An Easy One-Step Multiconventional Refining Approach for Producing Potential Biolubricants from Black Soldier Fly (BSF) Fat ( Hermetia illucens )

Abstract

Abstract BSF-Fat, the residue of the insect protein production process, represents a renewable, nonfood lipid feedstock for preparation of “green base oils” used as biolubricants. Yet, BSF-Fat-based biolubricants require chemical modification of alkyl esters to render adequate properties. Our developed multiconventional refining approach successfully formulated BSF alkyl esters from BSF triglycerides while obtaining a high purity, more valuable commercial BSF free fatty acid (BSFFfA) fraction (94% yield) by an easy one-step soap cleavage of the refined BSF oil. BSF alkyl esters from condensation reactions of the purified BSFFfA fraction and the refined BSF oil with 2-ethylhexanol (2EtH) and trimethylolpropane (TMP) were analyzed and further confirmed by FTIR spectra for effective molecule absorption by ester functional groups (stretching vibrations at 1743–1746 1/cm corresponding to C═O). A crystallization temperature of –18 °C for 168 h, pour point of –27 °C, viscosity index of 163, flash point (COC) of 211 °C, and kinematic viscosity at 40 and 100 °C of 6 and 2 cSt, respectively, highlighted the best performance of BSF alkyl esters beyond that of vegetable oil-based biolubricants. A bicycle braking test also highlighted their performance comparable to that of existing commercial hydraulic lubricants mineral oil based; thereby, this developed approach can expand BSF alkyl esters’ true potential for applications.