Effect of Exhaust Gas Recirculation (EGR) on the Performance and Emission Characteristics of Diesel Engine with Sunflower Oil Methyl Ester

Transesterified fuels (biodiesel) from vegetable oils are alternative fuels for diesel engines. They are renewable and offer potential reduction in CO and HC emissions due to higher O2 contents in vegetable oil. Many research studies have reported that exhaust from biodiesel fuel has higher NOx emissions while HC and PM emissions are significantly lower than operated with diesel fuel. The aim of the present investigation is to reduce NOx emissions. Exhaust gas recirculation (EGR) is one of the most effective technique for reducing NOx emissions in compression ignition engines. A twin cylinder four stroke water cooled direct injection (DI) diesel engine was used for conducting test with (Sunflower methyl ester:SFME) biodiesel blends with diesel fuel combined with EGR technique. The results showed that for a 7.5kW power output, B20 SFME with 15% EGR rate produce 25% less NOx emissions compared to diesel fuel for the same level smoke emissions.