Property Modeling, Energy Balance and Process Simulation Applied to Bioethanol Purification

Abstract

The use of renewable sources has been an alternative to decrease the negative environmental impacts of fossil fuels. In this context, bioethanol from sugarcane has proved to be a successful option to gasoline. However, bioethanol purification through conventional distillation requires high-energy demand. For this reason, energy balance calculations are very useful to estimate steam demand. As a result, simpler alternatives for estimation of steam consumption from spreadsheet calculations have been encouraged. In contrast, many efforts have focused to solve complex flowsheets including tear streams, which increases convergence complexity for each change on feed composition and additional components. In this work, mathematical models were fitted to bioethanol–water mixture property data and applied to energy balance calculations involved in the conventional process for hydrated bioethanol purification. Total steam consumption was obtained for volume percentages of bioethanol in the wine feed stream of 6, 8 and 10 °GL considering potential losses found in the industrial reality. The calculated data were compared to simulations carried out in the Aspen Plus® software. Similar values of total steam consumption were found comparing the two approaches, where the average absolute relative deviation was kept below 5%. Moreover, simulated temperature and composition profiles agreed to process data. Finally, mathematical models and energy balance calculations proved to be a simpler and faster alternative to estimate total steam consumption involved in the hydrated bioethanol purification from wine.