【摘要】 间二甲苯(MX)和乙苯(EB)混合氧化是一种制备间苯二甲酸(IA)和苯甲酸(BA)的新方法,为深入研究MX-EB混合氧化反应规律,在Aspen Customer Modeler软件平台上构建了该反应器数学模型,进行模拟仿真研究。提出了双曲型MX-EB混合氧化动力学模型,机理分析表明EB的引入会加速MX氧化过程,混合氧化与纯组分氧化比较具有更高的MX转化效率,在此基础上构建了年产25万吨IA的混合氧化反应器模型。计算表明,原料中EB含量增加、反应压力升高、催化剂浓度增大及反应器含水量降低都会使得MX转化率及IA收率提高、液相杂质间羧基苯甲醛(3-CBA)浓度下降,同时反应体系中苯甲酸浓度及燃烧副反应增加。通过模拟获得了混合氧化的适宜反应条件为:原料中EB与MX质量比0.05左右、操作压力1.1～1.25 MPa、催化剂浓度200～300 mg/kg、含水量8%～10%。更多还原

【Abstract】 Co-oxidation of m-xylene(MX) and ethylbenzene(EB) is a new technology to produce isophthalic acid(IA) and benzoic acid(BA). In order to understand the characteristics of MX-EB co-oxidation, the reactor model was established in Aspen Customer Modeler platform and simulated. The hyperbolic kinetic equations of MX-EB co-oxidation were proposed, and mechanism analysis indicated that the introduction of EB would promote the oxidation of MX, which resulted in higher MX conversion, higher IA yield and lower reaction pressure compared with pure component oxidation. Based on this, a co-oxidation reactor model with an annual productivity of 250 000 tons of IA was established. The simulation results showed that the increase of EB content, reaction pressure, catalyst concentration and the decrease of water content would increase the conversion of MX and the yield of IA, and the mass fraction of 3-CBA would decrease, while the concentration of benzoic acid and the consumption of side reactions correspondingly increased. The optimal conditions for MX-EB co-oxidation process are as follows: the mass ratio of EB to MX in raw material is about 0.05, the operating pressure is 1.1 MPa to 1.25 MPa, the catalyst concentration is 200 mg/kg to 300 mg/kg, and the water content is 8% to 10%.更多还原