Abstract: 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.

Abstract: 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. A method for manufa.cturing 1,3-butylene glycol 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 the 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, and a liquid concentrated with a low boiling point component containing water is distilled off from above a feed plate; and in a product column used in the product distillation step, a 1,3-butylene glycol liquid feed having 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.

Abstract: 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.