Engine performance and emissions from the combustion of low-temperature Fischer?Tropsch synthetic diesel fuel and biodiesel rapeseed methyl ester blends

The combustion of oxygenated biodiesel (rapeseed methyl ester (RME)) improves the engine-out particulate matter, hydrocarbon and carbon monoxide (CO) emissions, while the low-temperature Fischer?Tropsch synthetic paraffinic diesel fuel improves engine-out NOx, CO, hydrocarbon and particulate matter emissions. Blending synthetic diesel (SD) fuel with oxygenated biodiesel could unlock potential performance synergies in the fuel properties (e.g. O2 content in RME and high cetane number of the synthetic fuels) of such blends and benefit engine performance and emissions. The combustion of synthetic diesel fuel/RME blend, named synthetic diesel B50, has shown similar combustion characteristics to diesel fuel, while simultaneous improvements in engine efficiency and smoke-NOx trade-off were achieved by taking advantage of the fuel's properties. The engine thermal efficiency was dependent on the fuel type, and followed the general trend: synthetic diesel > SDB50 > diesel > RME. Therefore, it has been shown that the design of a synthetic fuel with properties similar to the fuel blends presented in this work could improve engine-out NOx, smoke and hydrocarbon emissions and maintain or improve engine performance.