Including The Addition Of Water Or Steam Patents (Class 203/83)
  • Publication number: 20140284202
    Abstract: Distillative process for obtaining ditrimethylolpropane from solutions includes separating ditrimethylolpropane from the solution in a first distillation unit into a first tops fraction comprising low-boiling compounds having a lower boiling point than ditrimethylolpropane and a first bottoms fraction; introducing the first bottoms fraction into a second distillation unit having at least 5 theoretical plates, said unit being configured as a thin-film evaporator with a column attachement and drawing off a second tops fraction comprising intermediate-boiling compounds having a lower boiling point than ditrimethylolpropane as well as withdrawing a second bottoms fraction from the second distillation unit and introducing the second bottoms fraction into a third distillation unit having at least 4 theoretical plates, said unit being configured as a thin-film evaporator with a column attachement, such that ditrimethylolpropane is obtained as a third tops fraction and high boilers are removed as a third bottoms frac
    Type: Application
    Filed: October 24, 2012
    Publication date: September 25, 2014
    Inventors: Guido D. Frey, Norman Nowotny, Kurt Schalapski, Heinz Strutz
  • Patent number: 8524047
    Abstract: A method of dehydrating tolylenediamine which includes subjecting tolylenediamine having a water content of 5-40 wt. % to first-stage distillation at a vacuum of 13-101.3 kPa and subjecting the bottoms from the first-stage distillation to second-stage distillation at a vacuum lower than 13kPa.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: September 3, 2013
    Assignee: Mitsui Chemicals Inc.
    Inventors: Toshiyuki Ogawa, Mitsunaga Dohzaki, Masaaki Sasaki
  • Patent number: 8372367
    Abstract: A method is provided for recovering boric acid from a solution containing boric acid and at least one lithium compound. The method comprises (a) passing the solution through an ion exchange resin such that boric acid accumulates on the resin; (b) removing the boric acid from the resin with an aqueous alcohol solution, thus obtaining a first solution comprising an alcohol, boric acid, and water; (c) converting at least a portion of the boric acid to trimethyl borate, thereby obtaining a second solution; (d) distilling an azeotrope from the second solution, wherein the azeotrope contains trimethyl borate; and (e) recovering boric acid from the azeotrope.
    Type: Grant
    Filed: October 25, 2010
    Date of Patent: February 12, 2013
    Assignee: EMC Metals Corporation
    Inventor: Willem P. C. Duyvesteyn
  • Patent number: 8183400
    Abstract: Embodiments of the present disclosure include processes and systems for recovering alkylene oxide. System embodiments include a stripping section located in an alkylene oxide recovery column to convert a feed stream comprising to a first gas phase portion comprising alkylene oxide, a condensing zone comprising at least a first condenser and a second condenser configured in series, and a reabsorption region located in the alkylene oxide recovery column above the last of the at least two condensers.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: May 22, 2012
    Assignee: Dow Technology Investments LLC
    Inventors: John F. Szul, James H. Mccain, Floyd L. Pfeffer, Harvey E. Andresen, Phillip R. Fairchild, Kent E. Newman
  • Patent number: 8053586
    Abstract: Systems and processes for recovering alkylene oxide, including an alkylene oxide recovery column including a stripping section located in the column to convert a portion of a feed stream to a gas phase including alkylene oxide; a reabsorption section in the column above the stripping section including a water stream to reabsorb the alkylene oxide in the gas phase portion and to produce an aqueous solution, a first stripping gas to strip carbon dioxide and oxygen from the aqueous solution by converting a portion of the aqueous solution to a gaseous portion, producing an alkylene oxide stream, and a side take-off located at a bottom portion of the reabsorption section for removal of the alkylene oxide stream; a condenser to partially condense the gas phase portion; and a top take-off for removal of a light impurity fraction.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: November 8, 2011
    Assignee: Dow Technology Investments LLC
    Inventors: Bernie B. Osborne, Fred A. Conneway, Clarence P. Stadlwieser, Harvey E. Andresen
  • Patent number: 5718810
    Abstract: A method for recovering methanol from sulfur-based wood pulping process vapors, which contain at least methanol and dimethyl disulfide. The method involves three steps. The first step consists of introducing the vapors into a first distillation tower at a vapor introduction point. The second step consists of introducing water into the first tower at a point above the vapor introduction point. The third step consists of heating liquid which is in the first tower below the vapor introduction point so that a liquid stream flows from the bottom of the first tower and a gas stream flows from the top of the first tower. The liquid stream contains most of the methanol originally in the vapors. The gas stream contains most of the dimethyl disulfide originally in the vapors. The liquid stream can then be distilled in a second distillation tower by conventional distillation to produce dry methanol. The first and third steps can be combined by introducing sufficiently heated vapors.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: February 17, 1998
    Assignee: The Dow Chemical Company
    Inventors: Lanny A. Robbins, Von G. Landon
  • Patent number: 5662780
    Abstract: A process for purifying acetic acid which comprises: introducing a feedstock aqueous solution of acetic acid having an acetic acid concentration of from 10 to 50% by weight into an extractor; supplying an extracting medium containing isopropyl acetate in an amount from 0.6 to 3.
    Type: Grant
    Filed: March 6, 1996
    Date of Patent: September 2, 1997
    Assignee: Showa Denko K.K.
    Inventors: Takaharu Sasaki, Masayuki Fujimoto, Takashige Miyanari, Hiroshi Nishino
  • Patent number: 5296104
    Abstract: Process for obtaining purified hydrogen peroxide solutions, consisting in evaporating the crude aqueous hydrogen peroxide solution containing the impurities and feeding by means of the vapour phase produced the foot of a distillation column provided in its lower part with a zone for washing the vapour phase with a small flow of liquid which refluxes in the bottom of the column and which has the same composition as the purified aqueous hydrogen peroxide solution forming the product leaving the column, in drawing off this purified product at a column height such that the draw-off is carried out above the vapour phase washing zone and in collecting at the bottom of the column a residue consisting of the small flow of washing liquid which contains most of the impurities. The washing zone has a diameter which is greater than that of the remainder of the column.Distillation column for carrying out the process.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: March 22, 1994
    Assignee: Interox International (Societe Anonyme)
    Inventors: Lido Signorini, Konstantin Glinos
  • Patent number: 5264117
    Abstract: Where side stream distillate strippers are used in the distillation of hydrocarbons, the required size of the distillation column and the amount of stripping gas or vapor required are reduced by passing components stripped from the distillates through a plurality of strippers in series, rather than directly back to the distillation zone.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: November 23, 1993
    Assignee: Sun Refining and Marketing Company
    Inventor: Gail M. DeLong
  • Patent number: 5244545
    Abstract: Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture comprising methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process comprises two distillation steps wherein acetone is separated from a mixture of methyl acetate, methyl iodide and acetone.
    Type: Grant
    Filed: October 9, 1991
    Date of Patent: September 14, 1993
    Assignee: Eastman Kodak Company
    Inventors: Steven L. Cook, Robert M. Schisla, Jr., Charles E. Outlaw, Joseph R. Zoeller
  • Patent number: 5124004
    Abstract: A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawn from the phase-contracting region of the distillation system. The return of streams withdrawn from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn.
    Type: Grant
    Filed: February 6, 1990
    Date of Patent: June 23, 1992
    Assignee: Trustees of Dartmouth College
    Inventors: Hans E. Grethlein, Lee R. Lynd
  • Patent number: 5106458
    Abstract: Methyl formate is removed from impure propylene oxide by contacting the impure propylene oxide in a treating zone with a basic ion exchange resin for a period of time sufficient to convert the methyl formate to formic acid and methanol, and by withdrawing a substantially methyl formate-free treated propylene oxide product from the treating zone.
    Type: Grant
    Filed: July 26, 1991
    Date of Patent: April 21, 1992
    Assignee: Texaco Chemical Company
    Inventors: Robert A. Meyer, Eileen T. Nguyen, William A. Smith
  • Patent number: 5064507
    Abstract: High purity phenol is obtained from cleavage of cumene hydroperoxide by treating the crude phenol product stream in a first treatment zone with an amine, a coarse distillation to obtain an overhead stream comprising phenol, alpha-methyl styrene, cumene, and impurities, and steam distillation of the overhead stream in combination with addition of an amine to the steam distillation column for a second amine treatment step.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: November 12, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Michael S. O'Donnell, Lamberto Crescentini
  • Patent number: 5057192
    Abstract: Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture containing methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process involves a water-methyl iodide extraction step wherein acetone is separated from a mixture of methyl acetate, methyl iodide and acetone.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: October 15, 1991
    Assignee: Eastman Kodak Company
    Inventors: Joseph R. Zoeller, Steven L. Cook, Charles E. Outlaw, Robert M. Schisla, Jr.
  • 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: 4902385
    Abstract: Practically anhydrous crude sec-butyl alcohol produced by catalytic direct hydration of n-butenes is freed by means of water from the azeotropically boiling and low-boiling by-products by continuous azeotropic distillation in a separation column, the prepurified anhydrous sec-butyl alcohol obtained is withdrawn and the high-boiling by-products are subsequently separated in a separate column.
    Type: Grant
    Filed: August 19, 1988
    Date of Patent: February 20, 1990
    Assignee: Deutsche Texaco Aktiengesellschaft
    Inventor: Gunther Osterburg
  • Patent number: 4898644
    Abstract: A process for removing volatile acids from aqueous solutions which involves steam stripping a volatile acid from an aqueous solution and contacting the vaporized acid with a reactable cation to form a salt of the acid. A preferred embodiment of apparatus comprises an elongated distillation column having therein a plurality of zones or stages wherein the volatile acid in the aqueous feed stream is vaporized by steam and then the vaporized acid is carried by the steam into a salt formation zone or stage to react with a reactable cation to form a salt of the acid.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: February 6, 1990
    Assignee: QO Chemicals, Inc.
    Inventor: Wendell E. Van Horn
  • Patent number: 4857151
    Abstract: Crude phenol containing methyl benzofuran and other impurities is distilled in the presence of water to recover a phenol bottoms having a reduced quantity of impurities. The water-phenol overhead is cooled to separate a water phase essentially free of methyl benzofuran, which is recycled to the distillation. The organic phase may then be further distilled, in the presence of water, as previously described, to eventually recover a reduced quantity of phenol in which impurities are concentrated.
    Type: Grant
    Filed: June 28, 1982
    Date of Patent: August 15, 1989
    Assignee: The Lummus Company
    Inventors: George D. Suciu, Ali M. Khonsari, Jamin Chen
  • Patent number: 4851086
    Abstract: Crude phenol, containing AMS by-product, and MBF impurity, is distilled in the presence of water to separate MBF impurity.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: July 25, 1989
    Assignees: The Lummus Company, Allied Corporation
    Inventors: Ali M. Khonsari, Jamin Chen, George D. Suciu, William B. Fisher, Lamberto Crescentini
  • Patent number: 4744869
    Abstract: A process for purifying methanol which comprises introducing crude synthetic methanol obtained by catalytic reaction of carbon oxide and hydrogen into a rectifying column either as such or after it is first introduced into a topping column and distilled with or without the addition of water to remove low-boiling components from the top of the topping column, and distilling it in the rectifying column to withdraw purified methanol from the top of the column and mainly water from the bottom of the column; wherein an auxiliary distillation column is provided side by side with the rectifying column, and the rectifying column and the auxiliary distillation column are operated under particular conditions.
    Type: Grant
    Filed: August 18, 1986
    Date of Patent: May 17, 1988
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Yoshihiko Saito, Osamu Hashimoto
  • Patent number: 4740273
    Abstract: A process for purifying diethoxymethane from a mixture containing ethanol and, optionally, water. The process involves the addition of an amount of water, DEM, or an appropriate mixture of any two or three of water, DEM and ethanol that is effective in moving the mixture into the two liquid phase region on an equilibrium tie-line which crosses the critical distillation boundary without the need for additional azeotrope-forming agents such as cyclohexane.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: April 26, 1988
    Assignee: Eastman Kodak Company
    Inventors: Daniel L. Martin, Peter W. Raynolds
  • Patent number: 4566947
    Abstract: A two-stage distillation method for separating a mixed liquid such as a dimethylformamide-containing aqueous liquid or a methanol-containing aqueous liquid, into light and heavy fractions. The mixed liquid is first subjected to a distillation treatment in a first distillation zone of a vapor recompression type. When the boiling point of the mixed liquid is close to that of the desired light fraction, the top product from the first distillation zone is recovered as the light fraction, while the bottom product is subjected to a further distillation treatment to obtain the heavy fraction as its bottom product. When the boiling point of the mixed liquid is close to that of the heavy fraction, the bottom product from the first distillation zone is recovered as the heavy fraction, while the top product from the first distillation zone is subjected to a further distillation treatment to obtain the light fraction as its top product.
    Type: Grant
    Filed: December 21, 1984
    Date of Patent: January 28, 1986
    Inventor: Hidemasa Tsuruta
  • Patent number: 4532012
    Abstract: Phenol containing MBF impurity is distilled in the presence of water and an extraction solvent for MBF (preferably AMS and/or cumene) to recover a phenol bottoms having reduced impurities. The use of solvent permits a reduction in the amount of water used, which reduces the amount of phenol in the overhead, thereby lowering costs.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: July 30, 1985
    Assignee: The Lummus Company
    Inventors: Ali M. Khonsari, George D. Suciu
  • 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: 4511437
    Abstract: A process for continuous rectification of a liquid mixture containing alcohols, particularly a liquid fermate, employs a plurality of distillation columns to which the liquid mixture is fed in parallel, and which have successively reduced operating pressures and temperatures from an initial one to a final one thereof. The top vapor distillate from the higher-pressure columns supplies driving heat to the sumps of the next successively lower-pressure columns. Direct steam at 130.degree. C. to 160.degree. C. is fed to the sump of the column operated at the highest pressure. Direct steam is generated by indirect heat exchange of water with the top vapor withdrawn from the columns, and the resulting direct steam is fed to the sumps of the next-lower-pressure columns. The apparatus can also include a section for the production of absolute alcohol.
    Type: Grant
    Filed: November 4, 1982
    Date of Patent: April 16, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Heck, Aladar Lienerth, Egon Malow, Karl-Heinz Schwarz, Uwe Faust
  • Patent number: 4504364
    Abstract: In the production of high purity phenol, a water-phenol mixture recovered from the top of a distillation column is contacted with a water immiscible solvent to extract methyl benzofuran and other by-products and impurities in phenol production therefrom, with the extraction being accomplished at a temperature at which the water-phenol mixture is present as a single phase liquid. The remaining mixture of phenol and water is recycled to the distillation.
    Type: Grant
    Filed: June 28, 1982
    Date of Patent: March 12, 1985
    Assignee: The Lummus Company
    Inventors: Jamin Chen, Ali M. Khonsari, George D. Suciu
  • Patent number: 4434029
    Abstract: A process for producing an unsaturated nitrile with saved energy by which the bottom stream from a recovery column is used as the heat source for at least one distillation column in the process and thereafter used to pre-heat a recovery column feed withdrawn from the bottom of an absorption column, characterized in that the bottom stream of the absorption column is previously heated by at least one source of waste heat in the process, the source being selected from (1) the circulating water in the quenching column, (2) the overhead vapor of the absorption column, (3) the overhead vapor of a dehydration column and (4) the overhead vapor of a product column.
    Type: Grant
    Filed: December 2, 1981
    Date of Patent: February 28, 1984
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Shigeru Kurihara, Hiroyuki Ohashi
  • 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: 4342627
    Abstract: The present invention relates to a continuous process for producing substantially anhydrous alcohols from aqueous solutions thereof by distilling a mixture of aqueous alcohol and an entrainer to a drying column withdrawing an azeotrope as a distillate and continuously recovering anhydrous alcohol with less than 0.1% by weight of water from the base of the drying column. The improvement resides in feeding the distillate to a condenser and introducing (a) the condensate therefrom in a substantially non-turbulent state into a decanter at a point close to the interface between the aqueous and organic phases present therein and (b) a specified amount of water, which is less than 0.25 volumes per volume of the anhydrous alcohol recovered, into the drying column at a point adjacent to that at which the organic hydrocarbon phase is returned as reflux.
    Type: Grant
    Filed: April 16, 1981
    Date of Patent: August 3, 1982
    Assignee: BP Chemicals Limited
    Inventors: Charles Cane, Bertram Yeomans
  • 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: 4238295
    Abstract: Substantial operating cost savings are realized in the recovery of acrylonitrile from an aqueous solution containing acrylonitrile by using the recovery column bottoms stream to provide heat to one or more distillation columns in the process.
    Type: Grant
    Filed: December 4, 1978
    Date of Patent: December 9, 1980
    Assignee: Standard Oil Company
    Inventor: Paul S. Odom
  • Patent number: 4070254
    Abstract: A process for preparing a purified methacrylic acid ester from a crude methacrylic acid ester containing an isobutyric acid ester as an impurity, comprising the steps of azeotropically distilling the crude methacrylic acid ester in the presence of water to separate as the top distillate the isobutyric acid ester and water together with a small amount of the methacrylic acid ester and recover as the bottoms the greater part thereof, separating the distillate into aqueous and organic phases and further azeotropically distilling the separating organic phase in the presence of water to separate as the distillate the isobutyric acid ester and water together with a very small amount of the methacrylic acid ester and recover as the bottoms the remainder thereof, thereby obtaining the purified methacrylic acid ester.
    Type: Grant
    Filed: June 7, 1976
    Date of Patent: January 24, 1978
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Ryoji Sato, Takanori Musha
  • Patent number: 4046641
    Abstract: A process and apparatus for the regeneration of washing oil which has been spent to recover naphthalene and/or benzol from coke oven gas. The spent washing oil is stripped by steam in a bubble column arranged as an integral part of a single main column that includes first, second and third exchange column sections disposed in a superimposed relation one above the other to receive the stripped vapors from the bubble column. The first exchange column section is fed with a mixture of toluene, xylene and naphthalene as a reflux, the second exchange column section is fed with water as the reflux and the third exchange column section is fed with benzol as the reflux. The head product from the column is condensed and passed through a first-phase separator to obtain a substantially anhydrous benzol fraction and a water fraction. These fractions are separately used as a reflux for the second and third exchange column sections.
    Type: Grant
    Filed: March 12, 1975
    Date of Patent: September 6, 1977
    Assignee: Dr. C. Otto & Comp. G.m.b.H.
    Inventor: Hansjurgen Ullrich
  • Patent number: 4008130
    Abstract: Fluorosilicic acid solutions, which normally undergo decomposition when distilled, thereby creating unwanted forms of SiO.sub.2, are rendered stable during distillation by providing in the fluorosilicic acid solution an amount of HF which is at least about 10 parts of HF per 36 parts of H.sub.2 SiF.sub.6 and an amount of H.sub.2 O which is at least about 54 parts of H.sub.2 O per 36 parts of H.sub.2 SiF.sub.6. The mixture is distilled to remove any excess H.sub.2 O and excess HF that is present, without encountering formation of SiO.sub.2, until an azeotropic solution containing about 36% H.sub.2 SiF.sub.6, about 10% HF and about 54% H.sub.2 O is reached. The ternary azeotrope, being of constant quality and concentration, is more suitable for use in various processes, such as processes for making fumed SiO.sub.2, than H.sub.2 SiF.sub.6 solutions which are not of constant quality or concentration.
    Type: Grant
    Filed: February 23, 1976
    Date of Patent: February 15, 1977
    Assignee: The Dow Chemical Company
    Inventors: Joel F. M. Leathers, Donald W. Calvin
  • Patent number: 3960672
    Abstract: Pure C.sub.1 -C.sub.3 alkanols are prepared from crude water containing alcohols in a continuous distillation process which includes an extractive distillation zone into which water and crude alcohols are introduced and from which is removed an impurities stream and a dilute aqueous alcohol stream; an alcohol concentration zone into which is introduced a dilute alcohol stream from the extractive distillation zone from which is withdrawn pure concentrated alcohols, a low boiling impurities stream and a high boiling impurities stream; and an impurities concentration zone into which is introduced the impurities stream from the extractive distillation zone and the high and low boiling impurities streams from the alcohol concentration zone from which is withdrawn high and low boiling impurities and an alcohol containing stream which is recycled to the extractive distillation zone with the crude alcohols.
    Type: Grant
    Filed: June 21, 1974
    Date of Patent: June 1, 1976
    Assignee: Veba-Chemie AG
    Inventors: Wilhelm Ester, deceased, by Brigitte Lovis, nee Ester, heir, by Wolfgang Ester, heir, Wilhelm Heitmann
  • Patent number: 3940450
    Abstract: Methyl tertiary butyl ether may be recovered from etherification reaction effluent by azeotropic distillation to recover methanol-ether azeotrope overhead which latter is azeotropically distilled in the presence of n-pentane to give pure ether bottoms substantially free of water and methanol.
    Type: Grant
    Filed: December 16, 1974
    Date of Patent: February 24, 1976
    Assignee: Texaco Inc.
    Inventor: Kung-You Lee