Produção de biodiesel etílico via catálise ácida em reator de fluxo contínuo com indução simultânea de ultrassom e microondas

Abstract

Continuing development of a new technology for the production of biodiesel ethyl, studies have been focused on the use of microwave and ultrasound, as contrary to the conventional method, where the methyl route has a higher reaction kinetics compared to ethyl route, reactions by microwave-assisted homogeneous acid catalysis in ethyl route gives better results than the methyl route. Thus, this work has perfected a monomode prototype machined stainless steel 316L continuous flow system, operating respectively at 2.45 GHz and 24 kHz for the production of biodiesel ethyl assisted by microwave and ultrasound simultaneously. In both cases the physical xiii principles involved in the ways of wave propagation as well, and the chemical characteristics of the reaction medium aiming to maximize the effect of the wave material interaction. Also, the prototype was combined with a Programmed Logic Control (PLC) for control of valves generating the microwave (magnetrons) allowing a mode of operation continues and to seek more efficient. The use of simultaneous ultrasonic aims at improving the homogeneity of the reaction mixture and solve a problem observed in earlier studies that it is the phase separation of glycerin and biodiesel after conversion exceeding 80%, which causes a decrease in catalytic activity of the acid catalyst by removal of the oily phase, as well as allowing the emergence of side reactions such as degradation of glycerin. In the prototype, they were tested via reactions with ethyl route soybean oil and sulfuric acid as a catalyst. We evaluated the biodiesel conversion percentage as a function of the power of microwave and ultrasound flow of the reaction mixture, the proportion of catalyst in relation to the total volume of the reactants and the molar ratio of oil / alcohol. The percentage of biodiesel oil conversion were determined according to standard EN 104103 by gas xiv chromatography with flame ionization detection (GC / FID).