A process for the production of a high purity first diol from a product stream comprising two or more C2 to C7 diols, said process comprising the steps of: (i) providing the product stream to a first distillation column; (ii) providing an extractant selected from the group of C3 to C6 sugar alcohols and mixtures thereof to the first distillation column; (iii) operating the first distillation column to obtain a first bottoms stream comprising at least a first diol and the extractant; (iv) providing the first bottoms stream to a second distillation column operating to obtain a second top stream comprising the first diol and diols with atmospheric boiling points at least 10° C. higher than the first diol, and (v) providing the second top stream to a third distillation column to obtain a third top stream comprising the first diol; wherein the product stream comprises 0.1 to 10 wt % of diols with atmospheric boiling points at least 10° C. higher than the first diol, calculated upon the total weight of C2 to C7 diols in the product stream.

A process for the production of a high purity first diol from a product stream comprising two or more C2 to C7 diols, said process comprising the steps of: (i) providing the product stream to a first distillation column; (ii) providing an extractant selected from the group of C3 to C6 sugar alcohols and mixtures thereof to the first distillation column; (iii) operating the first distillation column to obtain a first bottoms stream comprising at least a first diol and the extractant; (iv) providing the first bottoms stream to a second distillation column operating to obtain a second top stream comprising the first diol and diols with atmospheric boiling points at least 10° C. higher than the first diol, and (v) providing the second top stream to a third distillation column to obtain a third top stream comprising the first diol; wherein the product stream comprises 0.1 to 10 wt % of diols with atmospheric boiling points at least 10° C. higher than the first diol, calculated upon the total weight of C2 to C7 diols in the product stream.

A process for the production of a high purity first diol from a product stream comprising two or more C2 to C7 diols, said process comprising the steps of: (i) providing the product stream to a first distillation column; (ii) providing an extractant selected from the group of C3 to C6 sugar alcohols and mixtures thereof to the first distillation column; (iii) operating the first distillation column to obtain a first bottoms stream comprising at least a first diol and the extractant; (iv) providing the first bottoms stream to a second distillation column operating to obtain a second top stream comprising the first diol and diols with atmospheric boiling points at least 10° C. higher than the first diol, and (v) providing the second top stream to a third distillation column to obtain a third top stream comprising the first diol; wherein the product stream comprises 0.1 to 10 wt % of diols with atmospheric boiling points at least 10° C. higher than the first diol, calculated upon the total weight of C2 to C7 diols in the product stream.

The present invention provides a process for recovering glycol from a process stream comprising glycol, water, dissolved salts, and hydrocarbons. The process comprises subjecting the process stream to a salt-enrichment process to obtain a salt-enriched stream having a salt concentration higher than salt concentration of the process stream, and a salt-reduced stream; subjecting the salt-enriched stream to a glycol reclaiming process to separate the salts and at least a portion of the hydrocarbons from the salt enriched stream to obtain a substantially salt-free water-glycol stream; and blending the salt reduced stream from the salt-enrichment process with the substantially salt-free stream to produce a reclaimed water-glycol stream

The present invention provides a process for recovering glycol from a process stream comprising glycol, water, dissolved salts, and hydrocarbons. The process comprises subjecting the process stream to a salt-enrichment process to obtain a salt-enriched stream having a salt concentration higher than salt concentration of the process stream, and a salt-reduced stream; subjecting the salt-enriched stream to a glycol reclaiming process to separate the salts and at least a portion of the hydrocarbons from the salt enriched stream to obtain a substantially salt-free water-glycol stream; and blending the salt reduced stream from the salt-enrichment process with the substantially salt-free stream to produce a reclaimed water-glycol stream

Provided is a method capable of manufacturing high-purity 1,3-butylene glycol having a high potassium permanganate test value, a very low content of low boiling point components, and a high initial boiling point with a high recovery rate.

The method for manufacturing 1,3-butylene is a method for obtaining purified 1,3-butylene glycol from a crude reaction liquid containing 1,3-butylene glycol. In a dehydration column used in a dehydration step, a liquid feed containing 1,3-butylene glycol and water with an acetaldehyde content of 1000 ppm or lower and a crotonaldehyde content of 400 ppm or lower is distilled under a condition of a reflux ratio of higher than 0.3, and a liquid concentrated with a low boiling point component containing water is distilled off from above a feed tray. In a product column used in a product distillation step, a 1,3-butylene glycol liquid feed with an acetaldehyde content of 500 ppm or lower and a crotonaldehyde content of 200 ppm or lower is distilled under a condition of a reflux ratio of higher than 0.1.

Provided is a method capable of yielding high-purity 1,3-butylene glycol having a very low content of a low boiling point component and a high initial boiling point, with a high recovery ratio. A reaction crude liquid containing 1,3-butylene glycol is subjected to product distillation to yield purified 1,3-butylene glycol, through dehydration including removing water by distillation and performing high boiling point component removal including removing a high boiling point component by distillation. A method for producing 1,3 butylene glycol, the method including: distilling a charged liquid having a water content of 1.2 wt.% or less in a product column for use in the product distillation under a condition of a reflux ratio of greater than 0.1; distilling off a liquid in which a low boiling point component is concentrated from above a charging plate; and extracting 1,3-butylene glycol from below the charging plate.

A system for producing ethanol comprises a rectifier column that receives a first process stream comprising from about 42% to about 60% ethanol, wherein the rectifier column purifies the first process stream to provide an ethanol product stream that is at least about 90% ethanol, and one or more evaporators configured to evaporate water from a second process stream, wherein the one or more evaporators generate vapor, and wherein at least a portion of the vapor supplies heat energy for separation of ethanol from water in the rectifier column.

A system for producing ethanol comprises a rectifier column that receives a first process stream comprising from about 42% to about 60% ethanol, wherein the rectifier column purifies the first process stream to provide an ethanol product stream that is at least about 90% ethanol, and one or more evaporators configured to evaporate water from a second process stream, wherein the one or more evaporators generate vapor, and wherein at least a portion of the vapor supplies heat energy for separation of ethanol from water in the rectifier column.

A high-purity 1,3-butylene glycol product that is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and/or unlikely to cause an acid concentration increase over time when the product is left in a state containing water is provided. A 1,3-butylene glycol product containing 1,3-butylene glycol, wherein, after the 1,3-butylene glycol product has been kept at 180° C. for 3 hours in air atmosphere, at least one of contents of compounds represented by the following Formula (A) or (B) is less than 8 ppm. In the following formula, R.sup.1 to R.sup.4 are the same as or different from each other, and each of R.sup.1 to R.sup.4 is a hydrogen atom, an alkyl group which has from 1 to 4 carbon atoms and may be substituted with a hydroxy group, or an alkenyl group which has from 2 to 4 carbon atoms and may be substituted with a hydroxy group.