Dynamic rate-based and equilibrium models for a packed reactive distillation column
Dynamic rate-based and equilibrium models for a packed reactive distillation column
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DOI：
10.1016/s0009-2509(03)00103-9
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发表时间：
2003-06-01
影响因子：
4.7
通讯作者：
Eldridge, RB
中科院分区：
文献类型：
--
作者：
Peng, JJ;Edgar, TF;Eldridge, RB
建立了甲基叔戊基醚（驯服）生产过程中填料反应精馏塔的动态速率模型和平衡模型。这两种类型的模型，由微分代数方程，在gPROMS和动态模拟进行了实施，研究驯服系统的反应精馏的动态行为。两种模型预测的动态响应基本相似，但稳态值存在一定差异。操作变量，如馏出液流量，回流比，和再沸器负荷，对控制变量（反应物转化率和产品纯度）的动态响应的影响进行了研究。反应物转化率的动态响应是非常非线性和非常规的，但产品纯度的响应是很好的近似线性一阶微分方程。完成基于速率的模型的动态模拟所需的CPU时间至少比平衡模型高一个数量级。因此，动态基于速率的模型比平衡模型复杂得多，并且基于速率的模型的简化对于基于模型的控制的实施是必要的。提出了一种新的方法来简化动态速率模型，假设传质系数是时不变的。该方法被证明是上级优于传统的简化方法。它可以减少多达三分之二的方程的数量，仍然准确地预测动态行为。(C)2003爱思唯尔科技有限公司版权所有。
Dynamic rate-based and equilibrium models were developed for a packed reactive distillation column for the production of tert-amyl methyl ether (TAME). The two types of models, consisting of differential algebraic equations, were implemented in gPROMS and dynamic simulations were carried out to study the dynamic behaviour of reactive distillation of the TAME system. The dynamic responses predicted by the two types of models are similar in general, with some differences in steady-state values. The influence of manipulated variables, such as distillate flow rate, reflux ratio, and reboiler duty, on the dynamic responses of the controlled variables (reactant conversion and product purity) was studied. The dynamic response of reactant conversion is very nonlinear and unconventional, but the response of product purity is well approximated by a linear first-order differential equation. The CPU time required to complete a dynamic simulation of the rate-based model is at least an order of magnitude higher than that for the equilibrium model. Therefore, the dynamic rate-based model is much more complicated than the equilibrium model, and simplification of the rate-based model is necessary for the implementation of model-based control. A new approach was proposed to simplify the dynamic rate-based model by assuming that the mass transfer coefficients are time invariant. This approach was demonstrated to be superior to the conventional simplification methods. It can reduce the number of equations by up to two-thirds and still accurately predicts the dynamic behaviour. (C) 2003 Elsevier Science Ltd. All rights reserved.