响应面法优化反应精馏合成N,N-二甲基乙酰胺工艺研究

Synthesis process of N,N-dimethylacetamide via reactive distillation using response surface methodology

N,N-二甲基乙酰胺是应用广泛的高沸点、非质子化溶剂,采用反应精馏技术合成N,N-二甲基乙酰胺,改进了传统的醋酸法工艺,考察了催化剂质量分数、回流比、反应温度和二甲胺/醋酸摩尔比等因素对N,N-二甲基乙酰胺收率的影响。在单因素实验的基础上,通过响应面分析实验确定反应精馏合成N,N-二甲基乙酰胺的最佳工艺条件为:催化剂质量为醋酸质量的3%,回流比为2.8∶1,反应温度为172℃,二甲胺/醋酸摩尔比为1.4∶1,此时,N,N-二甲基乙酰胺的收率可达93.34%。

N,N-dimethylacetamide（ DMAC） is widely used in the fields of petroleum processing and industrial organic synthesis as an aprotic organic solvent with high boiling point. A reactive distillation method is applied to replace traditional process to synthesize DMAC. The effects of the concentration of catalyst,reflux ratio,reaction temperature and ratio of n（ dimethylamine） and n（ acetic acid） on the yield of DMAC are studied. The optimum process condition is determined by response surface methodology based on one-factor experiment,which are shown as follows： 3% mass fraction of catalyst,2. 8 of reflux ratio,172℃ of reaction temperature and 1. 4 of n（ dimethylamine） / n（ acetic acid）.Under the optimal condition,the yield of DMAC can research about 93. 34%.