Sidhu S, Graham J, Striebich R
Environmental Science and Engineering, University of Dayton Research Institute, OH 45469-0132, USA.
Chemosphere. 2001 Feb-Mar;42(5-7):681-90. doi: 10.1016/s0045-6535(00)00242-3.
Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuel-rich conditions in the temperature range of 800-1200 degrees C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 microm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%. 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels.
机动车排放是空气污染的主要人为来源，会导致城市空气质量恶化。在本文中，我们报告了在约24个大气压下、800 - 1200摄氏度温度范围内富燃料条件下，对四种不同替代柴油燃料（即压缩天然气（CNG）、二甲醚（DME）、生物柴油和柴油）颗粒形成的实验室研究结果。使用单脉冲激波管模拟压缩点火（CI）燃烧条件。气态燃料（CNG和DME）在空气中预混合，而液体燃料（柴油和生物柴油）使用高压液体喷射器注入。使用扫描电子显微镜进行表面分析的结果表明，由上述所有四种燃料燃烧形成的颗粒平均直径小于0.1微米。从重量分析结果和燃料喷射量可知，在上述测试条件下，CNG、DME、生物柴油和柴油的相对颗粒产率分别为0.30%、0.026%、0.52%和0.51%。颗粒的化学分析表明，DME燃烧颗粒的可溶性有机成分（SOF）最高，为71%，其次是生物柴油（66%）、CNG（38%）和柴油（20%）。这表明，无论是气态燃料还是液体燃料，含氧燃料的SOF都高于非含氧燃料。
