Liquid-liquid equilibrium for systems composed by biodiesel from catolé oil (Syagrus cearensis), methanol and glycerol

Abstract

The biodiesel inclusion in the Brazilian energy matrix still faces challenges due to the lack of diversity of raw material and the high costs associated with the stages of production, purification and phase separation of the biofuel. In this work, the potential of Catolé (Syagrus cearensis) was evaluated as an alternative source for biodiesel production, through methyl transesterification by alkaline catalysis. Given the absence of reported data on this oilseed, the aim of the present paper is to characterize the oil and biodiesel in terms of density, kinematic viscosity, and acid value. A liquid-liquid equilibrium (LLE) study of Catolé biodiesel-methanol-glycerin systems at 298.15, 308.15 and 323.15 K at atmospheric pressure was also carried out. Results showed that Catolé seed oil is a viable alternative for biodiesel production, with parameters found in accordance with the quality standards and an ester yield of 97.1%. Ternary diagrams showed that the solubility of the components lowers at low temperatures. Tie-lines evidenced higher affinity of methanol with the glycerin-rich phase. Distribution and selectivity coefficients were determined and the Othmer-Tobias and Hand correlations were applied to verify the quality of the experimental data. The determination indices (>0.97) proved the thermodynamic consistency of the data.