Zavala Miguel, Huertas Jose Ignacio, Prato Daniel, Jazcilevich Aron, Aguilar Andrés, Balam Marco, Misra Chandan, Molina Luisa T
a Molina Center for Energy and the Environment , La Jolla , CA , USA.
b Instituto Tecnológico de Monterrey , Monterrey , Mexico.
J Air Waste Manag Assoc. 2017 Sep;67(9):958-972. doi: 10.1080/10962247.2017.1310677. Epub 2017 Apr 5.
Off-road vehicles used in construction and agricultural activities can contribute substantially to emissions of gaseous pollutants and can be a major source of submicrometer carbonaceous particles in many parts of the world. However, there have been relatively few efforts in quantifying the emission factors (EFs) and for estimating the potential emission reduction benefits using emission control technologies for these vehicles. This study characterized the black carbon (BC) component of particulate matter and NOx, CO, and CO EFs of selected diesel-powered off-road mobile sources in Mexico under real-world operating conditions using on-board portable emissions measurements systems (PEMS). The vehicles sampled included two backhoes, one tractor, a crane, an excavator, two front loaders, two bulldozers, an air compressor, and a power generator used in the construction and agricultural activities. For a selected number of these vehicles the emissions were further characterized with wall-flow diesel particle filters (DPFs) and partial-flow DPFs (p-DPFs) installed. Fuel-based EFs presented less variability than time-based emission rates, particularly for the BC. Average baseline EFs in working conditions for BC, NOx, and CO ranged from 0.04 to 5.7, from 12.6 to 81.8, and from 7.9 to 285.7 g/kg-fuel, respectively, and a high dependency by operation mode and by vehicle type was observed. Measurement-base frequency distributions of EFs by operation mode are proposed as an alternative method for characterizing the variability of off-road vehicles emissions under real-world conditions. Mass-based reductions for black carbon EFs were substantially large (above 99%) when DPFs were installed and the vehicles were idling, and the reductions were moderate (in the 20-60% range) for p-DPFs in working operating conditions. The observed high variability in measured EFs also indicates the need for detailed vehicle operation data for accurately estimating emissions from off-road vehicles in emissions inventories.
Measurements of off-road vehicles used in construction and agricultural activities in Mexico using on-board portable emissions measurements systems (PEMS) showed that these vehicles can be major sources of black carbon and NO. Emission factors varied significantly under real-world operating conditions, suggesting the need for detailed vehicle operation data for accurately estimating emissions inventories. Tests conducted in a selected number of sampled vehicles indicated that diesel particle filters (DPFs) are an effective technology for control of diesel particulate emissions and can provide potentially large emissions reduction in Mexico if widely implemented.
用于建筑和农业活动的越野车辆会大量排放气态污染物，在世界许多地区可能是亚微米级碳质颗粒的主要来源。然而，在量化这些车辆的排放因子（EFs）以及评估使用排放控制技术实现潜在减排效益方面，相关努力相对较少。本研究使用车载便携式排放测量系统（PEMS），在实际运行条件下对墨西哥选定的柴油动力越野移动源的颗粒物黑碳（BC）成分以及氮氧化物、一氧化碳和碳氢化合物的排放因子进行了表征。所采样的车辆包括两台反铲挖掘机、一台拖拉机、一台起重机、一台挖掘机、两台前端装载机、两台推土机、一台空气压缩机以及一台用于建筑和农业活动的发电机。对于其中部分选定车辆，还通过安装壁流式柴油颗粒过滤器（DPF）和部分流式DPF（p-DPF）进一步对排放进行了表征。基于燃料的排放因子比基于时间的排放率变化更小，尤其是对于黑碳而言。工作条件下黑碳、氮氧化物和一氧化碳的平均基线排放因子分别为0.04至5.7、12.6至81.8以及7.9至285.7克/千克燃料，并且观察到排放因子高度依赖于运行模式和车辆类型。提出了按运行模式对排放因子进行测量的频率分布，作为表征实际条件下越野车辆排放变异性的一种替代方法。安装DPF且车辆怠速时，基于质量的黑碳排放因子减少幅度很大（超过99%），而在工作运行条件下，p-DPF的减少幅度适中（在20%至60%范围内）。实测排放因子中观察到的高变异性也表明，在排放清单中准确估算越野车辆排放需要详细的车辆运行数据。
使用车载便携式排放测量系统（PEMS）对墨西哥用于建筑和农业活动的越野车辆进行测量表明，这些车辆可能是黑碳和氮氧化物的主要来源。在实际运行条件下，排放因子差异显著，这表明在准确估算排放清单时需要详细的车辆运行数据。对部分采样车辆进行的测试表明，柴油颗粒过滤器（DPF）是控制柴油颗粒物排放的有效技术，如果广泛应用，在墨西哥可能实现大幅减排。
