Biodiesel production from swine manure via housefly larvae (Musca domestica L.)
Although biodiesel is a sustainable and renewable diesel fuel, the current feedstock predominantly from edible oils limits the economic feasibility of biodiesel production and thus the development of a cost effective non-food feedstock is really essential. In this study, approximately 21.6% of crude grease was extracted from housefly (Musca domestica L.) larvae reared on swine manure, and the extracted greasewas evaluated for biodiesel production concerning the variables affecting the yield of acid-catalyzed production of methyl esters and the properties of the housefly larvae-based biodiesel. The optimized process of 8:1 methanol/grease (mol/mol) with 2 vol% H2SO4 reacted at 70 C for 2 h resulted in a 95.7% conversion rate from free fatty acid (FFA) into methyl esters. A 90.3% conversion rate of triglycerides (crude grease) to its esters was obtained from alkaline trans-esterification using sodium hydroxide as catalyst. The major fatty acid components of this larvae grease were palmitic (29.1%), oleic (23.3%), palmitoletic (17.4%) and linoleic (17.2%). The housefly larvae-based biodiesel has reached the ASTM D6751-10 standard in density (881 kg/m3), viscosity (5.64 mm2/s), ester content (96.8%), flash point (145 C), and cetane number (52). These findings suggest that the grease derived from swine manure grown housefly larvae can be a feasible non-food feedstock for biodiesel production.