Estudo cinético de óleo de fritura utilizando catalisador bifuncional de Mo/H-Beta

Abstract

Studies involving the use of zeolites as catalysts in biomass degradation to obtain biofuels have become common in several fields of research in recent years, the application of these minerals is basically due to the thermal resistance, chemical, selectivity and large surface area, which provides the desirable properties for the catalysts employed in suchs processes. Frying oil is a type of biomass, classified as a biofluid. It is basically composed of triglycerides, has high viscosity and acidity, is available in considerable quantities at low cost, factors that contribute to the use of this source for biofuel production. In this work, molybdenum oxide impregnated H-Beta zeolite was studied as a bifunctional catalyst for frying oil degradation through kinetic study. For the study, initially, the physicochemical properties of the frying oil were analyzed in order to characterize it. Thereafter, thermal analyzes were performed to evaluate the frying oil degradation through different heating ratios (β) (5, 10, 15 and 20 °C/min), the temperature range examined was between 27 °C and 600 °C. The data were used to perform and evaluate the kinetic study using the Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) free kinetic models to obtain the activation energies in the thermal and thermocatalytic processes, as well as their conversion rates by the action of temperature. In the characterization parameters, the frying oil presented an acidity of 0.77 mgNaOH/g, kinematic viscosity of 32.55 mm2/s and specification density of 0.923 g/cm3, results compatible with the literature. The kinetic model that best described the experimental data was the free Ozawa-Flyn-Wall kinetic model, ratified by the higher determination coefficients (R2) in relation to the Kissinger-Akahira-Sunose kinetic model. Through the kinetic models, it was found that the Mo / H-Beta catalyst showed activity, ratified by the low activation energy from the 10% conversion of the thermocatalytic process in relation to the thermal decomposition process of the frying oil, showed reductions of more than 40% apparent activation energy at 50% conversion as well as reduced frying oil conversion temperatures.