Estudo da hidrólise catalítica do óleo de soja em reator de leito fixo

Abstract

Much of the world's energy production is generated from fossil fuels. The problem goes beyond the scarcity of fossil resources to include the emission of pollutants. Oleochemistry is an industrial segment that encompasses several processes for transforming vegetable oils and animal fats into products with high added value, including biofuels. The hydrolysis reaction, aiming at the production of free fatty acids, is of great importance for the industry. The process can be carried out thermally, as a liquid-liquid or gas-liquid reaction, or using catalysts, which accelerates the reaction and allows the process to be carried out under moderate conditions of temperature and pressure. One of the most common reactors in the chemical industry, used in catalytic processes is the packed bed reactor, because it is a versatile reactor and suitable for large quantities of materials. The present work aims to study the acid hydrolysis reaction of soybean oil, using γ-Al2O3 as a catalyst in a packed bed reactor. The γ-Al2O3 catalyst was prepared by calcination of the bohemite at 500 ºC and characterized in terms of its structure by the X-ray diffraction method (DRX) and the textural properties were determined by N2 Fisisorption. The influence of WHSV on the conversion of triglycerides in the pecked bed reactor at a temperature of 250 ºC and a pressure of 50 bar was studied. For the WSHV of 0.41 h-1, a 97% conversion was obtained. The rate constant, activation energy and pre-exponential factor of the first stage of the hydrolysis reaction were determined. Different temperatures were studied in order to obtain kinetic parameters of the reaction For the temperatures of 240 ºC, 250 ºC and 260 ºC rate constants obtained, respectively, were 0.0371; 0.0713; 0.1427 min -1. The activation energy found was 153,06 KJ /mol and the pre-exponential factor equal to 1.41 * 1014. The determination of the activation energy and the reaction rate constant of the first reaction step, with the considerations made in this Dissertation are an important starting point for the determination of the hydrolysis mechanism of soybean oil in a fixed bed.