Investigation of diesel fuel and soybean methyl esters emission in high-speed diesel engine

Biodiesel is one of renewable and environmentally friendly biofuels that can be used in the diesel engine with little or no modification in the engine. In the present paper، the performance and emission characteristics of conventional diesel fuel and biodiesel blends produced from soybean oil (B2، B5 and B10) were compared. Tests were performed at steady-state conditions in a direct injection diesel engine with 90 kW power. During the test، the fuel consumption and pollutant emissions were measured. Experimental results showed that relative to diesel، biodiesel had an approximately 5-8% increase in the brake specific fuel consumption (BSFC) due to the lower heating value (LHV) of biodiesel. However، biodiesel significantly reduced carbon monoxide (CO) and unburned hydrocarbons (HC)، while nitric oxides (NOx) and carbon dioxide (CO2) emissions increased slightly. Observations showed that the smoke decreased significantly، due to the oxygen availability of the biodiesel fuel.