Performance and emissions of camelina oil derived jet fuel blends under distributed combustion condition

Abstract

Renewable biofuels offer good performance characteristics as fossil liquid fuels while reducing the emission of pollutants and greenhouse gases helping promote sustainability. Colorless distributed combustion (CDC) for gas turbine applications offers robust means of providing understanding of performance and emissions characteristics using liquid biofuels. In this study, performance and emission characteristics are reported from the combustion of a liquid biofuel, hydroprocessed esters and fatty acids synthetic paraffinic kerosene (HEFA-SPK), derived from camelina oil. Currently HEFA-SPK is approved in up to a 50% blend with jet fuel (JP-8) for commercial and military applications. Experiments conducted on various blended ratios of HEFA-SPK to JP-8 are reported, ranging from 100% JP-8 to 100% HEFA-SPK. Experiments were carried out on a swirl-assisted burner at thermal intensity of 5.7 MW/m-atm, with oxidizer preheated and fuel pre-vaporized to 600 K. Distributed combustion conditions were achieved by reducing the oxygen concentration in the oxidizer through adding diluent gases of N2 and CO2 simulating internal entrainment of hot reactive gases. The effect of blended fuel properties on flame structure (through OH* chemiluminescence) and emissions are reported here. HEFA-SPK and JP-8 showed ultra-low NO emission under CDC, ranging between 2 and 2.5 ppm. HEFA-SPK showed significant reduction in CO of up to 50% compared to JP-8 fuel. This study revealed that camelina oil derived fuel produced from biomass can be used as a mixture component with JP-8, maintaining high combustion performance while providing ultra-low CO emission. The biofuels also help support reduction of lifecycle CO2 emission.