Abstract: Carboxylic acids produced by carbonylation and having iodide and oxidisable impurities are purified by contacting with hydrogen peroxide and recovering the purified acid by distillation or evaporation. Preferably a strong acid such as sulphuric acid is used as a catalyst. Product contamination by sulphur from sulphuric acid and by excess peroxide may be reduced by the use of metal salts in the recovery step.

Abstract: Acetic acid and/or acetic anhydride containing methyl crotonate, vinyl acetate, or both as impurities, is contacted with ozone in an amount of excess molar to the carbon-carbon double bond in said methyl crotonate and/or vinyl acetate and the impurities produced by ozone-treatment are removed off by distillation. A large quantity of impurities such as aldehydes are produced after treatment by treating acetic acid and/or acetic anhydride containing much amount of unsaturated compounds as impurities with ozone. Distilling the ozone-treated acetic acid and/or acetic anhydride make it possible to remove methyl crotonate and vinyl acetate, which are unsaturated compounds difficult to remove by the conventional separation methods, to give high-quality acetic acid and/or acetic anhydride excellent in the residence time in the potassium permanganate test.

Abstract: This invention provides an improved method for recovering an organic acid as a salt from various process streams by addition of a crystallizing base to a concentrated solution of neutralized organic acid. The addition of such a base causes crystallization of the salt. This process provides more efficient recovery of organic acid salt from a fermentation process stream than traditional recrystallization and it may be used essentially as a one step purification process. The improved method is particularly applicable to the recovery of trisodium or tripotassium citrate from process streams produced in the fermentation and recovery of citric acid, with the addition of a crystallizing base such as sodium hydroxide, potassium hydroxide or ammonia.

Abstract: The present invention relates to a process for inexpensively and effectively recovering a high-purity organic acid, according to which a crude organic acid is subjected to extraction treatment with an organic solvent to obtain an organic solvent extract containing an organic acid; the organic solvent extract is mixed with a high-pressure gas to precipitate and separate impurities thereby obtaining a solution containing a high-purity organic acid; and the organic acid is separated from the solution to obtain a high-purity organic acid.

Abstract: In a process for removing iodide compounds from a liquid composition comprising carboxylic acids having 2 to 6 carbon atoms or anhydrides thereof, by passing the liquid composition through a silver, mercury, palladium and/or rhodium-exchanged strong acid cation exchange resin, prior to contacting with the metal-exchanged resin the composition is contacted with a cation exchanger in the acid form to remove at least a portion of the metal ion contaminants in the liquid composition which have been found to displace the silver, mercury, palladium and/or rhodium from the metal-exchanged resin.

Abstract: A process for production of lower alkanoic acids. A reaction mixture comprising a substituted malonic acid, an acid catalyst, and a limited amount of water is heated to a temperature sufficient to hydrolyze and decarboxylate the ester. The reaction mixture is maintained at the temperature by periodic addition of limited amounts of water, and the reaction is continued for a period of time sufficient to remove substantially all of the alcohol and carbon dioxide generated by the hydrolysis reaction, thereby converting substantially all of the ester to alkanoic acid. The process is particularly useful for the production of valproic acid.

Abstract: Waste acetic acid, which is contaminated by nitrogen compounds and also by hardly hydrolyzable halogen compounds, is purified by adding a complex-forming metal or one of the compounds thereof and a basic compound. The resultant mixture is kept at a temperature between 25.degree. and 118.degree. C. over a period of time of 1 to 6 hours. Finally, purified acetic acid is removed from the mixture by distilling.

Abstract: A method is provided for removing iodide compounds, particularly alkyl iodide compounds, from iodine-containing liquids, particularly carboxylic acids and anhydrides manufactured by the carbonylation of alcohols, ethers, esters, and the like in the presence of a rhodium catalyst and an alkali metal or alkaline earth metal salt, particularly a lithium salt, wherein the carboxylic acid or anhydride is contacted with a silver or mercury salt coordinated to a polymeric resin containing functional groups having the capability to quaternize with or form ionic salts with the alkyl halides.

Abstract: The present invention discloses a method to separate each component from a mixed solution of organic solvents obtained during the production of .alpha.-L-aspartyl-L-phenylalanine methyl ester, which is useful as a sweetener, namely, a mixed solution of acetic acid and toluene or a mixed solution of acetic acid, toluene and formic acid, recovering each component with a high recovery ratio with as small number of operations as possible. The method rationalizes the process and is highly valuable in practical use.

Abstract: Formic acid difficult to separate from acetic acid by conventional distillation or rectification because of the close proximity of their boiling points. Formic acid can be readily separated from acetic acid by using azeotropic distillation. Effective agents are cyclopentane and tetrachloroethylene.

Abstract: Formic acid cannot be easily removed from formic acid-acetic acid mixtures by distillation because of the closeness of their boiling points. Formic acid can be readily removed from mixtures containing it and acetic acid by extractive distillation. Typical effective agents are 2-nitrotoluene, 1-nitropropane and m-nitrobenzoic acid.

Abstract: A process for removing iodide derivatives from liquid acetic acid and/or acetic anhydride comprises contacting the liquid acetic acid and/or acetic anhydride with a strong acid cation exchange resin having from about 4% to about 12% crosslinking, a surface area in the proton exchanged form of less than 10m.sup.2 g.sup.-1 after drying from the water wet state and a surface area of greater than 10m.sup.2 g.sup.-1 after drying from a wet state in which water has been replaced by methanol. The resin has at least one percent of its active sites converted to the silver form preferably from 30 to 70 percent.

Abstract: This invention relates tot he use of ion exchange resins having metal-exchanged thiol functional groups in removing iodide impurities from carboxylic acids and/or carboxylic acid anhydrides. More particularly, this invention provides a process for removing iodide impurities from liquid carboxylic acids and/or carboxylic acid anhydrides using ion exchange resins in which thiol functional groups have been exchanged with silver, palladium or mercury.

Abstract: Acetic acid produced by the low water carbonylation of methanol and containing iodide, unsaturates and carbonyl impurities is purified by treatment with ozone.

Abstract: A process is disclosed for counter-current positive displacement of an aliphatic carboxylic acid of 1 to 5 carbon atoms from a filter cake of an aromatic polycarboxylic acid containing the aliphatic carboxylic acid wherein mother liquor retained by the aromatic polycarboxylic acid has a concentration of the aliphatic carboxylic acid of 5000 ppmw, or less, based upon weight of the aromatic polycarboxylic acid present. This method is useful for the manufacture of crude terephthalic acid which is used after purification for the preparation of polyesters used for the manufacture of fabrics, fibers and plastic bottles.

Abstract: 4-Methyl-2-pentanone cannot be easily separated from acetic acid by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanone can be readily removed from acetic acid by extractive distillation. Typical effective agents are dimethlsulfoxide (DMSO); DMSO and adipic acid; DMSO, adipic acid and adiponitrile.

Abstract: A process for the isolation of a carboxylic acid of the general formula (I)R.sup.1 --COOH (I),in which R.sup.1 denotes hydrogen, methyl, ethyl, or vinyl, from a dilute aqueous solution thereof by extraction with a secondary amide of the general formula (II) ##STR1## in which R.sup.1 has the meanings stated, and R.sup.2 and R.sup.3 are independently of each other C.sub.1 -C.sub.8 -alkyl, C.sub.3 -C.sub.8 -cycloalkyl, C.sub.4 -C.sub.20 -cycloalkylalkyl, aryl, C.sub.7 -C.sub.20 -aralkyl, or R.sup.2 and R.sup.3 together form a 1,4- or 1,5-alkylene group which may be mono- to penta-substituted by C.sub.1 -C.sub.4 -alkyl, wherein the losses of secondary amide (II) are compensated by the addition of the corresponding amine of the general formula (III) ##STR2## in which R.sup.2 and R.sup.3 have the meanings stated above.

Abstract: A process for recovering acetic acid from a mother liquor containing acetic acid, formic acid, acetic anhydride and formic acetic anhydride comprising the steps of:(a) heating said mother liquor to a temperature greater than or equal to about 70.degree. C. for a time period ranging from about 1 hour to about 24 hours to convert all of said formic acetic anhydride to acetic acid and gaseous carbon monoxide and to fully deplete either said acetic anhydride or said formic acid, whichever is initially present in a stoichiometric lesser amount and thereby produce a mixture comprising acetic acid and either acetic anhydride or formic acid, whichever has been depleted; and(b) separating said acetic acid from the remainder of said mixture produced in step (a) is provided.

Abstract: Disclosed is a method for reducing olefinic impurities in solutions of carboxylic acids and/or anhydrides. The invention is especially useful for removing substantially all, i.e., greater than 90 percent of trace amounts of olefinic impurities.

Abstract: A process for recovering acetic acid from an aqueous acetic acid solution comprises contacting the solution with a solvent comprising a diluent component and an extractant component. The extractant component is selected from the group consisting of di-2,4,4-trimethylpentyl-n-octyl phosphine oxide, tri-2,4,4-dimethylpenthyl phosphine oxide and mixtures thereof, and the diluent component comprises at least one high molecular weight ketone. This invention is useful in recovering acetic acid from both low concentration and concentrated aqueous acetic acid streams, and is particularly useful in recovering acetic acid from aqueous acetic acid waste streams in processes for the production of terephthalic acid and cellulose acetate.

Abstract: Disclosed is a process for the recovery of acetyl values from an ethylidene diacetate stream obtained from an acetic anhydride production system. The process comprises hydrolyzing ethylidene diacetate in a liquid phase, hydrolysis zone containing a non-volatile, acidic catalyst and maintained under boiling conditions to obtain a mixture of acetaldehyde, acetic acid and water and then oxidizing the mixture in a liquid phase, oxidation zone containing a cobalt oxidation catalyst to obtain a mixture of acetic acid and water. The process optionally includes a means for reducing substantially the concentration of iodine in the EDA used in the process.

Abstract: Iodine and its compounds are separated from the carbonylation products acetic acid, acetic anhydride or ethylidene diacetate obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction in the presence of an iodine-containing catalyst. The quantity of total iodine contaminating the carbonylation products is reduced to less than 20 ppb iodine by treating the products at 20.degree.-200.degree. C. with peracetic acid, diacetyl peroxide or a compound yielding these two agents under the reaction conditions, and separating them distillatively.

Abstract: Acetic acid cannot be easily removed from acetic acid - water mixtures by distillaton because of the closeness of their boiling points and the deviation from ideal solution behavior. Acetic acid can be readily removed from the mixtures containing it and water by using extractive distillation. Typical effective agents are sulfolane and adiponitrile.

Abstract: A method is provided for removing an anion from an aqueous liquid, such as a fermentation broth. The aqueous broth is contacted with a water-immiscible ion exchange liquid to extract the anion from the broth. The anion exchange liquid is then back extracted with an aqueous phase, to remove the anion, preferably for other uses.

Abstract: Superior quality magnesium calcium acetate (hydrate) granules of industrial grade are produced from a concentrated aqueous solution of magnesium acetate containing limited amounts of calcium acetate. The hot solution, or process liquor, is carefully pH-adjusted prior to further processing, and may be slightly acidified with excess acetic acid to offset downstream hydrolysis during the granulation/drying stage.Process liquor hydrolysis is avoided by maintaining liquor temperature and residence time within prescribed limits.Process liquor may be optionally clarified of mineral insolubles deriving from raw material, and of excess, unwanted calcium acetate solids prior to further processing. From such clarified liquor a purer, technical grade magnesium acetate (hydrate) granular product is derived.Hot process liquor may be passed through a short residence time heating zone prior to granulation/drying in order to provide additional sensible heat going to the granulation/drying operation.

Abstract: Acetic acid is difficult to separate from water by conventional distillation or rectification because of the close proximity of their boiling points. Acetic acid can be readily separated from water by using azeotropic distillation. Typical examples of effective agents are ethyl n-valerate and 4-methyl-2-pentanone.

Abstract: Acetic acid containing iodide, unsaturates and carbonyl impurities is purified by treatment with ozone in the presence of an oxidation catalyst. The acetic acid product may be further contacted with activated carbon or ion-exchange resins for additional removal of impurities.

Abstract: Acetic acid containing iodide, unsaturates and carbonyl impurities is purified by treatment with ozone and thereafter contacted with activated carbon and/or an ion-exchange resin for removal of impurities.

Abstract: An alcohol such as methanol is reacted with carbon monoxide in a liquid reaction medium containing a rhodium catalyst stabilized with an iodide salt, especially lithium iodide, along with alkyl iodide such as methyl iodide and alkyl acetate such as methyl acetate in specified proportions. With a finite concentration of water in the reaction medium the product is the carboxylic acid instead of, for example, the anhydride. The present reaction system not only provides an acid product of unusually low water content at unexpectedly favorable reaction rates but also, whether the water content is low or, as in the case of prior-art acetic acid technology, relatively high, is characterized by unexpectedly high catalyst stability; i.e., it is resistant to catalyst precipitation out of the reaction medium.

Abstract: Acetic acid is recovered from the mother liquor used to oxidize para-xylene to terephthalic acid by adding at least one organic compound having a melting point below 140.degree. C. and an atmospheric boiling point above 230.degree. C.

Abstract: This invention relates to a method for removing halides from liquid carboxylic acid contaminated with a halide impurity by contacting the liquid halide-contaminated acid with a silver(I)-exchanged macroreticular resin. The halide reacts with the resin-bound silver and is removed from the carboxylic acid stream. The present invention also relates to an improved method for producing silver-exchanged macroreticular resins suitable for use in the present invention.

Abstract: A process for producing isophthalic acid by oxidation of m-xylene with an oxygen-containing gas in a hydrous acetic acid solvent in the presence of a cobalt/manganese/bromine system catalyst, the process being capable of industrially advantageously producing high-purity isophthalic acid having excellent whiteness, the process comprising (1) a step of carrying out an oxidation reaction in a main oxidation reactor under specified ranges of a catalyst concentration, a reaction temperature and an oxygen concentration in a discharge gas such that the concentration of 3-carboxybenzaldehyde becomes 500 to 10,000 ppm, (2) a step of further carrying out an oxidation reaction in a post oxidation reactor such that the concentration of 3-carboxybenzaldehyde becomes 100 to 800 ppm, separating crude isophthalic acid, evaporating remaining mother liquor and recovering acetic acid, and (3) mixing the crude isophthalic acid with purified acetic acid, stirring the resultant mixture at 100.degree. C.

Abstract: There is provided a process for recovering acetic acid from methyl acetate wherein the methyl acetate is hydrolyzed catalytically to methanol and acetic acid in the same tower or column that is used to separate the methanol from the acetic acid and the hydrolysis and separation are carried out coextensively in the vessel. The process is employed suitably in a process for the partial oxidation of a polymethylbenzene to a polycarboxylic acid in the presence of an oxidation catalyst and an acetic acid solvent.

Abstract: A method of separating and purifying a spent solvent generated in a nuclear fuel cycle and containing a phosphate and a higher hydrocarbon. This method comprises treating the spent solvent at a temperature not greater than the freezing point of the higher hydrocarbon but not less than the freezing point of the phosphate to selectively freeze the higher hydrocarbon, and separating a resulting frozen solid mainly composed of the higher hydrocarbon from a remaining solution containing the phosphate in a higher concentration. The remaining solution may further be subjected to low-temperature vacuum distillation to separate the solution into the phosphate and a deterioration product thereof.

Abstract: 4-Methyl-2-pentanone cannot be easily separated from acetic acid by distillation because of the closeness of their boiling points. 4-Methyl-2-phentanone can be readily removed from acetic acid by extractive distillation. Typical effective agents are dimethylformamide (DMFA); DMFA and m-toluic acid; DMFA, p-toluic acid and isobutyl heptyl ketone.

Abstract: A process for preparing a carboxylic acid of high purity comprises preparing an undersaturated solution of a salt of the carboxylic acid; subjecting the undersaturated salt solution to water-splitting electrodialysis to form base and a supersaturated solution of the carboxylic acid; and, then crystallizing the carboxylic acid from the supersaturated solution. In the preferred embodiment, the undersaturated solution is a fermentation broth containing sodium succinate and the carboxylic acid obtained is succinic acid.

Abstract: An alcohol such as methanol is reacted with carbon monoxide in a liquid reaction medium containing a rhodium catalyst stabilized with an iodide salt, especially lithium iodide, along with alkyl iodide such as methyl iodide and alkyl acetate such as methyl acetate in specified proportions. With a finite concentration of water in the reaction medium the product is the carboxylic acid instead of, for example, the anhydride. The present reaction system not only provides an acid product of unusually low water content at unexpectedly favorable reaction rates but also, whether the water content is low or, as in the case of prior-art acetic acid technology, relatively high, is characterized by unexpectedly high catalyst stability; i.e., it is resistant to catalyst precipitation out of the reaction medium.

Abstract: A method of manufacturing a material for medical and pharmaceutical products from pyroligneous acid extracted as water content in smoke generated by baking arbor and bark. Pyroligneous acid is heated, and resultant evaporation gas in a temperature range 98.degree. to 103.degree. C. is extracted and liquified by cooling.

Abstract: A process for producing vinyl acetate which comprises reacting acetic anhydride with hydrogen in the presence of a catalyst comprising(a) a metal belonging to Group VIII of the Periodic Table or a compound of the metal, and(b) (i) an acidic substance, or (ii) a halideis disclosed.

Abstract: An improved method for dehydration and concentration of an aqueous solution containing an organic compound is disclosed. The solution is evaporated to produce a gaseous mixture comprising an organic compound vapor and a water vapor. The water vapor is selectively removed from the gaseous mixture by permeation through an aromatic polyimide gas separation membrane while the gaseous mixture being kept in contact with a surface on one side of the gas separation membrane at a temperature of 70.degree. C. or higher to obtain a gaseous mixture comprising the organic compound vapor and a reduced amount of a water vapor.

Abstract: A process for removing iodine or soluble iodide impurities from a carboxylic acid or carboxylic acid anhydride, the carboxylic acid or carboxylic acid anhydride having been by a carbonylation process. The process includes: step (a) treating impure carboxylic acid or carboxylic acid anhydride containing iodine or soluble iodide impurities with an unsupported scavenger at a temperature of between 20.degree. and 250.degree. C. and step (b) thereafter separating the treated carboxylic acid or carboxylic acid anhydride from the scavenger. The scavenger is a silver salt in the absence of a trialkyl phosphine, a triaryl phosphine and a heterocyclic aromatic nitrogen compound. The preferred scavenger for acetic acid and acetic anhydride is silver acetate.

Abstract: 4-Methyl-2-pentanone cannot be easily separated from formic acid or acetic acid by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanone can be readily removed from formic acid or acetic acid by extractive distillation. Typical effective agents are sulfolane; sulfolane and heptanoic acid; sulfolane, azelaic acid and ethylene glycol diacetate.

Abstract: Compositions which comprise a calcium magnesium acetate double salt are useful in deicing compositions. Deicing compositions comprising those compositions and processes for their preparation are described.

Abstract: Formic acid cannot be easily removed from acetic acid by distillation because of the closeness of their vapor pressures. Formic acid can be readily removed from acetic acid by extractive distillation. Typical extractive distillation agents are acetyl salicylic acid and butyl benzoate; acetyl salicylic acid and ethylene carbonate.

Abstract: Organic iodine compounds are separated from carbonylation products of methanol, methyl acetate and dimethyl ether and from mixtures of such carbonylation products by a process wherein the iodine compounds are removed by liquid phase extraction with a non-aromatic hydrocarbon.

Abstract: Aqueous glyoxylic acid solutions, essentially free of other acids, are recovered from aqueous solutions which still contain other acids, by a method in which the aqueous solution is mixed with an organic nitrogen compound at as high as 50.degree. C., the phases are separated, and the glyoxylic acid is extracted from the organic phase with water, at a higher temperature.

Abstract: A process for removing volatile acids from aqueous solutions which involves steam stripping a volatile acid from an aqueous solution and contacting the vaporized acid with a reactable cation to form a salt of the acid. A preferred embodiment of apparatus comprises an elongated distillation column having therein a plurality of zones or stages wherein the volatile acid in the aqueous feed stream is vaporized by steam and then the vaporized acid is carried by the steam into a salt formation zone or stage to react with a reactable cation to form a salt of the acid.

Abstract: A process is provided for removing water from a mixture of hydrogen fluoride (HF), a carboxylic acid, e.g., acetic acid, and water by extractive distillation in the presence of a Lewis base as solvent, which does not azeotrope with water, forms bonds with the HF and carboxylic acid which can be broken by heat and has a boiling point at atmospheric pressure at least about 20.degree. C. above that of the carboxylic acid, e.g., N-methyl-2-pyrrolidone, and taking off an overhead vapor comprising a major proportion of the water in said mixture. The extractive distillation may be advantageously integrated in an overall process with the production of an aromatic ketone, e.g., 4-hydroxyacetophone, by the Friedel-Crafts acylation of an aromatic compound, e.g., phenol, with the carboxylic acid, using HF as catalyst, to produce a product mixture comprising the aromatic ketone, HF, carboxylic acid and water, and the removal of aromatic ketone from the product mixture by means of a solvent assisted distillation.

Abstract: A process for treating carbonylation catalyst solutions which contain a rhodium component and a lithium component to remove metallic corrosion products comprises contacting the catalyst solution with a cation exchange resin in the lithium form.

Abstract: A process for removing iodine or soluble iodide impurities from a carboxylic acid or carboxylic acid anhydride, the carboxylic acid or carboxylic acid anhydride having been by a carbonylation process. The process includes: step (a) treating impure carboxylic acid or carboxylic acid anhydride containing iodine or soluble iodide impurities with an unsupported scavenger at a temperature of between 20.degree. and 250.degree. C. and step (b) thereafter separating the treated carboxylic acid or carboxylic acid anhydride from the scavenger. The scavenger is a silver salt in the absence of a trialkyl phosphine, a triaryl phosphine and a heterocyclic aromatic nitrogen compound. The preferred scavenger for acetic acid and acetic anhydride is silver acetate.