乙酸正戊酯酯化反应动力学探讨与催化精馏模拟

在间歇釜式反应器中，以NKC-9阳离子交换树脂为催化剂，对乙酸和正戊醇催化合成乙酸正戊酯的酯化过程进行了研究。实验考察了不同催化剂用量及反应温度对乙酸转化率的影响，同时测定了实验条件下乙酸正戊酯酯化反应的反应动力学数据。采用拟均相模型对实验数据进行关联，得到了平衡常数和反应速率常数的计算式。在本实验条件下，该酯化反应为吸热反应，反应热及正、逆反应活化能分别为8.339kJ/mol、50.191kJ/mol和41.852kJ/mol，平衡常数及正、逆反应速率常数与温度的关系式分别为：K=54.2173e^-8338.8/RT，k₁=95402.5e^50191/RT，k₂=1759.6e^41852.2/RT。结合测定的动力学方程，建立了基于严格数学模型的过程模拟计算方法，对乙酸正戊酯催化精馏酯化过程进行过程模拟优化。优化后的操作条件为精馏段板数3、反应段板数9、提馏段板数14、进料位置7、混合进料酸醇摩尔比1.1∶1，此时塔釜乙酸正戊酯摩尔分数与正戊醇转化率达到99%以上。

Study on esterification kinetics of n-amyl acetate synthesis and catalytic distillation simulation

The n-amyl acetate synthesis from the esterification reaction of acetic acid and n-amyl alcohol over an acidic cation exchange resin catalyst, NKC-9, was studied in a batch reactor. The effects of catalyst dosage and reaction temperature on the conversion of acetic acid were investigated. And the kinetic data of the esterification reaction was measured under optimal reaction conditions. The pseudo-homogeneous kinetic model was used to correlate the experimental data and determine the equation of equilibrium constant and reaction rate constant. As evidenced by the experimental results that under the operating conditions of this investigation the esterification reaction was endothermic, and the enthalpy of reaction, activation energies of the forward and reverse reactions were 8.339kJ/mol, 50.191kJ/mol and 41.852kJ/mol, respectively. The equations of equilibrium constant and forward and reverse reaction rate constant with temperature were obtained respectively as K=54.2173e^-8338.8/RT,k₁=95402.5e^50191/RT, and k₂=1759.6e^41852.2/RT. Combined with the reaction kinetics measured, a simulation program based on the rigorous mathematical model was established, and the catalytic distillation process of n-amyl acetate synthesis was simulated. 3 Trays in rectifying section, 9 trays in reaction section, 14 trays in stripping section, feed location of 7th tray and feed molar ratio of acid to alcohol of 1.1:1 were the optimized operating conditions, under which the bottom n-amyl acetate purity and n-amyl alcohol conversion were both obtained over 99%.