The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

The present invention relates to a process for separating 1-methoxypropan-2-ol in a stream S3 from an aqueous stream comprising 1-methoxypropan-2-ol and 2-methoxypropan-1-ol, wherein the process comprises providing a stream S0 comprising 1-methoxypropan-2-ol, 2-methoxypro-pan-1-ol and water, and having a molar ratio of 1-methoxypropan-2-ol:2-methoxypropan-1-ol in the range of from 1:5 to 5:1. A further aspect of the invention also relates to 1-methoxypropan-2-ol obtained or obtainable from said process, as well as to a mixture of 1-methoxypropan-2-ol and 2-methoxypropan-1-ol, preferably obtained or obtainable from said process, which preferably comprises in the range of from 95 to 100 weight-% 1-methoxypropan-2-ol and ≤0.5 weight-% of 2-methoxypropan-1-ol, each based on the total weight of the mixture.

The present invention relates to a process for separating 1-methoxypropan-2-ol in a stream S3 from an aqueous stream comprising 1-methoxypropan-2-ol and 2-methoxypropan-1-ol, wherein the process comprises providing a stream S0 comprising 1-methoxypropan-2-ol, 2-methoxypro-pan-1-ol and water, and having a molar ratio of 1-methoxypropan-2-ol:2-methoxypropan-1-ol in the range of from 1:5 to 5:1. A further aspect of the invention also relates to 1-methoxypropan-2-ol obtained or obtainable from said process, as well as to a mixture of 1-methoxypropan-2-ol and 2-methoxypropan-1-ol, preferably obtained or obtainable from said process, which preferably comprises in the range of from 95 to 100 weight-% 1-methoxypropan-2-ol and ≤0.5 weight-% of 2-methoxypropan-1-ol, each based on the total weight of the mixture.

The invention provides a process for refining non-petroleum based ethylene glycol, wherein impurities having a boiling point close to that of ethylene glycol are separated. In the process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic agent together with the non-petroleum based ethylene glycol to obtain an azeotrope containing ethylene glycol. Then the azeotropic agent in the azeotrope is separated and removed to obtain an ethylene glycol crude product which is further purified to obtain ethylene glycol.

The invention provides a process for refining non-petroleum based ethylene glycol, wherein impurities having a boiling point close to that of ethylene glycol are separated. In the process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic agent together with the non-petroleum based ethylene glycol to obtain an azeotrope containing ethylene glycol. Then the azeotropic agent in the azeotrope is separated and removed to obtain an ethylene glycol crude product which is further purified to obtain ethylene glycol.

The invention provides a process for refining non-petroleum based ethylene glycol, wherein impurities having a boiling point close to that of ethylene glycol are separated. In the process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic agent together with the non-petroleum based ethylene glycol to obtain an azeotrope containing ethylene glycol. Then the azeotropic agent in the azeotrope is separated and removed to obtain an ethylene glycol crude product which is further purified to obtain ethylene glycol.

The present disclosure provides for organic solvent production via distillation and dehydration by: directing portions of a feed stream to a first and second distillation columns operating at a different pressures from each other, wherein the organic solvent is preferably an alcohol and more preferably ethanol; generating, in the first distillation column, a vaporous first overhead stream; directing the vaporous first overhead stream directly to a rectification system; generating, in the second distillation column, a vaporous second overhead stream; forming a condensed second overhead stream from the vaporous second overhead stream; directing, at least a portion of the condensed second overhead stream to the rectification system; generating, via the rectification system, a third overhead stream; directing at least a portion of the third overhead stream to a separation system; and generating, in the separation system, an enriched solvent stream.

The present disclosure provides for organic solvent production via distillation and dehydration by: directing portions of a feed stream to a first and second distillation columns operating at a different pressures from each other, wherein the organic solvent is preferably an alcohol and more preferably ethanol; generating, in the first distillation column, a vaporous first overhead stream; directing the vaporous first overhead stream directly to a rectification system; generating, in the second distillation column, a vaporous second overhead stream; forming a condensed second overhead stream from the vaporous second overhead stream; directing, at least a portion of the condensed second overhead stream to the rectification system; generating, via the rectification system, a third overhead stream; directing at least a portion of the third overhead stream to a separation system; and generating, in the separation system, an enriched solvent stream.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.