Abstract: The separation of ethyl tertiobutyl ether from mixtures with ethanol is based on heteroazeotropic distillation with water as the entrainer using two distillation columns, coupled with an overhead decanter. Purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column. The separation method may be incorporated into an ETBE production unit in which isobutene (contained in a C.sub.4 -cut from steam cracking, catalytic cracking, or dehydrogenation of isobutane) is etherified by ethanol. Ethanol separated from the ETBE is then recycled to the etherification zone.

Abstract: An improved process for separation of valuable components of a waste stream resulting from production of an olefin polymerization procatalyst by the addition to the waste stream of a separation solvent of intermediate boiling point, subjecting the resulting mixture to a first distillation zone to separate the desired waste stream components from the upper portion of the zone and passing the bottoms product to a second distillation zone wherein separation solvent is recovered from the upper portion of the zone for recycle and passing the bottoms product to disposal or further processing.

Abstract: The present invention provides a continuous method of purifying eicosapentaenoic acid and esters of eicosapentanoic acid, comprising (a) fractionally distilling a starting mixture containing eicosapentaenoic acid or esters of eicosapentaenoic acid using a system of at least three distillation columns connected in flow arrangement to separate a fraction containing eicosapentaenoic acid or esters of eicosapentaenoic acid and other C.sub.20 fatty acids from a fraction containing lower-number carbon fatty acids and from a fraction containing higher-number carbon fatty acids, and (b) continuously collecting the fraction containing eicosapentaenoic acid or esters of eicosapentaenoic acid, wherein the pressure in the distillation columns is maintained at 10 Torr or below and wherein the bottom temperature of the distillation columns is maintained at 210.degree. C. or below.

Abstract: A process to modernize existing urea plants which use a stripping with carbon dioxide, and to increase urea yields and flexibility under overload conditions while at the same time reducing energy consumption, corrosion phenomena and possible risks of explosive mixtures. The plant includes: a passivation stage with the introduction of an oxidizing agent and reduction of the air fed to the system; a medium pressure distillation stage of the products leaving the stripping section, and a condensation of the products of the distillation, effected in a pre-evaporation phase to concentrate at low pressure the urea solution.The modernized plant, includes at the start at least a reactor, a scrubber, a condenser, a stripper and the evaporators, includes also a passivation section, a medium pressure distillation section, and a distillation section with double-effect technique.

Abstract: For the separation of tert. butyl ethyl ether from mixtures with ethanol, there are provided two distillation stages, the first being carried out at a pressure p.sub.1 equal to or higher than 1 bar, the second at a pressure p.sub.2 below p.sub.1 by a value .DELTA.p or 0.5 to 12 bars, p.sub.2 then being 0.5 to 10 bars. The second column distillate is partly supplied as reflux to the head of the second column and is in part recycled to the head of the first column. The purified TBEE is collected at the bottom of the first column and the purified ethanol at the bottom of the second column.This separation process can be integrated into a TBEE production unit comprising etherification by ethanol of the isobutylene contained in a C.sub.4 fraction from a catalytic cracking or steam cracking stage. The ethanol separated from the TBEE is then recycled to the etherification zone.

Abstract: A process for removing inorganic compounds from glycol recovery still bottoms resulting from the manufacture of poly(ethylene terephthalate), the novel process using a small amount of phosphoric acid to precipitate the antimony and then removing the titanium dioxide and antimony compound by a centrifuge. The novel process for removing the inorganic compounds from the recovery polyester bottoms includes the steps of distilling ethylene glycol from the spent glycol until the remaining bottoms have a solids concentration from about 15% to about 45%; adding phosphoric acid to the bottoms to form an antimony compound and removing the antimony and titanium precipitates from the bottoms by a centrifuge.

Abstract: In the diisopropyl ether production process, the distallation step for the separation of aqueous IPA recovered from the DIPE extraction operations is modified to avoid carrying out the distillation under conditions that yield IPA-water azeotrope providing lower overall process cost. The determination has been made that the overhead and bottom streams form an aqueous IPA fractionation process operated under off-azeotrope conditions in DIPE production can be recycled, respectively, to the DIPE reactor and extractor operations. Recycling the water and IPA overhead mixture eliminates the requirement for adding fresh water to the DIPE reactor. Returning the water and IPA bottom stream to the extractor reduces the requirement for distilled water addition to the extraction step. As a consequence, a less complex and costly aqueous IPA separation process is implemented.

Abstract: Disclosed herein is a process for removing chloroprene by subjecting chloroprene-containing 1,2-dichloroethane to heat treatment at a temperature in the range of from the boiling point (85.degree. C.) of 1,2-dichloroethane to the thermal cracking temperature (300.degree. C.) of 1,2-dichloroethane. In particular, the process can be suitably applied to a liquid distillate from a low-boiling material separation column in a step in which 1,2-dichloroethane used as a raw material for production of vinyl chloride is purified by using a fractionation column.

Abstract: A process for the recovery of heat and chemicals from spent liquor by evaporating water out from it in order to concentrate the liquor and be feeding the concentrated liquor thereby obtained and air into the soda-ash furnace. In order to increase the dry-matter content of the liquor to a level higher than usual, without at the same time increasing the viscositty of the liquor immoderately, at least the final concentrating (5, 9) of the liquor and its feeding (16) into the soda-ash furnace (4) are carried out under pressure at a temperature higher than the atmospheric boiling point of the liquor.

Abstract: Butter oil is heated under high vacuum and sparged for up to about 6 hours to remove cholesterol. Walls surrounding a vapor space above the sparged mass preferably are heated to remove cholesterol with reduced loss of desirable low molecular weight components. Alternatively, the temperature of the butter oil is lowered, and the butter oil is sparged with steam for an additional period of up to about 3 hours to partially hydrolyze triglycerides to mono- and di-glycerides and free fatty acids. The low cholesterol butter oil then is cooled before being exposed to air, thus avoiding oxidation which produces off-flavors. The resulting low-cholesterol butter fat and products made therefrom have composition and organoleptic characteristics substantially similar to those of natural butter oil and butter.

Abstract: Process and apparatus for recovering clean water and solids from aqueous solids are disclosed. Aqueous solids are mixed with a low viscosity, relatively volatile, water-immiscible light fluidizing oil to obtain a mixture which will remain fluid and pumpable after removal of essentially its entire water content. The mixture of solids, water and fluidizing oil is subjected to a dehydration step by means of a plurality of mechanical vapor recompression evaporators operating in staged array whereby substantially all of the water and at least part of the light oil are evaporated and subsequently recovered. The light fluidizing oil is then largely separated from the solids. Residual fluidizing oil may be removed from the solids by direct contact with a hot blowing gas such as blowing steam. The invention is characterized by the conservation of energy through the use of heat exchangers whereby condensate gives up its heat to the feed.

Abstract: High purity isopropyl acetate and ethanol are recovered from a process stream containing isopropyl acetate, ethanol and water by a multiple step process including extracting substantially all of the ethanol from the stream using water as a solvent, stripping the extract stream to remove substantially all of the remaining isopropyl acetate as an overhead recycle stream, which is combined with the fresh feed stream prior to the extraction step, fractionating the ethanol-rich stripping column bottoms stream to produce a ethanol-water azeotropic overhead stream and using a portion of the fractionating column bottoms stream as the solvent for the extraction step.

Abstract: A process for the purification of crude benzoic acid obtained by the catalytic oxidation of toluene in the liquid phase, which is contaminated with impurities including phthalic acid and benzylbenzoate, the process involves distilling the crude benzoic acid in a first distillation in the presence of an aliphatic amine or a mixture of aliphatic amines of the formulaHNR.sup.1 R.sup.2whereinR.sup.1 represents hydrogen or a straight-chain or branched hydroxyalkyl or aminoalkyl radical with 1 to 6 carbon atoms andR.sup.2 represents a straight-chain or branched hydroxyalkyl or aminoalkyl radical with 1 to 6 carbon atoms,and/or the salts of these amines, recovering from this distillation (a) a purified benzoic acid and (b) a benzylbenzoate containing residue, working up the residue by a second distillation and chlorinating the distillate resulting from this second distillation to give a benzoylchloride virtually free of benzonitrile.

Abstract: A process for producing hydrazine containing at least 98 percent by weight of N.sub.2 H.sub.4 which admixes an aqueous solution of hydrazine with an alkali metal hydroxide to form a hydrazine solution having a N.sub.2 H.sub.4 concentration of at least 70 percent by weight. The molar ratio of alkali metal hydroxide to water is less than about 0.5:1. The concentrated hydrazine solution is distilled in a fractional distillation apparatus at an overhead vapor temperature below about 50.degree. C. and at a pressure of less than about 60 mm Hg.

Abstract: A process for treating naphthenic fractions with a caustic blend of sodium and potassium hydroxide, preflashing the naphthenic fraction to remove water and then flashing the dewatered fraction to remove the neutral oils and the materials that were not formed into the acid salts. The naphthenic salt mixture is then quenched and acidified so as to recover the naphthenic acids. Naphthenic acids recovered from the process of the present invention have acid numbers which are generally higher than the naphthenic acids heretofore produced from the corresponding feed streams. The process provides for the flashing of the water which otherwise would cause foaming and not permit the recovery of the acid salt for the enhanced separation of the naphthenic acids.

Abstract: (CF.sub.3 SO.sub.2).sub.2 O is formed by reaction of CF.sub.3 SO.sub.3 H with P.sub.2 O.sub.5 and taken out of the reaction system by distillation, but the residue of the distillation contains a considerable amount of unreacted CF.sub.3 SO.sub.3 H. From the residue unreacted by adding water or a phosphoric acid solution, preferably the latter, to the residue to obtain a fluidic mixture containing an adequate amount of water and subjecting the mixture to distillation, preferably under reduced pressure at temperatures ranging from 180.degree. to 280.degree. C. It is possible to form additional CF.sub.3 SO.sub.3 H during the recovery process by adding a metal salt of CF.sub.3 SO.sub.3 H to the aformentioned mixture since the metal salt is decomposed by phosphoric acid contained in the mixture.

Abstract: A process for the separation of butanol and butoxyacetaldehyde which involves subjecting a composition which contains these two compounds to a distillation at a pressure of at most 660 mbar. According to a special embodiment the composition to be distilled contains as essential components water, butanol, butoxyacetaldehyde, butylglycol and, if desired, also butyraldehyde.

Abstract: A process to purify t-butylstyrene from product containing substantial amounts of t-butylethylbenzene and small amounts of alkenyl-substituted styrene impurities by a combination of vacuum fractionation and vacuum evaporation in the presence a polymerization inhibitor, and treatment with a carbonaceous adsorbent. Such a product to be purified can be prepared by catalytically, oxidatively dehydrogenating over an alkaline pyrophosphate in the vapor phase t-butylethylbenzene containing about 95 wt. % or more of the p-isomer which can be made by alkylating ethylbenzene with isobutylene in a controlled manner in the presence of cooled concentrated sulfuric acid.

Abstract: A process for producing low alcoholic wine includes the following steps: evaporating alcohol-containing wine in a vacuum evaporator so that a first mixture comprising water, alcohol and flavoring substance is separated from a second mixture having a low-alcoholic content, separating water from said first mixture in a multistage flavor substance apparatus and drawing off a third mixture comprising alcohol and flavoring substance, distilling alcohol from the third mixture, adding the water from the multistage flavor substance apparatus to a mixing vessel in an amount, which together with the low-alcohol second mixture and the flavoring substances produces a quantity of low-alcoholic wine having an alcoholic content below legally determined values for low-alcoholic wine, the process allowing only outputs of low-alcoholic wine, distilled alcohol and flavoring substances and inputs of essentially only the alcohol-containing wine.

Abstract: A process for recovering N-methylpyrrolidone contained in an N-methylpyrrolidone-containing liquid formed in the process for preparing a polyarylene thioether by the dehalogenosulfidation of a dihalogeno-aromatic compound and an alkali metal sulfide in the presence of N-methylpyrrolidone as the polymerization solvent, which comprises (a) subjecting the N-methylpyrrolidone-containing liquid to distillation to distill and recover the majority of contained N-methylpyrrolidone while recovering a distillation residue having such a flowability that flow transferring of the distillation residue is possible, and (b) supplying the distillation residue to an air-tight mixer for a highly-viscous fluid, which has a vent and is provided with a heater, to treat the distillation residue under the conditions of a temperature in the mixer of 190.degree. to 310.degree. C.

Abstract: Provided by this invention is a process for producing a purified hydrazine hydrate having a low total organic carbon concentration and which involves:a first step which includes distilling an aqueous solution of hydrazine hydrate in the presence of at least one salt selected from the group consisting of chloride, sulfate, phosphate and carbonate of (a) the metals of Group Ia and IIa of the Periodic Table of the Elements, (b) ammonium or (c) hydrazinium to concentrate the aqueous solution of hydrazine hydrate by distilling water and the majority of the total organic carbon constituents off and separating the resultant concentrate as a bottom product, anda second step which includes distilling the resultant concentrate to recover a purified aqueous solution of hydrazine hydrate as a top product and separating an aqueous solution of the above salt as a bottom product.

Abstract: N-Ethylpiperazine is isolated by distillation from a mixture consisting per 100 kg ofa=from 30 to 90 kg of N-ethylpiperazineb=from 7 to 40 kg of N,N'-diethylpiperazinec=from 3 to 20 kg of piperazined=from 0 to 30 kg of ethanole=from 0 to 40 kg of water andf=from 0 to 5 kg of concomitants,by performing the distillation in the presence of x=y+e= from 3b to 12b of water, y being the quantity of water which has to be added, if necessary, to meet this condition, and successively separating from this mixture the fractions1. water, ethanol, N,N'-diethylpiperazine and other highly volatile concomitants,2. water, if present in excess,3. piperzine and4. pure N-ethylpiperazineas overhead products.

Abstract: A liquid product (4) leaving a furnace (2) is introduced into a series of cyclone separators (5, 6, 7). The liquid product to be vaporized is introduced tangentially into the top portion (5a, 6a, 7a) of each cyclone to place the product into contact with a side wall (5b, 6b, 7b) of the cyclone. A gaseous phase (11, 12, 13) formed in each cyclone is collected in the central zone (8, 9, 10) of the cyclone and is then introduced into a vacuum distillation column (3). The liquid phase obtained in each cyclone is collected at the bottom (5c, 6c, 7c) of the cyclone and then is introduced tangentially into the top (6a, 7a) of the following cyclone or, in the case of the last cyclone, is introduced directly into the vacuum distillation column (3). The side wall (5b, 6b, 7b) of each cyclone (5, 6, 7) is heated to a temperature near the maximum temperature allowable for avoiding all thermal deterioration of the product.

Abstract: A process is described for the production of pure tetrafluoroethylene from a gas formed in the pyrolysis of a fluorocarbon compound having 1 to 4 carbon atoms, which can contain a hydrogen atom and a chlorine atom. The pyrolysis gas, after hydrogen chloride or hydrogen fluoride and also if necessary steam have been separated off, is condensed under pressure and distilled in a plurality of columns, in the first column the low boilers being distilled off, preferably with a reflux ratio of 6 to 15 kg per kg of tetrafluoroethylene produced, and in the second column tetrafluoroethylene, preferably with a reflux ratio of 3 to 5 kg per kg of tetrafluoroethylene produced. Per kg of tetrafluoroethylene produced, from 0.6 to 2 kg of difluoromonochloromethane are fed into the second column as a distillation aid. The novel process makes it possible to produce pure tetrafluoroethylene at comparatively reduced energy and apparatus costs.

Abstract: Distillation residues from the purification of caprolactam are worked up by heating in the presence of sodium hydroxide or potassium hydroxide and in the presence of a high-boiling hydrocarbon at from 250.degree. to 500.degree. C. and continuously removing the caprolactam.

Abstract: A process and apparatus are disclosed for recovering olefins, particularly C.sub.3, C.sub.4, and C.sub.5 olefins, from gaseous mixture thereof with lower-boiling components. The olefin-containing gas mixtures is compressed and cooled to yield vapor and condensate streams, the vapor stream is further cooled forming additional condensate, both condensate streams are combined and adiabatically flash evaporated, and the remaining liquid is distilled to recover the desired olefins in a liquid bottoms products. Flash vapor, and optionally the distillation vapor product, are recycled to the compression step.

Abstract: In the hydroformylation of alkenes to aldehydes, rhodium is recovered from the stripped overhead of the hydroformylation reactor by condensing the overhead, removing the bulk of the aldehyde product from the condensed overhead, stripping the residue which remains with nitrogen gas to remove minor amounts of highly volatile aldehyde product remaining in the residue and redistilling the residue to remove components from the condensed overhead which are lower boiling than the catalyst components. The catalyst components including rhodium and phosphine ligand are returned to the hydroformylation reactor.

Abstract: There is disclosed an improved process for the manufacture of glyoxylic acid obtained by oxidation of glycolic acid. For processing purposes alkyl esters of these acids are employed. Increased efficiency is obtained by recovering glycolate rich streams from one or more distillation operations and after treatment to remove acetic acid by-product the streams are recycled to the oxidation reaction.

Abstract: A method of and system for recovering a solvent from a mixture of solvent and hydrocarbons, the system comprising at least two evaporation flasks successively fed with a charge consisting of said mixture to be separated, at least one steam generator performing the condensation of the solvent, a circuit for conveying the evaporated solvent and connecting the flasks to the generator and a circuit of an intermediate fluid in gaseous phase including a compressor for raising the condensation temperature of this fluid, the latter circuit connecting the generator to heat exchangers arranged upstream of each flask.

Abstract: Apparatus for reducing the amount of water in the feed to a methanol-to-gasoline (MTG) conversion reactor is described. The output products of a dehydration reactor and an aqueous methanol feed are supplied to a primary distillation tower or separator. A dimethylether (DME)/methanol mixture is taken as overhead from the primary tower and can be sent to the MTG conversion reactor to produce hydrocarbons boiling in the gasoline range. Bottoms from the primary tower, containing methanol and water, are supplied to a secondary distillation tower or separator. A methanol stream is drawn as overhead from the secondary tower and is passed to an acid catalyzed dehydration reactor where an equilibrium mixture of dimethylether, methanol, and water is produced. The equilibrium mixture is passed from the dehydration reactor to the primary distillation tower. In preferred embodiments, the conversion reactor feed from the primary distillation tower may be of a gaseous or liquid phase.

Abstract: Ultrapure or anhydrous hydrazine is produced in a process which comprises distilling aqueous solutions of hydrazine having at least 70 percent by weight of N.sub.2 H.sub.4 at pressures below about 20 millimeters. Aqueous solutions of hydrazine are dehydrated with solid inorganic compounds such as alkali metal hydroxides which are essentially carbon-free. The concentrated hydrazine solution is then distilled at reduced pressures and temperatures which minimize the hazardous conditions present when using processes of the prior art. Monopropellant hydrazine suitable for use in spacecraft engines can be produced having a N.sub.2 H.sub.4 concentration of at least 99.5 percent and less than 5 parts per million of volatile carbonaceous materials.

Abstract: Ammonia which is present in fuel cell power plant water in free form, in ionic form, and in forms combined with carbon dioxide, is removed from the power plant water by steam stripping. Water which has been used to cool the fuel reformer effluent, and thus has become contaminated with ammonia, is fed to a first steam stripper wherein a first portion of the ammonia contaminant is removed. The partially stripped water is then fed to a second steam stripper wherein further amounts of ammonia are removed from the water with steam. The ammonia laden steam from the two strippers is combined and vented through a single vent thus conserving the amount of water lost from the system.

Abstract: A method and apparatus for treating the distilled water obtained from an evaporation process sea water desalination plant is provided wherein carbon dioxide is extracted from sea water in the high temperature stages of the desalination plant and where the carbon dioxide thus extracted is dissolved into the water, along with calcium, thereby converting the distilled water into the quality suited for city tap water.

Abstract: A method for passivating the surface of the strippers of the urea plants, where the temperatures are very high, where the pressures range from 120 to 240 Kg/cm.sup.2 and where the effluent process flow from the synthesis reactor undergoes one or more falling-film evaporations, preferably in countercurrent with a driving gas consisting of NH.sub.3 or CO.sub.2, characterized by the fact that the passivation is carried out by means of a sinergistic combination of oxygen, preferably injected into the bottom of at least one stripper, and of a second passivating agent, preferably injected into the process flow entering the head of at least one stripper, wherein said second passivating agent is injected in the liquid state or as a liquid solution, before or contemporaneously to the start of the evaporation.

Abstract: A process for the purification of 1,2-dichloroethane is described, in which the crude product, containing not more than 3% by weight of high-boilers, is distilled in a first column at 125.degree. to 180.degree. C. in such a way that the bottom product contains not more than 7% by weight of high-boilers. The purified, vaporous 1,2-dichloroethane discharged at the head of this column is used to heat product streams containing 1,2-dichloroethane. The bottom product from the first column is distilled in a second column, advantageously at a pressure of 5 to 40 kPa, together with a feed composed of vaporous 1,2-dichloroethane obtained from the reaction of ethylene with chlorine. The process makes it possible to purify 1,2-dichloroethane with a saving in energy.

Abstract: A method of and apparatus for reducing the amount of water in the feed to a methanol-to-gasoline (MTG) conversion reactor is described. The output products of a dehydration reactor and an aqueous methanol feed are supplied to a primary distillation tower or separator. A dimethylether (DME)/methanol mixture is taken as overhead from the primary tower and can be sent to the MTG conversion reactor to produce hydrocarbons boiling in the gasoline range. Bottoms from the primary tower, containing methanol and water, are supplied to a secondary distillation tower or separator. A methanol stream is drawn as overhead from the secondary tower and is passed to an acid catalyzed dehydration reactor where an equilibrium mixture of dimethylether, methanol, and water is produced. The equilibrium mixture is passed from the dehydration reactor to the primary distillation tower. In preferred embodiments, the conversion reactor feed from the primary distillation tower may be of a gaseous or liquid phase.

Abstract: Crude cumene hydroperoxide is purified by subjecting it to an evaporation step at a pressure of about 2 to 10 (preferably 3 to 7) mg Hg abs. and a temperature of about 150.degree. F. to about 210.degree. F. (pref. about 175.degree. F. to 195.degree. F.) to remove light impurities and then subjecting the residue from the first evaporation step to a second evaporation step also at a temperature of about 135.degree. F. to 210.degree. F. (pref. about 150.degree. F. to 185.degree. F.) but at a pressure of about 0.5 to about 8 (preferably 1 to 3) mm Hg abs. to obtain a distillate significantly reduced in color bodies, water, acetophenone, and dimethylbenzyl alcohol, and sodium.

Abstract: This invention provides a process for isolating and recovering butene-1 of high purity at high yield. Firstly, a butane-butene fraction containing 0.1 to 7 wt % of isobutylene, 10 to 50 wt % of butene-1 and 5 to 20 wt % of isobutane is rectified to reduce the content of isobutane to not more than 0.1 wt %. Then, the rectified butane-butene fraction is passed through a reactor packed with an extrusion molded silica-alumina catalyst to polymerize isobutylene at a reaction velocity as high as 50 times or more of that of butene-1, thus forming oligomers of isobutylene. Finally, the hydrocarbon mixture from the reactor is rectified to remove the oligomers of isobutylene and the other C.sub.4 -hydrocarbons.

Abstract: For the distillation of a stream consisting essentially of alcohols of 6-20 carbon atoms, water and methanol, the methanol is first separated from the homogeneous, aqueous solution as the overhead product by distillation under a head pressure of 500-1,000 mbar. The bottoms discharge is mechanically separated under normal pressure and at a temperature of 5.degree.-95.degree. C. in a phase separator to obtain a discrete water phase preferably containing at least two thirds of the feedstream water. The remaining organic phase is then transferred from the phase separator into a second distillation column and the organic phase is dewatered in the latter at 100-500 mbar. The head product from the second column is conducted to a second phase separator; the aqueous phase is separated therein at a temperature of 5.degree.-95.degree. C. and optionally returned into the first phase separator. The bottom product from the second distillation column is passed into a downstream distillation stage wherein the C.sub.6 to C.

Abstract: Middle phase emulsions are broken by subjecting the emulsion to a first atmospheric distillation step to remove water, followed by a second vacuum distillation step to recover oil. The residue contains the surfactant. The atmospheric distillation is generally carried out by steam distillation.

Abstract: A process for the separation of ethylene glycol from glycolated water obtained from the bottom of an ethylene oxide desorption column in a process for the manufacture of ethylene oxide by catalytic oxidation of ethylene by oxygen in the vapor phase, comprising feeding said glycolated water directly from the bottom of said ethylene oxide desorption column into the top of a separation column having therebelow up to 12 theoretical plates and adding sufficient indirect heat to said glycolated water to form two streams; a first gaseous stream consisting essentially of steam which is removed from the top of said separation column and introduced into said ethylene oxide desorption column to serve therein as the desorption fluid, and a second aqueous stream containing from about 40% to 90% by weight of ethylene glycol which is removed from the bottom of said separation column.

Abstract: C.sub.1 -C.sub.4 -alkyl pentenoates are obtained from reaction mixtures which contain this and which are obtained by reacting butadiene, or a butadiene-containing hydrocarbon mixture, with carbon monoxide and a C.sub.1 -C.sub.4 -alkanol, in the presence of a cobalt carbonyl catalyst and a tertiary nitrogen base at elevated temperatures and under superatmospheric pressure by a process in which(a) the liquid reaction mixture freed from excess carbon monoxide is treated with hydrogen at elevated temperatures and under from 5 to 80 bar,(b) hydrocarbons are distilled off from the resulting liquid reaction mixture,(c) the C.sub.1 -C.sub.4 -alkyl pentenoate, the alkanol and the nitrogen base are then distilled off under reduced pressure, and(d) the C.sub.1 -C.sub.4 -alkyl pentenoate is obtained by fractional distillation from the distillate containing this compound, the alkanol and the tertiary nitrogen base.

Abstract: A process for the production of a crude dimethyl terephthalate suitable for hydrolyzing into a fiber grade terephthalic acid involves separating a crude ester obtained from the production of dimethyl terephthalate by the Witten process by vacuum distillation at elevated pressure in a three-column series arranged distillation system. In the first distillation column of the system the crude is separated into a methyl p-toluate-rich fraction as head product; in a second column of the series, into a fraction rich in methyl ester of terephthalaldehydic acid as head product; and in a third distillation column, a crude dimethyl terephthalate fraction. The crude dimethyl terephthalate fraction has a methyl ester of terephthalaldehydic acid content of 0.01-0.1% by weight as a head product.

Abstract: Distillation of the heavy waste stream from the manufacture of phenol via the cumene process provides an overhead stream containing phenol, acetophenone and 2-phenyl propionaldehyde. Extraction of the overhead stream with aqueous caustic removes the phenol and subsequent distillation of the remaining two components in the presence of a catalytic amount of caustic provides a substantially pure acetophenone distillate.

Abstract: A process to recover acrylic acid or methacrylic acid by using a split quench process which allows acrylic acid or methacrylic acid to be recovered from the resulting aqueous solutions by a combination of solvent extraction and azeotropic dehydration that minimizes the amount of solvent required.

Abstract: The disclosure relates to a process for separating the catalyst system from reaction mixtures which are obtained by reacting methyl acetate and/or dimethylether with carbon monoxide and optionally hydrogen at elevated temperatures to acetic anhydride and optionally ethylidene diacetate in the presence of a catalyst system consisting of carbonyl complexes of noble metals belonging to group VIII of the Periodic System, acetic acid, an organophosphorus or organonitrogen compound, methyl iodide and optionally compounds of carbonyl-yielding common metals, and which issue from the reaction zone under a pressure of 25 to 150 bars at a temperature of 100.degree. to 250.degree. C. More particularly, the reaction mixture coming from the reaction zone is introduced into a separator heated to 60.degree. to 140.degree. C. and released to a pressure of 0.5 to 3.

Abstract: A process for separating highly pure butene-2 and butene-1 from a C.sub.4 hydrocarbon fraction containing isobutane, n-butane, butene-1, butene-2, and at least one diolefinic hydrocarbon and/or at least one acetylenic hydrocarbon, which comprises, (1) as a step A, treating the C.sub.

Abstract: A solar desalination system in which fresh water is derived from sea water by focussing solar ray energy from a collecting reflector onto an evaporator tube located at substantially the focal apex of the reflector. The reflector/evaporator tube assembly is mounted on a horizontal open grid platform which may support a plurality of parallel reflector/evaporator tube assemblies. The reflectors may serve as pontoons to support the desalination system unit on a body of sea water. The solar heat generated vapor is condensed in condenser tubes immersed in the sea water. Intermittently sea water concentrate is withdrawn from the evaporator tubes. Velocity of the vapor passing from the evaporator tubes to the condensers may be utilized for generating power.

Abstract: High purity alkyl glyoxylate is produced from complex mixtures containing alkyl glyoxylate, alkyl glycolate, water, alcohol and miscellaneous impurities. High purity alkyl glyoxylate is useful in the synthesis of alkyl glyoxylate polymers.

Abstract: Water is removed from methanesulfonic acid to produce an anhydrous product of high purity by spraying wet methanesulfonic acid (MSA) onto the walls of a vertical, heated tube which is maintained at reduced pressure. The water evaporates as the acid flows down the walls of the tube and dry MSA is removed at the bottom.