Emission Characteristics and Microscopic Morphology of Particles from China V Diesel Bus Fueled with Biodiesel Blends

Abstract:

A diesel bus certified to meet China Ⅴ emission standards is selected as the research object to explore the mass， number， size distribution and microscopic morphology of particles by fueled with different used cooking oil （UCO） biodiesel blends during China typical city bus driving cycle （CCBC） experimentally. The results show that the mass and the number of particles emitted from the diesel bus decrease as the mixing ratio of the UCO biodiesel increases， and the typical microscopic morphology of particles by fueled with biodiesel blends is similar to that by fueled with diesel. The particles consist of dozens of quasi-spherical basic carbon particles， mainly in irregular shapes such as chain and branch. Moreover，the particles by fueled with biodiesel blends have smaller basic carbon particle size， larger fractal dimension and more compact spatial structure than those by fueled with diesel. In the process of oxidation， the particles by fueled with biodiesel blends are easier to be oxidated at agglomerating area， and the fractal dimension and the average size of basic carbon particles increase with the oxidation. However， the oxidation mainly occurs at the outermost carbon layer of the particles by fueled with diesel， and the fractal dimension and the average size of basic carbon particles decrease.