Abstract: The present invention relates to a process for preparing hydrocyanic acid (HCN) by catalytic dehydration of gaseous formamide in a reactor which has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to a reactor for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide, which reactor has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to the use of the reactor of the present invention in a process for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide.

Abstract: A process for purifying crude caprolactam which has been obtained by 1) converting a mixture (I) comprising 6-aminocapronitrile and water to a mixture (II) comprising caprolactam, ammonia, water, high boilers and low boilers in the presence of a catalyst, then 2) removing ammonia from mixture (II) to obtain a mixture (III) comprising caprolactam, water, high boilers and low boilers, then 3) completely or partly removing water from mixture (III) to obtain crude caprolactam (IV) comprising caprolactam, high boilers and low boilers, which comprises a) feeding the crude caprolactam and an inorganic acid which has a boiling point above the boiling point of caprolactam under the distillation conditions of the following steps b) to h) to a first distillation apparatus C1, b) distilling the crude caprolactam and the inorganic acid in the first distillation apparatus C1, and removing a first substream in the bottom region and a second substream in the top region of the distillation apparatus C1, c) feeding the second

Abstract: A process for removing high boilers from crude caprolactam which comprises high boilers, caprolactam and in some cases low boilers, and which has been obtained by a) reacting 6-aminocapronitrile with water to give a reaction mixture b) removing ammonia and unconverted water from the reaction mixture to obtain crude caprolactam, which comprises c) feeding the crude caprolactam to a distillation apparatus to obtain a first substream via the top as a product and a second substream via the bottom, by setting the pressure in the distillation in such a way that the bottom temperature does not go below 170° C., and adjusting the second substream in such a way that the caprolactam content of the second substream is not less than 10% by weight, based on the entire second substream.

Abstract: The invention relates to a method for removing, by distillation, 6-aminocapronitrile from mixtures that contain 6-aminocapronitrile, adipodinitrile and hexamethylenediamine, by a) removing the hexamethylenediamine from the mixture while obtaining a mixture (I) that has a hexamethylenediamine content of less than 1 wt. -%, b) removing completely or partially the 6-aminocapronitrile from mixture (I) while obtaining a mixture (II) whose content in substances that have a higher boiling point as 6-aminocapronitrile under distillation conditions and that cannot be formed by dimerization reactions when 6-aminocapronitrile is thermally treated is less than 1 wt. -%, and c) completely or partially removing from mixture (II) the hexamethylenediamine that might be present while obtaining a mixture (IV) whose hexamethylenediamine content is higher than that of mixture (II), and a mixture (V) whose hexamethylenediamine content is lower than that of mixture (II).

Abstract: A process for the recovery of a Lewis acid from a reaction mixture (I) which has been obtained in the hydrocyanation of an olefinically unsaturated compound to a nitrile which has a miscibility gap with water under certain pressure and temperature conditions, in the presence of a catalyst system comprising a Lewis acid and a complex compound.

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 amine (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 process for the removal of water from a mixture comprising water and zinc chloride, which comprises adding to said mixture comprising water and zinc chloride an aprotic, polar diluent whose boiling point in the case where an azeotrope is not formed between said diluent and water under the pressure conditions of the distillation mentioned below is higher than the boiling point of water and which is in liquid form at this boiling point of water or which forms an azeotrope or heteroazeotrope with water under the pressure and temperature conditions of the distillation mentioned below, and distilling the mixture comprising water, zinc chloride and the diluent with removal of water or said azeotrope or said heteroazeotrope from this mixture, giving an anhydrous mixture comprising zinc chloride and said diluent.

Abstract: A process is provided for the regeneration of a heterogeneous catalyst used for the preparation of compounds containing NH2 groups by the hydrogenation, with hydrogen, of compounds containing at least one unsaturated carbon-nitrogen bond, wherein a) the feed of the compound to be hydrogenated is stopped and b) the heterogeneous catalyst is treated with a compound of the formula R1R2N—CO—R3??(I), in which R1 is hydrogen or C1-C4 alkyl and R2, R3 independently of one another are each hydrogen or C1-C4 alkyl or together are a C3-C6 alkylene group, or mixtures of such compounds, at a pressure ranging from 0.1 to 30 MPa and a temperature ranging from 100 to 300° C., with the proviso that the compound of formula (I) is in liquid form during the treatment.

Abstract: A process for distillative removal of ammonia from solutions (I) which include a lactam and ammonia comprises effecting said removal in a distillation apparatus (a) at an absolute pressure of less than 10 bar.

Abstract: A process for preparing a polymer, which comprises a) reacting a mixture (I) containing 6-aminocapronitrile and water in the presence of a catalyst to obtain a mixture (II) containing caprolactam, ammonia, water, high boilers and low boilers, then b) removing ammonia from mixture (II) to obtain a mixture (III) containing caprolactam, water, high boilers and low boilers, then c) removing all or some of the water from mixture (III) to obtain a mixture (IV) containing caprolactam, high boilers and low boilers and then d) feeding mixture (IV) to a polymerization reaction, and also the polymer obtainable by this process, the use of the polymer for producing fibers, sheetlike structures and moldings, and also fibers, sheetlike structures and moldings obtainable using such a polymer.

Abstract: A material useful as catalyst for the hydrogenation of alpha, omega-dinitriles comprises (a) iron or a compound based on iron or mixtures thereof, (b) from 0.001 to 0.3% by weight based on (a) of a promoter based on 2, 3, 4 or 5 elements selected from the group consisting of aluminum, silicon, zirconium, titanium and vanadium, (c) from 0 to 0.3% by weight based on (a) of a compound based on an alkali and/or alkaline earth metal, and also (d) from 0.001 to 1% by weight based on (a) of manganese.

Abstract: An oxidic composition which is suitable as a catalyst precursor comprises

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: A process is provided for reducing the content of a monounsaturated aliphatic amine (III) in a mixture (IV) containing an aminonitrile (I) or a diamine (II), or mixtures thereof, and the amine (III), wherein a) the mixture (IV) is reacted with an anionic nucleophile (V),  which contains a nucleophilic atom selected from the group comprising oxygen, nitrogen and sulfur,  which is capable of taking up an H+ ion to form an acid with a pKa ranging from 7 to 11, measured in water at 25° C., and  which has a relative nucleophilicity, measured in methyl perchlorate/methanol at 25° C.,  ranging from 3.4 to 4.7 when oxygen is the nucleophilic atom,  ranging from 4.5 to 5.8 when nitrogen is the nucleophilic atom, and  ranging from 5.5 to 6.8 when sulfur is the nucleophilic atom,  in an amount ranging from 0.

Abstract: Passivated iron useful as catalytically active component after activation is activated by hydrogen at elevated temperature and elevated pressure in the presence of a nitrile.

Abstract: A material useful as catalyst for the hydrogenation of alpha, omega-dinitriles comprises

Abstract: A polyamide is prepared by reacting at least one dinitrile and at least one diamine with water at a temperature from 90 to 400° C. and a pressure from 0.1 to 50*106 Pa in a molar ratio of at least 1:1 for water to the sum total of dinitrile and diamine in the presence of a heterogeneous catalyst selected from the group consisting of aluminum oxide, tin oxide, silicon oxide, oxides of the second to sixth transition group of the periodic table, oxides of the lanthanides and actinides, sheet-silicates and zeolites.

Abstract: A process is provided for reducing the content of a monounsaturated aliphatic amine (III) in a mixture (IV) containing an aminonitrile (I) or a diamine (II), or mixtures thereof, and the amine (III), wherein

Abstract: A process is provided for the preparation of cyclic lactams of formula (II): in which n and m can each have the values 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 and the sum of n+m is at least 3, preferably at least 4, and R1 and R2 are C1-C6-alkyl, C5-C7-cycloalkyl or C6-C12-aryl groups, by reacting a compound (I) of the formula in which R1, R2, m and n are as defined above and R are [sic] nitrile, carboxamide and carboxylic acid groups, with steam in the gas phase.

Abstract: The invention relates to a method for producing cyclic lactams of formula (II) by reacting a compound (I) of formula (I) with water in the presence of an organic, liquid dilution agent in the liquid phase. In formula (II), n and m respectively can have the values 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 and the sum of n+m is at least 3, preferably at least 4 and R1 and R2 represent C1-C6 alkyl, C5-C7 cycloalkyl or C6-C12 aryl groups. In formula (I), R1, R2, m and n are defined as above and R represents nitrile, carboxylic acid amide and carboxylic acid groups. The inventive method is characterized in that a) compound (I) is reacted with water in the liquid phase in the presence of an organic, liquid dilution agent (III) to form a mixture (IV) containing a lactam (II) and said mixture (IV) is subjected to an aqueous treatment to obtain a two-phase system.