Abstract
A series of combustion experiments were performed employing a micro-jet engine under diverse conditions. These conditions encompassed a spectrum of Biofuel mixture ratios spanning from 10 to 50, alongside rotating speeds ranging between 80,000 and 100,000rpm. The primary objective was to clarify the combustion characteristics and exhaust gas components of Biofuel (fatty acid ethyl esters) derived from coconut oil. Comparing the combustion efficiency of jet fuel and Biofuel-blended fuel, the findings exhibited a marginal enhancement in efficiency when Biofuel mixtures comprised up to 50% Biofuel. This increase was ascribed to the increase in the oxygen content within the fatty acid ethyl ester constituents and the relatively low heating values of the ethyl esters compared with those of the jet fuel. On the other hand, the specific fuel consumption increases with higher Biofuel blending ratios. This is because, as the Biofuel blending ratio increases, the lower heating value decreases, necessitating more fuel for stable combustion. Gas analysis revealed various effects on greenhouse gas emissions. While CO emissions increased slightly, CO$_2$ and NO emissions decreased with an increase in the Biofuel blending ratio.
