Steady State Multiplicities in an Ethylene Glycol Reactive Distillation Column
Steady State Multiplicities in an Ethylene Glycol Reactive Distillation Column
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DOI：
10.1021/ie00035a025
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发表时间：
1994-11
影响因子：
4.2
通讯作者：
A. Ciric;P. Miao
中科院分区：
文献类型：
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作者：
A. Ciric;P. Miao
提出了一系列同伦连续研究，探索由环氧乙烷和水生产乙二醇的反应蒸馏塔中的稳态多重性。乙二醇塔具有两组多重性：在大滞留体积值时发生的三分支多重性和在小滞留体积值时发生的复杂之字形多重性。最佳色谱柱具有三个稳态，并且在小滞留体积下，色谱柱可以具有多达九个稳态。计算研究表明，多重性不受进料或滞留体积分布的影响，也不是由多个反应、反应速率的温度依赖性或反应放热引起的。三分支多重性是由双线性反应速率和反应物之间的大挥发性差异之间的耦合产生的。分析结果表明，当氧化物进料已被消耗且水开始在蒸气沸腾流中积聚时，出现该多重性的较低转折点。多重性的上部转折点通过一系列复杂的之字形路线发生，从而创建了第二组多重性。这种折返多重性更加复杂，并且受到反应物挥发性差异和动力学反应速率常数的影响。
A series of homotopic continuation studies are presented that explore steady state multiplicities in a reactive distillation column producing ethylene glycol from ethylene oxide and water. The glycol column has two sets of multiplicities: a three-branch multiplicity that occurs at large values of the holdup volume and a complex switchbacking multiplicity that occurs at small values of the holdup volume. The optimal column has three steady states, and at small holdup volumes, the column can have as many as nine steady states. The computational studies show that the multiplicities are not affected by feed or holdup volume distribution and are not caused by multiple reactions, the temperature dependency of the reaction rate, or the exothermic heat of reaction. The three-branch multiplicity arises from coupling between the bilinear reaction rate and the large volatility differences between the reactants. Analytical results show that the lower turning point of this multiplicity occurs when the oxidefeed has been consumed and water begins to accumulate in the vapor boilup streams. The upper turning point of the multiplicity takes place via a series of complex switchbacks that create a second set of multiplicities. This switchbacking multiplicity is more complex, and is influenced by the reactant volatility difference and the kinetic reactionrate constants.