Performance and Emissions of a Heavy-Duty Common Rail Direct Injection Engine Fueled with Philippine Coconut Methyl Ester (CME) - Diesel Blends

The Philippine Biofuels Act of 2006 (RA 9367) requires commercial diesel fuel to be mixed with Coconut Methyl Ester (CME) in accordance with the Philippine Clean Air Act of 1999 (RA 8749). As of 2015, the blend percentage is at 2% CME v/v, contrary to the scheduled 5% as stipulated in the biofuels act. Researches done locally showing the performance and emissions of CME-fueled engines are few and thus the basis for the CME percentage increase is still questionable and hampers the drive for the further implementation of the policy. The study investigates the influence of varying percentages of CME blends (2%, 5%, 10%, 15%, 20% v/v) to the performance and emissions of a heavy-duty turbocharged common rail direct injection (CRDI) engine. The engine is run at steady state at partial load (50Nm and 250 Nm) and at near full load (500Nm). Each run is set at three pedal positions, α (25%, 50% and 60%), controlled directly from the engine control unit. Results show a significant increase in brake specific fuel consumption at higher percentages of CME with a maximum of 3.16% at higher loads and at 25% α. Nitrous Oxides (NO_x) is of particular importance in dealing with biofuel methyl esters and is found to significantly increase at higher percentages of CME with a maximum of 8.91% at higher loads across all α. Carbon monoxide (CO) and hydrocarbons of diesel (HCD) were found to not be significantly affected by the usage of CME. Nevertheless, there is still some potential in the usage of CME due to the fact that power and torque is still achievable at the expense of higher fuel consumption; but with the opportunity of being self-sufficient as a coconut-producing country.