The present invention discloses a process for preparing 4-aminodiphenylamine, which process uses nitrobenzene and aniline as raw materials, a complex base catalyst as condensation catalyst and a powdery composite catalyst as hydrogenation catalyst, and comprises five process stages: condensation; separation I; hydrogenation; separation II; and refining. The process can be continuously carried out. By selecting a complex base catalyst to catalyze the condensation reaction and separating it prior to the hydrogenation, the problem that the complex base catalysts thermally decompose in the hydrogenation reaction is avoided, the selectable range of hydrogenation catalysts is largely enlarged so that it is possible to select cheaper hydrogenation catalyst, and the selection of production process and equipment is easier and further industrialization is easier. The complex base catalysts used in the present invention are inexpensive and have higher catalytic activity. The process can be carried out at mild conditions and can adapt to broad range of water content, by-product is less and conversion and selectivity are higher. The operational strength is low, no corrosive liquid is produced, and environment pollution is reduced. The purity of 4-aminodiphenylamine prepared can exceed 99 wt.-%, and the yield in the industrial production process can be over 95%.
本发明公开了一种制备4-
氨基
二苯胺的方法,该方法使用
硝基苯和
苯胺作为原料,复合碱基
催化剂作为缩合
催化剂,粉状复合
催化剂作为加
氢催化剂,并包括五个工艺阶段:缩合;分离I;加
氢;分离II;和精制。该方法可以连续进行。通过选择复合碱基
催化剂催化缩合反应并在加
氢之前分离它,避免了复合碱基
催化剂在加
氢反应中热分解的问题,大大扩大了可选择的加
氢催化剂范围,从而可以选择更便宜的加
氢催化剂,并且生产工艺和设备的选择更容易,进一步工业化更容易。本发明中使用的复合碱基
催化剂价格低廉且具有较高的催化活性。该方法可以在温和条件下进行,并且可以适应广泛的含
水量范围,副产物较少,转化率和选择性较高。操作强度低,不产生腐蚀性液体,减少了环境污染。制备的4-
氨基
二苯胺的纯度可以超过99重量%,工业生产过程中的产率可以超过95%。