Abstract: The invention relates to a process for preparing 1,6-hexanediol, preferably with at least 99.5% purity, which are especially virtually free of 1,4-cyclohexanediols, from a carboxylic acid mixture which is obtained as a by-product of the catalytic oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-comprising gases and by water extraction of the reaction mixture, by hydrogenating the carboxylic acid mixture, esterifying and hydrogenating a substream to hexanediol.

Abstract: The present invention relates to a process for the work-up of polymer solutions comprising N-methyl-2-pyrrolidone and a polymer where the polymer solution is hydrogenated with hydrogen in the presence of a hydrogenation catalyst. The present invention also relates to the product obtainable from said process, and to its use for producing, in particular, polyarylene ether products.

Abstract: Provided are catalysts suitable for the production of tetrahydrofuran from 1,4-butanediol. Also provided are methods of use of these catalyst, as well as catalyst systems. The catalysts described herein contain only Lewis acidity, but not Brønsted acidity, which results in decreased production of ether byproducts.

Abstract: The invention relates to a process for preparing 1,6-hexanediol and caprolactone, preferably with at least 99.5% purity, which are especially virtually free of 1,4-cyclohexanediols, from a carboxylic acid mixture which is obtained as a by-product of the catalytic oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-comprising gases and by water extraction of the reaction mixture, by hydrogenating the carboxylic acid mixture, esterifying and hydrogenating a substream to hexanediol and cyclizing 6-hydroxycaproic ester, the 1,4-cyclohexanediols being removed either in the course of fractionation of the esterification mixture or last from the caprolactone.

Abstract: The process relates to a process for preparing delta-valerolactone (VLO) in the gas phase by catalytic dehydrogenation over at least two different catalysts.

Abstract: The invention relates to a method for purifying N-alkyl-substituted pyrrolidones which have contaminants with a higher degree of oxidation, by hydrogenation of the same and distillation.

Abstract: The present invention relates to a novel process for preparing alkyl polycarboxylates from an aqueous solution of an ammonium salt of the polycarboxylic acid by reactive distillation, and to a process for hydrogenating the alkyl carboxylates prepared in this way.

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: In a process for preparing a supported hydrogenation catalyst with increased hydrogenation activity, which comprises a hydrogenating metal and/or an oxide of a hydrogenating metal on an Al2O3-containing support material, said calcined supported hydrogenation catalyst is treated before or after the final shaping thereof and before use thereof in the hydrogenation with a base solution having a pH of >10 at a temperature in the range from 20 to 120° C. for 1 to 300 hours.

Abstract: The present invention provides a process for preparing ?-caprolactone in a purity of more than 99% by cyclizing 6-hydroxycaproic esters in the liquid phase at from 150 to 400° C. and from 1 to 1020 hPa abs., and removing and condensing the compounds which are volatile under cyclization conditions, which comprises thermally treating the remaining bottom product of the cyclization in at least one further reactor, removing and condensing volatile compounds and obtaining ?-caprolactone by distillation from the condensates.

Abstract: The invention provides 1,6-hexanediol having a proportion by weight of nitrogen of less than 5 ppm, and polymers obtained by reacting the 1,6-hexanediol with at least one reactive compound. The 1,6-hexanediol is obtained by distilling a mixture including 1,6-hexanediol and more than 500 ppm of at least one carboxylic acid, ester, or both, having a boiling point higher than that of the 1,6-hexanediol and being in contact with the 1,6-hexanediol at a temperature range greater than or equal to 100° C. for at least 5 minutes before, during, or before and during, the distillation, followed by collection of the 1,6-hexanediol. In certain embodiments of this invention, the 1,6-hexanediol has a proportion by weight of nitrogen of less than 3 ppm and less than 2 ppm.

Abstract: Process for preparing tetrahydrofuran, 1,4-butanediol and/or gamma-butyrolactone by hydrogenation of 1,4-butynediol, wherein 1,4-butynediol is vaporized in a hydrogen-comprising gas stream and hydrogenated in gaseous form over at least one catalyst which comprises at least one of the elements of groups 7 to 11 of the Periodic Table of the Elements.

Abstract: The present invention relates to a process for the catalytic hydrogenation of 1,4-butynediol to tetrahydrofuran at at least the decomposition temperature of 1,4-butynediol, wherein 1,4-butynediol is vaporized in a hydrogen-comprising gas stream and is hydrogenated in gaseous form over at least one catalyst, comprising at least one of the elements from groups 7 to 11 of the Periodic Table of the Elements.

Abstract: The invention relates to a process for preparing ?-caprolactone from 6-hydroxycaproic ester in the gas phase in the presence of activated carbon as a catalyst and subsequent distillation.

Abstract: The present invention relates to a process for preparing at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group, at least comprising the stages: (a1) oxidation of a composition (A), at least comprising one cyclic olefin with Z cycles and 7 to 16 carbon atoms and at least two C—C double bonds, by means of dinitrogen monoxide to give a composition (A1), (a2) separating off the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C—C double bonds from the composition (A1) in order to obtain a composition (A2), and (b) distillative treatment of the composition (A2) from step (a2) in order to obtain a composition (B), comprising the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group and less than 1.0% by weight of the at least one compound with Z?1 cycles and 7 to 16 carbon atoms with at least one aldehyde group, where Z can be 1, 2, 3 or 4.

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 present invention provides a process for preparing 2-methyltetrahydrofuran by one-stage hydrogenation of furfural with a hydrogen-comprising gas in the presence of a structured bed of at least one copper catalyst and at least one catalyst which comprises at least one noble metal from groups 8, 9 and/or 10 of the periodic table of the elements applied on a support material.

Abstract: The present invention relates to a process for preparing plastics using 1,6-hexanediol having an aldehyde content of less than 500 ppm, a process for preparing 1,6-hexanediol having an aldehyde content of less than 500 ppm and also 1,6-hexanediol having an aldehyde content of less than 500 ppm.

Abstract: A process which isolates tetrahydrofuran from a stream of tetrahydrofuran, alkanol and high boilers, by: (a) separating off a first stream of tetrahydrofuran and alkanol as azeotrope in a first distillation stage; (b) feeding part of the first stream into a reactor for esterifying maleic anhydride, giving a second stream of tetrahydrofuran and monoalkyl maleate; (c) separating the second stream into a third stream of monoalkyl maleate and a fourth stream of tetrahydrofuran in a second distillation stage; (d) feeding the fourth stream of tetrahydrofuran from the second distillation stage and the part of the first stream from (a) which is not fed to the reactor into a third distillation stage to obtain a product stream of tetrahydrofuran and a sixth stream of tetrahydrofuran and alkanol; (e) recirculating the sixth stream from the third distillation stage into the first distillation stage or the reactor in (b).

Abstract: The invention provides 1,6-hexanediol having a proportion by weight of nitrogen of less than 5 ppm, and polymers obtained by reacting the 1,6-hexanediol with at least one reactive compound. The 1,6-hexanediol is obtained by distilling a mixture including 1,6-hexanediol and more than 500 ppm of at least one carboxylic acid, ester, or both, having a boiling point higher than that of the 1,6-hexanediol and being in contact with the 1,6-hexanediol at a temperature range greater than or equal to 100° C. for at least 5 minutes before, during, or before and during, the distillation, followed by collection of the 1,6-hexanediol. In certain embodiments of this invention, the 1,6-hexanediol has a proportion by weight of nitrogen of less than 3 ppm and less than 2 ppm.