Modified oil from Schizochytrium sp. microalgae as a lubricity improver for diesel

The potential of bio-oil derived from the microalgae Schizochytrium sp. is investigated as a lubricity enhancer for diesel fuels. The bio-oil underwent a series of modifications. Initially, it was subjected to transesterification, a process that yielded a mixture of fatty acid methyl esters (FAMEs). Subsequently, the oil was epoxidized to enhance its oxidative stability. The modified bio-oil (MBO) was then blended with diesel at different volumetric ratios (5 %, 10 %, and 20 %), and physicochemical and tribological properties were assessed following standard procedures. The findings exhibited a 227 % enhancement in oxidative stability after epoxidation, thereby meeting regulatory stipulations. It is noteworthy that the incorporation of a mere 5 % MBO resulted in approximately 30 % reduction in friction and a 71 % decrease in wear scar depth. This is primarily attributable to the higher polarity and viscosity of the MBO relative to diesel, which promote the formation of a tribolayer. These findings support the feasibility of using Schizochytrium sp. derived MBO as an effective and sustainable lubricity improver for diesel. • A modified bio-oil (MBO) was obtained by a transesterification reaction. • The oxidation stability of the MBO was improved by an epoxidation reaction. • The MBO slightly changed main diesel properties but improved the diesel lubricity. • The addition of 5 % of MBO to diesel highly reduced friction and wear. • The higher polarity/viscosity of the MBO regarding diesel explained these results.