Tests were conducted using an ASTM Aviation Supercharge CFR engine to determine whether high levels of fuel-bound nitrogen lead to increased nitric oxide emissions in a supercharged engine. Fuel nitrogen levels were formulated by doping several different fuels with pyridine.
The results of the testing on this particular engine indicate that the effects of fuel nitrogen on nitric oxide emissions were so small that they were masked by the uncertainties associated with the experimental procedures used.
Comparisons with the results from other researchers suggest that the results of this study are probably associated with stratification of the fuel-air mixture. It is recommended that additional tests be conducted to investigate the effects of fuel-air mixing on fuel-nitrogen conversion.