And Returning Distillation Product To A Previous Distillation Zone Patents (Class 203/82)
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Patent number: 4277314Abstract: A process for isolating 1,3-butadiene by means of a selective solvent from a C.sub.4 -hydrocarbon mixture which contains 1,3-butadiene, propyne, hydrocarbons which are more soluble than 1,3-butadiene in the selective solvent and hydrocarbons which are less soluble than 1,3-butadiene in the selective solvent, wherein the C.sub.4 -hydrocarbon mixture is separated, using one or more extractive distillation zones, into a distillate containing the less soluble hydrocarbons, a stream of 1,3-butadiene and a stream containing the more soluble hydrocarbons, and the propyne is separated off either by distillation of the C.sub.Type: GrantFiled: May 18, 1979Date of Patent: July 7, 1981Assignee: BASF AktiengesellschaftInventors: Alfred Lindner, Klaus Volkamer, Ulrich Wagner
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Patent number: 4272344Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to elevated temperatures in a distillation system in the presence of a new polymerization inhibitor comprising 2,6-dinitro-p-cresol. Also disclosed is a distillation method and apparatus for use with this inhibitor.Type: GrantFiled: August 30, 1979Date of Patent: June 9, 1981Assignee: Cosden Technology, Inc.Inventor: James M. Watson
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Patent number: 4189354Abstract: The instant invention is directed to a process for the production of diisocyanatodiphenyl methane isomers having an adjusted content of chlorine compounds comprising:(a) separating diisocyanatodiphenyl methane isomers from a polyisocyanate mixture of the diphenyl methane series in a first distillation stage,(b) subjecting said separated isomers to a second distillation stage using a recycle ratio of from 0.1 to 10 and wherein from 0.5 to 10% by weight of the feed into said second distillation stage is run off as the sump product,(c) subjecting the head product of said second distillation stage to a third distillation stage whereby readily volatile impurities are freed therefrom, and(d) working up the sump product of said third distillation stage to obtain purified 4,4'-diisocyanatodiphenyl methane and, optionally, purified 2,4'-diisocyanatodiphenyl methane.Type: GrantFiled: May 22, 1978Date of Patent: February 19, 1980Assignee: Bayer AktiengesellschaftInventors: Gunther Ellendt, Hermann Fischer, Peter Fischer
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Patent number: 4170548Abstract: An energy efficient process for the separation of two close boiling point components contained in a multi-component feed stream. The feed stream is distilled in a first column to produce a relatively light fraction containing substantially all the more volatile close boiling point component, along with part of the less volatile close boiling point component and a bottoms product. The relatively light overhead fraction from the first column is fed to a second column to produce an overhead product, consisting substantially of the more volatile close boiling point component and a bottoms product consisting substantially of the less volatile boiling point component. The bottoms product from the first column is fed to a third column to produce an overhead vapor consisting substantially of the less volatile close boiling point component, which overhead vapor is passed to the second column to supply part of the reboiling energy requirements for said column.Type: GrantFiled: November 4, 1977Date of Patent: October 9, 1979Assignee: Dresser Engineering CompanyInventor: Ralph G. Ruth
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Patent number: 4166774Abstract: 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: GrantFiled: December 5, 1977Date of Patent: September 4, 1979Assignee: The Standard Oil CompanyInventor: David R. Wagner
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Patent number: 4166771Abstract: A mixture of C.sub.4 -hydrocarbons is extractively distilled with sulfolane and acetone or methylethyl ketone as the selective solvent; the rich solvent containing 1,3-butadiene and vinylacetylene is stripped and a small quantity of the ketone is allowed to leave overhead. Thereby the further fractionation of the stripper overhead results in a very efficient separation of 1,3-butadiene and vinylacetylene.Type: GrantFiled: March 23, 1977Date of Patent: September 4, 1979Assignee: Phillip Petroleum CompanyInventors: Donald M. Haskell, Clarence G. Houser, Fred T. Sherk
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Patent number: 4163695Abstract: An accumulator vessel is divided into two compartments by an overflow baffle divider and is used in combination with two fractionators. Overhead product from a first fractionator is passed into the first compartment of the accumulator. Liquids from the first compartment pass to the second fractionator as feed. Bottoms product from the second fractionator then passes to the second accumulator compartment from which it is passed as preferred reflux for the first fractionator.Type: GrantFiled: September 1, 1977Date of Patent: August 7, 1979Assignee: Phillips Petroleum CompanyInventor: Paul H. Archerd
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Patent number: 4134797Abstract: A process for the recovery of ethylene oxide containing low levels of aldehydic impurities from an impure aqueous ethylene oxide solution containing the same is provided in which the impure solution is treated in a novel multi-stage, countercurrent distillation zone for improved separation of said aldehydic impurities and recovery of an ethylene oxide-containing product stream having the desired low concentration of aldehydic impurities.Type: GrantFiled: February 21, 1978Date of Patent: January 16, 1979Assignee: Halcon Research & Development CorporationInventor: Brian J. Ozero
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Patent number: 4131538Abstract: A method and apparatus for separating a predetermined fraction from a crude oil includes preheating the crude oil to vaporize a portion, and feeding the two-phase crude to a first stage flash evaporator. In the first stage evaporator, a vapor portion is separated from residual liquid and the residual liquid is used by means of heat exchange to preheat the crude oil. The vapor fraction from the first stage evaporator has an approximate 90% ASTM distillation temperature about 50-60.degree. F higher than the first stage evaporator temperature. The vapor fraction is condensed to form a condensate, and the condensate is conveyed to a stripping column for mass transfer with ascending vapors from a second stage boiling type evaporator. The second stage evaporator is operated at a vaporization temperature approximately equal to the 5% ASTM vaporization temperature of the predetermined petroleum fraction collected as liquid from the second stage evaporator.Type: GrantFiled: October 20, 1977Date of Patent: December 26, 1978Assignee: Riley-Beaird, Inc.Inventors: Charles D. Rose, Frederick W. Gilbert
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Patent number: 4070254Abstract: 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: GrantFiled: June 7, 1976Date of Patent: January 24, 1978Assignee: Nippon Zeon Co., Ltd.Inventors: Ryoji Sato, Takanori Musha
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Patent number: 4057491Abstract: N-methyl-2-pyrrolidone is recovered from the raffinate and extract phases produced by its use in hydrocarbon extraction processes, particularly lube oil extraction, through the use of flash evaporation and/or distillation followed by gas stripping. Water buildup in the recovered solvent is prevented by employing solvent dehydration means in the solvent recovery line after gas stripping. Proper control of process parameters enables the dehydration means to remove excess water without requiring additional heat input to the process.Type: GrantFiled: March 26, 1976Date of Patent: November 8, 1977Assignee: Exxon Research & Engineering Co.Inventors: James D. Bushnell, Milton D. Leighton, Thomas M. McDonald
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Patent number: 4043875Abstract: An improved technique employing first and second flash vaporization stages for purifying radioactive liquids is described. The liquid is first flash-evaporated in the first vaporization stage and the resulting vapor is conducted to a first direct condenser. Enriched liquid obtained from the second vaporization stage is applied via a circulating pump to the first direct condenser to condense by contact the vapor from the first vaporization stage and to form a mixture with this condensate. The resulting mixture is thus flash-evaporated in the second vaporization stage. A portion of the enriched liquid obtained from the second vaporization stage is withdrawn from the loop formed by said second vaporization stage, said circulating pump, said first direct condenser, and the connecting conduits therebetween for further processing, e.g., recycling to the first vaporization stage, or for discharging.Type: GrantFiled: December 17, 1975Date of Patent: August 23, 1977Assignee: Vereinigte Delstahlwerke AG. (VEW)Inventors: Gundolf E. Rajakovics, Heinz Gabernig, Guenter Peter Klein
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Patent number: 4014752Abstract: A process and installation for vaporizing liquids and in particular radioactive liquids. A two-step flash vaporization is carried out. The vapor exiting from a first vaporizing stage is condensed by means of liquid taken from a second vaporizing stage, the latter liquid being injected into a condenser into which the vapor steam from the first vaporizing stage is being conducted. The thus formed mixture is conducted into the second vaporizing stage.Type: GrantFiled: January 30, 1973Date of Patent: March 29, 1977Assignee: Vereinigte Edelstahlwerke AGInventors: Gundolf Rajakovics, Heinz Gabernig, Gunter Peter Klein
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Patent number: 4008131Abstract: A method is provided for removal of excess water which tends to build up in recycle streams and reduces the rate of pure acid production during operation of a distillation system for purification of crude acetic acid containing water and methyl iodide. The crude acid is introduced into the upper half of a distillation zone. The methyl iodide, a major proportion of water and an equivalent amount of acid are removed overhead from the zone. A minor proportion of the water containing a small amount of acetic acid is removed as a liquid sidedraw at a point near the top of the distillation zone. A product acid stream essentially dry and substantially free of methyl iodide is removed from the bottom of the distillation zone. The overhead stream can be stored, disposed of or preferably recycled to the acid-producing step. The liquid water sidedraw may either be discarded or subjected to rectification for recovery of acid values.Type: GrantFiled: December 11, 1975Date of Patent: February 15, 1977Assignee: Monsanto CompanyInventor: Jerry L. Price
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Evaporative and centrifugal apparatus for effecting concentration and/or purification of feed stocks
Patent number: 3957588Abstract: A low temperature purification system is provided which is particularly adapted for use to mechanically purify in a continuous operation solutions containing solids and dissolved substances. The purification system includes a solution supply means, and a centrifugal vacuum evaporator to which the solution to be purified is fed. Drive means is operatively connected to the evaporator for subjecting the solution within the evaporator to centrifugal acceleration and causes the solids in the solution to be displaced outwardly of the axis of rotation of the solution and the liquid of the solution to be displaced inwardly toward the axis of rotation. Outlet means is embodied in the evaporator for discharging the solids therefrom. The liquid as it is being displaced inwardly is simultaneously subjected to a reduced pressure to produce vapor which is conducted to a condenser means wherein the vapor is condensed to a substantially pure liquid.Type: GrantFiled: May 29, 1975Date of Patent: May 18, 1976Assignee: Pollution Control, Inc.Inventor: Gerald F. Humiston -
Patent number: 3954566Abstract: An improved arrangement is described for self-controlling the evaporation rate in the first stage of a two-stage expansion type evaporation installation for radio-active liquid purification, as described e.g. in the U.S. patent application Ser. No. 328065 filed on Jan. 30, 1973, in case of failure of the main circulating pump of the second stage. Such failure causes a pressure drop at the mixing condenser between first and second stage and normally, thus, a pressure drop in the first stage too. Such pressure drop leads to unwanted evaporation in the first stage and transfer to the second stage of excessive and insufficiently purified fluid from the first stage. A flow throttle element such as a diaphragm or a necked-down section of steam conduit is interposed between the vapor exit of the first stage and the mixing condenser in which the vapor is condensed by contact with a portion of the liquid from the second stage circulated therethrough by the pump.Type: GrantFiled: January 23, 1975Date of Patent: May 4, 1976Assignee: Vereinigte Edelstahlwerke AGInventor: Gundolf E. Rajakovics
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Patent number: 3953300Abstract: Styrene of exceptional purity is separated from a mixture of hydrocarbons including it, xylenes, saturated and olefinic hydrocarbons and ethyl benzene by means of a two-step extractive distillation process through the use of a high boiling polar solvent such as N-formyl morpholine in admixture with an amount of water in the range of from 1% to 30% by weight.Type: GrantFiled: July 11, 1975Date of Patent: April 27, 1976Assignee: Snam Progetti, S.p.A.Inventors: Alessandro Ginnasi, Alessandro Vetere, Pierantonio Martera
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Patent number: 3940450Abstract: 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: GrantFiled: December 16, 1974Date of Patent: February 24, 1976Assignee: Texaco Inc.Inventor: Kung-You Lee