EMISSION CONTROL AND PERFORMANCE CALIBRATION FOR BIOETHANOL BASED FUEL COMBUSTION IN SPARK IGNITION ENGINES UNDER IDLE AND LOW LOAD CONDITIONS

Fuel crisis over the past few decades encourages the use of alternative fuels, particularly for transportation. Bioethanol derived from edible sources have been widely used as a partial substitute to gasoline. In the distillation process to separate bioethanol, a hydrous bioethanol has to be dehydrated at a cost to yield anhydrous ethanol. Anhydrous ethanol is blended with gasoline in different proportions to fuel current gasoline engines, for instance, E85 (15% gasoline with 85% anhydrous ethanol). This work presents the effects of preheating anhydrous and hydrous E85 fuels on exhaust gas emissions, combustion characteristics and performance of a four-cylinder port fuel injection gasoline engine, calibrated for maximum brake torque timing and stoichiometric fuel-to-air equivalence ratio at low load condition. Additionally, the effects of minimizing fuel quantity injected to the combustion chamber of the engine running with hydrous bioethanol are revealed, under lean-burn idle conditions. The results suggest to calibrate the engine for performance and emissions by adjusting ignition timing and injection duration, or adding fuel preheating element for bioethanol based fuels.