苯胺、尿素和甲醇催化精馏合成苯氨基甲酸甲酯反应

采用催化精馏装置，以γ-Al₂O₃为催化剂，考察了反应操作条件对苯胺(AN)、尿素和甲醇合成苯氨基甲酸甲酯(MPC)反应的影响，并考察了γ-Al₂O₃催化剂的活性稳定性。结果表明，MPC合成反应的适宜的操作条件为反应温度180℃，反应压力0.80～0.85 MPa，回流比0.50,反应原料分为2股进料，其中，苯胺、尿素和甲醇的混合液以n(AN)∶n(Urea)∶n(Methanol)=1∶5∶75的比例在反应段上方进料，进料速率0.3 mL/min，另一部分纯甲醇在反应段下方进料，进料速率5.0 mL/min。在此条件下，苯胺转化率为99.0%，MPC收率和选择性分别为69.5%和70.2%，γ-Al₂O₃催化剂连续运行408 h后，其催化活性几乎没有变化。

Synthesis of Methyl N-phenyl Carbamate From Aniline,Urea and Methanol by Catalytic Distillation

The effect of operation conditions on the synthesis of methyl N-phenyl carbamate (MPC) from aniline (AN), urea and methanol was studied in a catalytic distillation unit with γ-Al₂O₃ as catalyst, and the stability of  γ-Al₂O₃ catalyst was investigated. Under the suitable operation conditions of reaction temperature 180℃, reaction pressure 0.80-0.85 MPa, reflux ratio of 0.50, one mixture feed stream of n(AN)∶n(Urea)∶n(Methanol)=1∶5∶75 with feed rate of 0.3 mL/min into the reaction zone at the upper section, another feed stream of methanol with feed rate of 5 mL/min into the reaction zone at the lower section, the conversion of aniline, MPC yield and selectivity were 99.0%, 69.5%, and 70.2%, respectively. In addition,  γ-Al₂O₃ still maintained the catalytic activity as the fresh one after continuous operation for 408 h in the catalytic distillation unit, indicating that it had a satisfactory stability in the synthesis of MPC.