Heterocyclic Patents (Class 203/58)
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Patent number: 5772853Abstract: 1-Propanol and t-amyl alcohol cannot be separated by distillation or rectification because of the closeness of their boiling points. 1-Propanol is readily separated from t-amyl alcohol by extractive distillation. Effective agents are dipentene, amyl acetate and 1,4-dioxane.Type: GrantFiled: November 17, 1997Date of Patent: June 30, 1998Inventor: Lloyd Berg
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Patent number: 5738763Abstract: 2-Methyl-1-propanol is difficult to separate from 2-methyl-1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be readily separated from 2-methyl-1-butanol by extractive distillation. Effective agents are hexyl formate, 2-heptanone and dipropyl amine.Type: GrantFiled: July 8, 1996Date of Patent: April 14, 1998Inventor: Lloyd Berg
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Patent number: 5723026Abstract: The production of high purity benzene and high purity toluene is obtained by utilizing the initial gas separating column for the treatment of the aromatic containing starting material as a separating column for separating a benzene rich from a toluene rich component. The benzene rich component is subject directly to distillation while the toluene is subject to predistillation to separate high boiling components and only then to extractive distillation is distilled to separate the high purity benzene from the high purity toluene.Type: GrantFiled: August 18, 1995Date of Patent: March 3, 1998Assignee: Krupp Koppers GmbHInventors: Martin Leisse, Hans-Jurgen Vollmer, Uwe Ranke
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Patent number: 5723024Abstract: 2-Methyl-1-propanol is difficult to separate from 1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be readily separated from 1-butanol by extractive distillation. Effective agents are ethyl benzene, amyl acetate and propoxypropanol.Type: GrantFiled: August 26, 1996Date of Patent: March 3, 1998Inventor: Lloyd Berg
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Patent number: 5723025Abstract: 2-Methyl-1-propanol is difficult to separate from 2-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be readily separated from 2-butanol by extractive distillation. Effective agents are hexyl acetate, dimethyl phthalate and p-xylene.Type: GrantFiled: September 19, 1996Date of Patent: March 3, 1998Inventor: Lloyd Berg
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Patent number: 5720857Abstract: 1,2,4-Trimethylbenzene is difficult to sepparate from 1,2,3-trimethylbenzene because of the proximity of their boiling points. They are readily separated by azeotropic distillation. Effective agents are 1-propanol, methyl formate and 1-nitropropane.Type: GrantFiled: January 2, 1997Date of Patent: February 24, 1998Inventor: Lloyd Berg
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Patent number: 5718809Abstract: T-Amyl alcohol and 2-methyl-1-propanol are difficult to separate by conventional distillation or rectification because of the proximity of their boiling points. T-Amyl alcohol can be easily separated from 2-methyl-1-propanol by extractive distillation. Effective agents are N,N-dimethylacetamide, cyclohexyl amine and glycerol.Type: GrantFiled: April 8, 1997Date of Patent: February 17, 1998Inventor: Lloyd Berg
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Patent number: 5716499Abstract: 2-Methyl-1-propanol is difficult to separate from 1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be easily separated from 1-butanol by azeotropic distillation. Effective agents are isobutyl acetate, methyl cyclohexane and 2-nitropropane.Type: GrantFiled: August 12, 1996Date of Patent: February 10, 1998Inventor: Lloyd Berg
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Patent number: 5705038Abstract: Phellandrene is difficult to separate from limonene by conventional distillation or rectification because of the proximity of their boiling points. Phellandreneecan be readily separated from limonene by extractive distillation. Effective agents are o-cresol, tripropylene glycol and isophorone.Type: GrantFiled: November 25, 1996Date of Patent: January 6, 1998Inventor: Lloyd Berg
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Patent number: 5693193Abstract: Propylene oxide is recovered through the use of an additive in a distillation solution, resulting in suppressed side reactions and reduced loss of product. Propylene oxide is produced by oxidizing ethylbenzene in a liquid phase with molecular oxygen to a obtain a reaction liquid containing ethylbenzene hydroperoxide; distilling the reaction liquid to obtain a concentrated solution of ethylbenzene hydroperoxide; further mixing and reacting the concentrated solution with propylene to obtain a mixed solution containing propylene oxide; and distilling the mixed solution to separate and recover propylene oxide. At least one compound selected from aliphatic saturated alcohols having 2 to 4 carbon atoms, allyl alcohol, saturated aliphatic hydrocarbons having 6 or 7 carbon atoms, benzene, ethers, ketones, nitriles, amines, pyridines, diamines, and aminoalcohols is added to the mixed distillation solution in an amount of 0.01-100 parts by weight per 100 parts by weight of propylene oxide.Type: GrantFiled: March 23, 1995Date of Patent: December 2, 1997Assignee: Sumitomo Chemical Company, LimitedInventors: Takashi DeGuchi, Kazuo Kimura, Naoto Meki, Masaru Ishino, Tetsuya Suzuta
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Patent number: 5693194Abstract: Butyraldehyde cannot be separated from ethanol by conventional distillation or rectification because they form a minimum boiling azeotrope. Butyraldehyde can be readily separated from ethanol by extractive distillation. Effective agents are 2-propanol, m-xylene and dimethylsulfoxide.Type: GrantFiled: November 25, 1996Date of Patent: December 2, 1997Inventor: Lloyd Berg
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Patent number: 5658435Abstract: 2-Methyl-1-propanol is difficult to separate from 2-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be easily separated from 2-butanol by azeotropic distillation. Effective agents are sulfolane, acetonitrile and acetal.Type: GrantFiled: September 17, 1996Date of Patent: August 19, 1997Inventor: Lloyd Berg
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Patent number: 5659095Abstract: A polymerization inhibitor composition for inhibiting the polymerization of aromatic vinyl monomers at elevated temperatures comprising:(a) a benzofuroxan derivative of the formula ##STR1## wherein R is C.sub.1 -C.sub.4 alkyl or alkoxy; R.sup.1 is a nitro group; and m and n are each independently 0, 1, or 2; and(b) a solvent selected from the group consisting of toluene, xylene, ethylbenzene, vinyltoluene, divinylbenzene, alpha-methylstyrene, and a C.sub.12 -C.sub.18 hydrocarbon,and methods for inhibiting the polymerization of aromatic vinyl monomers at elevated temperatures using this composition.Type: GrantFiled: March 13, 1996Date of Patent: August 19, 1997Assignee: Uniroyal Chemical Company, Inc.Inventors: Howard Stephen Friedman, Gerald John Abruscato, John Matthew DeMassa, Anthony Vincent Gentile, Anthony Vincent Grossi
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Patent number: 5645695Abstract: 2-Methyl-1-propanol is difficult to separate from 2-methyl-1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-propanol can be readily separated from 2-methyl-1-butanol by azeotropic distillation. Effective agents are tetrahydrofuran, methyl acetate and toluene.Type: GrantFiled: July 8, 1996Date of Patent: July 8, 1997Inventor: Lloyd Berg
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Patent number: 5582693Abstract: 3-Carene and limonene cannot be separated from each other by rectification because of the closeness of their boiling points. They are readily separated by azeotropic distillation. Effective agents are: cyclopentanol, 2-nitropropane, ethyl formate amyl acetate dimethyl carbonate, tetrahydrofuran, acetic acid and 2-amino-amethyl-1-propanol.Type: GrantFiled: January 11, 1996Date of Patent: December 10, 1996Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5538599Abstract: A process is provided whereby phenol is separated from 1-phenyl ethanol, acetophenone or mixtures by extractive distillation with sulfolane as extractive distillation agent which decreases phenol volatility relative to 1-phenyl ethanol and acetophenone.Type: GrantFiled: June 5, 1995Date of Patent: July 23, 1996Assignee: ARCO Chemical Technology, L.P.Inventors: Tim T. Wong, Stephen H. Harris, Thomas S. Zak, Te Chang
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Patent number: 5470443Abstract: Isopropanol is difficult to separate from 2-butanone by conventional distillation or rectification because of the proximity of their boiling points. Isopropanol can be readily separated from 2-butanone by extractive distillation. Effective agents are o-cresol, ethylene glycol and nitroethane.Type: GrantFiled: January 10, 1995Date of Patent: November 28, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5466345Abstract: o-Xylene cannot be separated from p-xylene and m-xylene by conventional distillation or rectification because of the proximity of their boiling points. o-Xylene can be readily separated from mixtures of p-xylene and m-xylene by azeotropic distillation. Effective agents are 3-methyl-1-butanol, methyl propionate and 3-pentanone.Type: GrantFiled: May 31, 1995Date of Patent: November 14, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5458741Abstract: Benzene is difficult to separate from cyclohexane or cyclohexene by conventional distillation or rectification because of the close proximity of their boiling points. Benzene can be readily separated from cyclohexane or cyclohexene by using extractive distillation. Effective agents are: for benzene from cyclohexane, methyl acetoacetate; for benzene from cyclohexene, ethyl acetoacetate.Type: GrantFiled: January 14, 1994Date of Patent: October 17, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5453166Abstract: Ethanol is impossible to separate from 2-butanone by conventional distillation or rectification because of the minimum boiling azeotrope between these two. Ethanol can be readily separated from 2-butanone by extractive distillation. Effective agents are dipromyl amine, phenol and dimethylsulfoxide.Type: GrantFiled: November 7, 1994Date of Patent: September 26, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5445716Abstract: Ethanol is difficult to separate from isopropanol by conventional distillation or rectification because of the proximity of their boiling points. Ethanol can be readily separated from isopropanol by extractive distillation. Effective agents are dipentene, anisole and ethyl benzene.Type: GrantFiled: October 18, 1994Date of Patent: August 29, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5439561Abstract: 3-Methyl-2-butanol is difficult to separate from 2-pentanol by conventional distillation or rectification because of the proximity of their boiling points. 3-Methyl-2-butanol can be readily separated from 2-pentanol by azeotropic distillation. Effective agents are 2,2-dimethyl butane, ethyl acetate and dioxane.Type: GrantFiled: November 28, 1994Date of Patent: August 8, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5437770Abstract: Ethanol is difficult to separate from isopropanol by conventional distillation or rectification because of the proximity of their boiling points. Ethanol can be readily separated from isopropanol by azeotropic distillation. Effective agents are sec. butyl acetate, hexene-1 and 1,3-dioxolane.Type: GrantFiled: September 13, 1994Date of Patent: August 1, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5436211Abstract: The invention concerns a process for the recovery of a solvent adsorbed in an adsorber, or other substances which are condensable. The adsorber (3) is, at first, heated to a temperature which is below the decomposition temperature of the solvent, then the adsorber chamber (2) is sealed off from the surroundings and a high negative pressure is applied to the adsorber chamber (2), as a result of which the solvent is desorbed. During a portion of the time when this high negative pressure is applied, the temperature of the adsorber (3) is brought to a value which is above the decomposition temperature of the solvent. In spite of this, there is no decomposition under the noted conditions, however, the high temperature does enable an almost complete desorption of the solvent. Finally, the desorbed solvent is drawn off from the adsorber chamber (2) and condensed.Type: GrantFiled: February 1, 1993Date of Patent: July 25, 1995Assignee: Pero KGInventor: Horst Erbel
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Patent number: 5425854Abstract: Methylene chloride is difficult to separate from tetrahydrofuran by conventional distillation or rectification because of the proximity of their vapor pressures. Methylene chloride can be readily separated from tetrahydrofuran by extractive distillation. Effective agents are 1-pentanol, 1,2-butanediol and 3-nitrotoluene.Type: GrantFiled: January 17, 1995Date of Patent: June 20, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5421965Abstract: Glycerine is difficult to separate from bis(hydroxymethyl)tetrahydrofuran by conventional distillation or rectification because of the proximity of their boiling points. Glycerine can be readily separated from bis(hydroxymethyl)tetrahydrofuran by azeotropic distillation. Effective agents are m-xylene, beta-pinene and dicyclopentadiene.Type: GrantFiled: August 1, 1994Date of Patent: June 6, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5407540Abstract: 3-Methyl-2-butanol is difficult to separate from 1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 3-Methyl-2-butanol can be readily separated from 1-butanol by extractive distillation. Effective agents are ethyl n-valerate, dimethylacetamide and dimethylsulfoxide.Type: GrantFiled: September 23, 1994Date of Patent: April 18, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5407541Abstract: 3-Methyl-2-butanol is difficult to separate from 2-pentanol by conventional distillation or rectification because of the proximity of their boiling points. 3-Methyl-2-butanol can be readily separated from 2-pentanol by azeotropic distillation. Effective agents are pentane, 2,2-dimethyl butane and dioxane.Type: GrantFiled: September 13, 1994Date of Patent: April 18, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5407542Abstract: 3-Methyl-2-butanol is difficult to separate from 1-butanol by conventional distillation or rectification because of the proximity of their boiling points. 3-Methyl-2-butanol can be readily separated from 1-butanol by azeotropic distillation. Effective agents are methyl acetoacetate and dioxane.Type: GrantFiled: September 13, 1994Date of Patent: April 18, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5405505Abstract: Benzene is difficult to separate from cyclohexane or cyclohexene by conventional distillation or rectification because of the close proximity of their boiling points. Benzene can be readily separated from cyclohexane or cyclohexene by using azeotropic distillation. Effective agents are: for benzene from cyclohexane, dimethoxymethane; for benzene from cyclohexene, methanol.Type: GrantFiled: January 14, 1994Date of Patent: April 11, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5405504Abstract: 1-Decene is impossible to separate from 2-octanone by conventional distillation or rectification because the two compounds form a minimum boiling azeotrope. 1-Decene can be readily separated from 2-octanone by azeotropic distillation. Effective agents are 1-propanol, 2-ethoxyethanol, and methanol.Type: GrantFiled: January 31, 1994Date of Patent: April 11, 1995Assignee: Lloyd BergInventors: Lloyd Berg, Randy W. Wytcherley
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Patent number: 5403448Abstract: 1-Decene is difficult to separate from 2-octanone by conventional distillation or rectification because of the proximity of their boiling points. 1-Decene can be readily separated from 2-octanone by azeotropic distillation. Effective agents are butyl propionate and 1-propanol.Type: GrantFiled: January 14, 1994Date of Patent: April 4, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5401365Abstract: A process is provided for separating benzene from non-aromatics in a highly aromatic stream containing olefins in a concentration range of from about 0.05 to about 5.0, which process comprises predistilling said highly aromatic stream to produce a distilled fraction having a concentration of C.sub.8 and heavier compounds of less than about 0.1 wt percent; and extracting said distilled fraction with a solvent comprising substituted morpholines in an extractive distillation zone to produce a highly-pure benzene stream.Type: GrantFiled: October 27, 1993Date of Patent: March 28, 1995Assignee: Chevron Research & TechnologyInventors: George T. Chen, Brenda M. Balaban, Gerd Emmrich, Bernhard Firnhaber
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Patent number: 5399244Abstract: Benzene and other aromatics are separated from a stream of mixed hydrocarbons containing both aromatics and non-aromatics by extractive distillation with a solvent system containing dimethyl sulfoxide and optionally a co-solvent, preferably water, followed by distillation stripping of the aromatics from the enriched solvent system, and recycle of the lean solvent system to the extractive distillation step.Type: GrantFiled: December 6, 1993Date of Patent: March 21, 1995Assignee: Glitsch, Inc.Inventors: Joseph C. Gentry, Lloyd Berg, John C. McIntyre, Randa W. Wytcherley
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Patent number: 5393385Abstract: Hexane is difficult to separate from vinyl acetate and/or methyl acrylate by conventional distillation or rectification because of the closeness of their boiling points. Hexane can be readily separated from vinyl acetate and/or methyl acrylate by extractive distillation. Effective agents are dimethylsulfoxide and dimethylformamide.Type: GrantFiled: March 14, 1994Date of Patent: February 28, 1995Assignee: Lloyd BergInventors: Lloyd Berg, Randi W. Wytcherley
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Patent number: 5391264Abstract: alpha-Phellandrene is difficult to separate from d-limonene by conventional distillation or rectification because of the proximity of their boiling points. alpha-Phellandrene can be readily separated from d-limonene by azeotropic distillation. Effective agents are n-butyl acetate and sulfolane.Type: GrantFiled: March 14, 1994Date of Patent: February 21, 1995Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5360520Abstract: 2-Butanol is difficult to separate from t-amyl alcohol by conventional distillation or rectification because of the proximity of their boiling points. 2-Butanol can be readily separated from t-amyl alcohol by extractive distillation. Effective agents are methyl caproate, adiponitrile and cyclopentanone.Type: GrantFiled: January 18, 1994Date of Patent: November 1, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5348625Abstract: Ethanol is difficult to separate from isopropanol by conventional distillation or rectification because of the proximity of their boiling points. Ethanol can be readily separated from isopropanol by extractive distillation. Effective agents are methyl caproate, cyclopentane and isobutyl acetate.Type: GrantFiled: January 14, 1994Date of Patent: September 20, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5338410Abstract: 2-Butanol is difficult to separate from t-amyl alcohol by conventional distillation or rectification because of the proximity of their boiling points. 2-Butanol can be readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are ethyl acetoacetate, nitroethane and 3-pentanone.Type: GrantFiled: January 18, 1994Date of Patent: August 16, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5338411Abstract: Ethanol is difficult to separate from isopropanol by conventional distillation or rectification because of the proximity of their boiling points. Ethanol can be readily separated from isopropanol by azeotropic distillation. Effective agents are methyl ethyl ketone, cyclopentane and 2-pyrrolidinone.Type: GrantFiled: January 14, 1994Date of Patent: August 16, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5332478Abstract: 1-Propanol is difficult to separate from 2-butanol by conventional distillation or rectification because of the proximity of their boiling points. 1-Propanol can be readily separated from 2-butanol by azeotropic distillation. Effective agents are t-butyl methyl ether, 1,4-dioxane and ethyl formate.Type: GrantFiled: January 14, 1994Date of Patent: July 26, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5320715Abstract: 1-Pentanol is difficult to separate from cyclopentanol by conventional distillation or rectification because of the closeness of their boiling points. 1-Pentanol can be readily separated from cyclopentanol by extractive distillation. Effective agents are ethylene glycol and sulfolane.Type: GrantFiled: January 14, 1994Date of Patent: June 14, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5288370Abstract: For the separation of butenes and butanes by extractive distillation, a charge mainly containing butenes and butanes is contacted in an extractive distillation column under pressure with a first selective polar solvent, S1 (e.g., dimethyl formamide), the butanes being collected at the top. The solvent S1 containing the butenes and passing out at the bottom is mixed with a second solvent, S2, having a boiling point intermediate between that of butenes and that of the solvent S1, the mixture passing into a desorption column under pressure, where the butenes are collected at the top. The mixture of solvent S1 and S2 is separated in a purification column under atmospheric pressure, the solvent S2 passing out at the top is recycled to the desorption column, and the solvent S1 passing out at the bottom is recycled to the extractive distillation column.Type: GrantFiled: March 20, 1992Date of Patent: February 22, 1994Assignee: Institut Francais Du PetroleInventors: Lionel Asselineau, Alexandre Rojey
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Patent number: 5277766Abstract: Heptane cannot be removed from heptane-vinyl acetate mixtures by distillation because of the minimum boiling azeotrope. Heptane can be readily removed from vinyl acetate by extractive distillation. Typical effective agents are dimethylsulfoxide, phenol, diisobutyl ketone and hexyl acetate.Type: GrantFiled: March 30, 1993Date of Patent: January 11, 1994Assignee: Lloyd BergInventor: Lloyd Berg
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Patent number: 5242550Abstract: For the separation of butanes and butenes by extractive distillation, a charge mainly containing butanes and butenes is contacted in an extractive distillation column under pressure with a polar solvent (e.g., dimethyl formamide), the butanes being collected at the head. The solvent containing the butenes passes into a second column under pressure, where the butenes are partly desorbed and collected at the head. The solvent still containing butenes is purified in a third column under atmospheric pressure and the solvent-containing vapor distillate thereof is returned, after compression, to the lower part of the second column.Type: GrantFiled: February 26, 1992Date of Patent: September 7, 1993Assignee: Institut Francais du PetroleInventors: Lionel Asselineau, Paul Mikitenlo
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Patent number: 5240567Abstract: The separation of vinyl acetate from methyl acrylate by distillation is difficult because of the closeness of their boiling points. Vinyl acetate can be readily removed from methyl acrylate by extractive distillation. Typical effective agents are phenol, methoxyethanol and isobutyl vinyl ether.Type: GrantFiled: April 2, 1993Date of Patent: August 31, 1993Assignee: Lloyd BergInventors: Lloyd Berg, Randi W. Wytcherley
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Patent number: 5238540Abstract: The method of obtaining a pure aromatic hydrocarbon from a hydrocarbon starting mixture includes extractively distilling the hydrocarbon starting mixture with a selective solvent; feeding the sump product of the extractive distillation through a first and second auxiliary boilers connected in series to form a cooled sump product at a temperature from 105.degree. to 120.degree. C.Type: GrantFiled: September 26, 1991Date of Patent: August 24, 1993Assignee: Krupp Koppers GmbHInventors: Luzian Skatulla, Hans-Christoph Schneider, Hans-Jurgen Vollmer
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Patent number: 5236559Abstract: Hexane cannot be removed from hexane--vinyl acetate--methyl acrylate mixtures because of the ternary azeotrope. Hexane can be readily removed from hexane--vinyl acetate--methyl acrylate mixtures by extractive distillation. Typical effective agents are phenol, diethylene glycol methyl ether and 2-nitropropane.Type: GrantFiled: January 22, 1993Date of Patent: August 17, 1993Assignee: Lloyd BergInventors: Lloyd Berg, Randi W. Wytcherley
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Patent number: 5234553Abstract: Process for obtaining a pure hydrocarbon from a starting material containing the hydrocarbon including performing an extractive distillation of the starting material containing the hydrocarbon in an extractive distillation column using a solvent comprising an N-substituted morpholine having substituents with no more than seven carbon atoms; feeding the sump product of the extractive distillation column into a distillation separator column at an entry point in a center portion of the distillation separator column; distilling off the hydrocarbon from the top of the distillation separator column but advantageously returning a minor portion of it as a reflux; drawing off solvent from the sump of the distillation separator column; feeding the solvent drawn off from the sump of the distillation separator column into an evaporator to form a vapor in the evaporator at the pressure, p.sub.2, the pressure p.sub.2 in the evaporator being lower than the pressure p.sub.Type: GrantFiled: July 22, 1992Date of Patent: August 10, 1993Assignee: Krupp Koppers GmbHInventors: Martin Kaiping, Udo Klaumunzner, Hans-Christoph Schneider, Hans-Jurgen Vollmer
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Patent number: 5230778Abstract: A method for the separation of Isoflurane from its admixture with other compounds produced in the chlorination of 2-difluoromethoxy-1,1,1-trifluoroethane including subjecting the mixture to distillation, distilling off the Isoflurane and effecting said distillation as an extractive distillation employing an extractive solvent which retards the vapor pressure of Isoflurane.Type: GrantFiled: May 1, 1992Date of Patent: July 27, 1993Assignees: Gavlin Associates, Halocarbon Product CorporationInventors: Gilbert Gavlin, Boris Goltsin