Particles, compositions and particle mass spectrometry emission characteristics with biodiesel and diesel exhaust after-treatment system

Biodiesel as a renewable and cleaner fuel would provide an alternative to banning fossil fuel vehicles. In this study, the effect of biodiesel produced from waste cooking oil on particles emitted from an urban bus, as well as their compositions and mass spectrometry characteristics were investigated using heavy-duty chassis dynamometer based on China city bus cycle (CCBC). The results showed that B10 (10 % biodiesel and 90 % diesel by volume) could reduce 22.8 % of the total particles and increase the proportion of accumulation particles due to better reduction effect on nucleation particles. After the diesel oxidation catalyst (DOC) coupled catalysed diesel particle filter (CDPF) after-treatment system (AT) was utilized, more than 99 % of the particles were reduced, and the nucleation particle proportion increased at low and middle speeds, but decreased at high speed. For the particle compositions, B10 led to a reduction in organic carbon (OC) and elemental carbon (EC), reduced the main ions emissions and 12.8 % of alkanes, but increased the fatty acid emissions by 61.2 % and decreased the PAHs by 25.6 %. The use of AT with B10 could reduce 70.9 % of the OC and EC emissions, as well as 67.1 % of the alkane, 63.4 % of the fatty acid emissions and 89.4 % of the total PAHs, but led to an increase in the main ions emissions. Particle mass spectrometry indicated that B10 led to more complex particle compositions.