利用模擬退火演算法和Aspen Plus ActiveX自動化伺服器進行使用混合溶劑之萃取蒸餾塔最適化

Abstract

本文利用模擬最適化來得出近似最適化用來分離共沸物的萃取蒸餾塔設計。隨著欲分離的共沸物和使用的共沸劑(Entrainer)複雜程度增加，藉由在MATLAB客戶端使用模擬退火演算法(SAA)，並在Aspen Plus伺服端建立簡化的蒸餾塔流程圖，可以解決最適化問題。在分離系統中的每個蒸餾塔都能進行最適化，而其總年度成本再被加總計算。本篇用兩個二組成共沸物和一個三組成共沸物分離系統來演示萃取蒸餾塔使用包含單一共沸劑和多種成份混合共沸劑的模擬最適化的結果，並討論幾種簡化流程圖的方法以確保模擬的穩定度和適當的功能運行。結果顯示在萃取蒸餾塔進行複雜的共沸物分離時且包含眾多從六到十二個設計變數的模擬下，此最適化方法是可行的。

Simulation-optimization was applied to determine near-optimal process designs in extractive distillation systems for the separation of an azeotropic mixture. As either the azeotropic mixture or the entrainer involved in the separation process became more complicated, simulated annealing algorithm (SAA) programed in the client (MATLAB) was coupled with a simplified flowsheet built in the server (Aspen Plus) to solve the optimization problems. Each column in the separation process was optimized and the total cost of the whole process was calculated. Two extractive distillation processes using single and mixed entrainers and one extractive distillation system for separating a ternary azeotrope were proposed. Various shortcuts for building a simplified flowsheet to assure the stability and proper function of the simulator were also discussed. The optimization results obtained by SAA-based optimization demonstrated that this method can be well applied for solving the optimization problem dealing with a complicated extractive distillation with design variables ranging from six to twelve.