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 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 invention relates to a process for preparing methylenediphenyldiamine (MDA) by reacting formaldehyde and aniline in the presence of an acidic catalyst, wherein the oxygen content in the process for preparing MDA is <10 000 ppm, based on all compounds present in the process. The invention further relates to the phosgenation of MDA to methylenediphenyl diisocyanate (MDI).

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 invention relates to a process for recovering acids from product streams of organic syntheses, which comprises the steps a) neutralization of the acid with a base, b) removal of the base by means of adsorption, c) recovery of the acid.

Abstract: The present invention relates to a process for preparing phenylalkan-1-ols in three stages, where an ester condensation in the presence of alkali metal or alkaline earth metal alcoholates is carried out in the first stage.

Abstract: The invention provides a process for preparing diphenylmethanediamine, comprising the steps of a) reacting aniline with formaldehyde in the presence of an acid, b) neutralizing the acid with ammonia, c) separating the reaction mixture from step b) into an aqueous phase and an organic phase, d) treating the aqueous phase obtained in step c) with an oxide or hydroxide of an alkaline earth metal, e) separating off the ammonia obtained in step d).

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 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 invention relates to processes for preparing 1,6-hexanediol and very pure ?-caprolactone from a dicarboxylic acid solution (DCS), comprising the steps of (a) esterification of the DCS with alcohols, (b) partial catalytic hydrogenation of the esters, (c) distillative removal of 1,6-hexanediol and low boilers as the top product, and (d) cyclization of the 6-hydroxycaproic ester present in the bottoms fraction in the presence of a higher-boiling alcohol than caprolactone.

Abstract: The invention relates to a process for preparing methylenediphenyldiamine (MDA) by reacting formaldehyde and aniline in the presence of an acidic catalyst, wherein the oxygen content in the process for preparing MDA is <10 000 ppm, based on all compounds present in the process. The invention further relates to the phosgenation of MDA to methylenediphenyl diisocyanate (MDI).

Abstract: The invention relates to a process for preparing reactive zinc by electrochemical reduction, wherein iron or steel is used as cathode material.

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 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 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 process for preparing phenylalkan-1-ols in three stages, where an ester condensation in the presence of alkali metal or alkaline earth metal alcoholates is carried out in the first stage.

Abstract: The present invention provides a process for preparing lactones from optionally substituted, saturated aliphatic diols having from five to 20 carbon atoms between the two ring-closing hydroxyl groups by catalytic dehydrogenation and cyclization in the liquid phase over at least one catalyst.

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 invention relates to a process for recovering acids from product streams of organic syntheses, which comprises the steps a) neutralization of the acid with a base, b) removal of the base by means of adsorption, c) recovery of the acid.

Abstract: The present invention provides a process for preparing ?-caprolactone in a purity above 99%, in which 6-hydroxycaproic ester comprising from 0.5 to 40% by weight of adipic diester is cyclized in the gas phase at from 150 to 450° C. in the presence of oxidic catalysts and ?-caprolactone is obtained from the cyclization product by distillation.