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An emission treatment study was conducted on a typical non-electronic control diesel engine using diesel oxidation catalyst (DOC)/particle oxidation catalyst (POC) / selective catalytic reduction catalyst (SCR) combined system to expect the engine would reach CN-V standard. The research was focused on the selection and the arrangement of the treatment units. The experiments results show that either particulate matters (PM) or NOx but not in the case of both can meet CN-V standard with only DOC+POC or SCR system, however, both PM and NOx can reach CN-V standard by employing DOC/POC/SCR combined system. There is no obvious influence on the pollutants conversion efficiency with the different arrangement order of the SCR and DOC+POC system. The passive regeneration of POC can be fully achieved by placing the DOC+POC ahead of the SCR system due to the sufficient amount of NO2 in the exhaust which can be utilized for PM oxidation, and also in this case the hydrothermal aging effect on the SCR catalyst could be reduced owing to the lower of the inlet temperature. The backpressure of the combined system can be less than 25 kPa through the application of ceramic-based POC and optimal design of the packaging structure. [ABSTRACT FROM AUTHOR]

The emission performance of a 4-cylinder SI (spark ignition) engine during cold-start and warm-up phase was investigated in the experiments using the integrated thermal management strategy. The HC, CO and NOx emissions during cold-start and warm-up phase were tested combined with an air-heater. The idiographic strategies include: firstly, the heater was used to preheat the engine cooling water before the engine cold-start; secondly, the hot exhaust gas of the heater was used to preheat the oxygen sensor and light-off the catalyst quickly; thirdly, exhaust gas of the heater was led in the intake port to preheat intake air during engine cold-start period. The results show that, before the three-way catalyst, the HC emission was decreased by 53%. CO emission does not show a significant difference, and was only decreased by 2.1%, but NOx emission was decreased by 52.9%. After three-way catalyst, HC, CO and NOx emissions were decreased by 58.7, 8.5 and 72.3%. These results indicated that the integrated thermal management strategy can effectively reduce the exhaust emissions during the cold-start and warm-up phase. [ABSTRACT FROM AUTHOR]

This paper describes an experimental study on a modern passenger car engine in order to evaluate the emission performance fueled with 6 gasoline fuels, 5 ethanol gasoline fuels and 1 methanol gasoline fuel. The results show that the emissions do not show significant differences using E10, M15 and normal gasoline fuels before the three-way catalyst. The average emissions of oxygen-fuels is lower than that of gasoline fuels, only the HC emission of methanol gasoline in idling condition is an exception. After the catalyst, the NOx emission of different fuels varied remarkably, sulfur and arene contents are the main factors, while the CO and HC emissions do not show significant correlation with the organic compound in fuels. Specific fuel consumption rate of ethanol and methanol gasoline fuels are a little higher than that of normal gasoline fuels, but using oxygen-fuel produced less CO2. Oxygen-fuels have only a little effect on engine power. The maximum power using ethanol and methanol gasoline fuels are a bit lower than normal gasoline. [ABSTRACT FROM AUTHOR]