采用非平衡级模型模拟催化精馏过程的研究

将化学反应分解成组分生成反应和消耗反应,定义组分的消耗反应速率常数,引入到传统的三对角矩阵法中,提出了改进的三对角矩阵法。用非平衡级模型模拟尿素醇解法合成碳酸二甲酯(DMC)的催化精馏反应过程,采用改进的三对角矩阵法进行求解。模拟结果和实验结果的比较表明,各工艺条件下DMC收率的平均相对误差为3.78%。改进的三对角矩阵法能避免在迭代过程中出现组分浓度为负值的情况,减缓由于迭代中组分浓度变化幅度过大引起的振荡现象。该算法适应快慢反应同时存在的体系,加宽了三对角矩阵法的适应范围。

Simulation of Catalytic Distillation Process Using Non-Equilibrium Stage Model

The reactions in distillation column were classified into generation reactions and consumption reactions.A improved tridiagonal matrix method was developed by definition of consumption reaction rate constant.The catalytic distillation process for synthesis of dimethyl carbonate(DMC)by urea methanolysis over solid catalyst was simulated by the established non-equilibrium stage model,and the improved tridiagonal matrix method was used to solve the model equations.Comparison of simulated results with experiment data shows that mean relative error of DMC yield is 3.78% under different conditions such as different total pressures and reaction temperatures.The improved tridiagonal matrix method could avoid the negative values of the liquid compositions during the calculations,and restrain the fluctuation of compositions by slowing down the variations of the values in the iteration.The simulated results show that the improved tridiagonal matrix method is appropriate for system containing components with broad range of boiling points and reactions with different rates.