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 relates to a process for the preparation of a deuterated ethanol from ethanol, D.sub.2O, a ruthenium catalyst, and a co-solvent.

The invention relates to a process for the preparation of a deuterated ethanol from ethanol, D.sub.2O, a ruthenium catalyst, and a co-solvent.

The invention relates to a process for the preparation of a deuterated ethanol from ethanol, D.sub.2O, a ruthenium catalyst, and a co-solvent.

The invention relates to a process for the preparation of a deuterated ethanol from ethanol, D.sub.2O, a ruthenium catalyst, and a co-solvent.

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.

A crude product stream of 1,4-butandiol and one or more of -butyrolactone, 2-(4-hydroxybutoxy)-tetrahydrofuran, 4-hydroxybutyl(4-hydroxybutyrate), and 3-(4-hydroxybutoxy)-tetrahydrofuran is supplied to a first distillation column. A side-draw of 1,4-butanediol and light components is removed, with the light components including at least some of those produced by reaction in the first distillation column. The stream is passed to a hydrogenation zone and subjected to hydrogenation in the presence of a hydrogenation catalyst. A 1,4-butanediol product stream having a reduced content of 2-(4-hydroxybutoxy)-tetrahydrofuran is recovered and passed to a second distillation column operated such that (4-hyroxybutyl)-4-hydroxybutyrate is removed as a bottom stream and a 1,4-butanediol stream is removed as overhead. The overhead stream removed is passed to a third distillation column and a purified 1,4-butanediol stream is recovered.

A crude product stream of 1,4-butandiol and one or more of -butyrolactone, 2-(4-hydroxybutoxy)-tetrahydrofuran, 4-hydroxybutyl(4-hydroxybutyrate), and 3-(4-hydroxybutoxy)-tetrahydrofuran is supplied to a first distillation column. A side-draw of 1,4-butanediol and light components is removed, with the light components including at least some of those produced by reaction in the first distillation column. The stream is passed to a hydrogenation zone and subjected to hydrogenation in the presence of a hydrogenation catalyst. A 1,4-butanediol product stream having a reduced content of 2-(4-hydroxybutoxy)-tetrahydrofuran is recovered and passed to a second distillation column operated such that (4-hyroxybutyl)-4-hydroxybutyrate is removed as a bottom stream and a 1,4-butanediol stream is removed as overhead. The overhead stream removed is passed to a third distillation column and a purified 1,4-butanediol stream is recovered.

A crude product stream of 1,4-butandiol and one or more of -butyrolactone, 2-(4-hydroxybutoxy)-tetrahydrofuran, 4-hydroxybutyl(4-hydroxybutyrate), and 3-(4-hydroxybutoxy)-tetrahydrofuran is supplied to a first distillation column. A side-draw of 1,4-butanediol and light components is removed, with the light components including at least some of those produced by reaction in the first distillation column. The stream is passed to a hydrogenation zone and subjected to hydrogenation in the presence of a hydrogenation catalyst. A 1,4-butanediol product stream having a reduced content of 2-(4-hydroxybutoxy)-tetrahydrofuran is recovered and passed to a second distillation column operated such that (4-hyroxybutyl)-4-hydroxybutyrate is removed as a bottom stream and a 1,4-butanediol stream is removed as overhead. The overhead stream removed is passed to a third distillation column and a purified 1,4-butanediol stream is recovered.

The embodiment of the present disclosure provides a system for co-producing a xylitol and a caramel pigment by utilizing a xylose mother liquid, including an extraction assembly, a refined hydrogenation assembly and a browning reaction assembly. The extraction assembly is configured to obtain an extracted liquid and a raffinate liquid respectively by performing an initial extraction on the xylose mother liquid; the refined hydrogenation assembly is configured to prepare a crystal xylitol by performing a refined hydrogenation process on the extracted liquid; the browning reaction assembly is configured to prepare the caramel pigment by performing a browning reaction process on the raffinate liquid.