Search Results

The addition of soybean methyl ester (SME) to diesel fuel has significantly reduced HC and PM emissions, but it increases the NOx emission slightly when measured with exhaust emission evaluation mode for heavy-duty DI diesel engines or D-13 mode in Japan. Also, under partial load conditions, the SME addition increases the PM emission due to an increase in the SOF emission. However, the addition of lighter fractions or kerosene to diesel fuel reduces NOx and PM emissions but increases HC and CO emissions measured by D-13 mode. In addition, under full load conditions, the lighter fuel seldom reduces PM emission. Therefore, the exhaust emissions emitted from the blends of SME, kerosene, and cetane improver to low sulfur diesel fuel are evaluated using the latest DI diesel engine with a turbo-charger and inter-cooler. The clean fuel reduces over 20% of PM under a wide range of engine conditions including D-13 mode without an increase in NOx, HC, and CO emissions.

Smoke emission from single-cylinder DI and IDI diesel engines was shown to strongly depend on oxygen content in fuel regardless of oxygenate molecular structure. Thus, with cetane improver and oxygenate used in combination in a proportion determined from blending properties and potential cost for modern heavy-duty DI diesel engines were assessed. The combined use of nitrate type cetane improver with glycol ether type oxygenate reduced particulate, HC, and CO emission but not that of NOx. Particulate reduction depended on oxygenate content. Oxygenate at less than 5% with cetane improver seldom worsened volume-based fuel economy compared with the base hydrocarbon fuel.

Under hot transient conditions, the effects of gasoline properties, such as the research octane number (RON), the motor octane number (MON) and types of components on acceleration performance were investigated using four ‘Premium Gasoline Required Vehicles’ which are Japanese commercial vehicles equipped with knock sensors (KSs) and an electronic control unit (ECU) to prevent the engines from knocking. Regarding the fuel, two series of fuels were used. One of them {Primary Reference Fuel Series (PRF series)} was prepared to investigate the effectiveness of the octane number of PRF (ON). The other {Components Series (COMP series)} was prepared to investigate the effects of fuel components on the same. Fuels in the COMP series had almost the same RON level, which was almost equal to 90. In the PRF series, the acceleration performance of all vehicles were improved as ON increased.