催化精馏合成N-异丙基苯胺

在Joback基团贡献法估算反应的G ibbs函数的基础上,得到了异丙醇与苯胺合成N-异丙基苯胺的平衡常数与反应温度的关系式。研究了回流比、异丙醇与苯胺的摩尔比、塔釜操作温度、苯胺进料口位置距塔顶的距离对异丙醇与苯胺催化精馏合成N-异丙基苯胺的影响,确定了适宜的工艺条件:回流比2.5~3.5、异丙醇与苯胺的摩尔比1.5、塔釜操作温度223℃、苯胺进料口位置距塔顶300~400mm。在优化条件下,苯胺的转化率可达到99%,N-异丙基苯胺的选择性可达到99.5%,N-异丙基苯胺的质量分数可稳定在98.8%以上。

Synthesis of N-Isopropylaniline by Catalytic Distillation

N-isopropylaniline was an important intermediate for pesticides,medicines and dyes.Its synthesis from aniline and isopropanol was studied by catalytic distillation over Cu-Cr/Al_2O_3 catalyst.By calculating Gibbs free energy change of the reaction and by means of Joback group contribution,correlation of reaction equilibrium constant with reaction temperature was obtained.Effects of reflux ratio,mole ratio of isopropanol to aniline,column bottom temperature and feeding location of aniline on conversion of aniline were investigated.Under optimal conditions:reflux ratio 2.5-3.5,mole ratio of isopropyanol to aniline 1.5,column bottom temperature 223℃,and feeding location of aniline 300-400mm from column top,conversion of aniline and selectivity of N-isopropylaniline stood at 99% and 99.5%,respectively,and mass fraction of N-isopropylaniline could be more than 98.8%.Conversion of aniline and selectivity of N-isopropylaniline could be improved 14.0% and 5.0% respectively when reaction took place under atmospheric pressure.Novel technology took merits of less investment,lower energy consumption,and simpler operation than traditional gas-solid catalytic process.