Abstract: A process for preparing dicarboxylic acids is described. More particularly a process is described for preparing adipic acid (1,6-hexanedioic acid), by the action of nitric acid, starting from cyclic ketones or alcohols which are the corresponding compounds from the standpoint of the number of carbon atoms, in the presence of one or more oxides of nitrogen at a molar concentration in the reaction mixture of greater than 2.5 mmol per kg of reaction mixture.

Abstract: A process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated in a reactor which is manufactured from a composite material which consists, on its side in contact with the reaction chamber, of a steel B with specific elemental composition which, on its side facing away from the reaction chamber, either directly or via an intermediate layer of copper, or of nickel, or of copper and nickel, is plated onto a steel A with specific elemental composition, and also partial oxidations of the dehydrogenated hydrocarbon and the reactor itself.

Abstract: A process for heterogeneously catalyzed partial dehydrogenation of a hydrocarbon, in which a reaction gas mixture input stream comprising the hydrocarbon to be dehydrogenated is conducted through a fixed catalyst bed disposed in a shaft and the reaction gas mixture input stream is obtained in the shaft by metering an input gas II comprising molecular oxygen upstream of the fixed catalyst bed into an input gas stream I which comprises molecular hydrogen and the hydrocarbon to be dehydrogenated and is flowing within the shaft toward the fixed catalyst bed.

Abstract: A process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated in a reactor which is manufactured from a steel with specific elemental composition on its side in contact with the reaction gas, and also partial oxidations of the dehydrogenated hydrocarbon and the reactor itself.

Abstract: The invention relates to methods for producing substituted acrylic acid esters and to the use of the latter for producing substituted ?-amino acids, such as gabapentin and pregabalin. The substituted acrylic acid esters are produced by Wadsworth-Emmons olefination with trialkyl phosphonoacetate in the presence of alkali carbonate as the base, in an aqueous solvent.

Abstract: Degradation acids obtained in the synthesis of carboxylic acids, in particular dicarboxylic acids, having from 8 to 16 carbon atoms may be isolated by separating the degradation acids in the form of a solid from the crude reaction mixture, then washing the degradation acids in the form of an oil with water at an elevated temperature. The resulting degradation acids having low oxidant and metal contents, and the metal catalyst may be recirculated back to the process.

Abstract: A method for manufacturing an alkanedicarboxylic acid by oxidizing cycloalkanol and/or cycloalkanone with an aqueous solution of nitric acid, which comprises using an adiabatic reactor comprising a feed nozzle enabling to feed cycloalkanol and/or cycloalkanone at a linear velocity not lower than 8×10?2 m/sec and a mixing apparatus.

Abstract: In a process for preparing acrylic acid, an acrylic acid-containing product gas mixture obtained by catalytic gas phase partial oxidation of a C3 precursor of acrylic acid, after direct cooling with a quench liquid, is fractionally condensed in a separating column provided with internals, rising into itself with sidestream takeoff of crude acrylic acid, and the acrylic acid oligomers which form are dissociated and the resulting dissociation gas is subjected to a countercurrent rectification before it is recycled.

Abstract: The present invention relates to a process for the manufacture of adipic acid, more particularly of adipic acid crystals. It relates more specifically to a process for the treatment of the adipic acid crystals obtained on conclusion of crystallization, which consists in dispersing the adipic acid crystals collected on conclusion of crystallization in a liquid medium, in stirring the said liquid medium and in then separating the said crystals from the said liquid medium and optionally drying them. The form of the crystals is modified in order to obtain pebbles with a substantially smooth surface.

Abstract: In a process for the preparation of acrolein or acrylic acid or a mixture thereof from propane, the propane is subjected, in a first reaction stage, to a partial dehydrogenation under heterogeneous catalysis to give propene, of the components contained in the product gas mixture formed in the first reaction stage other than propene and propane at least a portion of the molecular hydrogen present is then separated off from said mixture and the product gas mixture is then used for the preparation of acrolein and/or acrylic acid by gas-phase catalytic propylene oxidation, molecular nitrogen being present for diluting the reaction gas mixture during the propylene oxidation.

Abstract: A method for manufacturing 3-hydroxy-3-methylbutanoic acid (HMB) in commercially viable amounts is disclosed. The reaction mixture cycles through an external heat exchanger while the primary reactant is added in a warmer so as to control and maintain a low temperature for the reaction mixture. The manufacturing process herein disclosed increases yield while decreasing reaction time from the synthetic processes currently practiced.

Abstract: The subject invention relates to a process for the crystallization of di-carboxylic acids comprising dissolving the crude dicarboxylic acid at a temperature sufficient to dissolve the crude diacid in the solvent, whereby portion of the said solvent evaporates, increasing the concentration of the dicarboxylic acid in the said solution, transferring the said solution from the evaporator to a crystallizer, comprising a solid cylindrical impeller conforming to the shape of the crystallizer related by means of a cylindrical shaft attached to the spped motor, adding the additives selected from surfactants, buffer salts and/or acid salts or mixture thereof in the said evaporated solution in the said crystallizer, cooling the said mixture resulting in the formation of crystals of dicarboxylic acids, wherein the said crystallization takes place in the annular space between the impeller and the crystallizer wall.

Abstract: A method for manufacturing 3-hydroxy-3-methylbutanoic acid (HMB) in commercially viable amounts is disclosed. The reaction mixture cycles through an external heat exchanger while the primary reactant is added in a warmer so as to control and maintain a low temperature for the reaction mixture. The manufacturing process herein disclosed increases yield while decreasing reaction time from the synthetic processes currently practiced.

Abstract: A method for manufacturing 3-hydroxy-3-methylbutanoic acid (HMB) in commercially viable amounts is disclosed. The reaction mixture cycles through an external heat exchanger while the primary reactant is added in a warmer so as to control and maintain a low temperature for the reaction mixture. The manufacturing process herein disclosed increases yield while decreasing reaction time from the synthetic processes currently practiced.

Abstract: Crystallization of adipic acid using low intensity ultrasonic agitation during crystallization results in purer product that is more readily handled. Apparatus for carrying out the process is also disclosed.

Abstract: A process for purification of adipic acid during crystallization by modifying the crystal morphology to decrease incorporation of impurities through the introduction of an effective amount of an additive to the crystallizing solution.

Abstract: Disclosed is an improved process for the preparation of adipic acid by the air oxidation of cyclohexane in the presence of acetic acid and a catalyst system comprising cobalt and zirconium and/or hafnium.

Abstract: The instant invention relates to a membrane solvent extraction and reaction system. More particularly it pertains to an improvement in the membrane solvent extraction system wherein a solute is extracted through a polymeric membrane from one solvent liquid phase to an extracting solvent liquid without direct contact between the liquid phases which are separated by the membrane and in which the extracting solvent has no greater solubility and usually substantially less solubility for the solute than the feed solvent. The impovement comprises converting the solute permeating across the membrane to a different chemical compound, whereby a high concentration gradient for the solute across the membrane is maintained to improve the separation of the solute from the feed solvent liquid phase.

Abstract: Processes for the autoxidative cleavage of selected ketones such as C.sub.4 -C.sub.10 cycloalkanones having at least one hydrogen or at least one R group on a carbon alpha to the carbonyl carbon or aryl alkyl ketones having the formula III ##STR1## comprising contacting a liquid phase comprising said ketone with elemental oxygen gas, preferably air, in the presence of a pulverized alkali metal hydroxide at a temperature of no more than 50.degree. C. for a time sufficient to produce an oxidized product are disclosed. Preferred cycloalkanones, 2-alkyl- and 2-arylcyclohexanone are autoxidized in pulverized sodium hydroxide/dimethoxyethane to produce 6-alkyl- or 6-aryl-6-oxohexanoic acids, respectively.

Abstract: A process for the decontamination of the distillation refinement residue from the process of oxidizing cyclohexane to KA oil is provided. The process comprises washing the distillation refinement residue with the crystallization by-product obtained in crystallizing adipic acid from the product stream of the process of oxidizing the KA oil with a strong acid. This crystallization residue comprises residual amounts of the strong acid and adipic acid, as well as substantial amounts of glutaric acid and succinic acid.

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: Waste streams from adipic acid manufacture containing nitric, succinic, glutaric and adipic acids and valuable catalytic metal as salts are treated with alcohols, thereby separating, as esters, succinic and glutaric acids which would contaminate pure adipic acid on recycling, and allowing the re-use of the resulting stream containing nitric acid and metal catalytic salts.

Abstract: Process for reducing the color forming tendency of alkanedioic acid esters by contact with an alkali metal borohydride in the presence of water.

Abstract: In the manufacture of adipic acid by nitric acid oxidation of cyclohexanol and cyclohexanone glutaric and succinic acids are recovered from the reaction by-product and waste stream by crystallizing adipic acid and succinic acid out of the stream leaving glutaric acid in the residue; forming succinic anhydride from the succinic acids so obtained; separating the succinic anhydride from the adipic acid by distillation thereby to recover succinic acid in anhydride form; and crystallizing, thereby to recover, the glutaric acid from the residue.

Abstract: C.sub.2 -C.sub.6 monocarboxylic and dicarboxylic acids are scrubbed from gas phase mixtures of such acids and water by gas absorption techniques utilizing a liquid solvent comprising a polyoxyalkylene glycol or a monoalkyl or dialkyl ether thereof. The solvent enriched with the acid is subjected to distillation to recover a substantially anhydrous acid product.

Abstract: A method for obtaining glutaric acid, succinic acid, and adipic acid from an acid mixture obtained as a by-product in the industry and comprising glutaric acid, succinic acid and adipic acid, which comprises the steps of: (1) contacting the acid mixture with urea of 1 to 2 moles per mole of the acid mixture, in solution, to deposit a urea-glutaric acid adduct so that the weight ratio of glutaric acid remaining in the solution to succinic acid is 1.2 or less when the adipic acid content is in the range of 0% by weight to 7% by weight and 1.