Positive Valve Overlap as an Effective Conversion Energy System Using Biodiesel

Abstract

Biodiesel, with the potential to reduce emissions, is an attractive source of renewable energy in the transportation sector, which supports blending of diverse sources such as soybean oil, coconut oil, groundnut oil, palm oil and waste cooking oil. This study presents an analysis of using positive valve overlap of 32 degrees on the performance and emission of a diesel engine fired by biodiesel from two sources (waste cooking oil biodiesel and palm oil biodiesel). The waste cooking oil (WC) and palm oil (PO) biodiesel were blended with diesel fuel in varying proportion of B5, B10, B15, B20, B50, B85, B100. A 2-cylinder diesel engine model was created in Ricardo Wave software environment where simulations were conducted to evaluate brake specific fuel consumption, brake thermal efficiency, brake torque, exhaust gas temperature, CO, HC, and NOx emission. Performance results shows that at 1200 rpm, brake specific fuel consumption of 0.28798 kg/kWh for B100 and 0.27895 kg/kWh for PO100, brake thermal efficiency of 32.55% for B100 and 32.66% for PO100, and brake torque of 33.51N.m for B100 and 34.60 N.m for PO100. Emission results shows that CO emission of 15.10 ppm for B100 and 18.03 ppm for PO100, HC of 45.36ppm for B100 and 45.24 ppm for PO100; NOx of 154.03 ppm for B100 and 167.53 ppm for PO100. The implication is that the palm oil derived biodiesel uses less fuel and produces more brake power and brake torque as compared to waste cooking oil biodiesel. Conversely, emission results show that the palm oil derived biodiesel produces more emissions than waste cooking oil biodiesel.