Effect of Gasoline Composition on the Emission of Polycyclic Aromatic Hydrocarbons from Motorcycle Engine

The influences of gasoline on the emission of polycyclic aromatic hydrocarbons (PAHs) from gasoline engine are investigated. These fuels included C92-Leadfree Gasoline (C92-LFG), C95-Leadfree Gasoline (C95-LFG), C98-Leadfree Gasoline (C98-LFG), these are Reforming Gasoline, T92-Leadfree Gasoline (T92-LFG), T95-Leadfree Gasoline (T95-LFG), T98-Leadfree Gasoline (T98-LFG), these are total-PAHs content for T92-LFG was 945μg/km, which is 0.83 times of magnitude higher than that for C92-LFG(517μg/km). The emission factor in total-PAHs content for T95-LFG(1045μg/km) is 0.54 times of magnitude higher than that for of C98-LFG (2709μg/km) is 1.08 magnitude higher than that of (1305μg/km). Under three times of T98-LFG operation conditions, the speed of 50 km/hr is found to have highest total-PAH emission factor and the 30 km/hr condition shows to have the lowest one. For exhaust emissions of both commercialized gasoline, the content of 2-ring PAHs in total emitted PAHs is 86-96%. The content of 3-ring PAHs is 2-12% and that of the higher rings is only 1-2%. Merely 3-ring AcPy is generated for the combustion of the Lead-free gasoline in the motorcycle engine, while other PAHs are consumed in the combustion reaction. But for the Lead-free Base gasoline, the Nap, AcPy, PA, FL, Pyr, BeP and BbC are generated, and other PAHs are consumed. 92-Leadfree 95-Leadfree 98-Leadfree Base Gasoline (92-LFBG), Base Gasoline (95-LFBG) and Base Gasoline (98-LFBG). The motorcycle engine was simulated for the idling condition and cruising speed at 30 and 50 km/hr. The concentration of 21 individual PAHs in the engine exhaust, original gasoline were determined and analyzed by a gas chromatography/mass spectrometer (GC/MS). The results of this were summarized as follows. The mean total-PAH (summation of 21 PAHs), among nine Lead-free fuel, the highest one is that C95-LFG (60.6 mg/L), secondly is T92-LFG(45.5 mg/L), C92-LFG(42.1 mg/L), C98-LFG(35.5 mg/L) T95-LFG(20.8 mg/L). The main PAHs INTRODUCTION Motor vehicles are proved to be a significant source of air pollutants in urban area. Among motor vehicles, motorcycles are popular in Taiwan for their mobility and convenience. This means that the excessive air pollution generated by the use of motorcycles does exist in the surrounding here. So, to realize and then control distribution in reforming gasoline is LM-PAH, next is MM-PAH and then is HM-PAH, the weight percent of LM-PAH, MM-PAH and total PAHs 4.62-11.1%, percent of are 85.5-92.8%, 2.57-3.40% and respectively. Besides, the weight Cracking Gasoline. The emission factor in improving air quality in Taiwan. The main primary pollutants in the motor vehicle exhaust can be carbon oxides, nitrogen oxides, alcohols, aldehydes, ketones, sulfur compounds, and hydrocarbons. In those hydrocarbons may include mono-aromatic composition on the exhaust emissions, including direct comparison of petroleum gas passenger emissions from similar liquefied (LPG) and unleaded petrol (ULP) [6], evaluate effects of aromatic contents in gasoline on air pollutant emissions from a four-stroke motorcycle engine [7], reduction of diesel sulfur content bring about reduced emissions of PAHs [8], biodiesel free from aromatic compounds and sulfur used to blend with the diesel fuel to reduce the emissions of PM, HC, and CO [9] and optimization of hydrocarbon compositions of gasoline to reach a lowest exhaust emission [10]. However, the effect of different commercialized gasoline, i.e. reforming gasoline and cracking gasoline, on the emission of PAHs from motorcycle is still not been reported in journals, to our knowledge. In present study, the influences of gasoline on the emission of polycyclic aromatic hydrocarbons (PAHs) from motorcycle engine are investigated. These fuels included 92,95 and 98-Leadfree Gasoline from company C (Reforming Gasoline) and T (Cracking Gasoline). The motorcycle engine was simulated for the idling condition and cruising speed at 30 and 50 km/hr. The concentration of 21 individual PAHs in the engine hydrocarbons (MAHs) and Polycyclic aromatic hydrocarbons (PAHs). Emitted PAHs are harmful human beings that partly occur from original gasoline, and are also produced as byproducts of incomplete fuel burning. Some PAHs are potential mutagens and carcinogens and are probably the major culprits of high cancer rate (IARC,1989) [1]. For the reason of the potential health impact of PAHs on human beings, the investigations of emissions of them from motor vehicles have caused a great attention. The previous studies had focused on the PAHs emission from three types, i.e. 2-stroke carburetor (2-Stk/Cb), 4-stroke carburetor (4-Stk/Cb) and 4-stroke fuel injection (4-Stk/FI) motorcycles and the toxicity also studied by total BaP equivalent [2], and the size distribution of PAHs in emission of a two-stroke carburetor motorcycle [3] showed that most of the 21 analyzed PAHs have two significant modes that peak at < 0.1 and 0.18–0.32μm, it imply that those emitted particulates rise a high health risk for that particulates smaller than 2.5μm traverse easily through the upper analyzed by (GC/MS). a gas chromatography/mass spectrometer lungs. Riddle et al.reported the emission factors for light-duty heavy-duty PAHs with MW up to 350 for and gasoline-powered vehicles (LDGV) diesel-powered vehicles (HDDV) operated under realistic driving conditions [4]. Spezzano et al. revealed the PAH emissions both in the gas and in the particulate phases from individual in-use, 2-S mopeds belonging to three different levels of emission legislation, without and with catalyst, and suggested that the gas/particle partitioning in moped exhaust is mainly driven by the high fraction of organic matter of the emitted particles and that absorption could be the main partitioning mechanism of PAHs [5]. Additionally, exhaust emissions from vehicles are not dependent only on automotive technologies, but also on fuel compositions. Several recent studies