Abstract: The present invention relates to a process for one-stage preparation of polyamines by reacting compounds comprising at least two nitrile groups (dinitrile) or at least one nitrile group and one amino group (amino nitrile) with hydrogen in the presence of heterogeneous transition metal catalysts.

Abstract: A process for the continuous preparation of adiponitrile by hydrocyanation of 3-pentenenitrile is described, wherein a) 3-pentenenitrile is hydrocyanated to give a reaction output comprising adiponitrile, b) in a work-up 1, a mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile is separated off as overhead product from the reaction output from the reactor R1 in a first distillation apparatus, c) the mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile from step b) is continuously isomerized in the presence of aluminum oxide as catalyst in a reactor R2 to give a product mixture comprising 3-pentenenitrile, d) cis-2-methyl-2-butenenitrile is separated off as overhead product from the reaction output from the reactor R2 in a distillation apparatus in a work-up 2 and discharged.

Abstract: A process for the continuous preparation of adiponitrile by hydrocyanation of 3-pentenenitrile is described, wherein a) 3-pentenenitrile is hydrocyanated to give a reaction output comprising adiponitrile, b) in a work-up 1, a mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile is separated off as overhead product from the reaction output from the reactor R1 in a first distillation apparatus, c) the mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile from step b) is continuously isomerized in the presence of aluminum oxide as catalyst in a reactor R2 to give a product mixture comprising 3-pentenenitrile, d) cis-2-methyl-2-butenenitrile is separated off as overhead product from the reaction output from the reactor R2 in a distillation apparatus in a work-up 2 and discharged.

Abstract: The present invention relates to a process for producing nylon-6,6 by a) providing a muconic acid starting material selected from muconic acid, esters of muconic acid, lactones of muconic acid and mixtures thereof, b) subjecting the muconic acid starting material provided in step a) at least to some extent to a reaction with hydrogen in the presence of at least one hydrogenation catalyst Hb) to give adipic acid, c1) subjecting the muconic acid starting material provided in step a) to some extent to a reaction with hydrogen in the presence of at least one hydrogenation catalyst Hc1) to give 1,6-hexanediol, or c2) subjecting the adipic acid obtained in step b) to some extent to a reaction with hydrogen in the presence of at least one hydrogenation catalyst Hc2) to give 1,6-hexanediol, d) subjecting the 1,6-hexanediol obtained in step c1) or c2) to amination in the presence of an amination catalyst to obtain hexamethylenediamine, e) subjecting the hexamethylenediamine obtained in step d) and at least a portion o

Abstract: The invention relates to a method for producing hexamethylenediamine, wherein a) a muconic acid starting material is provided, which is selected from among muconic acid, esters of muconic acid, lactones of muconic acid, and mixtures thereof, b) the muconic acid starting material is subjected to a reaction with hydrogen in the presence of at least one hydrogenation catalyst in order to form 1,6-hexanediol, and c) the 1,6-hexanediol obtained in step b) is subjected to amination in the presence of an amination catalyst in order to obtain hexamethylenediamine. The invention further relates to hexamethylenediamine which can be produced by means of said method.

Abstract: The invention relates to a process for preparing hexane-1,6-diol, in which a) a muconic acid starting material is provided, selected from muconic acid, esters of muconic acid, lactones of muconic acid and mixtures thereof, b) the muconic acid starting material is subjected to a reaction with hydrogen in the presence of at least one hydrogenation catalyst to hexane-1,6-diol, and c) the output from the hydrogenation in step b) is subjected to a distillative separation to obtain hexane-1,6-diol.

Abstract: A process is described for preparing purified caprolactam, comprising the steps a) extraction of crude caprolactam, obtained from the Beckmann rearrangement of cyclohexanone oxime, with an organic extractant, b) removal of the organic phase from step a), c) distillative separation of the organic extractant from the organic phase from step b) giving rise to water-containing lactam extract, being preceded by addition of the distillative separation, aqueous alkali metal hydroxide solution in an amount of from 0 to 10 mmol/kg of caprolactam, d) addition of 0 to 30 mmol of alkali metal hydroxide/kg of caprolactam to the water-containing lactam extract from step c), e) distillative removal of water from the water-containing lactam extract treated with alkali metal hydroxide from step d), f) freeing the caprolactam from step e) from by-products lower- and higher-boiling than caprolactam by distillation, with addition in steps c) and d) together of at least 1.5 mmol of alkali metal hydroxide/kg of caprolactam.

Abstract: The present invention relates to an improved process for batchwise or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles in the presence of 1,4-diazabicyclo[2.2.2]octane as catalyst.

Abstract: A process is described for preparing purified caprolactam, comprising the steps a) extraction of crude caprolactam, obtained from the Beckmann rearrangement of cyclohexanone oxime, with an organic extractant, b) removal of the organic phase from step a), c) distillative separation of the organic extractant from the organic phase from step b) giving rise to water-containing lactam extract, being preceded by addition of the distillative separation, aqueous alkali metal hydroxide solution in an amount of from 0 to 10 mmol/kg of caprolactam, d) addition of 0 to 30 mmol of alkali metal hydroxide/kg of caprolactam to the water-containing lactam extract from step c), e) distillative removal of water from the water-containing lactam extract treated with alkali metal hydroxide from step d), f) freeing the caprolactam from step e) from by-products lower- and higher-boiling than caprolactam by distillation, with addition in steps c) and d) together of at least 1.5 mmol of alkali metal hydroxide/kg of caprolactam.

Abstract: The present invention relates to an improved process for batchwise or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles in the presence of 1,4-diazabicyclo[2.2.2]octane as catalyst.

Abstract: The present invention relates to a process for preparing diols by hydrogenating a mixture comprising carboxylic acid, carboxylic anhydrides and/or carboxylic esters/lactones by means of a cobalt-comprising catalyst, wherein alkali metal and/or alkaline earth metal ions are added to the hydrogenation feed, excluding alkali metal and/or alkaline earth metal ions of mineral acids.

Abstract: The present application relates to an improved process for preparing 6-hydroxycaproic esters from the by-product mixtures which are obtained in the oxidation of cyclohexane to cyclohexanol and cyclohexanone with oxygen or oxygen-comprising gas mixtures.

Abstract: The invention relates to an apparatus for separating a liquid substance mixture by distillation, a method for producing a tetrahydrofuran homopolymer and copolymer in which the oligomers in a liquid starting mixture containing oligomers are separated by distillation in such an apparatus, tetrahydrofuran homopolymers and copolymers which can be obtained using said method and have a narrow distribution of the relative molar mass, and the use thereof.

Abstract: The present invention relates to a process for preparing diols by hydrogenating a mixture comprising carboxylic acid, carboxylic anhydrides and/or carboxylic esters/lactones by means of a cobalt-comprising catalyst, wherein alkali metal and/or alkaline earth metal ions are added to the hydrogenation feed, excluding alkali metal and/or alkaline earth metal ions of mineral acids.

Abstract: The iron-containing catalyst suitable for use as a catalyst contains a) iron or a mixture containing iron and an iron-based compound. The iron has an average crystallite size ranging from 1-35 nm measured by X-ray diffraction.

Abstract: The present application relates to an improved process for preparing 6-hydroxycaproic esters from the by-product mixtures which are obtained in the oxidation of cyclohexane to cyclohexanol and cyclohexanone with oxygen or oxygen-comprising gas mixtures.

Abstract: The disclosure relates to a process for purifying crude caprolactam. The process involves converting a first mixture of 6-amino capronitrile and water to a second mixture of caprolactam ammonia, water, high boilers and low boilers using a catalyst. The ammonia is removed from the second mixture to obtain a third mixture. Water is removed from the third mixture to give crude caprolactam, high boiler and low boilers. Purified caprolactam is then obtained by a series of distillation steps.

Abstract: A process for reducing the level of an aliphatic monounsaturated amine (IV) in a mixture (V) containing an aminonitrile (I) or a diamine (II) or a dinitrile (III) or mixtures thereof as well as said mine (IV) by a) reacting said mixture (V) with an anionic nucleophile (VI) which contains a nucleophilic atom selected from the group consisting of oxygen, nitrogen and sulfur, which is capable of taking up an H+ ion to form an acid having a pKa value in the range from 7 to 11, as measured in water at 25° C., and which has a relative nucleophilicity, as measured in methyl perchlorate/methanol at 25° C., in the range from 3.4 to 4.7 when said nucleophilic atom is oxygen, in the range from 4.5 to 5.8 when said nucleophilic atom is nitrogen, and in the range from 5.5 to 6.8 when said nucleophilic atom is sulfur, in an amount in the range from 0.01 to 10 mol per mole of said amine (IV) in said mixture (V) at a temperature in the range from 50 to 200° C.

Abstract: A catalyst for the hydrogenation of C4-dicarboxylic acids and/or derivatives thereof, preferably maleic anhydride, in the gas phase comprises a) 20-94% by weight of copper oxide (CuO), preferably 40-92% by weight of CuO, in particular 60-90% by weight of CuO, and b) 0.005-5% by weight, preferably 0.01-3% by weight, in particular 0.05-2% by weight, palladium and/or a palladium compound (calculated as metallic palladium) and c) 2-79.995% by weight, preferably 5-59.99% by weight, in particular 8-39.95% by weight, of an oxidic support selected from the group consisting of the oxides of Al, Si, Zn, La, Ce, the elements of groups IIIA to VIIIA and of groups IA and IIA of the Periodic Table of the Elements.

Abstract: Crude water-containing tetrahydrofuran is purified by passing the crude tetrahydrofuran through three distillation columns, withdrawing water from the bottom of the first column, recycling water-containing tetrahydrofuran from the top of the second column into the first column, passing a sidestream of the first column into the second column, recycling the bottom product of the third column into the first column, and withdrawing a distillate at the top of the first column. Additionally, a sidestream of the second column is passed into the third column and the purified tetrahydrofuran is recovered as the top product of the third column.