Method for removal of MW176 cyclic acetal formed during the production of 1,3-propanediol
申请人:——
公开号:US20040087818A1
公开(公告)日:2004-05-06
The present invention is an improvement upon the process for the production of 1,3-propanediol (PDO) wherein an aqueous solution of 3-hydroxypropanal (HPA) is formed, and the HPA is subjected to hydrogenation to produce a crude PDO mixture comprising PDO, water, MW176 acetal, and high and low volatility materials, wherein the crude PDO mixture is dried to produce a first overhead stream comprising water and some high volatility materials and a dried crude PDO mixture as a first distillate bottoms stream comprising PDO, MW176 acetal, and low volatility materials, and wherein the dried crude PDO mixture is distilled to produce a second overhead stream comprising some high volatility materials, a middle stream comprising PDO and MW176 acetal, and a second distillate bottoms stream comprising PDO and low volatility materials. The improvement on this process comprises treating the crude PDO mixture and/or the dried crude PDO mixture and/or the PDO product with an acidic zeolite, an acid form cation exchange resin, or a soluble acid to convert the MW176 cyclic acetal to more volatile materials which can be easily separated from PDO by distillation.
本发明是对生产1,3-丙二醇(PDO)的工艺的改进,其中形成3-羟基丙醛(HPA)的水溶液,然后对HPA进行加氢以产生包含PDO、水、MW176缩醛以及高挥发性和低挥发性材料的粗PDO混合物,其中将粗PDO混合物干燥以产生第一顶部流包括水和一些高挥发性材料,以及干燥的粗PDO混合物作为第一馏分底流包括PDO、MW176缩醛和低挥发性材料,然后将干燥的粗PDO混合物蒸馏以产生第二顶部流包括一些高挥发性材料,一个中间流包括PDO和MW176缩醛,以及第二馏分底流包括PDO和低挥发性材料。对这个工艺的改进包括处理粗PDO混合物和/或干燥的粗PDO混合物和/或PDO产品与酸性沸石、酸性阳离子交换树脂或可溶性酸,将MW176环缩醛转化为更易通过蒸馏与PDO分离的挥发性材料。