In this study, the potential of biodiesel fuel and oxygenated fuel (ethylene glycol mono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel (EGBE 0~20 vol-%) was reduced in comparison with diesel fuel and it was reduced approximately 64% at 2000 rpm, full load in the 20% of blending rate. But torque and brake specific energy consumption (BSEC) didn't have large differences. Also, the effects of exhaust gas recirculation (EGR) on the characteristics of NOx emission has been investigated. Consequently, it was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel and oxygenated fuel(10%) and cooled EGR rates (5~10%) in a DI diesel engine.

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. CRDI (common rail direct injection) diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. An commercial CRDI diesel engine used to commercial vehicle was fueled with diesel fuel and 5% biodiesel blended fuel (BDF 5%) with city mode in excess of 300 hours. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. To check the engine parts (valve, injector), the engine was inspected after test. It was concluded that there was no unusual deterioration of the engine, or any unusual changes in engine power and exhaust emissions in spite of operation of 300 hours with BDF 5%.

Biodiesel fuel (BDF) can be effectively used as an alternative fuel in diesel engines. The BDF, however, may affect performance and exhaust emissions of the diesel engine because it's physical and chemical properties are different with from the diesel fuel such as viscosity, compressibility and so on. To investigate an effect of injection timing on characteristics of performance and exhaust emissions with the BDF in an IDI diesel engine, this research applied the BDF derived from soybean oil in this study. The engine was operated with six different injection timings from TDC to BTDC 12 ˚CA and six different loads at the engine speed of 1500 and 2000 rpm. In less then the BDF 20, it showed the similar trend compare to the diesel fuel. But, the best injection timing was 2˚CA retarded compare to the diesel fuel with BDF 50.

Biodiesel as alternative energy source of the traditional petroleum fuels has increased interest, because environmental pollution based exhaust emissions from vehicle became serious. The advantage of biodiesel produced from esterification of vegetable and animal oils can be used without the modification of existing diesel engine, but glycerin is generated by production process. In this study, the usability of non-esterification biodiesel as an alternative fuel was investigated in a indirect injection diesel engine. The non-esterification biodiesel has not generated glycerin in esterification process and reduced the 20 percent of cost because it has not used methanol in the production process. Experiments were conducted by using the 5, 10 and 20 percentage of biodiesel and 4 and 8 percentage of biodiesel with 1 and 2 percentage of WDP in baseline diesel fuel. The smoke emission of biodiesel was reduced in comparison with diesel fuel, but power, torque and brake specific energy consumption was similar to diesel fuel.

Biodiesel fuel as an alternative fuel for diesel engine has a great possibility to solve the problem such as air pollution caused by exhaust gas emission of the automobile. In this study, the usability of non-esterfied biodiesel fuel as alternative fuel is investigated in an indirect injection diesel engine. New concept biodiesel fuel has no glycerin generated by esterfication process and reduces the 20% of cost because of no use of methanol in the production process. Experiments were conducted by using the four blends with different volumetric percentage of biodiesel (0, 20, 50 and 100) in baseline diesel fuel. The smoke emission of biodiesel fuel was reduced in comparison with diesel fuel, but power and brake specific energy consumption was similar to diesel fuel

산유국으로부터 에너지 독립을 하고 대기오염방지를 위한 배기배출물을 저감시키기 위하여 대체연료에 많은 관심을 가지고 있다. 폐유나 새로운 식물성 기름과 동물성 기름으로부터 생성할 수 있는 바이오디젤유가 압축점화기관인 디젤기관에 구조적인 변화없이 사용될 수 있다. 이 논문에서는 4행정 직접분사식 디젤기관을 이용하여 순수 디젤유와 바이오디젤 혼합유(바이오디젤 10% 및 20% 함유)의 연료소비율과 배기배출물에 미치는 영향을 제시했으며, 특히 실험에 사용된 바이오디젤 연료는 우리 실험실에서 유채유로부터 직접 생산되었다. 이 연구 결과 바이오디젤 혼합유가 디젤유 보다 연료소비율과 질소산화물은 약간 증가 되었고 일산화탄소와 매연은 상당히 감소되었다.

Transesterfication of vegetable oils and methanol with alkaline catalyst was carried out to produce biodiesel fuel by continuous process. The process consists of two static mixers, one tubular reactor and two coolers and gave 96~99% of methyl ester yield from soybean oil and rapeseed oil. Experimental variables were the molar ratios of methanol to vegetable oil, alkaline catalyst contents, flow rates, mixer element number. The optimum ranges of operating variables were as follows; reaction temperature of 70℃, l:6 of molar ratio of methanol to oil, O.4%(w/w) sodium hydroxide based on oil, static mixer elements number of 24 and 4 min. residence time.