With
the cost of traditional lipid feedstocks constituting 70%
of the total cost of biolubricant production, it is urgent to find
a new lipid source for the biodiesel and biolubricant industry. With
the elevated acid value (61.8 mg of KOH/g) of housefly larval lipids,
converting the free fatty acid (FFA) into a biolubricant could serve
as a value-added approach to the larval diesel industry, other than
pretreatment by acid-catalyzed esterification for biodiesel production.
This study developed a method of producing high-purity fatty acid n-octyl esters (FAOEs) from housefly (Musca domestica L.) larvae. The housefly larva free fatty acids (HLFFAs) from the
larva lipids were obtained by wipe-film short-path distillation. FAOEs
were produced by esterifying n-octanol with HLFFAs
(catalyzed by benzenesulfonic acid under the following conditions:
catalyst loading, 2 wt %; molar ratio of n-octanol
to FFA, 3:1; temperature, 100 °C; time, 2 h). Excess n-octanol was effectively removed by high-vacuum (80 Pa)
distillation at 90 °C. The unreacted FFAs were neutralized using
demethylated crude glycerin, which is a byproduct of biodiesel production.
A practical method of producing high-purity fatty acid n-octyl esters (99.19 wt %) derived from housefly larva lipids was
thus developed, and the product could serve as a replacement for certain
low-viscosity mineral lubricants such as liquid paraffin, polyalphaolefin
6, and SN 500.