In this report results from measurements of exhaust emissions from buses conducted by IVL between 2010 and 2015 are presented. The measurements are parts of three different studies of which the latest was conducted between 2014 and 2015. The measured emissions from all studies form a relatively large data set, which may be used for various analyses. This is the reason why IVL has chosen to present results from all three studies in this report, even if the focus lies on the latest study. The main objectives of the latest study were to: • measure emissions from Euro VI buses. • measure both NO (nitrogen oxide) and NO2 (nitrogen dioxide) and not only NO which was the case in the previous studies. • measure emissions from buses driving in real world traffic and not only during controlled conditions as was the case in the previous studies. In this report emissions of nitrogen oxides (NOX), carbon monoxide (CO) and particle mass (PM) are presented. The emissions have been analysed with respect to Euro class, exhaust aftertreatment and fuel type. The most important findings were: • The average emissions of NOX and particles from the tested Euro VI buses are significantly lower than from the tested Euro V buses. • The median particle emission from Euro V buses driving on 100% RME (Rapeseed Methyl Esther) was 88% lower compared to buses driving on (low blended) diesel. This result is based on measurements of buses from only one manufacturer. • The median nitrogen oxide emission from Euro V buses driving on 100% RME was 35% higher compared to buses driving on (low blended) diesel. This result is based on measurements on buses from only one manufacturer. However, the difference of the average values was not statistically significant. • No decrease in NOX emissions was observed going from Euro III to Euro V. • A constant decrease of particle emissions (by mass) was observed going from Euro III to Euro VI, with the exception of Euro IV buses using EGR. • Measured average NO2 share of NOX is in relatively good accordance with data from the road vehicle emission model HBEFA. However, the results indicate that the ratio is not only dependent on the Euro standard and the exhaust aftertreatment system but also on vehicle manufacturer. • Three out of the six buses which were tested fuelled with both (low blended) diesel and 100% RME did show a reduction of particle emissions when fuelled with RME. The remaining three buses showed an increase in PM emissions and a simultaneous increase in CO emissions. Den här rapporten finns endast på engelska. Svensk sammanfattning finns i rapporten.
In this report results from measurements of exhaust emissions from buses conducted by IVL between 2010 and 2015 are presented. The measurements are parts of three different studies of which the latest was conducted between 2014 and 2015. The measured emissions from all studies form a relatively large data set, which may be used for various analyses. This is the reason why IVL has chosen to present results from all three studies in this report, even if the focus lies on the latest study. The main objectives of the latest study were to: • measure emissions from Euro VI buses. • measure both NO (nitrogen oxide) and NO2 (nitrogen dioxide) and not only NO which was the case in the previous studies. • measure emissions from buses driving in real world traffic and not only during controlled conditions as was the case in the previous studies. In this report emissions of nitrogen oxides (NOX), carbon monoxide (CO) and particle mass (PM) are presented. The emissions have been analysed with respect to Euro class, exhaust aftertreatment and fuel type. The most important findings were: • The average emissions of NOX and particles from the tested Euro VI buses are significantly lower than from the tested Euro V buses. • The median particle emission from Euro V buses driving on 100% RME (Rapeseed Methyl Esther) was 88% lower compared to buses driving on (low blended) diesel. This result is based on measurements of buses from only one manufacturer. • The median nitrogen oxide emission from Euro V buses driving on 100% RME was 35% higher compared to buses driving on (low blended) diesel. This result is based on measurements on buses from only one manufacturer. However, the difference of the average values was not statistically significant. • No decrease in NOX emissions was observed going from Euro III to Euro V. • A constant decrease of particle emissions (by mass) was observed going from Euro III to Euro VI, with the exception of Euro IV buses using EGR. • Measured average NO2 share of NOX is in relatively good accordance with data from the road vehicle emission model HBEFA. However, the results indicate that the ratio is not only dependent on the Euro standard and the exhaust aftertreatment system but also on vehicle manufacturer. • Three out of the six buses which were tested fuelled with both (low blended) diesel and 100% RME did show a reduction of particle emissions when fuelled with RME. The remaining three buses showed an increase in PM emissions and a simultaneous increase in CO emissions.
In this report results from measurements of exhaust emissions from buses conducted by IVL between 2010 and 2015 are presented. The measurements are parts of three different studies of which the latest was conducted between 2014 and 2015.