各類非均勻相共沸蒸餾系統及隔牆塔製程之設計與控制

Design and Control of Various Heterogeneous Azeotropic Distillation Systems and Divided-Wall Column Processes

吳義章(Yi-Chang Wu)

指導教授 ： 錢義隆

共同指導教授 ： 黃孝平(Hsiao-Ping Huang)

國立臺灣大學/工學院/化學工程學研究所/博士(2014年)

https://doi.org/10.6342/NTU.2014.03051

摘要

本論文探討各類非均勻相共沸蒸餾系統及隔牆塔製程之設計與控制。第一部分探討工業級分離程序甲基丙烯酸甲酯(MMA, Methyl Methacrylate)為重點，進料包含三個成分甲基丙烯酸甲酯、甲醇及水，本論文提出此分離程序的改良簡化設計，設計流程可簡化成雙塔設計包含一個非均勻相共沸蒸餾塔、一個分相槽及一個汽提塔，此雙塔設計可更進一步探討將其簡化為單塔設計包含一個非均勻相共沸蒸餾塔、一股側流及一分相槽。本研究同時也進一步探討了系統在進料動態擾動下之控制效果。研究中提出一個雙點溫度控制環路，可以有效穩定住產量增減以及進料組成變化之擾動。
第二部分以Pyridine除水分離以甲苯為共沸劑系統，及1,4-Dioxane除水分離系統含不純物三乙胺(Triethylamine,TEA)為例，探討非均勻相共沸蒸餾製程，以隔牆塔設計節能的潛力。經由最適化比較穩態設計與傳統設計，可以知道經由隔牆塔節能設計後，不僅可以顯著的降低總能耗，此外，非均勻相共沸蒸餾塔的隔牆塔設計，仍然保有兩個重要的再沸器熱負載操作變數，故此沒有阻礙到動態干擾排除的表現。
最後部分為探討非均勻相共沸蒸餾之分相槽配置的動態分析，兩種配置主要的不同在於非均勻相共沸蒸餾塔塔頂汽相流，設計一的塔頂汽相直接進入分相槽進行液液分相；設計二塔頂汽相流則進入回流槽，塔頂餾出物再進入分相槽中。本論文，我們將針對此兩設計探討動態控制策略，設計一以雙點溫度控制策略，可以有效的排除大範圍的進料組成干擾。

關鍵字

非均勻相共沸蒸餾 ； 隔牆蒸餾 ； 甲基丙烯酸甲酯 ； 吡啶 ； 1,4-二噁烷

並列摘要

The design and control of three dehydration process systems via heterogeneous azeotropic distillation and dividing-wall column design will be investigated in this thesis.
In the first part, the azeotropic distillation system to separate out methyl methacrylate (MMA) from a mixture including methyl methacrylate, methanol, and water is studied. In this work, a simple design flowsheet is devised with a distillation column, a bottom decanter, and a stripper. This column/decanter/stripper design can further be simplified into an even simpler design flowsheet with only one distillation column with sidedraw and a middle decanter. Optimal design and dynamic control of this simplified separation process are investigated in this report. It is shown that the product purity specifications can be maintained despite feed disturbances by holding a tray temperature above the sidedraw location and another one below the sidedraw location.
In the second part, energy-saving potential of heterogeneous azeotropic dividing-wall columns are investigated via a demonstrating example for the separation of pyridine and water using toluene as entrainer and another example of 1,4-dioxane dehydration process with small amounts of triethylamine (TEA) impurity. By comparing the optimized design of this dividing-wall column with the original design, significant reduction in the reboiler duty can be obtained. Furthermore, because two important control degree-of-freedoms are still preserved in the dividing-wall column, no hampering of the control performance can be observed.
In the last part, we discuss the dynamics and control of heterogeneous azeotropic distillation column with two different decanter configurations. The main difference of these two configurations is the layout after condensing top vapor stream. For the first design, top vapor stream will go directly into a decanter. For the second design, top vapor stream will go into reflux drum and then the distillate stream goes into a decanter. In the thesis, we will investigate the proper overall control strategy for these two configurations. Overall control strategy of the first design is proposed with dual-temperature control loops. Large perturbations of the feed composition can be handled.

並列關鍵字

heterogeneous azeotropic distillation ； dividing-wall column distillation ； methyl methacrylate ； pyridine ； 1,4-dioxane

參考文獻

[71] 高堂凱， 醋酸去水製程中進料雜質對非均相共沸蒸餾塔的設計與控制之影響(II), 碩士論文, 國立臺灣大學化學工程研究所 (2005).

[1] Julka, V.; Chiplunkar, M.; O’Young, L., Selecting Entrainers for Azeotropic Distillation, Chem. Eng. Prog., 2009,105(3), 47.

[3] Chiang, T. P.; Luyben, W. L., Comparison of Energy Consumption in Five Heat-Integration Distillation Configurations. Ind. Eng. Chem. Process Des. Develop. 1983, 22, 175.

[4] Chiang, T. P.; Luyben, W. L., Comparison of the Dynamic Performance of Three Heat-Integrated Distillation Configurations. Ind. Eng. Chem. Res. 1988, 27, 99.

[7] Triantafyllou, C.; Smith, R. The Design and Operation of Fully Thermally Coupled Distillation Columns. Trans. Inst. Chem. Eng. 1992, 70A, 118.