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The goal of this work is to evaluate the influence of different pretreatments in the kinetics of enzymatic hydrolysis of sugarcane bagasse and to propose a reliable methodology to easily perform sensitivity analysis and updating kinetic parameters whenever necessary. A kinetic model was modified to represent the experimental data of the batch enzymatic hydrolysis of sugarcane bagasse pretreated with alkaline hydrogen peroxide. The simultaneous estimation of kinetic parameters of the mathematical model was performed using the Pikaia genetic algorithm using batch hydrolysis experimental data obtained with different enzymatic loads. Subsequently, Plackett-Burman designs were used to identify the kinetic parameters with the higher influence on the dynamic behavior of the process variables, which were re-estimated to describe experimental data of the hydrolysis of bagasse pretreated with phosphoric acid + sodium hydroxide. The methodology was accurate and straightforward and can be used whenever there are changes in pretreatment conditions and/or fluctuations in biomass composition in different harvests.

Some important properties of biodiesel such as viscosity, melting point, thermal stability, and cetane index can be directly related to the chemical composition of the biomass source used. However, the viscosity of castor oil ethyl ester (COEE) is about four times greater than the biodiesel viscosity specification, and this fact restricts the uses of this biofuel. The main goal of this work is to investigate the physical–chemical properties of COEE in ethanol blends and present an option to decrease the castor oil biodiesel viscosity specification. COEE viscosity is 14.413 mm2/s. The results show an evident decrease in biodiesel viscosity with the addition of ethanol. Samples with 30, 40, and 50 vol % of ethanol present the following viscosities 5.316, 4.044, and 3.136 mm2/s, respectively. These results are in agreement with Brazilian National Agency of Petroleum, Natural gas and Biodiesel (ANP), and European (EN 14214) specifications. Three correlations that describe the decrease in viscosity and density with ethanol concentration, and the variation of viscosity with the density in COEE ethanol blends were obtained. The behavior of COEE ethanol blends with diesel also were analyzed. The increase in solubility of ethanol in commercial diesel was verified because COEE acts as a cosolvent in an ethanol–diesel mixture.