Reologia de fluidos envolvidos no processo de obtenção de bioetanol

• Ano de defesa: 2015
• Autor(a) principal: Bofo, Daniele Cristina dos Santos [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Microbiologia industrial; Reologia; Controle de processo; Bioetanol - Industria; Cana-de-açúcar; Saccharomyces cerevisiae
• Link de acesso: http://hdl.handle.net/11449/127710

This study aimed to study the rheology of sugarcane molasses, yeast cream and fermentation broths of Saccharomyces cerevisiae SA-1, under different conditions, in concentric cylinder rheometer. For molasses, the rheological behavior is evaluated at different concentrations (20, 30, 40, 50, 60 and 70°Brix) and temperatures (21, 32, 43, 54, 65, 76, 87 and 98°C). The rheological behavior of yeast cream was evaluated at concentrations of 0.15, 0.25, 0.35, 0.45, 0.55 and 0.64g ml-1 and temperatures of 20, 30, 40, 50, 60, 70 and 80°C. And for the fermentation process, the rheological behavior of the fermentation broths was evaluated at 32 to 38°C from 0 to 10 hours. The experimental results of the molasses samples showed Newtonian behavior at concentrations from 20 to 40°Brix and pseudoplastic behavior at concentrations from 50 to 70°Brix. For these results, the Power law model presented the best fit. Furthermore, the dependence of the behavior index and consistency index of the fluid of the power law model were modeled in relation to temperature and solid concentration by a polynomial model and an Arrhenius type equation, respectively. The experimental results obtained from the yeast cream samples were adjusted in four different models and the Power Law showed the best accuracy and pseudoplastic behavior in all concentrations. The dependence of the behavior index and the fluid consistency index, obtained in the Power Law in relation to temperature and solids concentration were modeled successfully by the quadratic model and by the Arrhenius type equation, respectively. For the fermentation process, models with second and third order terms for the factor time (t), first order for the factor temperature (T) and the combination of these were built to predict the behavior of experimental data percentage of yeast, acidity, pH, percentage of total soluble solids and ethanol in the temperature range and...