Abstract: Lactic acid is separated from a fermentation broth by using an adsorbent comprising a water-insoluble macroreticular or gel weakly basic anionic exchange resin possessing tertiary amine or pyridine functional groups or a strongly basic anionic exchange resin possessing quaternary amine fuctional groups. The resins are in sulfate form and have a cross-linked acrylic or styrene resin matrix. Lactic acid is desorbed with water or dilute inorganic acid, e.g., sulfuric. The pH of the feed is maintained below the ionization constant (pKa) of lactic acid to obtain high selectivity.

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: Method for the recovery of citric acid from a liquor containing the same, wherein successively,in a first step, the liquor containing the citric acid is put into contact with a cationic resin in the hydrogen form during a duration sufficient to reach an optimal adsorption of the citric acid,in a second step, the resin is treated by means of an elution agent and the fraction of eluate rich in purified citric acid is recovered.

Abstract: The invention relates to a process for recovering sugar, sugar alcohol and organic acids comprising citric, malic and quinic acids from a juice extracted from almond hulls. Residues from the extraction is also recovered.

Abstract: Recovery of citric acid from a citric acid fermentation broth.

Abstract: For the preparation of 3-hydroxy-3-methyl-glutaric acid a process is disclosed based on the direct oxidation with nitric acid of 3-methyl-1,3,5-pentanetriol.

Abstract: Salts of citric acid are separated from a fermentation broth by a two-step process utilizing an adsorbent comprising a water-insoluble, macroreticular gel, weakly basic, anionic exchange resin possessing tertiary amine functional groups or pyridine functional groups, said anionic exchange resin comprising a crosslinked acrylic or styrene resin matrix and a desorbent comprising water or dilute sulfuric acid. The pH of the feed, a fermentation broth, containing citric acid, is adjusted and maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity in the first step wherein citric acid is adsorbed onto the adsorbent. Then, citric acid is converted to a salt by a reaction with an aqueous alkaline liquid solution and is eluted immediately at the void volume in the alkaline solution.

Abstract: A process for the separation of one or more hydroxy paraffinic dicarboxylic acids from a feed mixture comprising said acid(s), and one or more olefinic dicarboxylic acids which process employs an adsorbent comprising a non-zeolitic, hydrophobic, crystalline silica molecular sieve material, to selectively reject the hydroxy paraffinic dicarboxylic acid(s) to a raffinate stream for the ultimate recovery of a purified quantity of such acid(s). The olefinic dicarboxylic acid(s) are thereafter removed from the adsorbent by contacting the adsorbent with a desorbent material and said acid(s) is (are) recovered to an extract stream. In a preferred embodiment the process uses a silicalite adsorbent, aqueous acetone desorbent and a simulated moving-bed countercurrent flow system utilizing therein a pre-pulse technique.

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: L-malic acid is separated by means of electrodialysis from reaction mixtures derived from biotechnical conversion of fumarate into L-malate. Fumaric acid present in the acid concentrate from the dialysis is separated from L-malic acid without precipitation reactions using stepwise crystallization. Crystallized L-malic acid is produced in high purity and large yield. The alkali concentrate obtained during electrodialysis is recycled back into the biotechnical conversion. The process operates without appreciable losses of valuable materials and is very economical.

Abstract: A process for producing citric acid or other suitable acids and/or their salts from fermentation solutions. The process comprises removing high molecular weight impurities by means of membrane filtration and/or addition adsorption on a nonionic adsorption resin and removing low molecular weight impurities by anion and cation exchange and/or precipitating a citric acid as a calcium salt.

Abstract: Citric acid is separated from a fermentation broth by using an adsorbent comprising a strongly water-insoluble, macroreticular or gel, basis anionic exchange resin possessing quaternary amine functional groups, said a anionic exchange resin having a cross-linked acrylic or styrene resin matrix and a desorbent comprising water or dilute sulfuric acid. The pH of the feed is maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity.

Abstract: Citric acid is separated from a fermentation broth by using an adsorbent comprising a water-insoluble macroreticular or gel weakly basic anionic exchange resin possessing tertiary amine functional groups or pyridine functional groups, said anionic exchange resin comprising a cross-linked acrylic or styrene resin matrix. Citric acid is desorbed by water or dilute sulfuric acid. The pH of the feed is maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity.

Abstract: Organic acids are prepared from their salts electrodialytically. At the same time, another acid is converted electrodialytically into the corresponding salt. Both electrodialytic conversions take place in the same electrodialysis unit. If the salt of the organic acid has been fermentatively prepared as, for example, malate from fumarate, it is possible both to prepare malic acid by electrodialysis and also to prepare fumarate from fumaric acid for the fermentation. Through coupling substrate and product streams in the electrodialysis, a closed circuit is formed.

Abstract: An aldehyde (R.sup.1 CHO) and optically active 3-hydroxybutyric acid (CH.sub.3 CH(OH)CH.sub.2 COOH) are reacted to form an optically active dioxanone. This dioxanone is reacted with a compound R.sup.2 --X to form an intermediate (R.sup.1 R.sup.2 CHOCH(CH.sub.3) CH.sub.2 COOH) which is then subjected to elimination to form an optically active secondary alcohol (R.sup.1 R.sup.2 CHOH) in good yield and purity.

Abstract: High yields of 2,2'-oxodisuccinate are secured by reacting maleate and malate in aqueous alkaline media containing mixtures of particular divalent (e.g., Ca.sup.2+) and solubilizing monovalent (e.g., Na.sup.+) cations. In a preferred embodiment, the process has both an elevated temperature primary reaction step and one or more low temperature maturation steps. Yields of 2,2'-oxodisuccinate are increased and formation of fumarate byproduct is minimized.

Abstract: The reaction mixture obtained in the enzymatic reaction of fumaric acid to form L-malic acid contains the L-malic acid and unreacted fumaric acid as their salts. To recover pure solutions of L-malic acid the reaction mixture is treated at 50.degree. to 150.degree. C. with cation exchangers. The eluate after concentration to 30 to 80 weight % content of L-malic acid is filtered. The pure L-malic acid is recovered by evaporating the solutions, in a given case after treatment with activated carbon.

Abstract: Aqueous acidic scrubbing liquors obtained when oxidation mixtures from the oxidation of cyclohexane are scrubbed with water are stabilized by a process in which the scrubbing liquors are heated at from 50.degree. to 130.degree. C. in the presence of a water-soluble vanadium compound.

Abstract: Citric acid is separated from a fermentation broth by using an adsorbent comprising a neutral, noniogenic, macroreticular, water-insoluble, crosslinked styrene-poly(vinyl)benzene and a desorbent comprising water and, optionally, acetone with the water. The pH of the feed is adjusted and maintained below the first ionization constant (pKa.sub.1) of citric acid to maintain selectivity.

Abstract: The invention relates to a process for the extraction of carboxylic acids from aqueous solutions with a carboxylic acid content below 8% by weight. A mixture of an aliphatic amine with a total carbon number of at least 10 and a phenol or naphthol is used as extracting agent. The molar ratio of phenol:amine or alkylated phenol:amine or naphthol:amine is in the range from 0.1:1 to around 1.1:1.

Abstract: A mixture of trialkyl phosphine oxides (HTRPO) was prepared having the formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are same or different alkyl groups of 5 to 9 carbon atoms and the total number of carbon atoms and the total number of carbon atoms per molecule is from 15 to 27. The mixture of trialkyl phosphine oxides (HTRPO) is useful as an extractant for recovering acids from aqueous solutions.

Abstract: In one of its embodiments this invention provides a process for recovering C.sub.4 -C.sub.6 dicarboxylic acid components contained in a waste byproduct stream derived from a reaction system in which adipic acid is produced by nitric acid oxidation of cyclohexanone/cyclohexanol.An important aspect of the process is the esterification and extraction of the C.sub.4 -C.sub.6 dicarboxylic acids in the aqueous byproduct stream with a mixture of C.sub.1 -C.sub.3 alkanol and C.sub.6 -C.sub.20 alkanol, and the subsequent recovery of di(C.sub.6 -C.sub.20 alkyl) esters of succinic acid, glutaric acid and adipic acid.In a broader aspect this invention provides a process for recovery of water miscible organic acid components contained in an aqueous solution as C.sub.6 -C.sub.20 alkyl esters of the organic acids.

Abstract: The yield of hydroxyacetic acid produced from formaldehyde, water and carbon monoxide in the presence of a sulfuric acid catalyst and using crude recycled hydroxyacetic acid as the reaction medium is improved by azeotropic distillation of crude, recycle hydroxyacetic acid with toluene. The distillation step reduces the water content of feed thereby increases conversion of formaldehyde to hydroxyacetic acid and reduces formic acid content in the product.

Abstract: A process for recovering carboxylic acids with a material of which the main component is a polymeric compound having a pyridine skeletal structure and a crosslinked structure, followed by desorbing the captured carboxylic acids by use of a desorbing agent.

Abstract: A process for recovering sodium citrate from a solution utilized in an absorption/stripping process for SO.sub.2 recovery, which involves cooling a portion of the stripping solution to precipitate sodium sulfate, which is separated from the mother liquor. Thereafter, the mother liquor portion is subjected to an evaporative crystallization to precipitate sodium citrate, which is reintroduced along with fresh absorbent solution into the SO.sub.2 absorption/stripping process.

Abstract: The invention relates to a process for the recovery of .alpha.-hydroxy- and .alpha.-amino-carboxylic acids from sugary media containing them.According to the process of the invention:in a first phase, the mixture from which it is proposed to recover the .alpha.-hydroxy- or .alpha.-amino-carboxylic acid and which contains the latter in the form of its calcium salt is contacted with a cationic resin in the calcium form for a sufficient time to reach optimal adsorption of said calcium salt and then,in a second phase, the previously saturated resin is eluted by resorting to water.The process according to the invention enables the quantitative production of a pure calcium salt.

Abstract: Citric acid can be extracted from aqueous citric acid solutions by contacting such solutions with an N-substituted alkyl amide containing a total of at least twelve carbon atoms.

Abstract: Process for recovering carboxylic acids from dilute aqueous solutions of alkali metal salts of such carboxylic acids by mixing such solutions with from 10 to 1000% of a supercritical solution comprising at least 10 mole % carbon dioxide at a pressure from 80 to 500 atm and preferably 100 to 350 atm and at a temperature of from 35.degree. to 200.degree. C. and preferably from 35.degree. to 100.degree. C. whereby the salt reacts with the carbon dioxide to form the carboxylic acid which dissolves in the supercritical fluid. The aqueous phase is allowed to separate from the supercritical fluid phase. The pressure of the supercritical phase is lowered which lowers the solubility of the carboxylic acid in the supercritical fluid so that an acid phase is formed separate from the supercritical fluid phase whereby recovery of the acid is effected.

Abstract: Carboxymethyloxysuccinic acid of improved purity may be prepared from its calcium salt by first precipitating the calcium as calcium carbonate by reaction with sodium carbonate, removing the calcium carbonate, acidifving the resulting solution of the sodium salt with sulfuric acid, extracting the free acid with a C.sub.4 or C.sub.5 alcohol or cyclohexanol and recovering the purified acid from the alcohol extracts.

Abstract: A process for purifying a salt of sulfonated unsaturated aliphatic carboxylic acid, and in particular, a salt of sulfonated oleic acid wherein unreacted saturated fatty acid impurities are removed by the steps of diluting the mixture of the salt of sulfonated acid and impurities with an amount of water sufficient to provide an aqueous solution containing from about 5 to about 30 percent by weight of the salt, adding a synthetic aliphatic or isoparaffinic hydrocarbon solvent having a boiling point in the range of about 150.degree. C. to about 260.degree. C. in an amount such that the hydrocarbon is present in about 10 to about 50 percent by volume, agitating the mixture for a time sufficient to provide an intimate contact of the solvent with the impurities, holding the mixture in a quiescent state for a time sufficient to allow the water and solvent to separate into layers, and then drawing off the purified aqueous layer.

Abstract: The concentration of hydrogen fluoride in crude glycolic acid made by the hydrogen fluoride-catalyzed reaction of formaldehyde and carbon monoxide can be reduced to less than about 1% by weight by removing the HF from the crude gylcolic acid by distillation or stripping with inert gas at a temperature above about 130.degree. C., thereby producing a polyglycolide subsequently convertible to glycolic acid by hydrolysis.

Abstract: It is disclosed that water soluble salts of carboxyalkyloxy succinic acids can be obtained in a form containing less than usual contamination by alkaline earth metal and related substances by treating the contaminated salts with alkali metal carbonate and separating (e.g., filtering) at an elevated temperature and at a selected pH region. The most important factor in obtaining this improvement is the use of the proper separating temperature, preferably within the range of 70.degree.-125.degree. C., especially a temperature of about 100.degree. C. In addition, the use of certain conditions of pH minimizes side reactions.

Abstract: The isomers of synthetic insect sex pheromones or their precursors are separated by selectively forming an inclusion complex with the E-isomer and urea or thiourea. In order for the E-isomer complex to form selectively it is necessry that the mono-olefin which forms the complex have a primary, linear chain of at least 7 atoms, a molecular diameter of 2.8-6A, and a polar functional group having transverse dimensions of less than 6A. Branching between the olefinic bond and the polar functional group is limited to methyl groups.

Abstract: The process comprises the hot treatment at a temperature of 80.degree. to 160.degree. C. by an amount of 5 to 50% of 85% of phosphoric acid, of the residues resulting from the distillation of reaction media containing hemiacetal-esters under substantially anhydrous conditions. These reaction media are selected from among those resulting from the reaction of alcohols and glyoxylic acid and those resulting from the treatment of glyoxylic hemiacetal-esters with P.sub.2 O.sub.5.

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: It is disclosed that water soluble carboxyalkoxy succinate tetrahydrate salt can be precipitated in high purity from alcohol-water solvent systems when operating at temperatures from about 50.degree. C to about 100.degree. C using seed crystals of either tetrahydrate or pentahydrate form or a mixture thereof. Useful temperatures are from about 45.degree. to about 75.degree. C. Preferred temperatures are above about 55.degree. C up to about 65.degree. C where tetrahydrate product is obtainable even where pentahydrate seed is used.

Abstract: A granular sorbic acid having improved properties is prepared in a very simple manner without need of any particular preparation as in conventional methods, i.e. by granulating by extrusion, powder having particle sizes of ASTM No. 70 sieve pass in the presence of water or water containing a surfactant. The resulting granule has a suitable hardness and hence scarcely collapses at the time of drying after granulation and subsequent handling, but has a rapid dispersibility into foods at the time of its use.

Abstract: It is disclosed that citric acid and salts thereof are readily produced by reacting acetone dicarboxyl ions, cyanide ions and alkali metal ions to produce an intermediate system which is subsequently reacted in an excess caustic system to form a salt of citric acid and that the salt is readily recovered by precipitation from the excess caustic system under proper conditions of concentration and temperature without requiring the formation of calcium salts. The recovered salt may be used directly or may be subjected to additional purification or may be converted to citric acid or other salts thereof by treatment with an acidification system such as sulfuric acid.