title: Volatile organic profiles and photochemical potentials from motorcycle engine exhaust.
abstract: This study surveyed emissions from 2- and 4-stroke new and in-use motorcycles. Emission tests were carried out on a dynamometer following the designated test procedure of the Economic Commission for Europe (ECE). Samples were derived during various driving stages, which included idle, acceleration, 30 km/hr cruise, 50 km/hr cruise, and deceleration. All test motorcycles (10 new and 15 in-use) complied with Taiwan Environmental Protection Administration's Phase III Motorcycle Emission Standards. The dominant volatile organic carbon (VOC) species were isopentane (53 and 295 mg/km, 2- and 4-stroke, respectively), 2-methylpentane (75 and 83 mg/km), 3-methylpentane (34 and 66 mg/km), and toluene (30 and 100 mg/km). The VOC emission factors for the 2-/4-stroke motorcycles were 311/344 (new) and 1479/433 (in-use) mg/km, respectively. In addition, the dominant carbonyl species for the new and in-use motorcycles were formaldehyde (0.4 and 0.7 mg/km, respectively), acetaldehyde (0.6 and 1.2 mg/km), and acetone (0.5 and 0.7 mg/km). The carbonyl compound emission factors for the 2- and 4-stroke motorcycles were 3.2/3.1 (new) and 5.3/4.6 (in-use) mg/km, respectively. The ozone formation potentials, based on an ECE test cycle, show that the values from the in-use motorcycles were higher than those from the new motorcycles. The dominant VOC species for the ozone formation potential were propylene (65 and 502 mg-O3/km, respectively), isopentane (98 and 501 mg-O3/km), 2-methylpentane (152 and 167 mg-O3/ km), 3-methylpentane (79 and 253 mg-O3/km), and toluene (127 and 398 mg-O3/km). Further, the dominant carbonyl species were formaldehyde (4.1 and 6.2 mg-O3/ km, new and in-use, respectively) and acetaldehyde (4.8 and 9 mg-O3/km).
authors.affiliation: Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan.
authors.forename: Jiun-Horng
authors.initials: JH
authors.lastname: Tsai
authors.forename: Yu-Yin
authors.initials: YY
authors.lastname: Liu
authors.forename: Chang-Yu
authors.initials: CY
authors.lastname: Yang
authors.forename: Hung-Lung
authors.initials: HL
authors.lastname: Chiang
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Chang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D006838:Hydrocarbons / Q000032:analysis*; D018986:Motor Vehicles; D009930:Organic Chemicals / Q000032:analysis; D010777:Photochemistry; D001335:Vehicle Emissions / Q000032:analysis*; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D006838:Hydrocarbons; D009930:Organic Chemicals; D001335:Vehicle Emissions