噴射引擎機車使用酒精汽油排放廢氣之觸媒轉化效率研究

Catalytic Converter Efficiency of Air Pollutant by Integrated Strategy of Fuel Injection Motorcycle and Ethanol-gasoline Blend

姚永真(Yong-Zhen Yao) ； 蔡俊鴻(Jun-Hong Cai) ； 柯雅琍(Ya-Li Ke) ； 黃慈閔(Ci-Min Huang) ； 蔡維澤(Wei-Ze Cai)

《燃燒季刊》 86期 (2014/08) Pp. 3-18

https://doi.org/10.30041/CQ.201408_(86).0002

摘要

本研究以2部四行程噴射引擎機車為對象，以E15酒精汽油為測試油品，於怠速條件下比較酒精汽油於無觸媒排氣管、新觸媒以及高里程含觸媒排氣管所致法定空氣污染物（CO、THC、NO）量測結果。結果顯示，與市售油相較，使用E15酒精汽油所致CO、THC及NO排放濃度於新車或過保固里程機車皆顯示有較低濃度。法定空氣污染物以新機車搭配新觸媒之排放濃度最低，並隨累計里程增加而提高。E15為燃料對過保固期機車之法定空氣污染物排放濃度仍較無觸媒機車為低，顯示觸媒轉化器仍對法定空氣污染物排放具有控制效果，惟控制效率不如新觸媒，觸媒轉化率僅有新觸媒之63%（CO）、48%（THC）及74%（NO）。觸媒之比表面積與表面結構分析結果顯示，過保固里程之觸媒有比表面積減少、平均孔徑變大、燒結情形顯著、表面有明顯被覆層等特性，使得表面積下降減少反應面積，為造成觸媒轉化效率下降主要原因。此外，不同組合（油品－機車－觸媒）之分析結果顯示，不同空氣污染物受觸媒及油品影響程度不同，尾氣排放CO受觸媒及油品影響，THC除油品影響外，機車引擎條件劣化及觸媒老化亦對THC排放具有影響，NO則受車輛及觸媒劣化影響較大。

關鍵字

怠速 ； 法定空氣污染物 ； E15酒精汽油 ； 三元觸媒

並列摘要

In this study, two four-stroke motorcycles with fuel-injection engine were selected as target to investigate the catalyst converter efficiency of criteria air pollutants (CO, THC, and NO). Three types of tailpipe were installed in the test motorcycles, respectively, including new catalyst, in-use catalyst in odometer 16,000 km, and no-catalyst. Ethanol-gasoline blend which contains 15 % (v/v) ethanol in gasoline (E15) was used as test fuel. The motorcycles were tested on an idling mode and analyzed by exhaust analyzer. The result shows that the CO, THC, and NO concentrations are lower than those of commercial fuel while using E15 as fuel in both new and in-use motorcycle. The lowest concentration of criteria air pollutants was observed in new motorcycle with new catalyst tailpipe, and the concentration increased with the increasing cumulative odometer. The result also indicated catalytic converter still work for criteria air pollutants in the in-use motorcycle, but the control efficiency is only achieved by 63% (CO), 48% (THC) and 74% (NO) as compared to those of new catalysts. The analysis result of specific surface area and catalyst surface structure showed that the in-use catalyst has less specific surface area, larger pore size, and more sinter than the new catalyst. This may the reason that caused low catalyst converter efficiency of in-use catalyst. In addition, with different fuel-motorcycle-catalyst scenario, the results showed that the catalyst and fuel may affect CO emissions, THC may influence by fuel, engine condition, and catalyst aging, and engine condition and catalyst aging may have impact on NO emissions.

並列關鍵字

Idle model ； criteria air pollutants ； E15 ethanol-gasoline blend ； three-way catalyst