The Influence Of Ethanol Fuel On Emission Characteristics And Exhaust Control Catalyst Of Motorcycle

The emissions of pollutants from vehicle engines into the atmosphere are becoming a more and more concern in China, because of its steady increasing number. The application of ethanol-gasoline blended fuel in our country is one of means to lessen these pollutant emissions from vehicles and save fossil fuels. But till now, few data are available for showing the effects of ethanol-blended gasoline on exhaust emissions characteristics and its influence on monolith catalytic converter.In this paper, two new four-stroke motorcycles, HONDA CG125, was chosen. Wheels of those two test vehicles were supported by rollers that simulated actually driving conditions. The testing was performed on this chassis dynamometer according to ECE40 (European driving cycle). Pollutant emissions were measured for the entire ECE40 cycle with constant volume sampling (CVS). The results can be summarized: E10 can improve emissions of CO and HC to some extend; hydrocarbon species except ethanol, acetaldehyde and ethylene emissions are decreased somewhat from E10. Additionally, the effect of ethanol addition to gasoline on the improvement of aromatic emissions is not obvious.SEM, EPMA and TG-DTA were applied for the characterization of coked catalyst samples, which were obtained from motorcycles having completed a 10000 km-testing program using common gasoline and E10 fuels, respectively. Result indicates: after a 10000km-testing program, catalysis conversions of HC, CO and NOx from E10 fueled engine decreased drastically; E10 can gives rise to more negative impact on efficiencies of catalyst converter than common gasoline, because it produces more carbon deposition; the quantity of carbon deposition on the radial positions of catalytic converters is center-layer > transition-layer > edge-layer; the majority of total carbon is deposited on precious mental (PM) sites, and carbenium ions produced on PM can combust at lower temperatures.After XPS and FTIR characteristic analysis on coked catalyst samples, conclusions can be drawn: carbon species are CxHy and CxHyO, respectively on the surface of gasoline and E10 fueled; FTIR confirms the presence of aromatic rings, alkyl groups and their partial oxidation products in carbon deposition on the surface of E10 fueled.