催化反应精馏法连续制备N,N-二甲基乙酰胺

Synthesis Continuous Technology on N,N-Dimethylacetamide through Catalysis Reaction Rectification

以路易斯酸为催化剂,醋酸-二甲胺为原料,催化反应精馏法合成 N,N-二甲基乙酰胺,研究并确定了该方法的最佳工艺参数。结果表明,在催化剂的质量分数 3%、n(二甲胺):n(醋酸)为(2.10～2.30):1、反应温度 170 ℃、反应时间为 8 h 时,所得精馏产品总收率大于72%,选择性大于 96%,醋酸转化率接近 100%。该合成工艺条件相对温和、操作弹性大、反应时间短、副产品少、三废污染少,特别是反应与精馏单元操作的部分耦合,简化了工艺流程。

N,N-dimethylacetamide is synthesized by catalysis reaction rectification method,Lewis acid is used as the catalyst,acetic acid and dimethylamine as raw material.Results show that when the mass concentration fraction quality of the catalyst is 3%,n(dimethylamine):n(acetic acid) is(2.10～2.30):1,reaction temperature is 170 ℃,reaction duration is 8 h,rate of fine product is more than 72%,selectivity exceeds 96% under the best process condition.Transition rate of the acetic acid approaches 100%.The process condition is relatively moderate,operation elasticity large,reaction duration short by-product much few,no three waste polluction.Especially technology of rectification is adopted,the rate of product,slectivity and transition rate are enhanced,operation process of the product separation is greatly simplified.