Experimental study on characteristics of biodiesel exhausted particle

A particle emission experiment of a direct-injection turbocharged diesel engine with biodiesel and diesel was carried out. A pump of 80 L/min and fiber glass filters with diameter of 90 mm was used to sample engine particles in exhaust pipe. The size distribution, soluble organic fraction (SOF) and 16 polycyclic aromatic hydrocarbons (PAHs) of particles were analyzed by a laser diffraction particle size analyzer and GC-MS. The results indicate that the volume weighted size distribution of biodiesel particle is single-peak and its median diameter d(0.5) and mean diameter d₃₂ are decreased with the increasing speed. At the high speed the d₃₂ and d (0.5) of biodiesel are larger than those of diesel, and quite the contrary at the low speed. SOF mass concentration and mass percentage of biodiesel are 12.3-31.5 mg/m³ and 38.2%-58.0% respectively, which are much higher than those of diesel. The total PAHs emission concentration of biodiesel is 2.9-4.7 μg/m, lower than that of diesel as much as 29.1%-92.4%.