反應性蒸餾三成份系統可行性分析：分解反應

Feasibility of Ternary Reactive Distillation Systems： Decomposition Reaction

陳晉仕(Chin-Shin Chen)

指導教授 ： 余政靖

國立臺灣大學/工學院/化學工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.02033

摘要

摘要

反應蒸餾程序具有經濟上的優勢，特別在可逆反應或是共沸現象出現時。但是迭代設計過程非常耗時，透過可行性分析能檢查程序是否可行，藉由刪除不可行的設計，化學工程設計師將能節省大量嘗試錯誤的時間，但是反應蒸餾塔的捷徑式設計與可行性分析至目前為止仍尚未發展完全。Guo等人曾對反應性三成份共沸系統可行性進行系統化分析，方法為Lee等人所發展的反應差異點圖形化逐板運算。此法有兩個限制，一為需要正向反應，二為產品能由蒸餾或是反應蒸餾達到。在本工作中發現可行性分析方法可透過容許逆反應來增強，給出較正確的可行性預測。兩個理論性的概念也被發現，分別是：一、反應平衡線上的汽液向量反轉與否跟該逐板運算的可行性結果一致。二、反應共沸點就是化學平衡下無限回流比逐板運算的極限點。可行性分析能藉二概念來簡化並加速。全部共113個三成份餾餘組成圖形(RCM)中，本工作將可行的由原先的Guo等人所預測的27個增加到48個，全部可行的RCM在本工作中分類為四種不同的類別，分別是：一、可行於反應平衡線與產品具有相同區間。二、可行於大的平衡常數。三、可行於小的平衡常數。四、可行於合適的平衡常數。也針對第二個類別提出不可行的情況下，利用多塔組態來生產的解決方案與分析方法。第三、第四個類別仍需由Guo等人提出使用entrainer的方式來得到高純度產品。共沸系統可行性也推廣到不同的沸點排序，發現為鏡向關係，這些結論均與模擬結果相符。最後進行理想三成份A↔B+C系統的可行性分析、最適設計與動態控制，發現可行性分析的確能幫助我們找到較具經濟優勢的設計架構，並且該架構具有動態上的可操控性。

關鍵字

反應蒸餾 ； 可行性

並列摘要

Abstract

The reactive distillation offers significant economic advantages in some systems, especially when reactions are reversible and/or when azeotropes are presented. The feasibility analysis helps us to check whether a process is feasible or not. It is crucial and important because there are fewer methods for shortcut designs and the iterative design is always time-consuming in reactive distillation column. A lot of time would be saved for the design procedures of reactive distillation by getting rid of infeasible cases and focusing on the feasible ones. Systematical research on feasibility analysis of ternary azeotropic systems has been done by Guo et al (Guo et all, 2004). The analysis method they used is tray-by-tray calculations with difference point. There are two feasibility criteria, which are positive reaction extent is required and products can be reached by distillation or reactive distillation. In this work, we find that the feasibility analysis of reactive distillation in this method can be augmented by admitting the reverse reaction which can be demanded by excess positive reaction. And two conecepts which could be used to accelerate the feasibility analysis are shown. The first one is that vectors at equilibrium line and tray-by-tray calculations method with difference point are equivalent in feasibility analysis. And pinch points of tray-by-tray calculations under chemical equilibrium and infinite reflux ratio is just the reactive azeotrope. The number of feasible cases are increased from 27 to 48 in 113 all possible ternary configurations. Nine cases are feasible with low equilibrium constants, and twelve cases could be feasible with proper equilibrium constants. Those results are compared well with reactive distillation column simulations. Design and control of ternary ideal system, A↔B+C, are also be explored. Better design, both on economical and energy saving, could be found by using the result of feasibility analysis. And the designs are shown to be workable in dynamic.

並列關鍵字

Reactive Distiilation ； Feasibility

參考文獻

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