本研究是以台灣地區，兩家石油公司所生產之市售95無鉛汽油和98無鉛汽油，以Span80為含氧乳化添加劑，與少量比例的水進行乳化混合，製成各種不同比例之乳化油，再將其加入四行程機車模擬引擎以動力計進行三種不同轉速條件運轉，採集在三種不同轉速條件下所產生之廢氣，以GC/MS分析排放廢氣中氣相及粒狀物相中所含之多環芳香烴化合物(PAHs)濃度，並比較不同混合比例所產生之差異。
研究結果顯示，在乳化油和市售油比較上，除了C95W20乳化油以外，其他的乳化油和無添加的市售油比較起來總平均PAHs都有減少，而且乳化油乳化比例不同，所排放的總平均PAHs濃度亦不相同，而且乳化油的水和乳化劑所含的比例越高，其排放的總平均PAHs濃度亦越高。
乳化油中C95W20之排放PAHs濃度BaPeq為最高，其PAHs濃度BaPeq為137μg BaPeq/Nm3，而排放PAHs濃度BaPeq最低者則是T98W5乳化油，其PAHs濃度BaPeq為14.6μg BaPeq/Nm3，除了C95W5、C95W10、C95W20，以外其他的乳化油之排放PAHs濃度BaPeq都比市售油低，而且乳化油的水和乳化劑所含的比例越高，其排放PAHs濃度BaPeq亦越高。
經研究結果得知，乳化油品，確實有減少PAHs排放的效果，但是添加的水和乳化劑的量超過一定的比例後，乳化油反而會出現反效果，像C95W20油品就是水和乳化劑含量超量反而造成總平均PAHs排放上升；而在BaPeq值方面，C公司95市售油品在乳化後出現增加的趨勢，顯示C公司95市售油品在乳化後排放較多高毒性PAHs，這是乳化油在日後運用上應該特別注意的地方。 Gasoline powered motorcycle engine was used to evaluate the two-phase emulsion fuels as an alternative additive. Although gasoline oil emulsion had adverse effect on engine and good for the formation in particular nitrogen oxides. In this study, two commercial gasoline were emulated by adequate fractions of Span-80 and water under ultrasonic vibration processes. Two phase emulsions as water-in-oli was fueled for small single spark engine to analyze polycyclic aromatic hydrocarbons (PAHs) in the exhaust of tailpipe. Twenty-one individual PAHs were primarily analyzed by gas chromatography equipped mass spectrometer (GC/MSD). The 4-stroke motorcycle engines were installed on a dynamometer to simulate 3 various transient modes including idling, 30 km/hr and 50 km/hr.
In this investigation, emulsion gasoline powered engine had lower PAHs emission concentration than two commercial gasoline powered engines exclude C95W20. However, the more Span-80 and water in emulsion gasoline would increase the total PAH emission. For the BaP equivalent concentration, C95W20 would emit the highest BaPeq concentration (137 ug BaPeq/Nm3) among those emulsion gasolines. The lowest emission concentration was emitted by T98W5 emulsion gasoline for 14.6 ug BaPeq/Nm3. The BaPeq concentration comparison of target gasolines, C95W5, C95W10, and C95W20 had more BaPeq emission than C95-LFG. It reveals that C95-LFG may not be the basis gasoline for emulsion. For all emulsion gasolines would increase the BaPeq emission under adding more Span-80 and water.
Indeed, the two-phase emulsion gasoline will decrease the PAHs emission from 4-stroke motorcycle engines. However, the proper emulsion conditions will deplete the PAH and its BaPeq emission in the exhaust of tailpipe. For these two commercial gasoline, T95-LFG is better than C95-LFG to mix as emulsion gasoline.
