The invention relates to a process for the preparation of a deuterated ethanol from an acetic acid, an acetate, or an amide by reaction with D.sub.2 in the presence of a transition metal catalyst.

The invention provides a process for the separation of a diol from a product stream. The process includes the steps of: i) separating the product stream comprising three or more C2 to C6 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, to produce a first stream comprising the three or more C2 to C6 diols; ii) separating the first stream comprising the three or more C2 to C6 diols into a) a second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group and b) a third stream comprising two or more diols; iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream.

The invention provides a process for the separation of a diol from a product stream. The process includes the steps of: i) separating the product stream comprising three or more C2 to C6 diols, C3 to C6 sugar alcohols, and C4 to C6 polyhydric alcohols with at least 3 hydroxyl groups in the molecule, and a catalyst, to produce a first stream comprising the three or more C2 to C6 diols; ii) separating the first stream comprising the three or more C2 to C6 diols into a) a second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group and b) a third stream comprising two or more diols; iii) hydrogenating the second stream comprising a first diol and unsaturated hydrocarbons and/or one or more compounds with a carbonyl group to provide a purified diol stream.

The present disclosure provides a method for co-producing a xylitol and a caramel pigment. The method includes: transporting a raw material of a xylose mother liquid in a raw material tank to a filter for filtering impurities to obtain a filtered raw material of the xylose mother liquid, and transporting the filtered raw material of the xylose mother liquid to a nanofiltration membrane device to obtain a decolorized xylose mother liquid; transporting the decolorized xylose mother liquid to a first ion exchange device to obtain an ion exchange liquid; and transporting the ion exchange liquid to a chromatographic separation device and obtaining an extracted liquid and a raffinate liquid; performing a refined hydrogenation process on the extracted liquid through a refined hydrogenation assembly to obtain a crystal xylitol, and performing a browning reaction process on the raffinate liquid through a browning reaction assembly to obtain the caramel pigment.

The present disclosure provides a method for co-producing a xylitol and a caramel pigment. The method includes: transporting a raw material of a xylose mother liquid in a raw material tank to a filter for filtering impurities to obtain a filtered raw material of the xylose mother liquid, and transporting the filtered raw material of the xylose mother liquid to a nanofiltration membrane device to obtain a decolorized xylose mother liquid; transporting the decolorized xylose mother liquid to a first ion exchange device to obtain an ion exchange liquid; and transporting the ion exchange liquid to a chromatographic separation device and obtaining an extracted liquid and a raffinate liquid; performing a refined hydrogenation process on the extracted liquid through a refined hydrogenation assembly to obtain a crystal xylitol, and performing a browning reaction process on the raffinate liquid through a browning reaction assembly to obtain the caramel pigment.

The present disclosure provides a method for co-producing a xylitol and a caramel pigment. The method includes: transporting a raw material of a xylose mother liquid in a raw material tank to a filter for filtering impurities to obtain a filtered raw material of the xylose mother liquid, and transporting the filtered raw material of the xylose mother liquid to a nanofiltration membrane device to obtain a decolorized xylose mother liquid; transporting the decolorized xylose mother liquid to a first ion exchange device to obtain an ion exchange liquid; and transporting the ion exchange liquid to a chromatographic separation device and obtaining an extracted liquid and a raffinate liquid; performing a refined hydrogenation process on the extracted liquid through a refined hydrogenation assembly to obtain a crystal xylitol, and performing a browning reaction process on the raffinate liquid through a browning reaction assembly to obtain the caramel pigment.

Process for preparing monoethylene glycol (MEG) by metal-catalyzed reaction of a dialkyl oxalate of the formula I ##STR00001##
where R.sup.1 and R.sup.2 are each, independently of one another, methyl, ethyl, n-propyl or isopropyl, with hydrogen (H.sub.2), wherein the dialkyl oxalate (I) is used as melt or as a solution in a solvent, dialkyl oxalate (I) and H.sub.2 are used in a molar ratio of H.sub.2:dialkyl oxalate (I) in the range from 4.0 to 30 and the reaction is carried out continuously in a reactor at a cross-sectional loading of 10 m/s, a temperature in the range from 150 to 270 C., a pressure in the range from 150 to 390 bar and in the presence of a chromium-free heterogeneous catalyst comprising copper.

Process for preparing monoethylene glycol (MEG) by metal-catalyzed reaction of a dialkyl oxalate of the formula I ##STR00001##
where R.sup.1 and R.sup.2 are each, independently of one another, methyl, ethyl, n-propyl or isopropyl, with hydrogen (H.sub.2), wherein the dialkyl oxalate (I) is used as melt or as a solution in a solvent, dialkyl oxalate (I) and H.sub.2 are used in a molar ratio of H.sub.2:dialkyl oxalate (I) in the range from 4.0 to 30 and the reaction is carried out continuously in a reactor at a cross-sectional loading of 10 m/s, a temperature in the range from 150 to 270 C., a pressure in the range from 150 to 390 bar and in the presence of a chromium-free heterogeneous catalyst comprising copper.

A process of purifying 1,4-butanediol (1,4-BDO) from a fermentation broth including separating solid materials, salts and water, and subjecting the resulting material to a two, three or four column distillation system, that can include a wiped film evaporator to produce a purified 1,4-butanediol product.

A process of purifying 1,4-butanediol (1,4-BDO) from a fermentation broth including separating solid materials, salts and water, and subjecting the resulting material to a two, three or four column distillation system, that can include a wiped film evaporator to produce a purified 1,4-butanediol product.