摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The invention relates to a process for preparing ε-caprolactone from 6-hydroxycaproic ester in the gas phase in the presence of activated carbon as a catalyst and subsequent distillation.
摘要:
The present invention provides an integrated process for continuously preparing 1,4-butanediol, which comprises the following stages: (I) reacting formaldehyde with acetylene in the presence of a copper catalyst at a pH of from 5 to 8 and a molar ratio of formaldehyde to acetylene of at most 2:1, (II) intermediately buffering the resulting butynediol-containing aqueous mixture for from 0.1 to 100 h, (III) hydrogenating the mixture obtained after the intermediate buffering and (IV) distilling the hydrogenation product obtained in stage III to obtain 1,4-butanediol.
摘要:
The present invention provides a process for distillatively purifying crude aqueous 1,4-butanediol (1), in which 1,4-butanediol (5) freed of components having lower boiling points than 1,4-butanediol and water is passed through three distillation columns (III, IV, V), components having a higher boiling point than 1,4-butanediol are drawn off from the bottom of the first column and conducted into the third (7), 1,4-butanediol from the top of the first column (6) is conducted into the second, the bottom product of the second column (9) is conducted into the third, the top product of the third column (11) is recycled at least partly into the first column, wherein the very pure 1,4-butanediol is withdrawn from a side draw of the second column.
摘要:
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.
摘要:
The present invention relates to a process for purifying 1,4-butynediol, which comprises compressing 1,4-butynediol to from 50 to 1500 bar, depressurizing it, waiting for phase separation to occur after depressurization and separating off the bottom phase, and a process for the hydrogenation of 1,4-butynediol to 1,4-butenediol and 1,4-butanediol using the purified 1,4-butynediol.
摘要:
The present invention relates to processes for making 1,4-butanediol, 1,4-butenediol, or a mixture thereof by processing 1,4-butynediol in a dynamic mixing apparatus in an inert gas atmosphere at from 25 to 150° C. at a shear rate in the radial gap between rotor and stator of the mixing apparatus of more than 100 000 sec−1; phase separating the processed 1,4-butynediol at a temperature of from 25 to 150° C.; removing a bottom phase to obtain purified 1,4-butynediol; and reacting the purified 1,4-butynediol with hydrogen in the presence of a catalyst.