Abstract: 2-Methyl-1-propanol cannot be separated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 2-Methyl-1-propanol is readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are butyl propionate, cyclohexane and 2,2-dimethoxypropane.

Abstract: t-Amyl alcohol cannot be separated from n-butanol by distillation or rectification because of the closeness of their boiling points. t-Amyl alcohol is readily separated from n-butanol by azeotropic distillation. Effective agents are propyl acetate, tetrahydrofuran and heptane.

Abstract: Acetone cannot be separated from a mixture of isopropanol and water because of the closeness of their boiling points. Acetone can be easily separated from isopropanol and water by extractive distillation. Effective extractive agents are 1-nitropropane, 3-carene, dimethylsulfoxide and 3-pentanone.

Abstract: A process for the separation of dimethyl ether and chloromethane in mixturesA process for the separation of dimethyl ether and chloromethane in mixtures by two distillation steps. In the first step, the mixture is subjected to an extractive distillation with water, aqueous salt solutions or organic liquids as extractant, the top product being chloromethane. In the second step, the dimethyl ether is separated from the extractant.

Abstract: 2-Butanol cannot be sparated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 2-Butanol is readily separated from t-amyl alcohol by extractive distillation. Effective agents are butyl ether, benzyl acetate and 1,2,4-trimethyl benzene.

Abstract: Methyl ethyl ketone cannot be separated from ethanol by distillation or rectification because of the closeness of their boiling points. Methyl ethyl ketone is readily separated from ethanol by extractive distillation. Effective agents are methyl benzoate, phenol, glycerol and nitroethane.

Abstract: Methyl ethyl ketone cannot be separated from ethanol by distillation or rectification because of the closeness of their boiling points. Methyl ethyl ketone is readily separated from ethanol by azeotropic distillation. Effective agents are amyl acetate, methyl formate, 2,2-dimethyl butane and 2,3-dimethyl butane.

Abstract: An olefin such as isobutylene is reacted with a carboxylic acid to produce the ester in the presence of an alkanol modifying agent effective to suppress olefin polymerization, at least part of the modifying agent being formed in situ by reaction of the olefin and water.

Abstract: The invention concerns a process for the separation of a mixture comprising ethylene, 1-butene, alpha-olefins containing at least 6 carbon atoms per molecule and possibly heavier hydrocarbon products, the ethylene content of the mixture being in the range 30% to 70% by weight, in which separation is effected in a distillation zone to obtain an overhead fraction comprising the major portion of the ethylene present in the mixture and between 0% and 100% by weight of the 1-butene present in the mixture, the process being characterized in that the zone is also supplied with supplemental 1-butene in an amount in the range 1 to 40 times the quantity (by weight) of 1-butene present in the mixture. In a preferred implementation of the process of the invention, the mixture originates form a homogenous liquid phase ethylene oligomerisation zone.

Abstract: A method for separating hexamethylcyclotrisiloxane that does not require the use of a distillation set up adapted for use with solids and that collects the hexamethylcyclotrisiloxane in the form of an easy-to-handle solution. The method comprising inducing the ascent in the gaseous state of a hexamethylcyclotrisiloxane-containing mixture of polydimethylcyclosiloxanes in a distillation column provided with a sidestream element in the middle region of the column so as to induce the ascent of gaseous hexamethylcyclotrisiloxane to at least the level of the sidestream element, supplying into said distillation column solvent having a boiling point below that of hexamethylcyclotrisiloxane and capable of dissolving hexamethylcyclotrisiloxane, so as to form a liquid mixture of hexamethylcyclotrisiloxane and said solvent in the vicinity of the sidestream element, and withdrawing the said liquid mixture from the sidestream element.

Abstract: 2-Butanol cannot be separated from isobutanol by distillation or rectification because of the closeness of their boiling points. 2-Butanol is readily separated from isobutanol by extractive distillation. Effective agents are propylene glycol propyl ether, 2-methoxyethanol and ethyl acetate.

Abstract: 2-Methyl-1-butanol and 3-methyl-1-butanol are difficult to separate from 1-pentanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-butanol and 3-methyl-1-butanol can be easily separated from 1-pentanol by azeotropic distillation. Effective agents are toluene, methyl acetate and tetrahydrofuran.

Abstract: 4-Methyl-2-pentanol cannot be separated from 3-methyl-1-butanol by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanol can be easily separated from 3-methyl-1-butanol by azeotropic distillation. Effective agents are m-xylene and cumene.

Abstract: 1-Propanol cannot be separated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 1-Propanol is readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are heptane, ethyl acetate and tetrahydrofuran.

Abstract: 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.

Abstract: Close boiling hydrocarbon impurities are separated from acetone by extractive distillation using a C.sub.9 -C.sub.14 alkane and/or a C.sub.8 -C.sub.12 aromatic hydrocarbon extractive distillation solvent.

Abstract: 2-Butanol cannot be separated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 2-Butanol is readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are methyl acetate, ethyl propionate and octane.

Abstract: The invention relates to an improved distillation method wherein hexamethylcyclotrisiloxane is isolated from a crude blend thereof by mixing the crude blend with a hydrocarbon co-solvent having a normal boiling point of 125.degree. C. to 150.degree. C. and distilling the resulting mixture in an apparatus having a reboiler, a fractionating column and a condenser, whereby deposition of solid hexamethylcyclotrisiloxane in the condenser is eliminated.

Abstract: 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.

Abstract: 2-Methyl-1-butanol is impossible to separate from 3-methyl-l-butanol because they both boil at 130.degree. C. 2-Methyl-1-butanol can be readily separated from 3-methyl-1-butanol by extractive distillation. Effective agents are o-xylene, 3-carene and 1-methoxy-2-propanol.

Abstract: 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.

Abstract: 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.

Abstract: A distillation method for the purification of crude propylene oxide containing contaminating quantities of water and methanol by partially purifying the crude propylene oxide in a plural stage distillation zone to provide a vaporized overhead distillate propylene oxide fraction containing a minor contaminating amount of vaporized water, andpassing the propylene oxide vapor fraction through a drying chamber containing a porous hygroscopic solid absorbent to selectively absorb water vapor onto the absorbent,and liquefying and recovering the thus-dehydrated purified propylene oxide.

Abstract: 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.

Abstract: 3-Methyl-2-butanol, 2-pentanol and 1-butanol are difficult to separate by conventional distillation or rectification because of the proximity of their boiling points. Mixtures of these three can be readily separated from each other by azeotropic distillation. Effective agents are hexyl acetate, hexane and 3-methyl pentane.

Abstract: 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.

Abstract: Compositions of N(CF.sub.3).sub.a (CHF.sub.2).sub.b (CH.sub.2 F).sub.c, where a, b and c are integers from 0 to 3 and a+b+c=3, and C.sub.n F.sub.m H.sub.2n+2-m, where n is an integer from 1 to 3 and m is an integer from 1 to 8, are disclosed. Also disclosed are compositions of N(CF.sub.3).sub.3 and butane, cyclopropane, dimethyl ether or isobutane. These compositions are useful as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.

Abstract: 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.

Abstract: 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.

Abstract: Propylene glycol is difficult to separate from ethylene glycol by conventional distillation or rectification because of the proximity of their boiling points. Propylene glycol can be readily separated from ethlene glycol by azeotropic distillation. Effective agens are m-diisopropyl benzene, 1-octene, 3-carene and myrcene.

Abstract: 2-Butanone is difficult to separate from isopropanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Butanone can be readily separated from isopropanol by azeotropic distillation. Effective agents are 3-methyl pentane, methyl t-amyl ether and acetonitrile.

Abstract: Propylene glycol is difficult to separate from 1,2-butanediol by conventional distillation or rectification because of the proximity of their boling points. Propylene glycol can be readily separated from 1,2-butanediol by azeotropic distillation. Effective agents are 2,2-dimethyl butane, 3-carene and diethyl benzene.

Abstract: 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.

Abstract: 1-Butanol is difficult to semarate from 2-pentanol by conventional distillation or rectification because of the proximity of their boiling points. 1-Butanol can be readily separated from 2-pentanol by azeotropic distillation. Effective agents are 1-octene, hexane and methyl cyclohexane.

Abstract: 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.

Abstract: 1-Butanol is difficult to separate from 2-pentanol by conventional distillation or rectification because of the proximity of their boiling points. 1-Butanol can be readily separated from 2-pentanol by extractive distillation. Effective agents are ethyl benzene, d-limonene and terpinolene.

Abstract: The present invention relates to a process for the preparation of tetrafluorophthalic acid and/or tetrafluorophthalic anhydride by reacting a compound of the formula ##STR1## in which X is a radical ##STR2## which is optionally mono- or polysubstituted on the aromatic nucleus by fluorine and/or chlorine and/or alkyl groups having 1 to 4 carbon atoms, or is a radical ##STR3## in which R.sub.1, R.sub.2 and R.sub.3 are as defined, with water, and subsequently removing the water still present by azeotropic distillation or extracting the tetrafluorophthalic acid and/or its anhydride with a water-insoluble solvent or solvent mixture.

Abstract: A process for producing acetaldehyde dimethylacetal comprising reacting acetaldehyde and methanol in the presence of an acid catalyst is disclosed, in which the reaction is carried out in a part of a rectification tower while conducting rectification to withdraw the water by-produced from the bottom of the tower and to recover a distillate containing the acetaldehyde dimethylacetal produced from the top of the tower. The distillate is subjected to azeotropic distillation in the presence of n-hexane or cyclohexane to separate methanol as an azeotrope with n-hexane or cyclohexane and a small amount of the acetaldehyde dimethylacetal and to recover high purity acetaldehyde dimethylacetal as a bottom.

Abstract: A process for the production of pure distilled isocyanates in which the corresponding amine is reacted with phosgene in a suitable solvent and working up of the isocyanate containing solution obtained by multistage distillation into pure isocyanate, pure solvent and a residue. The residue is then charged to a vessel containing at least one hydrocarbon having a high boiling point. The contents of this vessel are then heated with stirring to distill off any free isocyanate present. The remaining residue is a solid which may be disposed of readily.

Abstract: Contaminants are removed from impure propylene oxide by fractionating in a first column to remove overhead essentially all of the pentenes and pentanes and most of the oxygen-containing impurities to provide a partially purified first propylene oxide bottoms fraction, extractively distilling the first bottoms fraction in a second extractive column using a C.sub.2 to C.sub.6 alkylene glycol extractive distillation agent to form a second overhead fraction comprising propylene oxide, hexenes, hexanes, water, residual quantities of pentenes and pentanes and oxygen-containing impurities, extractively distilling the second overhead fraction in a third column using a C.sub.6 to C.sub.10 alkane hydrocarbon extractive distillation agent to form a third bottoms fraction comprising the extractive distillation agent, propylene oxide, hexenes, hexanes, residual quantities of pentenes and pentanes and water, and extractively distilling said third bottoms fraction in a fourth column using a C.sub.6 to C.sub.

Abstract: Crude propylene oxide is purified by a distillation process wherein it is (a) extractively distilled in a first column using a C.sub.2 to C.sub.6 alkylene glycol extractive distillation agent to form a first overhead fraction comprising propylene oxide, C.sub.5 -C.sub.7 hydrocarbons, methanol, water and oxygen-containing impurities, (b) wherein the first overhead fraction is separated in a plurality of intermediate distillation columns to provide an intermediate propylene oxide overhead fraction consisting essentially of propylene oxide and water, and (c) the intermediate propylene oxide overhead fraction is charged to a final distillation column using a C.sub.2 to C.sub.6 alkylene glycol extractive distillation agent to form a final overhead fraction consisting essentially of propylene oxide.

Abstract: 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.

Abstract: This invention relates to a process for the production of absolute alcohol from aqueous alcohol, whereby saving of energy to a greater extent is rendered possible in a more simple process, as compared with the prior art azeotropic distillation method using benzene or cyclohexane. That is, aqueous alcohol is subjected to extractive distillation in a first distillation column under such a condition that a liquid and gas of a solvent simultaneously coexist using low pressure propane, propylene and butane as the solvent, absolute alcohol substantially free from water is recovered from the bottom of the distillation column and subjected to stripping of hydrocarbons in a second distillation column, during which the gaseous phases of the first and second distillation columns are mixed and compressed, utilized through recompression as a heat source of a reboiler of the first distillation column, subjected to separation of water content and recycled to the upper parts of the first and second distillation columns.

Abstract: Impure propylene oxide is purified by a distillation process wherein it is (a) extractively distilled in a first column using a C.sub.2 to C.sub.6 alkylene glycol extractive distillation agent to form a first overhead fraction comprising propylene oxide, C.sub.5 -C.sub.7 hydrocarbons methanol, water and oxygen-containing impurities, (b) wherein the first overhead fraction is separated in a second column into a second overhead fraction comprising most of the pentanes, pentenes and oxygen-containing impurities and a partially purified propylene oxide bottoms fraction comprising propylene oxide, hexenes, hexanes, and only residual quantities of pentenes and pentanes, (c) wherein the partially purified bottoms fraction is extracting distilled in a third column using a C.sub.7 -C.sub.

Abstract: Toluene cannot be separated from methyl isobutyl ketone by conventional distillation or rectification because of the minimum boiling azeotrope. Toluene can be readily separated from methyl isobutyl ketone by using azeotropic distillation. Typical examples of effective agents are 1-butanol, 2-methoxyethanol and n-heptane.

Abstract: For preparing at least one boric oxide in an anhydrous or hydrated form and of general formula B.sub.2 O.sub.3, xH.sub.2 O, in which x is a number from 0 to 3, a methyl borate hydrolyzate comprising boric oxide and methanol is introduced into a distillation column is introduced the product from, at least one compound (preferably a hydrocarbon such as, e.g., 2,3-dimethyl butane or 2-methyl pentane) forming a heteroazeotrope with methanol, said heteroazaeotrope having a boiling point below that of the azeotrope formed by methyl borate with methanol and at least one compound having a boiling point higher than that of methyl borate, said compound not forming an azeotrope with a boiling point below that of said heteroazeotrope and then at the head of the column said heteroazeotrope is recovered and at the bottom of the column a suspension containing at least one boric oxide.

Abstract: A process for the fractionation of a gaseous mixture containing hydrogen, light aliphatic hydrocarbons and light aromatic hydrocarbons wherein following compression of the mixture and separation of one or more light fractions, a gas is contacted with light aliphatic hydrocarbons and then hydrogen is separated by permeation. A series of distillation steps makes it possible to isolate the aliphatic hydrocarbons and the aromatic hydrocarbons subsequent to the separations.

Abstract: The present invention provides an improved process for the separation of impurities from a lower alkylene oxide, such as propylene oxide, by a process wherein the impure propylene oxide is first fractionally distilled to separate higher and lower boiling impurities, then the partially purified alkylene oxide is subjected to extractive distillation to separate additional impurities, the purified propylene oxide being separated as an overhead fraction.

Abstract: An extractive distillation process for separatin at least one C.sub.4 -C.sub.10 alkene (monoolefin) from at least one close-boiling alkane employs a solvent mixture of (a) at least one saturated alcohol (preferably cyclohexanol) and either (b1) at least one sulfolane (preferably cyclotetramethylene sulfone) or (b2) at least one glycol compound (preferably tetraethylene glycol) or (b1)+(b2).

Abstract: Cycloalkanes, preferably cyclohexane and/or cyclopentane, are separated from close-boiling alkanes by extractive distillation employing as solvent a mixture of (a) at least one N-hydroxyalkyl-2-pyrrolidone, preferably N-(.beta.-hydroxyethyl)-2-pyrrolidone, and (b) at least one saturated C.sub.5 -C.sub.9 alcohol, preferably cyclohexanol.