The effect of fuel specifications and different aftertreatment systems on exhaust gas odour and non-regulated emissions at steady state and dynamic operation of DI-Diesel engines

Diesel exhaust gas contains low molecular aliphatic carbonyl compounds and strongly smelling organic acids, which are known to have an irritant influence on eyes, nose and mucous membranes. Thus, diesel exhaust aftertreatment has to be considered more critically than that of gasoline engines, with respect to the formation of undesired by-products. The results presented here have been carried out as research work sponsored by the German Research Association for Internal Combustion Engines (FVV). The main objective of the three year project was to evaluate the behaviour of current and future catalyst technology on the one hand (oxidation catalyst, CRT system, SCR process), and regulated and certain selected non-regulated exhaust gas emission components and exhaust gas odour on the other hand. Modern DI-diesel engines for both passenger cars and HD trucks were investigated in combination with an olfactometer, specially developed for this purpose, whose principle is also described in the paper