以數學規劃法作非對稱內熱整合蒸餾塔最適化設計

Abstract

蒸餾系統是目前應用在分離物質上最重要的技術，但其能量使用效率上的低落造成許多能源的浪費，因此對於蒸餾程序之改善國際上已有許多研究討論，本文將針對內熱整合之技術進行探討研究。 內熱整合蒸餾塔(Heat Integrated Distillation Column, HIDiC)為單一蒸餾塔的內部熱整合架構，是一整合蒸氣再壓縮與非絕熱蒸餾塔優點的蒸餾塔。在日本與荷蘭的研究已行之有年，其高能源使用效率已多方面的被證實，但成本的考量方面的研究較少被提出。且之前的研究大多討論的是對稱型內熱整合蒸餾塔(symmetric HIDiC)，對於精餾段語氣提段板數不同的非對稱型內熱整合蒸餾塔(asymmetric HIDiC)架構尚未有完整的研究，所以本文利用數學規劃法提出一普遍且完整之模式，包含能量使用以及年總成本之計算，比較傳統蒸餾塔(Conventional Distillation Column)與兩種不同內熱整合蒸餾塔的最佳設計架構，並分析非對稱式內熱整合蒸餾塔的結構對其能量與成本的影響。

Distillation is by far the most applied separation technology, but its low energy efficiency is also recognized as a major drawback. In order to overcome this drawback, various novel ideas and approachES have been proposed in literature. The subject of this work is on the design of internal energy-integrated distillation system. Studies on internally heat-integrated distillation column(HIDiC) are proceeding for many years. HIDiC was proved to be effective in energy saving, but so far only few works addressed about its economic point of view and “asymmetric” structure. This work aims to develop a general model of mixed-integer nonlinear program (MINLP) for HIDiC design where exergy consumption and total annualized cost (TAC) are both taken into account. After the optimization, the results of asymmetric HIDiC are compared with those of conventional distillation column and symmetric HIDiC in the two aspects (exergy consumption and TAC). The follow-up analysis shows how the structure of asymmetric HIDiC to influence the energy efficiency and total cost.