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 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.

Provided is a method capable of manufacturing 1,3-butylene glycol having a high potassium permanganate test value. A method for manufacturing 1,3-butylene glycol, which is a method for obtaining purified 1,3-butylene glycol from a crude reaction liquid containing 1,3-butylene glycol, the method including: a dehydration step of removing water by distillation; a high boiling substance removal step of removing a high boiling point component by distillation; and a product distillation step of obtaining purified 1,3-butylene glycol, wherein in the product distillation step, a product column is used in which a liquid feed having a 1,3-butylene glycol concentration of 97% or higher, 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, and a liquid concentrated with acetaldehyde and crotonaldehyde is distilled off from above a feed plate, and 1,3-butylene glycol is extracted from below the feed plate.

A high-purity 1,3-butylene glycol product is provided, which is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water. A 1,3-butylene glycol product in which at least one of a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm.

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 liquid feed containing 1,3-butylene glycol 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 high boiling point component and a low dry point, with a high recovery ratio. A method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol, in which, in a high boiling point component removal column for use in the removing a high boiling point component, a charged liquid containing 1,3 -butylene glycol is distilled under conditions that (i) a reflux ratio is greater than 0.02 in a case where a concentration of 1,3-butylene glycol in the charged liquid is 95% or less, or a reflux ratio is greater than 0.01 in a case where the concentration of 1,3-butylene glycol in the charged liquid is greater than 95%, and (ii) a bottom ratio of less than 30 wt. %, high-purity 1,3-butylene glycol is distilled off from above a charging plate, and a liquid in which a high boiling point component is concentrated is extracted from below the charging plate.

Aspects of the present invention relate to systems and processes for obtaining desired mercaptans or thiophenes from a feed stream containing a mixture of mercaptans, thiophenes and other components. In one aspect of the invention, a system for separating one or more components from a feed stream of mixed mercaptans includes one or more distillation columns in connection with a feed containing mercaptans, the distillation column having a rectification section, a stripping section, and a feed side section separated from a side draw section by a dividing wall that extends from the rectification section to the stripping section. The distillation column further being in connection with a condenser and a reboiler; and a distillate stream, a side drawn stream, and a bottoms stream.

The use transmission/absorbance of visible light to determine accurate separation of distillation products emerging from a condenser is described. Changes in wavelength and intensity of light transmitted through or absorbed by the distillate, post condenser, determine when a new fraction passes through the condenser, and may be directed to an appropriate collection vessel.

An installation and a process which jointly implement compression of acid gases from a hydroconversion or hydrotreatment unit and gaseous effluents from a catalytic cracking unit.