The purposes of improving air pollution and suggesting energy resources have intensified research on various alternative energy for diesel combustion engines to solve severe environmental influences caused by air pollution. In this study, the applicable possibility of biodiesel and oxygenates (EGBE) was investigated as a cuspy method on decreasing the smoke emission. The smoke emission of blending fuel (biodiesel and EGBE) was reduced in comparison with commercial diesel fuel and it was reduced almost 63% at 2000 rpm, full load. But torque and brake specific energy fuel consumption rate didn't have any large changes. Also, the effectiveness of exhaust gas recirculation (EGR) for the reduction of NOx emission has been investigated. It was shown that simultaneous reduction of NOx and smoke emission was achieved with biodiesel(90%), oxygenates (10%) and cooled EGR rates (10%) in an IDI diesel engine.

In this study, the possibility of biodiesel fuel and oxygenated fuel(dimethoxy methane, DMM) was investigated as an alternative fuel for a naturally aspirated direct injection diesel engine. The smoke emission of blending fuel (diesel fuel 90vol-% + DMM 10vol-%) was reduced approximately 70% at 2500rpm, full load in comparison with the diesel fuel. But, engine power and brake specific energy consumption showed no significant differences. But, NOx emission of biodiesel fuel and DMM blended fuel increased compared with commercial diesel fuel due to the oxygen component in the fuel. It was needed a NOx reduction counter plan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with diesel fuel (95 vol-%) and DMM (5 vol-%) blended fuel and cooled EGR method (15%).