近年のガソリン車における規制·未規制大気汚染物質排出量と排出傾向

摘要

We investigated on emissions of regulated and non-regulated substances in exhausts of the gasoline vehicles which met the severe regulationstandard for emission of late years. Benzene, toluene and xylene emissions were highly conelated with THC emission (r 0.9, n = 45, p <0.01) in the cold mode examinations. In the hot mode examinations, most of non-regulated substances were not detected However, onepassenger vehicle that tas exhaust gas rechuilation (EGR) system and lean-bum engin, specifically tas high emissions of the benzenoid athigh velocity (steady state of 80 km/h). The high emissions were due to the high EGR ratio on high speed drive. Incomplete combustedproducts containing benzene ring, which are hard to reduce by catalyst, increased in a high EGR rate state.Dividing 11 mode to lst cycle, 2nd cycle, and 3rd + 4th cycles, mission of respective substance discharged at corresponding cycle wasmeasured. For all of analyzed substances except CO2 and NH3, more amounts than 74% of 11 mode emissions were determined at lst cycle.Therefore, it is necessaiy to reduce the missions (lining lst cycle (120 seconds from start) until a ratalyst reached the appearance temperatureof its activity or develop the catalyst which works at the low temperature.In hot start modes, emissions of 10.15 mode were compared with JC08 emissions. Most of JC08 mode emissions were higher than 10.15mode emissions. Especially PAHs were not detected in 10.15 mode emissions, but detected in JC08 mode. On the case that acceleration anddeceleration are almost a ruai driving, missions of incomplete combusted products increased because of difficulty of combustion control.