Kean A J, Sawyer R F, Harley R A
Department of Mechanical Engineering, University of California, Berkeley, USA.
J Air Waste Manag Assoc. 2000 Nov;50(11):1929-39. doi: 10.1080/10473289.2000.10464233.
The use of diesel engines in off-road applications is a significant source of nitrogen oxides (NOx) and particulate matter (PM10). Such off-road applications include railroad locomotives, marine vessels, and equipment used for agriculture, construction, logging, and mining. Emissions from these sources are only beginning to be controlled. Due to the large number of these engines and their wide range of applications, total activity and emissions from these sources are uncertain. A method for estimating the emissions from off-road diesel engines based on the quantity of diesel fuel consumed is presented. Emission factors are normalized by fuel consumption, and total activity is estimated by the total fuel consumed. Total exhaust emissions from off-road diesel equipment (excluding locomotives and marine vessels) in the United States during 1996 have been estimated to be 1.2 x 10(9) kg NOx and 1.2 x 10(8) kg PM10. Emissions estimates published by the U.S. Environmental Protection Agency are 2.3 times higher for both NOx and exhaust PM10 emissions than estimates based directly on fuel consumption. These emissions estimates disagree mainly due to differences in activity estimates, rather than to differences in the emission factors. All current emission inventories for off-road engines are uncertain because of the limited in-use emissions testing that has been performed on these engines. Regional- and state-level breakdowns in diesel fuel consumption by off-road mobile sources are also presented. Taken together with on-road measurements of diesel engine emissions, results of this study suggest that in 1996, off-road diesel equipment (including agriculture, construction, logging, and mining equipment, but not locomotives or marine vessels) was responsible for 10% of mobile source NOx emissions nationally, whereas on-road diesel vehicles contributed 33%.
柴油发动机在非道路应用中是氮氧化物（NOx）和颗粒物（PM10）的重要来源。此类非道路应用包括铁路机车、船舶以及用于农业、建筑、伐木和采矿的设备。这些来源的排放才刚刚开始得到控制。由于这些发动机数量众多且应用广泛，这些来源的总活动量和排放量尚不确定。本文提出了一种基于柴油消耗量估算非道路柴油发动机排放的方法。排放因子按燃料消耗量进行归一化，总活动量通过总燃料消耗量估算。据估计，1996年美国非道路柴油设备（不包括机车和船舶）的总废气排放量为1.2×10⁹千克NOx和1.2×10⁸千克PM10。美国环境保护局公布的排放估算值在NOx和废气PM10排放方面均比直接基于燃料消耗量的估算值高出2.3倍。这些排放估算值存在差异主要是由于活动量估算的不同，而非排放因子的差异。由于对这些发动机进行的实际使用排放测试有限，目前所有非道路发动机的排放清单都存在不确定性。本文还给出了非道路移动源柴油燃料消耗的区域和州级细分情况。结合道路上柴油发动机排放的测量结果，本研究结果表明，1996年非道路柴油设备（包括农业、建筑、伐木和采矿设备，但不包括机车或船舶）占全国移动源NOx排放量的10%，而道路柴油车辆占33%。
