Tie Line Analysis of Ternary Phase Diagram for Purification of Castor Oil Biodiesel/Methanol/Glycerol System at 20 °C And 30 °C
Authors: Adama KK, Aluyor EO, Audu TOK
The final product of biodiesel production is often taken as a ternary mixture of the specific biodiesel, methanol and glycerol to certain degree of purity. Tie line analysis of ternary phase diagram for castor oil biodiesel/methanol/glycerol system was investigated in this research to provide experimental data for the purification of the biodiesel system. Measurements were carried out at temperatures of 20°C and 30°C and time of 2 mins to 32 mins at intervals of 2 mins using cloud point titration procedure under isothermal conditions. Gas chromatography (GC) methodology using ASTM D6584 standard was employed for the analysis of the mixture component mass compositions to obtain the tie line data. The distribution coefficient, K, and solvent selectivity, S, were evaluated to ascertain the extracting capacity of methanol and for the location of immiscibility of the ternary components. The influence of temperature on K and S were also investigated. The results obtained revealed that two liquid phases existed at the investigated temperatures and the optimum areas of influence of the mixture components were located using the tie line ternary phase diagrams. Methanol was observed to preferentially distribute to the lower glycerol-rich phase than the upper biodiesel-rich phase though biodiesel solubilized more methanol than glycerol.
Affiliations: Department of Chemical/Petroleum Engineering, Alex Ekwueme Federal University, Ndufu Alike Ikwo (AE- FUNAI), Ebonyi State, Nigeria
Keywords: Phase Diagram, Purification, Castor Oil Biodiesel, Methanol, Glycerol, Tie Line, Temperature
Published date: 2018/12/30