Production of New Surfactant-free Microemulsion Biofuels: Phase Behavior and Nanostructure Identification

摘要

New surfactant-free microemulsion biofuels are synthesized and characterized in this work. Moringa and safflower plants have been used for providing the required oils because of their excellent resistance in dry and harsh environmental conditions. Methyl tert-butyl ether (MTBE), 1-heptanol, 1-octanol, oleic acid, 1,4-dioxane, and dibutyl ether have been used as biofuel additives. The obtained phase behavior results show that the microemulsion region of ternary phase diagrams in these systems decreases as follows: oleic acid 1-octanol 1-heptanol MTBE dibutyl ether 1,4-dioxane. The nanostructures formed in these types of ternary mixtures are investigated by conductivity, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) techniques. Three different micro regions, including ethanol in oil (E/O), bicontinuous (B.C.), and oil in ethanol (O/E), have been recognized using electrical conductivity experiments along ethanol dilution lines. According to the presented results, the E/O region regarding the studied microemulsions is wider than the B.C. and O/E regions. Thus, the proposed formulation according to the reverse micelle microemulsion formation can be considered as a useful approach for biofuel production. It is also shown that the kinematic viscosities and densities of the formulated biofuels in this article satisfy the approved biofuel standards.