Comparison of fuel Properties and Combustion Characteristics of Ethyl Ester Type Biodiesels
Biodiesel, a renewable and biodegradable alternative diesel fuel, is one of the most common type of biofuels for diesel engines. It has many environmental benefits and significantly reduces toxic pollutants and greenhouse gas emissions compared to petroleum diesel fuel. Considering renewable energy forless emissions, biodiesel is one of the best alternative fuels for diesel engines. Depend on the availability of feedstock, in Southeast Asia region, palm oil and coconut oil are considered as the primary sources of biodiesel production and while in Europe and America region, rapeseed oil and soybean oil are the main feedstock for biodiesel production respectively. In this study, in order to compare fuel properties and combustion characteristics of ethyl ester type biodiesel, three vegetable oil namely coconut oil, palm oil and rapeseed oil were chosen. Then processed to coconut oil ethyl ester (CEE), palm oil ethyl ester (PEE) and rapeseed oil ethyl ester (REE) by the transesterification process. The analyses were carried out to study and compare fuel properties and engine test experiments were done for combustion characteristics and exhaust gas emissions. Regarding the fuel properties of CEE, PEE and REE, they have comparable fuel properties to the standard biodiesel (ASTM D6751)in most of the important parameters such as density and kinematic viscosity. From the engine test experiments, the combustion characteristics of PEE is better than those of CEE and REE and the exhaust gas emissions from CEE and PEE are the lower than that of REE.
Keywords: Biodiesel, Ethyl Ester, Fuel Properties, Combustion Characteristics, Exhaust Gas Emissions.