Applying the handprint approach to assess the air pollutant reduction potential of paraffinic renewable diesel fuel in the car fleet of the city of Helsinki

Abstract

Ambient air pollution is a global environmental challenge, especially in densely populated regions. In urban areas, road traffic is an important source of fine particulate matter (PM2.5) and nitrogen oxide (NOx) emissions, primarily due to exhaust gases. The adoption of paraffinic renewable diesel fuels for urban transportation has been suggested as a more sustainable and less air polluting alternative to conventional fossil fuels. The aim of this study is, therefore, to examine whether the transition from the conventional fossil fuel diesel to paraffinic renewable diesel (hydrotreated vegetable oil [HVO] according to the EN 15940 standard) can reduce PM2.5 and NOx emissions in an urban environment. The life cycle assessment-based handprint approach is utilized to calculate and demonstrate the emissions reduction. The reduction potential is quantified for Euro 4, 5 and 6 passenger diesel cars using actual car fleet, mileage, local temperature, and laboratory emissions measurements for 2018 in Helsinki, Finland. Our study shows that the use of HVO can reduce PM2.5 and NOx emissions in urban areas. According to our results, PM2.5 emissions could be reduced by 49% for the defined location and car fleet by replacing conventional fossil-fuel diesel with HVO. In the case of NOx emissions, the local reduction potential is 7%. Overall life cycle emissions reduction potentials of NOx and PM2.5 emissions are 11% and 44%, respectively, if conventional diesel is replaced by HVO. Thus, the manufacturer of HVO can communicate the air quality handprint, and in particular, the NOx and PM2.5 handprints, that their product can achieve.