Background

Road transport is an important contributor to the European Union’s total greenhouse gas emissions. This study aims at summarizing methane (CH₄) and nitrous oxide (N₂O) exhaust emissions from L-category, light-duty and heavy-duty vehicles in the European Union. The assessment is based on measurements carried out in the Vehicle Emission Laboratory of the Joint Research Centre between 2009 and 2019. The exhaust chemical composition from a fleet of 38 L-category vehicles Euro 1 to Euro 4 (2- and 3-wheelers, small quadricycles such as quads and minicars), 63 light-duty vehicles from Euro 5b to Euro 6d-TEMP (passenger cars, including hybrid vehicles), and 27 light commercial and heavy-duty vehicles from pre-Euro I to Euro VI (including lorries, buses and garbage trucks) was analyzed by Fourier-transform infrared spectroscopy.

Results

CH₄ emission factors monitored were from 1 to 234 mg/km for L-category vehicles (mean: 39 mg/km), from 0.1 to 40 mg/km for light-duty vehicles (mean: 7 mg/km), and from non-detectable to 320 mg/km for heavy-duty vehicles (mean: 19 mg/km). N₂O emission factors monitored were from non-detectable to 5 mg/km for L-category vehicles (mean: 1 mg/km), from non-detectable to 40 mg/km for light-duty vehicles (mean: 7 mg/km), and from non-detectable to 118 mg/km for heavy-duty vehicles (mean: 19 mg/km). According to the 100-year Global Warming Potential of these greenhouse gases, these emissions corresponded to a range from negligible up to 9 g/km of CO₂-equivalent for CH₄ and from negligible up to 32 g/km of CO₂-equivalent for N₂O.

Conclusions

The higher contributors of CH₄ were the two-stroke mopeds included in the L-category vehicles, while the higher emissions of N₂O were found in the modern (Euro 5–6 or Euro V–VI) diesel light- and heavy-duty vehicles. Among them, vehicles complying with Euro 6 and Euro VI standard were associated to higher N₂O emissions compared to those associated to Euro 5 and pre-Euro IV standards, which could be attributed to the introduction of the after-treatment systems designed to fulfill more stringent NOx standards. These updated emission factors and unique on its kind database represent a source of information for legislators and modelers to better assess the greenhouse gas emission reduction in the EU transport sector.

中文翻译：

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欧洲公路车辆的温室气体排放因子

背景

公路运输是造成欧盟温室气体排放总量的重要因素。本研究旨在总结甲烷（CH ₄）和一氧化二氮（N ₂O）欧盟L类，轻型和重型车辆的废气排放。该评估基于联合研究中心的车辆排放实验室在2009年至2019年之间进行的测量。从38辆L级类别的1欧元至4欧元（2轮和3轮小车）的车队中排放的化学成分四轮车（例如四轮车和微型车），63辆从Euro 5b到6d-TEMP的轻型车辆（客车，包括混合动力车）以及27辆从Euro I到VI VI（包括货车）的轻型商用和重型车辆，公共汽车和垃圾车）通过傅里叶变换红外光谱法进行了分析。

结果

监测到的CH ₄排放因子对于L类车辆为1至234 mg / km（平均：39 mg / km），对于轻型车辆为0.1至40 mg / km（平均：7 mg / km），以及重型车辆检测不到320 mg / km（平均：19 mg / km）。监测的L 2类车辆的N ₂ O排放因子从不可检测到5 mg / km（平均：1 mg / km），对于轻型车辆从N2 O排放因子从不可检测到40 mg / km（平均：7 mg / km） km），重型车辆则从不可检测到118 mg / km（平均：19 mg / km）。根据这些温室气体的100年全球变暖潜势，这些排放量对应的范围是从可忽略不计的最高9 g / km的CO _2-相当于CH ₄到可忽略不计的最高32 g / km的CO ₂-相当于N ₂ O

结论

CH _4的主要贡献者是L类车辆中的两冲程轻便摩托车，而N ₂ O排放较高的是轻型和重型柴油（欧洲5-6或欧洲V-VI）。值班车辆。其中，与欧5和欧IV之前的标准相比，符合欧6和欧VI标准的车辆的N ₂ O排放较高，这可能归因于引入了旨在满足以下要求的后处理系统：更严格的氮氧化物标准。这些更新的排放因子及其同类数据库中的独特性为立法者和建模者提供了信息源，以更好地评估欧盟运输部门的温室气体减排量。