全回流催化精馏塔的模拟计算

Simulation of Catalytic Distillation Columns with Total Reflux

针对反应产物是最轻或最重组分的可逆反应系统,塔的馏出物仅仅是产物,成为单端出料的全回流催化精馏塔,将该类过程的模拟计算简化为初值问题,提出了快速有效的求解方法。假定转化率,根据全塔物料衡算及化学反应计量方程,确定塔出料端的组成,模型方程就成为边值已知的一组微分方程,可用数值积分法求解。本文提出的操作型计算方法是转化率的单变量迭代过程,用Newton迭代法达到快速收敛。对于设计型计算,转化率是给定的,可直接用积分求解,得到所需催化填料和惰性填料的高度,大大缩短了计算时间。对实际工业系统进行了计算,并作了实验验证,获得了满意的结果。

An algorithum enabling considerable CPU time saving is developed for distillation accompained by simultaneous heterogeneous catalytic reactions with total reflux. By taking advantage of either bottom or top product only, the original boundary value problem is shifted to a initial-value problem. For prediction purposes, a single variable iteration, i. e., the iteration of conversion, is suggested. According to stoichiomatric equation and overall material balance for individual components, the composision of the only product, i. e., the boundary values of the model equation, can then be determined with the assumed value of the conversion. Newton Method is used for better convergence. For design purposes, the conversion is specified and the required packed catalyst hight is simply obtained by numerical integation without iteration. Experiments show good agreement with the computation.