生物柴油发动机非常规排放的FTIR检测

FTIR Detection of Unregulated Emissions from a Diesel Engine with Biodiesel Fuel

采用傅里叶变换红外光谱FTIR,研究了汽车发动机燃用生物柴油的非常规排放物。所用燃料分别为纯柴油、纯生物柴油、生物柴油掺混比为20%的B20混合燃料。结果表明,该机燃用纯柴油和B20燃油的甲醛排放差别不大,纯生物柴油的甲醛排放则明显高于柴油。燃用B20燃油的乙醛排放略低于纯柴油;纯生物柴油的乙醛排放在中低负荷低于纯柴油,在高负荷时高于柴油及B20燃油。燃用B20燃油和纯生物柴油的丙酮排放要高于柴油,但排放量均较低。随着生物柴油掺混比例的增加,发动机甲苯和二氧化硫均呈逐渐下降趋势,纯生物柴油的二氧化硫排放大幅降低。燃用生物柴油后,发动机的二氧化碳排放有所降低,表明了生物柴油有利于温室气体的控制。

Biodiesel,as one of the most promising alternative fuels,has received more attention because of limited fossil fuels.A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions.A diesel fuel,a pure biodiesel fuel,and fuel with 20% V/V biodiesel blend ratio were tested without engine modification.The present study examines six typical unregulated emissions by Fourier transform infrared spectroscopy（FTIR） method： formaldehyde（HCHO）,acetaldehyde（C2H4O）,acetone（C3H6O）,toluene（C7H8）,sulfur dioxide（SO2）,and carbon dioxide（CO2）.The results show addition of biodiesel fuel increases the formaldehyde emission,and B20 fuel has little change,but the formaldehyde emission of pure biodiesel shows a clear trend of addition.Compared with the pure diesel fuel,the acetaldehyde of B20 fuel has a distinct decrease,and the acetaldehyde emission of pure biodiesel is lower than that of the pure diesel fuel at low and middle engine loads,but higher at high engine load.The acetone emission is very low,and increases for B20 and pure biodiesel fuels as compared to diesel fuel.Compared with the diesel fuel,the toluene and sulfur dioxide values of the engine show a distinct decrease with biodiesel blend ratio increasing.It is clear that the biodiesel could reduce aromatic compounds and emissions of diesel engines.The carbon dioxide emission of pure biodiesel has a little lower value than diesel,showing that the biodiesel benefits control of greenhouse gas.