Modelagem termodinâmica do equilíbrio líquido-líquido do sistema {Biodiesel de Chichá (Sterculia striata) + Glicerol + Etanol}.

Abstract

The main sources of biofuel production from energy sources have been sought from many alternatives of time, but also of great impetus, in the last decade, by the need to use oil and its alternatives, having one for new sources. of vegetable oil and technologies that enable its applications. The chichá (Sterculia striata) is a large tree, from 8 to 25 meters high, found in the Brazilian Atlantic Forest, with rapid growth, resistant to low temperatures and different altitudes. The seeds are cylindrical and flat with a black skin that comes off as it dries. It has up to 42% oil in its kernel, being a potential application for the maintenance of oil mainly in Brazil. In recent years, research can make the production of biodiesel, ethyl, technically and economically viable. In this sense, much has been done regarding the reactional aspects of this process. However, little has been researched aiming to solve the problems related to the separation and purification steps. Knowing the behavior of the phases of the systems is vital for the design, operation and control of these units. In order to carry out an adequate modeling of biodiesel production, thermodynamic knowledge of the mixture, information from kinetic data and use of considerations, when necessary, are necessary. This work reports experimental results and thermodynamic modeling of the Liquid−Liquid Equilibrium (LLE) of the chicha biodiesel (Sterculia striata) + glycerol + ethanol system. Binodal curves and tie-lines were obtained at different temperatures (303,15, 318,15 e 333,15 K) and pressure (101,3 kPa). The quality of the experimental data was made. Non-random two-liquid models (NRTL) and analytical solutions of groups (ASOG) were used to correlate the LLE data. Both models fit the experimental data well with root mean square (rmsd) deviations of no more than 1.5%.