Algae based lubricants and drop-in fuels

Abstract: The microalgal species Botryococcus braunii (B. braunii) offers the ability to convert carbon dioxide into renewable hydrocarbons. This work evaluated B. braunii race B hydrocarbons as a biobased lubricant and potential source for producing aviation fuel. Characterization of B. braunii biomass determined that 55.6% of the dry weight was extractable oil comprised primarily of C₃₁ and C₃₃ botryococcenes. Extracted botryococcene oil was hydrocracked and distilled to isolate the kerosene fraction. The hydrocracked botryococcene kerosene displayed a high net energy density, negligible sulfur content, high flash point, and excellent low temperature properties. However, the high olefin and aromatic content would necessitate further hydrotreatment or blending to meet Jet A specifications. As a lubricant, botryococcene oil displayed a remarkably high viscosity index of 369, favorable cold flow properties, marginally better oxidation stability than soybean oil, and tribological performance comparable to soybean oil and PAO oil.