Abstract: Process for dehydrating aliphatic alcohols admixed with water wherein the alcohols-water mixture is subjected to a first fractionation in the presence of a selective solvent, giving a vapor effluent containing dehydrated light alcohols and a liquid phase containing heavy alcohols, water and the selective solvent, said liquid phase being subjected to a second fractionation giving as vapor effluent an hetero-azeotropic mixture of water and heavy alcohols and, as liquid effluent, the selective solvent, which is fed back, said hetero-azeotropic mixture being condensed and separated into:(a) a light phase of high alcohol content which is subjected to a third fractionation giving a vapor effluent which is fed back and dehydrated heavy alcohols as liquid effluent, and(b) a heavy phase which is subjected to a fourth fractionation giving a vapor effluent which is fed back and water as liquid effluent.

Abstract: A process for the isolation of hydroquinone, pyrocatechol, phenol and carboxylic acid from the reaction mixture containing the same such as one obtained by reaction of phenol with percarboxylic acid is disclosed. The reaction mixture is fed to a first rectification column and subjected to distillation whereby there is obtained a bottoms product containing pyrocatechol, hydroquinone and phenol. The top product is largely condensed and recycled, there being withdrawn from the top of the rectification column a mixture comprising phenol and carboxylic acid. The phenol and carboxylic acid mixture are continuously fed to a second rectification column where carboxylic acid is separated from phenol and substantially pure phenol is withdrawn from the stripping section and/or bottom of the second rectification column.

Abstract: Crude acetonitrile is purifed to 99+ weight percent by a continuous distillation procedure.

Abstract: A method of purification of crude .beta.-phenylethyl alcohol to give a highly pure .beta.-phenylethyl alcohol suitable as a perfume, which comprises subjecting the crude .beta.-phenylethyl alcohol to azeotropic distillation in the presence of an azeotropic solvent selected from water, an alkylene glycol, an alkylene glycol monoalkyl ether and a mixture of two or more kinds of these solvents, or extractive distillation in the presence of an extractive solvent selected from glycerine, an alkylene glycol, a polyalkylene glycol, an alkylene glycol monoalkyl ether, a polyalkylene glycol monoalkyl ether and a mixture of two or more kinds of these solvents.

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.

Abstract: A process and apparatus for the separation of components from a mixture which forms an azeotrope is disclosed by subjecting the mixture to extractive distillation to remove one of the components and regeneration to separate another component from the extracting agent added to the extractive distillation column. According to the invention, a first side stream is withdrawn from the extractive distillation column, passed in heat exchange with the bottoms from the extractive distillation column en route to the regeneration column and returned to the extractive distillation column at a point below the point at which it is withdrawn. A second side stream from the extractive distillation column is withdrawn, passed in heat exchange with the bottoms of the regeneration zone and returned to the extractive distillation column. For this purpose, separate heat exchangers are used for the respective side streams.

Abstract: Metal chlorides such as aluminum chloride (AlCl.sub.3) are separated from a mixture containing metal chlorides including AlCl.sub.3 and ferric chloride (FeCl.sub.3). In order to effect this separation, the mixture is subjected to a fractional distillation process utilizing an array of distillation columns. According to this process, the mixture is introduced into a first distillation column which is operated at temperatures and pressures sufficient to separate FeCl.sub.3 from the mixture while avoiding the formation of a solid solution of FeCl.sub.3 and AlCl.sub.3 within the column. At least one additional distillation column is then employed to separate metal chlorides from the remaining mixture from the first column.

Abstract: A multi-stage evaporator is used to remove water from the extracted distillation or stripper tower bottoms recycled as quench liquid to the quench tower of an acrylonitrile purification and recovery system. This results in a significant decrease in the amount of waste quench tower bottoms produced by the system. Use of a multi-effect evaporator represents a significant energy savings as compared with other techniques for decreasing the water content of the recycle stream.

Abstract: A method for separating a mixture of reaction products produced in the catalytic etherification of a lower isoolefin with methanol wherein said reaction product comprises a mixture of ether, methanol, unreacted hydrocarbon and tertiary alcohol which comprises adding water to said reaction product to form a hydrocarbon phase containing said ether and an aqueous phase containing methanol and a tertiary alcohol, separating said hydrocarbon phase to recover a methyltertiary alkyl ether, introducing said alcohol-containing aqueous phase into a distillation column to separate a methanol fraction overhead, withdrawing a side stream rich in tertiary alcohol from said distillation column, stripping this side stream in a stripping column to separate a second methanol fraction overhead and a tertiary alcohol bottoms fraction and recycling the methanol overhead fraction from the stripping column to the upper part of the distillation column and recycling the overhead methanol fraction from the distillation column to the f

Abstract: Anhydrous or substantially anhydrous formic acid is obtained by hydrolysis of methyl formate, in a process wherein(a) methyl formate is hydrolyzed,(b) the methanol and excess methyl formate are distilled from the hydrolysis mixture obtained,(c) the bottom product of distillation (b), consisting of formic acid and water, is extracted, in a liquid-liquid extraction, with an extractant which in the main takes up the formic acid,(d) the resulting extract phase, consisting of formic acid, the extractant and a part of the water, is subjected to distillation,(e) the top product obtained from this distillation and consisting of all or part of the water introduced into the distillation, and part of the formic acid, is recycled, as vapor, into the lower part of the distillation column of stage (b),(f) the bottom product of distillation stage (d), consisting of the extractant, with or without part of the water, and the greater part of the formic acid, is separated by distillation into anhydrous or substantially anhydrou

Abstract: A process for distilling ammoniacal solutions is disclosed comprising the utilization of two distillation columns operating at different pressures, the ammoniacal solution to be distilled being sent--after being mixed with the ammoniacal vapors flowing from the top of the column operating at the lower pressure--to the column operating at the higher pressure, from the bottom of which the partially distilled ammoniacal solution is sent to the column operating at the lower pressure; the liquid ammonia being recovered at the top of the column operating at the higher pressure while the residual ammoniacal solution is withdrawn from the bottom of the column operating at the lower pressure.

Abstract: A distillation device is provided which comprises a vaporization zone, a condensation zone, a vapor permeable barrier between the vaporization zone and the condensation zone comprising a membrane having a plurality of openings, and means for maintaining an air pressure gradiant across the barrier whereby air pressure on the vaporization zone side of the membrane is greater than air pressure on the condensation zone side of the membrane.

Abstract: A method for the removal of aromatic hydrocarbon from mixtures containing non-aromatic hydrocarbon by liquid-liquid extraction and extractive distillation is described. Isoenthalpic expansion of the rectification column bottom solvent stream and addition of water to the selective solvent can be used to reduce heat consumption.

Abstract: The recovery of alcohol from fermentation liquors is accomplished by the evaporation of the liquor feed and simultaneous rectification of the volatile component. Evaporation of the liquor feed can be accomplished by a single flash evaporation or multiple effect evaporation combined with the flash evaporation in which the flash evaporator is one effect of the multiple effect evaporator. A concentrated alcohol component is recovered along with a concentrated residue useful as a fertilizer or animal feed supplement.

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.

Abstract: A process for recovering pure benzene from hydrocarbon mixtures containing the same and non-aromatic compounds which are gaseous and difficultly condensible is described in which the feedstock is fed to an initial distillation column operated at atmospheric or sub-atmospheric pressure. Overhead comprising benzene and non-aromatics is obtained and a portion thereof condensed. The condensible material is in part returned to the distillation column and in part subjected to extractive distillation to recover pure benzene. Those components which did not condense, i.e. the non-condensible and difficultly condensible components and entrained aromatics are fed to a reflux vessel such as a scrubber, stripper, or the like for recovery of any benzene or other valuable components which might be soluble in a selective solvent and used for such recovery. The selective solvent can be the same solvent used for the extractive distillation.

Abstract: A process for separating acetonitrile from a crude olefinically unsaturated nitrile which comprises passing a reaction gas obtained in the ammoxidation of propylene or isobutylene through a quenching column, an absorption column with water, an extractive distillation column for the olefinically unsaturated nitrile and a stripping column for acetonitrile successively, condensing the acetonitrile-containing vapor from the top of the stripping column, evaporating the condensate acetonitrile-containing liquid into a gas, subjecting the resulting gas mixture to a vapor-liquid separation and subjecting the gas separated to an incineration while withdrawing the liquid separated.

Abstract: A process for isolating butadiene, with the aid of a selective solvent, from a C.sub.4 -hydrocarbon mixture which contains butadiene and small amounts of styrene and may contain oxygen, hydrocarbons more soluble than butadiene in the selective solvent and hydrocarbons less soluble than butadiene in the selective solvent, in which process the C.sub.4 -hydrocarbon mixture is separated by extractive distillation into a distillate which contains the less soluble hydrocarbons, a stream of butadiene and a stream containing the more soluble hydrocarbons, and in which a mixture of styrene and C.sub.4 -hydrocarbons is removed from the C.sub.4 -hydrocarbon mixture in a distillation zone upstream of the extractive distillation, the top product of the said distillation zone being fed to the extractive distillation.

Abstract: A process for the simultaneous manufacture of pure methyl tertiary butyl ether (MTBE) and a substantially isotubene-free mixture of C.sub.4 -hydrocarbons, by reacting the isobutene contained in the mixture of C.sub.4 -hydrocarbons with excess methanol in the liquid phase at elevated temperatures on strongly acid, macroporous, organic ion exchange resins.The process has the following steps:(a) methanol and isobutene are reacted in a molar ratio of 2:1 to 5:1 at temperatures between 30.degree. and 100.degree. C.;(b) the unconverted hydrocarbons are then removed as the top product under a pressure of 2 to 10 bars from a first rectification column;(c) the bottom product from this first column is rectified in a second column under normal pressure or under a slight excess pressure of up to 2 bars at the top of the column, the bottom product of this rectification is recycled to reaction zone (a), if necessary, after separating off a portion of the tertiary butanol formed and the C.sub.

Abstract: A process of recovering an n-hexane product which is free from aromatic compounds by extractive distillation from a mixture of aromatic and non-aromatic compounds. The mixture is fed to and distilled in a first distillation column, from which a benzene-containing sump product and the overhead product consisting of non-aromatic compounds are withdrawn. The distillate is laterally withdrawn above the feeding point of the feed mixture and transferred to the upper portion of a second distillation column. The hexane cut is withdrawn as sump product from the second distillation column and fed to an extractive distillation column approximately in the middle thereof and is extracted in the extractive distillation column with a selective solvent which is fed above the feeding point of the hexane cut consisting of the sump product of the second distillation column. The sump product containing the selective solvent is withdrawn from the extractive distillation column and the overhead thereof vapors are condensed.

Abstract: 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.

Abstract: 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.

Abstract: The separation of butadiene-1,3 from other C-4 hydrocarbons of lesser degree of unsaturation by extractive distillation with alkoxynitrile or aqueous alkoxynitrile as selective solvent is carried out with improved selectivity, without appreciable formation of butadiene-1,3 polymer and with consequent savings in energy by adding to the alkoxynitrile or aqueous alkoxynitrile an organic cosolvent which is dimethyl sulfoxide, sulfolane, butyrolactone, N-methyl pyrrolidone, morpholine, or trimethyl phosphate and/or an inhibitor which is 2,4-dinitrophenol or 2,4-dinitro-ortho-cresol. The organic cosolvent is present in the selective solvent composition in an amount of 5 to 30 percent by weight and the inhibitor in an amount of 0.05 to 0.6 percent by weight.

Abstract: 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.

Abstract: Process for separating benzene and/or toluene from mixtures thereof with saturated hydrocarbons, by extractive distillation using an aliphatic N-alkylamide as extraction solvent, comprising introducing in the distillation column, above the level of introduction of the extraction solvent, liquid water in an amount and under such conditions that said water is completely vaporized without substantially diluting the solvent, condensing the vapors discharged from the top of the column and dividing the resulting condensate into a phase of liquid saturated hydrocarbons, and a phase of water.

Abstract: A trisubstituted phosphate is employed as extractive distillation solvent in the separation of cumene and phenol.

Abstract: A process for recovering alkoxyketone compounds from mixtures of the alkoxyketone compound and the corresponding 1-alkoxy-2-alkanol compound by extractive distillation with diols, triols and polyols as extractants.

Abstract: A lower carboxylic acid such as acetic acid is separated and recovered from an aqueous medium by the steps which include contacting, in an extraction zone, the aqueous medium with an extracting agent such as trioctyl phosphine oxide dissolved in an organic solvent such as a mixture of paraffins having a boiling range of about 160.degree. C. to 175.degree. C.

Abstract: Acetylenic hydrocarbons are removed from a C.sub.4 - or C.sub.5 - hydrocarbon mixture containing a C.sub.4 - or C.sub.5 - diolefin respectively. The feedstock (e.g. a C.sub.4 - or C.sub.5 - cut from an ethylene plant) is extractively distilled to remove paraffins and mono-olefins in the raffinate, using acetonitrile (ACN), dimethyl formamide (DMF), furfural, acetone, dimethylacetamide or N-methyl-2-pyrrolidone mixed with 0-12 weight percent water as the extraction solvent. The bottoms from this first extractive distillation is subjected to a second extractive distillation in which virtually acetylenes-free solvent is used. Isoprene is withdrawn as the distillate with substantially reduced acetylenes content. The bottoms of the second extractive distillation is split three ways. Two streams are handled conventionally (recycle and heavies removal). The third is stripped free of acetylenes so that it may be used as solvent in the second extractive distillation.

Abstract: Phenol-, cyclohexanone-, and cyclohexylbenzene-containing mixtures are extractively distilled employing an N-substituted lactam to provide overhead a high purity cyclohexanone and a kettle product containing phenol, cyclohexylbenzene when it is present in the mixture treated, and the N-substituted lactam.

Abstract: Phenol-, cyclohexanone-, and cyclohexylbenzene-containing mixtures are extractively distilled employing an organic carbonate to provide overhead of high purity cyclohexanone and a kettle product substantially free of cyclohexanone and containing phenol, the organic carbonate, and, when present in the mixture, cyclohexylbenzene.

Abstract: Phenol-, cyclohexanone-, and cyclohexylbenzene-containing mixtures are extractively distilled to provide overhead of cyclohexanone and a kettle product substantially free of cyclohexanone by employing an N,N-disubstituted amide. When substantially no cyclohexylbenzene is present in the mixture to be extractively distilled, the kettle product will be essentially composed of the amide and phenol.

Abstract: Phenol-, cyclohexanone-, and cyclohexylbenzene-containing mixtures are extractively distilled to provide overhead of cyclohexanone and a kettle product containing phenol and, when present, cyclohexylbenzene by employing a trisubstituted phosphate agent or solvent.

Abstract: Formic acid is purified by extractive distillation of its aqueous solutions using a basic extractant, followed by distillation of the bottom mixture first obtained, the extractant used being N-formylmorpholine.

Abstract: Hydrocarbons having different degrees of saturation are separated by extractive distillation using selective solvent comprising a mixture of dimethylsulfone, methylethylketone and sulfolane.

Abstract: A process for separating mixtures of close boiling, high-molecular weight alkenes and alkanes which employs phenoxide-catalyzed alkyl displacement.

Abstract: A float valve arrangement is disposed in a mixing condenser that is arranged intermediate the first and second stage of a two-stage evaporation installation suitable for purifying radio-active liquids. In normal operation, vapor evaporated in the first stage extends via a first conduit into the mixing condenser where such vapor is condensed by contact with a portion of the liquid in the second stage that is circulated back to the mixing condenser via a pump. The normal vapor pressure generated in the first stage keeps the float valve open and permits the steam to displace, into the second stage, liquid present in the mixing condenser. During start-up and shutdown of the installation wherein vapor from the first stage is no longer present, the resulting rise in liquid level in the mixing condenser causes the float valve to close and to prevent any backflow of liquid into the first stage via the first conduit.

Abstract: A crude alcohol-containing mixture comprising a saturated aliphatic alcohol of not more than three carbon atoms and associated impurities is processed in a three-tower distillation system to permit recovery of the desired alcohol product in highly concentrated and purified form. In the first tower the crude feed is subjected to extractive distillation with water to remove substantially all the impurities overhead. An aqueous bottoms stream from the first tower containing 5 to 10 wt.% alcohol and only minor amount of impurities is fed to the second tower where the alcohol product is concentrated and recovered. Overhead and intermediate purge streams containing low boiling and hgh boiling impurities are removed from the second tower and are fed to the third tower along with the overhead from the first tower. Stripped aqueous effluent is withdrawn from the bottom of the second tower and is recycled in part to the first tower.

Abstract: Allyl alcohol is produced in simple and economical fashion from propylene and oxygen by reacting propylene, oxygen and acetic acid over a palladium-containing catalyst in the presence of water; condensing the reaction product to form a condensate containing allyl acetate, acetic acid and water; treating the condensate with an acid catalyst and separating the resulting product by distillation into a head product consisting essentially of an allyl acetate/allyl alcohol/water azeotrope and into a sump product consisting essentially of acetic acid, allyl alcohol and water; recycling the head product to the acid catalyst stage; separating the sump product in a second distillation into an allyl alcohol/water head product and into a second sump product consisting essentially of acetic acid and water and recycling this sump product to the initial reaction.

Abstract: 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.