Abstract: The present invention relates to a method for depleting halide ions from liquid ammonia, wherein the liquid ammonia is brought into contact with a strongly basic ion exchanger, where the basic structure of the strongly basic ion exchanger is a covalently crosslinked polymer matrix. Furthermore, the present invention relates to the use of an ammonia obtainable according to the invention as starting material in the production of amines.

Abstract: Alkali metal ions are separated off from alkoxylates containing alkali metal ions by a process comprising: a) dilution of the alkali metal-containing alkoxylate with an inert solvent, b) treatment of the alkali metal-containing solution of the alkoxylate with a cationic exchanger in order to obtain a substantially alkali metal-free solution of the alkoxylate, and c) removal of the solvent from the substantially alkali metal-free solution of the alkoxylate in order to obtain a substantially alkali metal-free and substantially solvent-free alkoxylate.

Abstract: Alkali metal ions are separated off from alkoxylates containing alkali metal ions by a process comprising:

Abstract: The present invention relates to a process for preparing hydroxyl-containing polymers, in particular for preparing polytetrahydrofuran with terminal hydroxyl groups, from the corresponding acyloxy-containing polymers by transesterification with alcohols in the presence of an alkali metal- or alkaline earth metal-containing catalyst, which entails the appropriate acyloxy-containing polymer being introduced together with the alcohol and the catalyst into a first prereactor (I) and converted therein at least partly to the hydroxyl-containing polymer, and the reaction solution being fed into the upper zone (IIa) of a distillation column (II) into whose lower zone (IIb) alcohol in vapor phase is additionally fed. This involves a phase exchange at the coherent and the disperse phase at the transition from the prereactor to the distillation column. Preferably, in addition to the first prereactor, a further 3 prereactors are used which serve as holdup reactors.

Abstract: A process for preparing 1,6-hexanediol from a carboxylic acid mixture obtained as by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-comprising gases and by aqueous extraction of the reaction mixture and comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols by esterification of the acids and hydrogenation, by a) reacting the mono- and dicarboxylic acids in the aqueous dicarboxylic acid mixture with a low molecular weight alcohol to form the corresponding carboxylic esters, b) conducting a first distillation to remove excess alcohol and low boilers from the esterification mixture obtained, c) conducting a second distillation to separate the bottom product into an ester fraction which is essentially free from 1,4-cyclohexanediols and a fraction which includes at least the larger proportion of the 1,4-cyclohexanediols, d) subjecting the ester fraction essentially free from 1,4-cyclohexanediols to a catalytic hydrogenation, and e)

Abstract: A process for reducing the amine content of amine-contaminated N-substituted lactams comprises treating the contaminated N-substituted lactams with an acid macroporous cation exchanger.

Abstract: In a process and an apparatus for the continuous preparation of alkyl esters of (meth)acrylic acid by reacting (meth)acrylic acid with alkanols having from 1 to 5 carbon atoms in a homogeneous, liquid, solvent-free phase at elevated temperature and in the presence of an acid esterification catalyst, in which the (meth)acrylic acid, the alkanol and the catalyst are fed to a reaction zone, the water formed is removed by rectification during a residence time as constituent of a mixture comprising alkanol in a rectification unit superposed on the reaction zone, the distillate thus obtained is separated into an organic phase comprising alkanol and an aqueous phase comprising water, the organic phase is returned to the rectification unit, the reaction mixture is discharged from the reaction zone and conveyed into a distillative separation zone comprising further rectification units and in the latter the alkyl (meth)acrylate formed is separated off.

Abstract: In the process for the continuous preparation of alkyl esters of (meth)acrylic acid by reacting (meth)acrylic acid with monohydric alkanols having from 1 to 8 carbon atoms in the presence of an acid esterification catalyst in a reaction zone, there is discharged from the reaction zone a product mixture which comprises the alkyl (meth)acrylate formed, the catalyst and the by-products formed during the course of the esterification having boiling points higher than that of the alkyl (meth)acrylate, and from which the alkyl (meth)acrylate is separated by distillation in a separation zone. The product mixture discharged from the reaction zone is fed to a rectification unit (I), in this unit the product mixture discharged is separated by rectification into at least one product (I) comprising the alkyl ester of (meth)acrylic acid and a product (II) comprising the catalyst, the product (I) is fed to a further rectification unit (II) and in this the alkyl ester of (meth)acrylic acid is separated off by rectification.