It is known that the transport sector has a fundamental importance in the modem society, as the economic development is directly linked to mobility. Over the years, the transport became linked to different environment...It is known that the transport sector has a fundamental importance in the modem society, as the economic development is directly linked to mobility. Over the years, the transport became linked to different environmental problems, which can be detached greenhouse gases emissions in the atmosphere, where in recent decades can be perceived the intensification and targeting of efforts in research and development of new technologies to reduce the levels of greenhouse gases emissions in the atmosphere. In this context, it can be highlighted the modem systems of electronic engine management, new automotive catalysts and the use of renewable fuels which contribute to reducing the environmental impact. This research had, as its purpose, the analysis of fuels characteristics used for testing, comparative analysis of gas emissions from a motor vehicle running on ethanol or natural gas fuels according to NBR 6601 and conducting tests to estimate the maximum catalytic efficiency. For the implementation of trial, a flex vehicle was installed in a chassis dynamometer equipped with a gas analyzer, in order that before the completion of the urban driving cycle, were determined the content of hydrocarbons corrected, carbon monoxide corrected, carbon dioxide and oxygen present in gas emissions from the engine. The research concluded that： the performance analysis for characterization of fuel showed consistent with ANP specifications; after tests performances, it can be stated that natural gas fuel was the fuel which had the highest content of hydrocarbons and carbon monoxide corrected, while ethanol had the highest amount of carbon dioxide and oxygen residue present in gas emissions; before a comparative analysis, the vehicle catalyst showed the best performance for reducing the content of hydrocarbon corrected present in exhaustion gases when it worked with natural gas fuel and showed maximum efficiency of 100% to reduce the content of carbon monoxide corrected for both fuels. Before this, it can be stated that the vehicle catalyst showed satisfactory performance, achieving good reduction levels of greenhouse gases emissions.展开更多
14%REO-2.5%LaO-33.5%ZrO-50%AlO(RE = Ce, Y, Pr) composites were prepared by a coprecipitation method. The Pd catalysts were obtained by an aqueous solution of Pd(NO)loaded on the rare earths modified composites with an...14%REO-2.5%LaO-33.5%ZrO-50%AlO(RE = Ce, Y, Pr) composites were prepared by a coprecipitation method. The Pd catalysts were obtained by an aqueous solution of Pd(NO)loaded on the rare earths modified composites with an initial wet impregnated method. The experiment results show that catalytic activity of the rare earths modified Pd/LaO-ZrO-AlOcatalysts is better than bare sample for methane oxidation. The structural characterization results reveal that the rare earths modified Pd catalysts increase amounts of surface active oxygen species by X-ray photoelectron spectroscopy(XPS) analysis and improve the dispersion of active component from H2-temperature programmed reduction(H2-TPR) measurement compared with bare sample. Especially,Pd/14%YO-2.5%LaO-33.5%ZrO-50%AlOsample exhibits highly active stability, it is related to the Pd particles highly dispersion,which was observed by transmission electron microscope(TEM) images.展开更多
Research in Early Days In early 1950s to 1960s, China began to study natural gas as an alternative fuel according to the State Science & Technology Commission’s requirment of widely utilizing natural gas. A testi...Research in Early Days In early 1950s to 1960s, China began to study natural gas as an alternative fuel according to the State Science & Technology Commission’s requirment of widely utilizing natural gas. A testing station for natural gas vehicles was established in Sichuan province展开更多
文摘It is known that the transport sector has a fundamental importance in the modem society, as the economic development is directly linked to mobility. Over the years, the transport became linked to different environmental problems, which can be detached greenhouse gases emissions in the atmosphere, where in recent decades can be perceived the intensification and targeting of efforts in research and development of new technologies to reduce the levels of greenhouse gases emissions in the atmosphere. In this context, it can be highlighted the modem systems of electronic engine management, new automotive catalysts and the use of renewable fuels which contribute to reducing the environmental impact. This research had, as its purpose, the analysis of fuels characteristics used for testing, comparative analysis of gas emissions from a motor vehicle running on ethanol or natural gas fuels according to NBR 6601 and conducting tests to estimate the maximum catalytic efficiency. For the implementation of trial, a flex vehicle was installed in a chassis dynamometer equipped with a gas analyzer, in order that before the completion of the urban driving cycle, were determined the content of hydrocarbons corrected, carbon monoxide corrected, carbon dioxide and oxygen present in gas emissions from the engine. The research concluded that： the performance analysis for characterization of fuel showed consistent with ANP specifications; after tests performances, it can be stated that natural gas fuel was the fuel which had the highest content of hydrocarbons and carbon monoxide corrected, while ethanol had the highest amount of carbon dioxide and oxygen residue present in gas emissions; before a comparative analysis, the vehicle catalyst showed the best performance for reducing the content of hydrocarbon corrected present in exhaustion gases when it worked with natural gas fuel and showed maximum efficiency of 100% to reduce the content of carbon monoxide corrected for both fuels. Before this, it can be stated that the vehicle catalyst showed satisfactory performance, achieving good reduction levels of greenhouse gases emissions.
基金Project suppored by National Natural Science Foundation of China(21673146)
文摘14%REO-2.5%LaO-33.5%ZrO-50%AlO(RE = Ce, Y, Pr) composites were prepared by a coprecipitation method. The Pd catalysts were obtained by an aqueous solution of Pd(NO)loaded on the rare earths modified composites with an initial wet impregnated method. The experiment results show that catalytic activity of the rare earths modified Pd/LaO-ZrO-AlOcatalysts is better than bare sample for methane oxidation. The structural characterization results reveal that the rare earths modified Pd catalysts increase amounts of surface active oxygen species by X-ray photoelectron spectroscopy(XPS) analysis and improve the dispersion of active component from H2-temperature programmed reduction(H2-TPR) measurement compared with bare sample. Especially,Pd/14%YO-2.5%LaO-33.5%ZrO-50%AlOsample exhibits highly active stability, it is related to the Pd particles highly dispersion,which was observed by transmission electron microscope(TEM) images.
文摘Research in Early Days In early 1950s to 1960s, China began to study natural gas as an alternative fuel according to the State Science & Technology Commission’s requirment of widely utilizing natural gas. A testing station for natural gas vehicles was established in Sichuan province
