Search Results

It is generally accepted that emissions of nitrogen oxides (NOx) increase as the volume fraction of bio diesel increases in blends with conventional diesel fuel. While many mechanisms based on bio diesel effects on in-cylinder processes have been proposed to explain this observation, a clear understanding of the relative importance of each has remained elusive. To gain further insight into the cause(s) of the bio diesel NOx increase, experiments were conducted in a single-cylinder version of a heavy-duty diesel engine with extensive optical access to the combustion chamber. The engine was operated using two bio diesel fuels and two hydrocarbon reference fuels, over a wide range of loads, and using undiluted air as well as air diluted with simulated exhaust gas recirculation.