| 摘要 |
<p>The present invention is a process for purification of 1,3-propanediol (PDO) by an inverted distillation sequence which comprises: (a) optionally removing water or other solvents from the crude 1,3-propanediol mixture; (b) distilling the crude 1,3-propanediol mixture under conditions which maximize the separation of components of the mixture which are heavier than 1,3-propanediol from the 1,3-propanediol and the components which are lighter than 1,3-propanediol; (c) drawing off a stream which contains at least most of the 1,3-propanediol and at least some of the components of the mixture which are lighter than 1,3-propanediol; and (d) distilling the stream of (c) to separate the 1,3-propanediol from components in the stream which are lighter than 1,3-propanediol and any residual components which are heavier than 1,3-propanediol.</p> |
