of silane and impurities comprising passing the mixture through a succession of zones connected in series, in a closed system, according to the following steps:(a) passing the mixture, in gaseous form, through a zone containing porous, granular charcoal as an adsorbent at a temperature in the range of about minus 40.degree. C to about minus 80.degree. C to provide a mixture of silane and remaining impurities in gaseous form;(b) passing the gaseous mixture from step (a) through a zone containing porous, granular magnesium silicate as a adsorbent at a temperature in the range of about minus 40.degree. C to about minus 80.degree. C to provide a mixture of silane and remaining impurities in gaseous form;(c) passing the gaseous mixture from step (b) into a distillation zone in such a manner that the impurities are removed overhead in gaseous form and at least about 95 per cent by weight of the silane is converted to liquid bottoms; and(d) recovering the bottoms.
    Type: Grant
    Filed: December 16, 1976
    Date of Patent: July 11, 1978
    Assignee: Union Carbide Corporation
    Inventor: Gregorio Tarancon
  • Patent number: 4089751
    Abstract: The relative volatility of cis-1,4-dichlorobutene-2 to trans-1,4-dichlorobutene-2 is increased when these two isomers are fractionated in the presence of 3,4-dichlorobutene-1.
    Type: Grant
    Filed: January 27, 1976
    Date of Patent: May 16, 1978
    Assignee: Denka Chemical Corporation
    Inventor: Lawrence A. Smith, Jr.
  • Patent number: 4071398
    Abstract: A continuous, low cost method of concentrating dilute streams containing fractions of adsorbable chemicals is disclosed which minimizes heat consumption and provides highly concentrated supplies of valuable chemicals which are suitable for reuse or sale without substantial further processing. The methods hereof are particularly adapted for concentrating waste condensates derived from pulp-making operations such as the Kraft or sulfite processes, but in general are also applicable for treating a wide variety of dilute organic or inorganic adsorbable chemicals.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: January 31, 1978
    Assignee: Flambeau Paper Company
    Inventor: Kenneth W. Baierl