甲苯液相空气氧化过程中苯甲醛生成的影响因素分析  

Effects of Operation Parameters on the Benzaldehyde Formation in the LiquidPhase Oxidation of Toluene

作　　者：唐盛伟[1] 梁斌[1] 吴潘[1] 张全忠[1] 刘长军[1] 

机构地区：[1]四川省多相流传质与反应工程重点实验室

出　　处：《四川大学学报（工程科学版）》2005年第5期76-81,共6页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金;中石化联合资助项目(20233040)

摘　　要：甲苯液相空气氧化是环境友好的苯甲醛生产工艺.在一内径为48 mm的鼓泡床反应器中,模拟工业反应器的操作条件,研究了温度、通气量、催化剂用量、苯甲酸初始添加量以及苯和水的初始含量等不同工艺参数对苯甲醛的浓度和选择性的影响.结果表明,甲苯液相空气氧化可认为是一串级反应,165 ℃时中间体苯甲醛的氧化反应的速率常数约为0.08 min-1.供氧充足的情况下,反应20 min后苯甲醛浓度接近其最大值.在20 ～100 min内,苯甲醛的浓度和收率几乎不随反应时间变化.反应100 min后,其浓度逐渐降低,温度越高,下降越快.反应体系中存在过量的水、不加入催化剂Co盐或引发剂苯甲酸时,反应受到抑制而使苯甲醛浓度随反应时间的延长而逐渐增大,苯甲醛的选择性也相对处于较高的水平.The liquid-phase oxidation of toluene by air is an environment benign technology for producing benzoic acid and benzaldehyde, In a Ф48 mm bubble column reactor, effects of operation parameters, such as air flow rate, temperature, and initial concentrations of benzoic acid, Co, benzene and water, on the concentration and selectivity of benzaldehyde were studied, The results show that, benzaldehyde is an intermediate in the consecutive reaction. At 165 ℃, the reaction rate constant of benzaldehyde oxidation is about 0. 08 min^- 1 In a suficiently aerated reaction system, benzaldehyde concentration reached a maximum after 20 minutes. It kept unchanged in the next 80 minutes and then gradually lowered. High temperature enhanced the drop of benzaldehyde concentration in the last period, In a situation of high water concentration, absence of catalyst or benzoic acid, the benzaldehyde concentration increases with reaction time because the further reaction is inhibited. And the selectivity keeps high.

关 键 词：甲苯 液相氧化 苯甲酸 工艺条件 

分 类 号：TQ245.12[化学工程—有机化工]