For the past years, Different Philippine local regulations have been imposed to address oil importation and to address environment concerns. One requirement is reduced emission from diesel engines and at the same time reduce the use of fossil fuels for the. In accordance to the Clean Air Act and the Biofuels Act, The Philippine government is looking for possible alternatives to fossil fuels, One of the biodiesel the country is currently using is coconut methyl ester due to the abundance of coconut trees in the country. This research shows the performance and emission characteristics of diesel blended with coconut methyl ester in a CRDi Passenger van and will help the government justify the increase in blend percentage mandated in commercial fuels.
This study is investigates 0%, 2%, 5% 10% and 20% Coconut Methyl Ester (CME)-diesel blends. The experiment consisted of Japanese 10-15 standard drive cycle test, steady state test at 40,60, & 80 kph was performed in the Vehicle Research and Testing Laboratory in the University of the Philippines Diliman equipped with chassis dynamometer, fuel flow meter and emissions analyzer. Performance parameters measured are Power, Specific Fuel Consumption and Mileage, while emission characteristics for CO, NOx, THC are measured. PM measurements were not measured for this experiment.
In both Drive cycle and steady state test specific fuel consumption and mileage improved with addition of CME, however results showed they are independent of CME percentage. The best improvement was observed with 5%CME blended with neat diesel at 4.8% and 8.5% for drive cycle and steady state test respectively.
Majority of the CME-diesel blends showed decrease in emission specifically in CO and THC emission which is consistent to published literature. For both steady state test and drive cycle test up to 29.5% decrease inn CO and up to 64% decrease in THC was observed. This can be attributed to the overall lean mixtures and in the increase of oxygenated fuel at higher CME blends. NOx emission however is consistent for all fuel blends in the drive cycle test while for the steady state test NOx emission is dependnt on the engine speed. Decreasing trend was obtained for 40 and 60 km/h while increasing trend was obtrained at 80 km/h, with respect to %CME.
Average power produced for all the speeds was basically constant for all the blends as compared with neat diesel. Lastly, maximum power showed insignificant changes although majority of the blends showed a minimal power reduction as compared to neat diesel.