Interest in the use of alternative fuels and combustion regimes is increasing as the price petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of new passenger car market. Unfortunately, lower CO2 emissions are countered with higher noise, nitrogen oxide (NOx) and particulate matter (PM) emissions. Noise and PM have traditionally been the obstacles toward consumer acceptance of Diesels passenger cars in North America, while NOx has been more an engineering challenge. Diesels are lean burning (excess oxygen) and reducing NOx to N2 in an oxygen rich environment is difficult. Adding oxygenated compounds to the fuel helps reduce PM emissions, but a truly PM-free fuel is unrealistic. Keeping combustion below 1700 K prevents NOx formation. Altering the combustion regime to burn at temperatures below the NOx threshold and accept a wide variety of fuels seems the best alternative. Homogeneous Charge Compression Ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the piston. Ignition is rapid and relatively cool, producing neither NOx nor PM. Unfortunately, it is hard to control since it is initiated by temperature and pressure instead of a spark or rich region of injected fuel. We are using intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to validate combustion modeling.
See more of Poster Session I
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)