This study compares emissions from Euro VI-D Diesel and CNG buses across temperatures from -7 °C to 35 °C. Pollutants including NOx, THC, CH4, CO, NH3, N2O, HCHO, Solid Particle Number larger than 23 nm (SPN23) and larger than 10 nm (SPN10) were measured. Both buses complied with Euro VI-D but exceeded European Commission's proposed Euro 7 limits, notably for NOx and SPN10. The CNG bus also surpassed NH3, CO, and CH4 limits, while the Diesel exceeded N2O limits. High NH3 emissions were observed from CNG (up to 0.320 g/kWh), with Diesel reporting lower levels (up to 0.021 g/kWh). HCHO emission from both vehicles were very low. SPN23 was under limits, but SPN10 exceeded Euro 7 limits at cold start tests. CNG's CH4 and N2O emissions constituted up to 4.6% and 3.5% of CO2 equivalent, respectively. Diesel bus showed negligible CH4 but N2O emissions represented up to 37% of CO2 equivalent.

中文翻译：

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欧盟 VI 柴油和 CNG 重型车辆的受管制和不受管制的排放。


本研究比较了欧 VI-D 柴油客车和 CNG 客车在 -7 °C 至 35 °C 温度范围内的排放量。测量的污染物包括NOx、THC、CH4、CO、NH3、N2O、HCHO、大于23 nm（SPN23）和大于10 nm（SPN10）的固体颗粒数。两辆公交车均符合 Euro VI-D 标准，但超出了欧盟委员会提议的 Euro 7 限制，特别是 NOx 和 SPN10 的限制。 CNG 公交车还超过了 NH3、CO 和 CH4 限值，而柴油公交车则超过了 N2O 限值。 CNG 中的 NH3 排放量较高（高达 0.320 克/千瓦时），而柴油报告的排放量较低（高达 0.021 克/千瓦时）。两辆车的甲醛排放量都非常低。 SPN23 在冷启动测试中低于限制，但 SPN10 超出了 Euro 7 限制。 CNG 的 CH4 和 N2O 排放量分别占 CO2 当量的 4.6% 和 3.5%。柴油公交车的 CH4 排放量可以忽略不计，但 N2O 排放量高达 CO2 当量的 37%。