Confecção de reator em fluxo contínuo para a produção de biodiesel etílico via catálise homogênea, com indução por micro-ondas e estudo dos parâmetros dielétricos dos constituintes e da reação

Abstract

In this paper presents data on the dielectric properties of constituents of the reaction of production of biodiesel and the reaction medium itself, where we measured the reactants, products and catalysts (acids): Brazil nut oil, ethanol, methanol, sulfuric acid, phosphoric acid, methanesulfonic acid, chlorosulfuric acid and glycerin. Since the frequency range 0.3 to 13 GHz and temperature range of 0 - 100 ° C. The reaction was carried evaluated with Brazil nut oil, ethanol (1:90) and sulfuric acid as catalyst at different catalyst concentrations ranging from 1 - 5% V/VT. This same reaction was studied in a prototype reactor microwave cylindrical geometry operating in continuous flow mode, transverse electric (TE) and frequency of 2.45 GHz. According dielectric study it was found that the main responsible by the heating in microwave cavity is sulfuric acid, whose dielectric absorption is up to 20 times higher than ethanol, despite it being the major component from the investigated reaction , its absorption is not predominant in the medium. As the oil which has the lowest absorption of all the constituents. Since the reaction medium shows a decrease of its absorption during the chemical reaction (at 2.45 GHz), this decrease being directly proportional to the concentration of sulfuric acid catalyst. A analysis with basis in frequency ISM (industrial, scientific and medical) there that the frequency most appropriate for this reaction is from 0.915 GHz. Regarding the dielectric properties of the catalysts (conductivity and penetration depth) it was observed that they vary linearly with temperature. The reactor was achieved optimal coupling between the emission source and a microwave cavity, as demonstrated by the power dissipated in the dielectric (water) had efficiency greater than 90%. In testing reaction times gave complete conversions lower than 10min emission, confirming the enormous potential of this technology for biodiesel production.