For diesel buses, this study has demonstrated that in-use emissions of NO measured in real traffic roughly correlates with the certification levels for NOx for Euro 2, Euro 3 and Euro 4. The NO2/NOx fraction for DPF equipped Euro 2 and Euro 3 diesel buses was estimated to approximately 25 %. The effect of vehicle age as regards NO-emissions was studied for Euro 3 EGR diesel buses and Euro 2 diesel buses equipped with DPF. For the EGR buses there was no evidence of ageing effects. For the DPF buses there seemed to be a tendency for increased NO emissions with increasing vehicle age. However, this does not necessarily imply that NOx emissions have increased an equal amount, since the reason for increased NO may be a deterioration in the NO to NO2 conversion that takes place in the DPF. It is not known whether a decrease in NO2 concentration will have any effect on the efficiency of the particle filter. CNG buses certified according to the EEV standard and equipped with catalysts displayed for NO emissions a statistical distribution that was similar to what is normally observed for modern gasoline passenger cars. Most buses in the data set had quite low emissions, but there were also 'high-emitters' which were few in number but had a clear influence on average emissions. The average NO emission was significantly higher (in relation to e.g. Euro 3) than was expected from the certification levels. This result indicates that the emissions of CNG buses need to be checked at regular intervals in order to maintain the environmental benefits associated with CNG technology. Further on, this study has demonstrated that remote sensing is a viable and cost-efficient alternative to more costly laboratory methods as regards emission measurements on in-use buses. If future development of remote sensing systems could allow for measurement of NO2, particles and NH3 (for SCR applications), the method would be further strengthened.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    On-road optical remote sensing measurements of in-use bus emissions


    Additional title:

    Optische Fernmessung von Omnibusemissionen im Straßenverkehr


    Contributors:


    Publication date :

    2005


    Size :

    8 Seiten, 4 Bilder, 3 Tabellen, 12 Quellen



    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Remote Sensing Measurements of On-Road Emissions in Five European Cities

    Mercer, A. / McArragher, S. / Coordinating Research Council | British Library Conference Proceedings | 1997


    Remote Sensing Measurements of On-Road Vehicle Emissions of an Important Greenhouse Gas: Nitrous Oxide

    Jimenez, J. L. / Nelson, D. D. / Zahniser, M. S. et al. | British Library Conference Proceedings | 1997


    An Evaluation of Remote Sensing Devices for On-Road Emissions Measurement

    Pedrosa, J. / Coordinating Research Council | British Library Conference Proceedings | 1996


    Pacific 2001: Cassiar Tunnel Study - Remote Sensing Emissions Measurements

    Burelle, C. A. / Coordinating Research Council | British Library Conference Proceedings | 2002


    Congestion and On-Road Vehicle Emissions as Measured by Remote Sensing

    Pokharel, S. S. / Coordinating Research Council | British Library Conference Proceedings | 2002