Exhaust emission toxicity evaluation for heavy duty diesel and natural gas engines. Part I: regulated and unregulated emissions with diesel fuel and a blend of diesel fuel and biodiesel 2001-24-0044

Natural gas has a favorable effect on both the engine performance and emissions. The heavy duty vehicles fueled with natural gas have very low emission levels, not easily obtainable with other fuels, and therefore they are considered the most practicable EEV (Enhanced Environmental Friendly Vehicles). Moreover, the assessment of fuel availability makes its use possible for a long time, whilst the new generation of feeding systems offers solutions to the problem of fuel composition variability. Nevertheless, the positive environmental aspects often are not totally known by people involved in natural gas application, therefore some limitations in the diffusion of this fuel in the transportation sector still appear.

This paper refers about the activities, under development at the Istituto Motori, aimed to evaluate the toxicity of engine exhausts gas, based on the analysis of components harmful to human health, such as the carbonyl compounds, PAHs and particulate matter. A research program to determinate the toxicity of the emissions of bus engines when fueled with natural gas and with diesel oil, pure or mixed with fuel from vegetable oil, was jointly planned by the Istituto Motori and the Istituto Superiore di Sanità (Italian National Institute of Health). The activity was co-funded by the two institutes together with the Italian Ministry of Environment. This study is now in progress, its design is illustrated and the first results are presented.