Stump Fred D, Knapp Kenneth T, Ray William D
a Atmospheric Research and Exposure Assessment Laboratory, U.S.- Environmental Protection Agency , Research Triangle Park , North Carolina , USA.
J Air Waste Manag Assoc. 1996 Dec;46(12):1149-1161. doi: 10.1080/10473289.1996.10467550.
Tailpipe and evaporative emissions from three pre-1985 passenger motor vehicles operating on an ethanol oxygenated and on a nonoxygenated (base) fuel were characterized. Emission data were collected for vehicles operating over the Federal Test Procedure at 90 °F, 75 °F, and 40 °F to simulate ambient driving conditions. The two fuels tested were a commercial summer-grade regular gasoline (the nonoxygenated base fuel) and an oxygenated fuel containing 8.8% ethanol, more paraffins and olefins, and less aromatics than the base fuel. The Reid vapor pressure (RVP) was adjusted to correspond to that of the base fuel. The emissions measured were total hydrocarbons (THCs), speciated hydrocarbons, spedated aldehydes, carbon monoxide (CO), and oxides of nitrogen (NOX). This study showed a general reduction in tailpipe emissions of THC, CO, benzene, and 1,3-butadiene when tested with the ethanol fuel. The ethanol fuel significantly reduced these emissions from the high emitting vehicle, MU098, at 90 °F, 75 °F, and 40 °F test temperatures. Additionally, the ethanol fuel reduced CO emissions from vehicle BU950, with and without catalyst, and from vehicle CI415 at 40 °F. Both formaldehyde and acetaldehyde emissions generally increased when tested with the oxygenated fuel. The acetaldehyde emissions were about double with this fuel. The limited data indicate that most emissions, including toxics, occur during the first 124 seconds of vehicle start-up. Diurnal evaporative emissions were less from the oxygenated fuel, while hot-soak evaporative emissions were greater from the oxygenated fuel (for all vehicles except MU098). Evaporative emissions were generally greatest at the 90 °F test temperature.
对三辆1985年前的乘用车在使用乙醇含氧燃料和非含氧（基础）燃料时的尾气排放和蒸发排放进行了表征。针对在90°F、75°F和40°F下按照联邦测试程序运行的车辆收集了排放数据，以模拟环境驾驶条件。测试的两种燃料分别是商业夏季级普通汽油（非含氧基础燃料）和一种含氧燃料，该含氧燃料含有8.8%的乙醇，与基础燃料相比，含有更多的石蜡和烯烃，芳烃含量更少。雷德蒸气压（RVP）被调整为与基础燃料的一致。测量的排放物包括总碳氢化合物（THC）、特定碳氢化合物、特定醛类、一氧化碳（CO）和氮氧化物（NOX）。这项研究表明，当使用乙醇燃料进行测试时，尾气中THC、CO、苯和1,3 - 丁二烯的排放总体上有所减少。在90°F、75°F和40°F的测试温度下，乙醇燃料显著降低了高排放车辆MU098的这些排放。此外，乙醇燃料在40°F时降低了车辆BU950（有催化剂和无催化剂情况下）以及车辆CI415的CO排放。使用含氧燃料进行测试时，甲醛和乙醛排放总体上有所增加。使用这种燃料时，乙醛排放约增加了一倍。有限的数据表明，包括有毒物质在内的大多数排放发生在车辆启动的前124秒内。含氧燃料的日间蒸发排放较少，而热浸蒸发排放较多（除MU098外的所有车辆）。蒸发排放在90°F测试温度下通常最大。
