透過外部和內部熱整合達到多成份蒸餾系統的最佳化設計及控制架構

Design and Control of A Complex Distillation Sequence with External/Internal Heat Integration

葉明泓(Ming-Hung Yeh)

指導教授 ： 陳誠亮

國立臺灣大學/工學院/化學工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101975

摘要

乙二胺是一種無色並帶有氨味的鹼性溶液，常作為重要的化工原料或中間體，是具高經濟價值的化合物之一。目前，在工業上生產乙二胺的主要製程中，反應器出口除反應物和產物外，還包含許多副產物所形成之胺類混合物，因此，有別於以往文獻中僅考慮水和乙二胺的共沸物分離，本次研究探討了共計6 種反應出料的物質，以提供更符合現實情況的程序設計作為參考。起初，在此次的製程中共有42種可能的分離序列，透過共沸物限制以及化工的經驗法則，最後可縮減至7種最具潛力的序列。後續在進行最佳化之流程時，以年度總成本為目標函數，除變壓蒸餾的高、低壓兩塔的組態之外，更將高壓塔塔底純度列為新的操作變數，探討共沸物組成對年成本的影響。此外，以往的研究是先決定最佳化序列，才實施熱整合等節能策略以達到降低成本的目的，而本次研究提供一套全新的最佳化流程，將變壓蒸餾的外部熱整合考量提前納入疊代過程，並透過數據來證明此方法確實可以找到不同於傳統疊代結果的真正最佳序列。隨後，透過程序動態控制驗證了此系統的操作可行性，在進料改變20%和組成改變10%的干擾下，皆能維持所有分離目標的高純度，並可透過內部和外部熱整合，節省下15.15%的年度總成本花費。

關鍵字

共沸物 ； 變壓蒸餾 ； 熱整合 ； 程序設計 ； 最佳化 ； 程序控制

並列摘要

Ethylenediamine (EDA), also known as Ethane-1,2-Diamine, is a valuable raw material and the main synthesis will produce several higher polyamines. In this study, different from the previous literature that only consider the azeotrope separation of H2O-EDA, it explored a total of 6 reaction products as fresh feed in the simulation. For the separation process, there are totally forty-two possible sequences. With the constraint of H2O-EDA azeotrope and heuristics in chemical engineering, there will be only seven promising sequences left. To minimize the total annual cost (TAC), the pressure-swing configuration and the purity of the bottom flow rate of high pressure (HP) column that how closes to the azeotrope are two new design variables which can be both optimized in this study. Different from the conventional optimization, this study provides a distinct method that the heat-integrated pressure-swing distillation (PSD) system will be taken into consideration during the iterative procedure. It is proved by data that this method can indeed find the truly optimal sequence distinct from the traditional iterative result based on the objective function, the lowest TAC. Afterwards, through the further energy-saving strategies, the optimal result will save TAC of 15.15% by the external and internal heat integration, known as dividing wall columns (DWC). Furthermore, the improved control structure is explored based on the optimal result in steady-state design and all of the desired purities can be kept within acceptable ranges with the advanced control strategies while disturbances of either throughput or composition change occur.

並列關鍵字

Azeotrope ； Pressure-swing distillation ； Heat integration ； Process design ； Optimization ； Dynamics control

參考文獻

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