Mathematical modeling of ethanol production processes using Aspen Custom Modeler® and EMSO® platforms

The concern involving the development and study of alternative energy sources has increased worldwide. Ethanol acts as one of the most promising fuel for the use on a large scale, and Brazil plays an important role due to its expertise on the production and use of alcohol as an automotive fuel. However, improvements in the process must be sought in order to maintain the country position in the renewable energy scenery. The fermentation step is the most likely to increase the process yield, thus studying this mechanism and its particularities is highly important in order to expand the presence of Brazilian ethanol in national and international markets. Bearing this in mind, a quick and cheap way to study this process is the use of computational simulators. The present work aimed in utilizing and comparing two softwares, Aspen Custom Modeler® and EMSO®, to simulate three ethanol fermentation systems, focusing on its implementation on the Virtual Sugarcane Biorefinery under development at Brazilian Bioethanol Science and Technology Laboratory. Based on experimental data and equations systems collected from different researches, ethanol fermentation process in batch and fed-batch operation mode, as well as a system consisting of a series of four continuous stirring tank reactors were successfully simulated, obtaining the concentrations of substrate, ethanol, and cells as a function of time and on steady state. The use and performance of both simulators are comparable. The greatest differences are on the shorter response time of EMSO®, and the user-friendliness of Aspen Custom Modeler®.