Simulation and economic evaluation of different process alternatives for the fermentation and distillation steps of ethanol production

Abstract

The intensification of climate change and other phenomena associated with the growing pollution of the planet have increasingly highlighted the need for energy sources that are less harmful to the environment. There is currently a strong trend towards the substitution of non-renewable and highly polluting energy sources, such as petroleum derivatives, by renewable sources, from the use of biomass, for example. Sugarcane is a widely used biomass for ethanol production in Brazil, which is the second largest ethanol producer in the world. Although well established in the country, ethanol production is very complex and process alternatives are continually being developed to make it more efficient. This work aims to simulate the fermentation and distillation stages of the ethanol production process from sugarcane juice, considering both the conventional route and alternative technologies, and compare them through an integrated economic analysis. In the simulations, the yeast growth rate in the fermenter was considered through the creation of a solid pseudocomponent, which is a differential of this work. For fermentation, the conventional route was compared with Low Temperature Fermentation and Vacuum Extractive Fermentation. For distillation, besides the conventional process, Double Effect Distillation was also analyzed. It was concluded that the process designs of Low Temperature Fermentation + Conventional Distillation and Vacuum Extractive Fermentation + Double Effect Distillation are economically advantageous when compared to the conventional one, with annual net profits up to 31.6% higher, showing the possibility of obtaining a more efficient and profitable process, or a reduction of up to 5% in the ethanol price through the implementation of these alternative technologies.