Produção de etanol hidratado e dióxido de carbono a partir do melaço de soja

Abstract

The present work aimed to carry out the synthesis and analysis of the alcoholic fermentation process from soy molasses, the main residue from the soybean protein concentration process (SPC). The plant produces solvent ethanol to be reintroduced into the process and hydrated fuel ethanol for commercialization. Additionally, the CO2 produced by fermentation will be purified and commercialized. The molasses contains approximately 57.3% of total sugars, but about 28.3% of the total is composed of raffinose and stachyose, sugars non-fermentable by Saccharomyces cerevisiae. These sugars must be enzymatically hydrolyzed to raise fermentable sugars and increase product yield. This process was simulated with simultaneous fermentation and hydrolysis using Saccharomyces cerevisiae as yeast and α-galactosidase as an enzyme. The process was conducted for 12 hours in 100 m3 tanks, with only yeast recycling. The process has three areas: Área 100 for fermentation and cell recycling, Área 200 for carbon dioxide purification, and Área 300 for solvent and fuel ethanol separation. In the end, an annual production of 143.08 m3 of solvent ethanol returned to the SPC process, 12 640,68 m3 of hydrated fuel ethanol was obtained, with a financial return of R$ 27 373 248,00 and 10,800 tons of carbon dioxide, with a financial return of R$ 60 225 000,00. Economic analysis demonstrated that with an annual net profit of R$ 13 306 150,38 and starting from the seventh year, the unit already shows a return on investment, justifying the viability of the project.