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.

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 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 present disclosure relates to the technical field of hexanediol production, and provides a production method and a production device of high-purity 1,6-hexanediol. A dipic acid and a C.sub.6 mixed alcohol are mixed to conduct esterification to obtain a product feed liquid including an adipic acid diester, and the high-purity 1,6-hexanediol is obtained through hydrogenation reduction and distillation. In addition to being used as a reaction raw material, the C.sub.6 mixed alcohol further acts as a water-carrying agent; water produced by the esterification is removed by azeotropy, thereby promoting a smooth reaction process to realize the esterification without a catalyst. The method does not need the catalyst during esterification, and the subsequent hydrogenation reduction can be directly conducted with no complicated post-treatment procedure required after the esterification. In addition, the method has simple preparation steps, recyclable C.sub.6 mixed alcohol, less wastewater production, desirable environmental protection, and high product purity and yield.

The present disclosure relates to the technical field of hexanediol production, and provides a production method and a production device of high-purity 1,6-hexanediol. A dipic acid and a C.sub.6 mixed alcohol are mixed to conduct esterification to obtain a product feed liquid including an adipic acid diester, and the high-purity 1,6-hexanediol is obtained through hydrogenation reduction and distillation. In addition to being used as a reaction raw material, the C.sub.6 mixed alcohol further acts as a water-carrying agent; water produced by the esterification is removed by azeotropy, thereby promoting a smooth reaction process to realize the esterification without a catalyst. The method does not need the catalyst during esterification, and the subsequent hydrogenation reduction can be directly conducted with no complicated post-treatment procedure required after the esterification. In addition, the method has simple preparation steps, recyclable C.sub.6 mixed alcohol, less wastewater production, desirable environmental protection, and high product purity and yield.

Provided are: a semiconductor treatment liquid comprising high-purity isopropyl alcohol, wherein the concentration of the oxolane compound expressed in formula (1) below when held for 60 days in a nitrogen atmosphere at 50° C. in a SUS304 container is 25 ppb or less on a mass basis in relation to the isopropyl alcohol; and a method for manufacturing said semiconductor treatment liquid. In the formula, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-3 alkyl group, and the total number of carbon atoms in R.sup.1 and R.sup.2 is 3 or less. R.sup.3 represents a hydrogen atom or an isopropyl group.

Provided are: a semiconductor treatment liquid comprising high-purity isopropyl alcohol, wherein the concentration of the oxolane compound expressed in formula (1) below when held for 60 days in a nitrogen atmosphere at 50° C. in a SUS304 container is 25 ppb or less on a mass basis in relation to the isopropyl alcohol; and a method for manufacturing said semiconductor treatment liquid. In the formula, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-3 alkyl group, and the total number of carbon atoms in R.sup.1 and R.sup.2 is 3 or less. R.sup.3 represents a hydrogen atom or an isopropyl group.

Provided are: a semiconductor treatment liquid comprising high-purity isopropyl alcohol, wherein the concentration of the oxolane compound expressed in formula (1) below when held for 60 days in a nitrogen atmosphere at 50° C. in a SUS304 container is 25 ppb or less on a mass basis in relation to the isopropyl alcohol; and a method for manufacturing said semiconductor treatment liquid. In the formula, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-3 alkyl group, and the total number of carbon atoms in R.sup.1 and R.sup.2 is 3 or less. R.sup.3 represents a hydrogen atom or an isopropyl group.