Effects of Philippine Coconut Methyl Ester on the Performance and Emissions of a Heavy Duty CRDI Engine

The Philippine Department of Environment and Natural Resources (DENR) has issued Department Order 2015-04 (DAO 2015-04) or the “The Implementation of Vehicle Emission Limits for EURO 4/IV, and In-Use Vehicle Emission Standards”. This policy, coupled with the Philippine Biofuels Act of 2016 (RA 9367) should greatly reduce the environmental impact of local automobile emissions. Commercial fuel is a mix of local coconut methyl ester (CME) and neat diesel blend. However, commercial diesel fuel is still at 2% v/v as of 2016 in contrast to the 5% v/v set by the policy, part due to the fact that only few local studies are done to show the effects of higher percentage of CME, with most recent studies showing results against increased CME usage. The study shows the effects of the usage of higher CME percentage in accordance to the set schedule of RA 9367. Five fuel blends with varying CME percentages v/v (2%, 5%, 10%, 15%, and 20%) are used in a heavy duty turbocharged common rail direct injection (CRDI) engine. The engine is run on an eddy current dynamometer with steady state measurements at 50 to 500Nm with 50Nm intervals. Each fuel is tested at three pedal positions, alpha, (25%, 50%, and 60%) controlled directly from the engine control unit (ECU). Results show that higher CME usage does not result in reduction of power and achieved torque. There is, however, a significant increase in brake specific fuel consumption at higher percentages of CME. No significant change in carbon monoxide (CO) and unburned hydrocarbons of diesel (HCD) is observed but there is a significant increase in Nitrous Oxides (NOx) concentration as CME percentage is increased. However, brake specific CO and HCD were found to be out of standard for near no load and near full load operations. A similar trend is observed for brake specific. Brake specific NOx is particularly more problematic since all measurements were observed to be out of standard with maximum values of 1350% of the set EURO 4/IV standard. However, it is also seen that the performance of each blend does not significantly differ from each other. Nevertheless, there is still some potential in the usage of CME due to the fact that power and torque requirements are still met at the expense of higher fuel consumption; but with the opportunity of being self-sufficient as coconut-producing country.