Method for manufacturing 1,3-butylene glycol, and 1,3-butylene glycol product

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 comprising:

• 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 dehydration step, a dehydration column is used in which 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 where a reflux ratio is greater than 0.3 and not greater than 100, and a liquid concentrated with a low boiling point component containing water is distilled off from above a feed plate, and
• in the product distillation step, a product column is used in which 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, a liquid concentrated with a low boiling point component is distilled off from above a feed plate, and 1,3-butylene glycol is extracted from below the feed plate.