Effect of Waste Cooking Oil Biodiesel on the Emissions of a Diesel Engine

This paper is focused on investigating the gaseous and particulate emissions of a 4-cyclinder natural-aspirated direct-injection diesel engine fueled with different mixed concentrations of biodiesel and diesel fuel, including pure diesel fuel, B10 (diesel containing 10%vol of biodiesel), B20, B30 and pure biodiesel. Experiments were conducted with five engine loads, corresponding to brake mean effective pressures of 0.165, 0.33, 0.496, 0.661 and 0.753 MPa at a constant speed of 1800 rpm. The results show that biodiesel leads to reduction of HC, CO and particulate mass concentrations and number concentrations but an increase in NOx. In addition, particulate samples were collected from the diluted exhaust and analyzed using thermogravimetric analyzer/differential scanning calorimetry (TGA/DSC). The TGA results show that with increasing biodiesel in the fuel or decreasing engine load, the volatile mass fraction of the particulate increases and the ignition temperature of the soot decreases.