Abstract: Process for purifying N-alkylpyrrolidones which due to a previous use comprise at least one of the impurities of the formula I or II where R is hydrogen or a C1-C20-alkyl group, wherein a basic compound is added to the N-alkylpyrrolidone to be purified and the temperature of the mixture is at least 80° C. not more than 20 minutes after addition of the basic compound and N-alkylpyrrolidone is distilled off from the mixture obtained.

Abstract: Processes for preparing tetrahydrofuran and/or butane-1,4-diol and/or gamma-butyrolactone are provided, including a process for preparing tetrahydrofuran (THF) from succinic acid that has been obtained by conversion of biomass, by conversion of the succinic acid to succinic anhydride, and hydrogenation of the succinic anhydride, with removal of certain secondary components.

Abstract: A process for decomposing formates in formate-containing compositions of matter comprises reacting formate-containing compositions of matter in the presence of at least one heterogeneous catalyst comprising lanthanum and at a temperature of from 80 to 180° C. and a pressure of from 0.1 to 60 bar, the formate-containing compositions of matter having a pH of from 6.5 to 10.

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: 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 Broønsted acidity, which results in decreased production of ether byproducts.

Abstract: A process for decomposing formates in formate-containing compositions of matter comprises reacting formate-containing compositions of matter in the presence of at least one heterogeneous catalyst comprising lanthanum and at a temperature of from 80 to 180° C. and a pressure of from 0.1 to 60 bar, the formate-containing compositions of matter having a pH of from 6.

Abstract: The present invention relates to a process for preparing adipic acid or at least one conversion product thereof, in which muconic acid is hydrogenated with hydrogen in the presence of at least one transition metal catalyst C and of an aqueous liquid A in a reaction zone, wherein the muconic acid is at least partly insoluble in the liquid A under the hydrogenation conditions.

Abstract: Method for preparing 1,4-butanediol having an APHA color index of less than 30 by treating substance mixtures comprising 1,4-butanediol by distillation of the 1,4-butanediol in the presence of complex hydrides.

Abstract: Process for purifying N-alkylpyrrolidones which due to a previous use comprise at least one of the impurities of the formula I or II where R is hydrogen or a C1-C20-alkyl group, wherein a basic compound is added to the N-alkylpyrrolidone to be purified and the temperature of the mixture is at least 80° C. not more than 20 minutes after addition of the basic compound and N-alkylpyrrolidone is distiiied off from the mixture obtained.

Abstract: Process for purifying N-alkylpyrrolidones which due to a previous use comprise at least one of the impurities of the formula I or II where R is hydrogen or a C1-C20-alkyl group, wherein a basic compound is added to the N-alkylpyrrolidone to be purified and the temperature of the mixture is at least 80° C. not more than 20 minutes after addition of the basic compound and N-alkylpyrrolidone is distilled off from the mixture obtained.

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: 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 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 present invention relates to a process for separating off solvents from solvent-comprising hydrogenation outputs from a catalytic hydrogenation process, which comprise at least one water-soluble hydrogenation product having at least one alcohol, lactone, ether, lactam or amino group in a solvent which is immiscible or not completely miscible with water and has a boiling point below 100° C., wherein water is added to the hydrogenation output, the solvent-comprising phase is separated off and recirculated to the hydrogenation.

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 Broønsted acidity, which results in decreased production of ether byproducts.

Abstract: The present invention relates to a process for preparing an isocyanate, comprising hydrogenating a mixture (Gi) comprising an amine in the presence of a hydrogenation catalyst comprising copper to obtain a mixture (Gii) comprising the amine, and reacting the mixture (Gii) with phosgene to obtain a mixture (Giii) comprising the isocyanate. The present invention further relates to the isocyanate preparable by this process.

Abstract: The present invention relates to a mixture comprising itaconic acid or an itaconic acid derivative and a primary amine of the formula (I) R—NH2??(I) where the molar ratio of primary amine to itaconic acid or the itaconic acid derivative is in the range from 0.5:1 to 20:1, wherein the mixture comprises 50 mole percent or less of 4-carboxypyrrolidones of the formula (II), derivatives of the 4-carboxypyrrolidones of the formula (II) and 4-carbamidopyrrolidones of the formula (III) based on the itaconic acid used or the itaconic acid derivative used and in which R is a linear or branched saturated aliphatic radical having 1 to 24 carbon atoms or a saturated cycloaliphatic radical having 3 to 24 carbon atoms. The invention further provides for the use of the inventive mixtures for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones, and also a process for preparing 1,3-alkylmethylpyrrolidones and/or 1,4-alkylmethylpyrrolidones.

Abstract: The present invention relates to a process for hydrogenating oligo- and/or polyesters obtainable by esterifying a DCS with a diol or diol mixture, said hydrogenation being performed in the presence of a catalyst whose catalyst precursor comprises copper oxide, aluminum oxide and at least one oxide of lanthanum, of iron, of tungsten, of molybdenum, of titanium or of zirconium, and to a process for preparing 1,6-hexanediol by catalytically hydrogenating ester mixtures which comprise, as main components, oligo- and polyesters of adipic acid and 6-hydroxycaproic acid, and are obtained by esterifying DCS with diols, especially 1,6-hexanediol or diol mixtures.

Abstract: Process for purifying N-alkylpyrrolidones which due to a previous use comprise at least one of the impurities of the formula I or II where R is hydrogen or a C1-C20-alkyl group, wherein a basic compound is added to the N-alkylpyrrolidone to be purified and the temperature of the mixture is at least 80° C. not more than 20 minutes after addition of the basic compound and N-alkylpyrrolidone is distilled off from the mixture obtained.