The challenge to NO<sub>x</sub> emission control for heavy-duty diesel vehicles in China

Abstract

Abstract. China's new "Twelfth Five-Year Plan" set a target for total NO x emission reduction of 10 % for the period of 2011-2015. Heavy-duty diesel vehicles (HDDVs) have been considered a major contributor to NO x emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring onroad emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS). The major finding is that neither the on-road distance-specific (g km −1 ) nor brake-specific (g kWh −1 ) NO x emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NO x emission factors for Euro II, Euro III and Euro IV buses are 11.3 ± 3.3 g km −1 , 12.5 ± 1.3 g km −1 , and 11.8 ± 2.0 g km −1 , respectively. No statistically significant difference in NO x emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NO x emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NO x emissions for HDDV fleet may be significantly underestimated. The new estimate in total NO x emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45 % compared to the previous study. Further, we estimate that the total NO x emissions for the na-

Effect of Nearby Forest Fires on Ground Level Ozone Concentrations in Santiago, Chile

“…Emission NO 2 /NOx ratios in biomass burning are, for a variety of fuels, in the 0.1-0.3 range [40,45]. These values are larger than those arising from vehicles, the most important NOx source in large cities [46]. During the year 2006 at the monitoring station in Wuppertal (Germany), an annual average NO 2 /NOx emission ratio of 0.12˘0.01 was reported by Kurtenbach et al, [47].…”

NO<sub>x</sub> emissions in China: historical trends and future perspectives

“…suggested that current emission standard implemented in Beijing (Euro IEuro IV) and nationwide might have limited impacts on reducing NO x emissions. Wu et al (2012) found the NO x emission factors for heavy-duty diesel buses did not improve in most cases as emission standards became more stringent, and that the average NO x emission factors of Euro II, Euro III and Euro IV buses in Beijing under the same typical driving cycle were all around 12 g km −1 . These findings are consistent with earlier work of Velders et al (2011) for Europe as well as Huo et al (2012b) for China, where similar noncompliance was identified.…”

Development of a vehicle emission inventory with high temporal–spatial resolution based on NRT traffic data and its impact on air pollution in Beijing – Part 1: Development and evaluation of vehicle emission inventory

“…The local emission factors were collected from a mass of measuring data from the Tsinghua University and China Automotive Technology & Research Center, such as bench testing and on-road vehicle emissions measurements in Beijing (Huo et al, 2009;Hu et al, 2012;Wu et al, 2012;. Meanwhile, the fuel consumption factors for vehicles were measured and included in this model.…”

“…The average vehicle running speed is one of the important Figure 1. Emission factors of NO x , HC, CO, PM and fuel consumption factors of gasoline and diesel (Huo et al, 2009;Hu et al, 2012;Wu et al, 2012; parameters of traffic data and is utilized to estimate traffic flow.…”