運用嚴謹程序模型進行混合共沸劑之萃取蒸餾的程序最優化

Optimal Design of Extractive Distillation with Mixed Entrainer Using Rigorous Process Models

方鈺鳳(Yu-Feng Fang)

指導教授 ： 吳哲夫

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/NTU202101177

摘要

在本篇論文中，使用化工商用模擬軟體Aspen Plus建立萃取蒸餾程序分離共沸物，而製程的設計對分離成本具有極大的影響，因此以最低化年度總成本為目標方程式，藉由運算軟體MATLAB使用模擬退火演算法進行程序最適化。
本文針對四種共沸物進行探討，分別為：二組成共沸物-丙酮/甲醇、乙醇/水以及三組成混合物-四氫呋喃/乙醇/水、乙腈/乙醇/水。設計參數為蒸餾塔總板數、混合物進料板、共沸劑進料板、共沸劑流量、共沸劑組成、塔壓。各系統皆以嚴謹模擬分離程序搭配Aspen Plus自動化伺服器結合MATLAB進行模擬最佳化。
結果顯示丙酮/甲醇系統以單一組成共沸劑乙醇胺為最適分離共沸劑，乙醇/水的最佳共沸劑為乙二醇，而四氫呋喃/乙醇/水萃取蒸餾系統以混合溶劑55莫爾比率的二甲基亞碸及45莫爾比率的乙二醇為最佳共沸劑，乙腈/乙醇/水系統在進料組成為較高莫爾比率乙腈時，則以單一組成二甲基亞碸為最適沸共沸劑，當調降混合物乙腈進料莫爾比率，則以90莫爾比率的二甲基亞碸混合10莫爾比率的乙二醇可得到最低年度總成本。模擬結果顯示使用模擬退火演算法進行多達6-13個設計參數的萃取蒸餾程序系統最適化是可行的且可節省大量人力與時間。

關鍵字

最適化 ； 模擬退火演算法 ； 混合溶劑 ； 共沸物 ； 萃取蒸餾

並列摘要

Extractive distillation is an effective process for separating azeotropes by adding a third solvent, called entrainer to achieve high purity products. Two binary azeotropes (acetone–methanol, ethanol–water) and two ternary mixtures (Tetrahydrofuran–ethanol–water, Acetonitrile–ethanol–water) using single or multiple component entrainer are discussed. The optimization of extractive distillations are of great importance to the economics. There are a number of design variables for each process with different entrainer, including total stages of the column, feed stage of column, entrainer flow rate, composition of the entrainer, and pressure of recovery column. By using Aspen Plus automation server, the simulated annealing algorithm (SAA) implemented in MATLAB with the extractive process built in Aspen Plus was automatically carried out the optimization. Furthermore, vacuum pressure is used in the entrainer recovery column to save total annual cost (TAC). The optimization results obtained by SAA-based optimization show this method can solve these process with several
variables and also save the time of searching the near-global optimal values.

並列關鍵字

Optimization ； Extractive distillation ； Mixed entrainer ； SAA ； Azeotrope

參考文獻

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