Abstract: The invention relates to a process for separating dimethyl isophthalate (DMI) and dimethyl orthophthalate (DMO) and other by-products from their mixture with dimethyl terephthalate (DMT), formed in the oxidation of p-xylene followed by esterification with methanol, by crystallization from the melt.Initially, the esterification product is here distilled once or several times. The DMT-rich fraction obtained is then subjected wholly or partially to one or several crystallizations from the melt, and the DMI-DMO fraction thus obtained is at least partially removed from the system. As an alternative, the DMT-rich fraction is first recrystallized from methanol, the methanol is then evaporated from the mother liquor and the remaining residue is subjected to one or several crystallizations from the melt. The DMI-DMO fraction thus obtained is again at least partially removed from the system.

Abstract: In a continuous alkoxidation-phosphorylation process for producing tributyl phosphate having low color utilizing excess butanol in the alkoxidation reaction which is heated by an alcohol flasher wherein the excess butanol is recovered after phosphorylation by two stage flash distillation, the bottoms product from the first stage going to the second stage, the overhead product from the second stage returning to the first stage flash distillation, and the bottoms from the second stage distillation going to final product washing and drying process while the overhead from the first stage flash distillation is fed to the process alkoxidation alcohol flasher, the improvement which comprises distilling in a distillation column the overhead product from the first stage flash distillation and then feeding the overhead from the distillation column to the alkoxidation alcohol flasher.

Abstract: A method for the separation of bis-(2-aminoethyl)ether from N-(2-methoxyethyl)morpholine via azeotropic distillation using an entrainer such as monoethanolamine is described. The N-(2-methoxyethyl)morpholine is selectively removed by the monoethanolamine. The N-(2-methoxyethyl)morpholine is then separated from the monoethanolamine by liquid-liquid extraction using a non polar hydrocarbon or aromatic extraction solvent and distillation.The N-(2-methoxyethyl)morpholine-monoethanolamine stream previously had no economic use. The separation is now economically effected and the N-(2-methoxyethyl)morpholine used as a polyurethane catalyst.

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: A method for recovery of extraction solvent from a dissolved solute wherein halogen gas evolution and halogen compound retention in the solute are minimized comprises heating a solution of a halogenated organic solvent and the extracted solute in the presence of an ammonium, Group I metal or Group II metal salt of an acid of carbon number 1 to 6, such as ammonium bicarbonate, ammonium carbonate, ammonium formate, sodium carbonate, sodium formate, or calcium formate, to recover the solvent and the solute.

Abstract: Carbon dioxide is cryogenically separated from methane and then is separated from the ethane by liquid extraction with water at high pressures of 500 to 2250 psia thus avoiding the CO.sub.2 --C.sub.2 H.sub.6 azeotrope problem. The process is particularly applicable to the recovery of high pressure pure carbon dioxide from the wellhead products of carbon dioxide flooding used in enhanced oil recovery. The high pressure pure carbon dioxide liquid is pumped for reinjection to the well.

Abstract: The reaction product from etherification of C.sub.4 -C.sub.7 isoolefins with methanol in the presence of an acidic catalyst is washed with water in the presence of inert hydrocarbons thereby removing methanol and a part of the tertiary alcohol. The aqueous extract solution bottoms is distilled to separate methanol as overhead. Tertiary alcohols are withdrawn as a side stream from a tray of the distillation column with a high concentration thereof and fed into the washing column.

Abstract: Tert.butyl alkyl ethers are produced from a C.sub.4 hydrocarbon feedstock containing isobutene, and the butene-1 is recovered at high purity by extractive distillation of the isobutene-free C.sub.4 hydrocarbon stream in the presence of a solvent chosen from acetone, acetonitrile, dimethylformamide, methanol, n-methylpyrrolidone, formylmorpholine and furfural.After removing the solvent, the extract is rectified, and the butene-1 separates as overhead product of high purity.

Abstract: A process for the production of a "fuel grade" mixture of methanol and higher alcohols from CO and H.sub.2.To reduce the amount of water contained in the mixture coming from the synthesis reactor of the alcohol synthesis the reaction product is cooled and fed to a secondary reactor wherein the reaction of conversion:CO+H.sub.2 O.revreaction.CO.sub.2 +H.sub.2is conducted in conditions near to equilibrium.The further reaction product is cooled down further so as to obtain a liquid phase constituted by the alcohols, and in which there are still dissolved some gases, and a gaseous phase containing the carbon dioxide produced in the secondary reactor together with the non-reacted gases. The gaseous phase is sent to a section of absorption of the CO.sub.2 wherein the absorbing liquid is constituted by the very alcoholic mixture produced; after removal of the CO.sub.2 the gas is partly recycled and partly let off in order to avoid the accumulation of inert gases contained in the feeding mixture.

Abstract: Ethylene oxide is recovered from aqueous solutions by extracting with carbon dioxide in the near-critical or super-critical state, thereby selectively removing the ethylene oxide from water, and thereafter recovering ethylene oxide from the carbon dioxide by distillation or other suitable means.

Abstract: Ethylene oxide is extracted from aqueous solutions by carbon dioxide under (near) super-critical conditions and thereafter recovered by distillation at sub-critical conditions. Improved distillation is obtained by adding to the carbon dixoide a gas (or gases) which adjust the critical temperature of the gas mixture of the top of the distillation column within the range of about 32.degree. C. to about 75.degree. C. Preferred gases are the saturated hydrocarbons, particularly propane, n-butane, isobutane and pentane.

Abstract: Alcohol/water mixtures, such as those produced by fermentation of biomass material, are separated by extraction of alcohol with a solvent, comprising a higher aliphatic alcohol in major amount and an aliphatic hydrocarbon in minor amount, especially suited to such extraction and to subsequent removal. The solvent alcohol desirably has a branched chain, or the hydrocarbon an unsaturated bond, or both. Conventional distillation steps to concentrate alcohol and eliminate water are rendered unnecessary at a considerable reduction in heat energy requirement (usually met with fossil fuel). Optional addition of gasoline between the solvent extraction and solvent recovery steps not only aids the latter separation but produces alcohol already denatured for fuel use.

Abstract: An improved distillation method and apparatus are provided for recovering anhydrous ethanol from fermentation or synthetic feedstocks. The system includes at least one stripper-rectifier tower, a dehydrating tower, and an azeotropic agent stripping tower. Substantial energy savings are realized by operating the dehydrating tower, and preferably also the azeotropic agent stripping tower, at a higher pressure than the stripper-rectifier tower and by condensing the overhead vapors from the dehydrating tower (or dehydrating tower and azeotropic agent stripping tower) to provide the heat required in the stripper-rectifier tower. In a preferred embodiment, two stripper-rectifier towers are used, one operating at a higher pressure than the other, in which case the higher pressure tower is heated as just described and the overhead vapors from the higher pressure tower are condensed to supply the heat required in the lower pressure tower.

Abstract: An improved process for recovering high purity resorcinol produced by the rearrangement of m-diisopropylbenzene dihydroperoxide in which the rearranged product mixture is neutralized, the neutralized mixture being filtered, the filtrate being admixed with toluene, the acetone being removed by distillation and the acetone-free rearranged product/toluene mixture being steam distilled to provide an aqueous resorcinol containing phase from which the resorcinol is recovered.

Abstract: A mixture of isomers of an alkylamine, for example ethylamine is separated into its constituent components by a process in which the mixture is first distilled and at least one pure component separated from the mixture. The remainder of the mixture is then subjected to a multi-stage liquid-liquid extraction, preferably in five theoretical stages using water as extractant. For example, in the separation of mixtures of ethylamines, substantially all of the mono-ethylamine and a large proportion of the di-ethylamine is recovered in the distillation stage. The use of a multi-stage extraction (instead of the more usual single-stage extraction) to treat the remainder of the mixture leads to an enhanced yield of tri-ethylamine and lower consumption of energy and of extractant.

Abstract: This invention relates to a method of separating close-boiling chlorosilanes from mixtures by employing the technique of liquid extraction with sulfolane and a hydrocarbon compound as co-solvents. The hydrocarbon compound employed is substantially immiscible in sulfolane and is present in sufficient amounts so that two liquid phases are formed, one being suloflane-rich and the other being hydrocarbon-rich. The mixture of chlorosilanes is intimately mixed with the two solvents and allowed to partition between the two phases. The preferred liquid extraction procedure is where the sulfolane and hydrocarbon solvent are in a countercurrent relationship within an extraction tower. Experimentally determined selectivity coefficients show that mixtures of (1) dimethyldichlorosilane and methyltrichlorosilane, (2) phenylmethyldichlorosilane and phenyltrichlorosilane, and (3) trimethylchlorosilane and tetrachlorosilane can be successfully separated by the techniques of this invention.

Abstract: Alcohol substantially free of water is produced by a process comprising extracting an aqueous alcohol solution with an organic solvent system containing an extractant for said alcohol thereby forming an organic solvent-alcohol phase and an aqueous phase, and vacuum distilling said organic solvent-alcohol phase thereby obtaining the product alcohol substantially free of water.

Abstract: A method of extraction of HI from an aqueous solution of HI and I.sub.2. HBr is added to create a two-phase liquid mixture wherein a dry phase consists essentially of HBr, I and HI and is in equilibrium with a wet phase having a far greater HBr:HI ratio. Using a countercurrent extractor, two solutions can be obtained: a dry HBr--HI--I.sub.2 solution and a wet essentially HBr solution. The dry and wet phases are easily separable, and HI is recovered from the dry phase, after first separating I.sub.2, as by distillation. Alternatively, the HI-HBr liquid mixture is treated to catalytically decompose the HI. HBr is recovered from the wet phase by suitable treatment, including high-pressure distillation, to produce an H.sub.2 O--HBr azeotrope that is not more than 25 mole percent HBr. The azeotrope may be returned for use in an earlier step in the overall process which results in the production of the aqueous solution of HI and I.sub.2 without major detriment because of the presence of HBr.

Abstract: A process for removing water from butylene oxides which comprises liquid extraction of crude butylene oxides with a solvent comprising acyclic, paraffinic hydrocarbons having from 7 to 9 carbon atoms per molecule.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: This invention provides an improved process for the separation and recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are recovered are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate.

Abstract: A process for extracting a fluorinated polymer which contains carboxylic ester functional groups with a liquid compound which is preferably a perchlorofluorocarbon having a boiling point in the range of 30.degree. to 125.degree. C. is described. Polymer so extracted can be fabricated into a membrane and hydrolyzed to ion exchange form to provide a membrane for electrolytic cells. When used as the membrane for a chloralkali cell, such membrane provides improved performance, e.g., a high level of current efficiency and low power consumption are maintained for an extended period of time when compared against a membrane of like construction fabricated from polymer which has not been so extracted.

Abstract: Disclosed is a method of recovering acetic acid by extracting from an acetic acid-containing aqueous solution with an organic extracting agent and subjecting the extract to distillation, said method comprising the first step of performing extraction by using a tertiary amine having a boiling point higher than that of acetic acid and being capable of forming a non-aqueus phase as the organic extracting agent in combination with an oxygen-containing, high-boiling-point organic solvent selected from the group consisting of di-isobutylcarbinol, isophorene, methyl benzoate, tributyl phosphate, 3,3,5-trimethylcyclohexanone and 2-ethoxyethyl acetate, the second step of performing dehydration by subjecting the extract to distillation, and the third step of subjecting the dehydrated mixture to distillation in a reduced pressure distillation column at a column bottom temperature of 120.degree. to 170.degree. C. to distill acetic acid and separate it from the organic extracting agent.

Abstract: A method for continuous azeotropic processing of vegetable and protein material provides for staged processing, separate dehydration, and flash desolventizing.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: In a process for the continuous preparation of pure organic solutions of percarboxylic acids having 2 to 5 carbon atoms, by(a) contacting aqueous hydrogen peroxide with a carboxylic acid containing 2 to 5 carbon atoms in the presence of an acid catalyst at a feed molar ratio of H.sub.2 O.sub.2 to carboxylic acid of 0.

Abstract: This invention provides a process for improving the recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream, wherein the byproduct stream is derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are isolated are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate. Monomethyl esters of these dicarboxylic acids are recovered and recycled in the process.

Abstract: Alcohol/water mixtures, such as those produced by fermentation of biomass material, are separated by extraction of alcohol with a solvent especially suited to such extraction and to subsequent removal. Conventional distillation steps to concentrate alcohol and eliminate water are rendered unnecessary at a considerable reduction in heat energy requirement (usually met with fossil fuel). Addition of gasoline between the solvent extraction and solvent recovery steps not only aids the latter separation but produces alcohol already denatured for fuel use.

Abstract: An improvement in the distillative refining of methylamines containing higher amine impurities wherein the higher amines accumulate in the distillation column, tending to cause flooding and product contamination. The improvement involves purging the column at the point the impurities concentrate, mixing the purge with water to form two phases, separating the phases and recycling the water phase for recovery of its methylamines content.

Abstract: A method for recovering isobutyric acid from a solution thereof in concentrated aqueous hydrogen fluoride, the latter having served as the reaction medium for effecting the carbonylation of propylene. The method features the partial removal of anhydrous hydrogen fluoride from said solution to provide an aqueous phase of reduced hydrogen fluoride content from whence the isobutyric acid is extracted with optimum efficiency with an immiscible organic solvent.

Abstract: This invention provides a process for improving the recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream, derived from an adipic acid manufacturing operation wherein there is involved nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are isolated are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate. Monomethyl esters of these dicarboxylic acids are recovered and recycled in the process.

Abstract: A process for the production of anhydrous or substantially anhydrous formic acid by hydrolysis of methyl formate which is carried out in a column having an upper fractionating section, a middle hydrolysis section and a lower extraction section and in which(a) the hydrolysis is carried out in the middle section of the columm, with water and methyl formate in countercurrent,(b) the resulting formic acid is extracted, in the lower section of the column, by means of a carboxylic acid amide which is fed into the lower end of the middle section of the column,(c) the extract phase, consisting in the main of formic acid and the carboxylic acid amide, is distillatively dehydrated, or substantially dehydrated, in the lower section of the column,(d) the methanol and uncovered methyl formate are removed by fractional distillation in the upper section of the column and(e) the pure formic acid or concentrated aqueous formic acid is distilled from the anhydrous or substantially anhydrous extract phase in a second column, le

Abstract: A crude naphthoquinone produced by an oxidation of naphthalene is purified by a reduced pressure distillation of a crude 1,4-naphthoquinone having an acid content of less than 5 equivalent % calculated as monobasic acid and the crude naphthoquinone is preferably treated by an oxidation of oxidizable impurities.

Abstract: A relatively large volume horizontal liquid separation chamber is provided as an intermediate part of the downcomers used to transfer the denser liquid phase between contiguous trays of a countercurrent liquid-liquid extraction column. The downcomers also include two smaller vertical conduits which carry the liquid into and out of the opposing ends of the chamber. The downward flowing denser liquid phase is thereby subjected to a separation step within the downcomers to produce a stream of the less dense liquid released above the upper tray.

Abstract: Cyclohexylbenzene is separated from a cyclohexylbenzene-cyclohexanone-phenol admixture by liquid-liquid extraction with a non-polar solvent such as hexadecane and a polar solvent, such as sulfolane, diethylene glycol, or mixtures with water. Cyclohexylbenzene is separated from the non-polar phase by fractional distillation. Phenol and cyclohexanone are separated from the polar solvent by fractional distillation.

Abstract: In order to prevent corrosion of the apparatus in extraction and extractive distillation processes where N-substituted morpholine is employed as the selective solvent an additive is added to the solvent which additive consists of (a) phosphoric acid, (b) a salt thereof, (c) a vanadium compound, (d) a molybdenum compound or (e) a mixture of two or more of these compounds, the addition being effected in an amount of about 0.005 to 0.02% by weight of the morpholine solvent.

Abstract: Disclosed is a process for separating 11-cyanoundecanoic acid, cyclohexanone and .epsilon.-caprolactam from a pyrolysis product obtained by pyrolyzing 1,1'-peroxydicyclohexylamine in the presence of steam at a temperature of 300.degree. to 1,000.degree. C. The pyrolysis product is first contacted with a mixture comprised of aqueous ammonia and at least one organic solvent selected from benzene, toluene and xylene, and the so prepared liquid is separated into the oily layer and the aqueous layer. On one hand, the oily layer is distilled to separate cyclohexanone therefrom. On the other hand, the aqueous layer is acidified to a pH of below 4.0 by adding thereto a mineral acid and maintained at a temperature of 40.degree. to 100.degree. C. to separate crude 11-cyanoundecanoic acid in molten form from the aqueous layer, and then, the separated crude molten 11-cyanoundecanoic acid is washed with hot water to extract .epsilon.-caprolactam therefrom.

Abstract: Crude phenol is recovered from CHP reaction products by continuously feeding to a main column separating in its uppermost section phenol from crude acetone, this fraction being removed overhead, and in the lower section crude phenol from higher boilers, including acetophenone and carbinol, the crude phenol being removed as a sidestream fraction from the main column at a point in the column above the feed-point wherein the total concentration of acetophenone plus carbinol is less than 1,000 ppm and the higher boiling compounds being removed as a base fraction.

Abstract: The formaldehyde hydrazone of UDMH can be removed from an aqueous solution f UDMH by codistillation with a hydrocarbon or other solvent which is inert to both acidic or basis mediums. The solvent can then be recovered from the hydrazone solution by washing with an acid solution and the solvent can be reused.

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: A method for separating and purifying methacrylic acid is disclosed in which an aqueous solution (A) of methacrylic acid containing acetic acid is brought into contact under counter-current flow with a mixed solvent (B) of methyl methacrylate and toluene in a ratio of from 3 : 2 to 1 : 9 by weight, to extract substantially the whole amount of methacrylic acid in solution (A) into mixed solvent (B); after which the methacrylic acid is separated and purified by distillation.

Abstract: Neopentyl glycol is recovered from an impure process stream by the steps of (1) extracting neopentyl glycol from the impure stream with an organic solvent or mixture of solvents, (2) flashing the neopentyl glycol solvent mixture in a thermosiphoning reboiler so as to separate the solvent from the neopentyl glycol under atmospheric conditions, and (3) refining the neopentyl glycol by atmospheric distillation.

Abstract: Styrene is inhibited against polymerization during the distillation thereof by incorporating therein, in an amount sufficient to inhibit polymerization thereof, the dinitrophenol solution recovered from styrene still residues or tars resulting from the distillation of styrene in the presence of dinitrophenol. The recovered dinitrophenol solution is a more effective polymerization inhibitor than dinitrophenol per se.

Abstract: Alkyl substituted benzene is used as a solvent to extract organic isocyanates from crude reaction mixtures containing organic isocyanates. The crude reaction mixture is admixed with the alkyl substituted benzene solvent and heated to a temperature in the range from 130.degree. C. to about 280.degree. C. for a solvent extraction period ranging from about 0.5 to about 24 hours. The alkyl substituents on the benzene contain between 1 and 15 carbon atoms and sufficient substituents to provide at least two carbon atoms in the substituents.

Abstract: 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.