Abstract
This paper discusses the effect of performance and emission characteristics for four stroke Spark Ignition engine by mixing fine plastic powder. In this experiment, net power, cylinder internal pressure, fuel consumption rate and concentration of harmful matters in exhaust gas such as NOx, CO and HC were measured in a single-cylinder motorcycle engine of 49.5 cc displacement equipped with fuel injection. Operating conditions for the engine were 14.8 in air fuel ratio, 3000 rpm in revolution speed, 32 °CA BTDC (MBT) in ignition timing. Four plastic powders of PMMA, PP, PE and PET with average particle size of 5 μm were used and two kinds of mixing ratio of 5 wt%, 10 wt% for plastic powder and gasoline were examined. Powder and air were uniformly mixed in a mixing chamber. The results show that any plastic powder worked partially alternative fuel to gasoline. PP and PE powder with high combustion quality and large lower heat value increased net power. But, in case of 10% mixing ratio, the increase of rate of change of net power and flame velocity were smaller due to the promotion of the coagulation. PMMA powder with high volatility and small lower heat value decreased combustion temperature estimated by the decrease of NOx concentration. PET powder with incombustibility increased cylinder pressure and flame velocity due to the turbulence of the flame front.
