Abstract:
The invention relates to a method for producing 1,6-hexanediol and caprolactone, preferably of at least 99.5% purity, which are especially substantially free from 1,4 cyclohexanediols, starting from a carboxylic acid mixture which is obtained as a byproduct of the catalytic oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or gases containing oxygen and by extraction of the reaction mixture with water, and by hydrogenation of the carboxylic acid mixture, esterification and hydrogenation of a partial flow to hexanediol and cyclization of 6-hydroxycaproic ester, the 1,4-cyclohexanediols being removed during fractionation of the esterification mixture or finally from the caprolactone.
Abstract:
The invention relates to a method for producing ε-caprolacton at a purity of 99%, wherein 6-hydroxycaproic acid ester having 0.5 to 40 weight % adipic acid diesters is cyclisized in the gas phase at 150 to 450˚C in the presence of oxidic catalysts, and ε-caprolacton is obtained by distillation of the cyclisization product.
Abstract:
The invention relates to a method for producing methylene diphenyl diamine (MDA) by reacting formaldehyde and aniline in the presence of an acidic catalyst, characterized in that in the production of MDA, the oxygen content in the process is
Abstract:
The invention relates to a method for producing 1,6-hexanediol, preferably of at least 99.5% purity, which hexanediol is especially substantially free from 1,4 cyclohexanediols, starting from a carboxylic acid mixture which is obtained as a byproduct of the catalytic oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or gases containing oxygen and by extraction of the reaction mixture with water, and by hydrogenation of the carboxylic acid mixture, esterification and hydrogenation of a partial flow to hexanediol.
Abstract:
The present invention relates to a method for producing phenylalkane-1-ols 5 using three steps, wherein in the first step an ester condensation is carried out in the presence of alkali or alkaline earth alcoholates.
Abstract:
The invention relates to a method for the recovery of diphenylmethane diamine, comprising the steps of A) reaction of aniline with formaldehyde in the presence of a mineral acid, B) neutralization of the mineral acid with a base, C) separation of the organic and inorganic phase, D) removal of the base from the inorganic phase by adsorption, c) recovery of the mineral acid.