Abstract
The motor vehicles are one of the main sources of pollutants emission in Poland, especially in urban areas. In age structure of Polish fleet of motor vehicles, old vehicles dominate. Over 40% of cars driving on Polish roads are older then 10 years and these old vehicles, usually not equipped with emissions control systems, are responsible for the larger part of traffic emissions. Considerable improvement in this situation would be achieved by an immediate withdrawal from the traffic of almost half the number of vehicles which are operated in Poland, what is obviously impossible. Therefore search for means that enable reduction in negative influence of old vehicles on environment, is in progress. The environmentally friendly fuels are regarded as very effective means and at the same time possible to use on a large scale to decrease emissions.
With regard to Diesel engines, the reduction in nitrogen oxides and particulates causes most difficulties. Although the fuel influence on NO x is comparatively not large, composition and parameters of diesel fuel have a big influence on particulate emissions and composition. Sulphur content is one of fuel proprieties, which has the most considerable influence on particulates.
The paper describes results of our research on particulates emissions from Diesel engines, most widespread in Poland, fuelled with research fuels of different sulphur contents. The sulphur content in research fuels varied from 2000 ppm (current limit in Poland) to 50 ppm (EURO IV limit, which will be in force in the European Community from 1 January 2005). An AVL Dynamic Particulate Analyser 480 was used for particulate emissions measurement.
The carried out experiments, confirmed the high influence of sulphur content in diesel fuel on particulate emissions and composition. Therefore, the sulphur content in diesel fuels available in Poland should be decreased, as soon as the stringent standards being in force in European Community.