| 摘要: | In this work, 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 99.5 wt% (or >99.3 vol%) 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 processes 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 the traditional azeotropic distillation process with benzene as the entrainer; the second is pervaporation process with the hydrophilic membrane. Additionally, we have conducted heat integration for the overall cassava-to-ethanol with 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$27.0x106, US$0.68, and 0.74, respectively, in the overall cassava-to-ethanol with azeotropic distillation process; and US$23.6x106, US$0.59, and 1.5 in the overall 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. |
