Reactive Nitrogen Species Emission Trends in Three Light-/Medium-Duty United States Fleets
Reactive Nitrogen Species Emission Trends in Three Light-/Medium-Duty United States Fleets
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DOI：
10.1021/acs.est.5b02392
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发表时间：
2015-09-15
影响因子：
11.4
通讯作者：
Stedman, Donald H.
中科院分区：
文献类型：
--
作者：
Bishop, Gary A.;Stedman, Donald H.
在丹佛（2005/2013年）、洛杉矶（2008/2013年）和塔尔萨（2005/2013年）进行了重复的燃料排放测量，得出了美国三支轻型/中型车队在道路上活性氮排放的长期趋势。减少氮氧化物(NOx)排放量在丹佛范围从21%(从5.6 + / - 1.3到4.4 + / - 0.2 g的氮氧化物/公斤燃料)到43%在塔尔萨(从4.4 + / - 0.3到2.5 + / - 0.1 g的氮氧化物/公斤燃料)自2005年以来,在舰队降低氨(NH3)排放的范围从丹佛没有变化(从0.45 + / - 0.09到0.44 + / - 0.02 g的NH3 /公斤燃料)自2005年以来下降28%在洛杉矶(从0.80 + / - 0.02到0.58 + / - 0.02 g的NH3 /公斤燃料)自2008年以来。大部分汽油车氮氧化物排放量的减少发生在2009年二级排放标准全面实施之前。小发动机柴油乘用车在使用过程中排放的大量氮氧化物，尽管数量不多，但对车队的收入贡献很大。NH3排放量的下降速度比NO排放量的下降速度慢，这是由于最新车辆中NH3排放量的适度减少，以及越来越多的装有主动催化转换器的旧车辆的排放量增加。此外，许多新车的活性氮排放现在主要是NH3。
Repeated, fuel-specific, emission measurements in Denver (2005/2013), Los Angeles (LA) (2008/2013), and Tulsa (2005/2013) provide long-term trends in on-road reactive nitrogen emissions from three light-/medium-duty U.S. fleets. Reductions in oxides of nitrogen (NOx) emissions ranged from 21% in Denver (from 5.6 +/- 1.3 to 4.4 +/- 0.2 g of NOx/kg of fuel) to 43% in Tulsa (from 4.4 +/- 0.3 to 2.5 +/- 0.1 g of NOx/kg of fuel) since 2005, while decreases in fleet ammonia (NH3) emissions ranged from no change in Denver (from 0.45 +/- 0.09 to 0.44 +/- 0.02 g of NH3/kg of fuel) since 2005 to a 28% decrease in LA (from 0.80 +/- 0.02 to 0.58 +/- 0.02 g of NH3/kg of fuel) since 2008. The majority of the reduction in gasoline vehicle NOx emissions occurred prior to the full implementation of the Tier II emission standards in 2009. High in-use NOx emissions from small-engine diesel passenger vehicles produced a significant contribution to the fleet means despite their small numbers. NH3 emissions decreased at a slower rate than NO emissions as a result of modest NH3 emission reduction among the newest vehicles and increased emissions from a growing number of older vehicles with active catalytic converters. In addition, the reactive nitrogen emissions from many new model year vehicles are now dominated by NH3.