Abstract: The invention relates to a process for distillatively preparing TDA from a reactant stream comprising TDA, high boilers and low boilers in a dividing wall column in which a dividing wall is disposed in the longitudinal direction of the column to form an upper combined column region (2), a lower combined column region (3), a feed section (4) having a rectifying section (5) and stripping section (6), and also a withdrawal section (7) having a rectifying section (9) and stripping section (8), which comprises the following steps: a. feeding the reactant stream (13) into the feed section (4) of the dividing wall column (1); b. drawing off a low boiler fraction via the top of the column (11); c. drawing off TDA via a side draw (14) in the withdrawal section (7) of the dividing wall column (1); d. drawing off a low boiler fraction via the bottom of the column (12).

Abstract: An oxidic composition which is suitable as a catalyst having divalent and trivalent iron in an atomic ratio of divalent to trivalent iron in the range from greater than 0.5 to 5.5 and oxygen as a counterion to the divalent and trivalent iron. The catalyst composition is useful in the hydrogenation of nitriles to amines.

Abstract: A process for the preparation of a dicarboxylic acid of the formula (I) —H—OOC-(n-C4Hx)—COO—H??(I) where x is 6 or 8, starting from acrylic acid, which comprises a) reacting a dicarboxylic acid diester of the formula (II) R1—OOC-(n-C4Hx)—COO—R2??(II) where x is 6 or 8, and R1 and R2, independently of one another, are C1-, C2-, C3- or C4-alkyl, aryl or heteroaryl and may be identical to or different from one another, with acrylic acid to give a dicarboxylic acid of the formula (I) and a mixture of acrylic acid esters of the formulae C2H3—COOR1 and C2H3—COOR2, where R1 and R2 are as defined above, b) separating the dicarboxylic acid of the formula (I) obtained in step a) from the reaction mixture obtained in step a), c) dimerizing the C2H3—COOR1, C2H3—COOR2 or mixture thereof obtained in step a) to give an n-butenedicarboxylic acid diester, and d) cleaving the dicarboxylic acid diester obtained in step c) into the corresponding dicarboxylic acid of the formula (I).

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

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: 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.

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

Abstract: A process is provided for the preparation of cyclic lactams of formula (II): 1

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.