|Abstract: ||本論文之內容主要進行木薯製造生質酒精之化工程序合成與設計，以年產量三萬公噸、純度達99.5 wt% 之酒精燃料為設計目標。以木薯為原物料，經過液化、醣化與發酵作用產生粗製酒精，之後進行濃縮、純化以達到無水酒精純度與產量要求。文中考慮兩種無水酒精純化的方法：第一種為共沸蒸餾，採用苯為共沸劑；第二種為滲透蒸發，使用親水性薄膜，將酒精與水分離。其次，針對滲透蒸發整體製程進行熱能整合，探討其節能減碳之成效。最後，進行生質酒精製程之經濟評估，吾人發現，共沸蒸餾整體製程之年製造成本、生質酒精每公升之製造成本以及化石能源比分別為US$27.0×106、US$0.68與0.74；滲透蒸發整體製程在熱能整合後之年製造成本、生質酒精每公升之製造成本以及化石能源比分別為US$23.6×106、US$0.59與1.5。
本論文研究主要應用“Aspen Plus”、“Aspen Custom Modeler”(ACM) 與“SuperTarget”三套化工程序軟體；前兩者用於程序合成與設計，後者則用於狹點分析及換熱器網路合成。
In this thesis, we have presented a chemical process synthesis and design for the production of bioethanol from cassava. The study aims to simulate a plant capacity of 30,000 metric tons per year of 99.9 wt% purity of ethanol fuel. Starting with cassava as the raw material, we use the liquefaction, saccharification, and fermentation process to accomplish the making of crude ethanol; then, we employ purification process to achieve the dehydrated ethanol production with a 99.5 wt% purity and the yield we desired. There are two kinds of purification process we use to separate ethanol and water. The first is azeotropic distillation process with benzene as the entrainer; the second is pervaporation process with the hydrophilic membrane. Then, we have carried out a heat integration for the cassava-to-ethanol combining pervaporation process. Ultimately, as seen from the economic analysis, we found that the yearly cost of manufacture, cost of bioethanol per liter, and fossil energy ratio (FER) are US$27.0×106, US$0.68, and 0.74, respectively, in the cassava-to-ethanol with azeotropic distillation process; and US$23.6×106, US$0.59, and 1.5 in the cassava-to-ethanol with pervaporation process after heat integration .
Three kinds of software are utilized in the research—Aspen Plus, Aspen Custom Modeler (ACM), and SuperTarget. The first and second are applied to implement the process synthesis and design; the third is applied to perform the pinch analysis and the synthesis of heat exchanger network.