MTBE/汽油对电喷汽油机非常规污染物排放特性的影响

采用气相色谱技术,分析研究了电喷汽油机燃用不同掺混比的甲基叔丁基醚(MTBE)/汽油混合燃料时,甲醛、乙醛、苯和未燃MTBE等非常规污染物排放特性,以及三效催化器对其净化效率的影响.研究结果表明:在不改变汽油机任何参数的情况下,随着MTBE掺混比的增大,苯排放明显降低,尤其在MTBE体积分数为20%时,约降低了50%,但排气中的甲醛、乙醛和未燃MTBE浓度却明显增加.三效催化器对于乙醛和MTBE的转化效率相对较低,而对于苯、甲醛的催化净化效率很高,其中苯的平均净化效率约为86%,催化后排气中甲醛浓度已低于检测限值.

Effects of MTBE Addition in Gasoline on the Unregulated Emissions from an EFI Gasoline Engine

Using the gas chromatography, the effects of methyl tert-butyl ether (MTBE) blended gasoline on benzene, formaldehyde, acetaldehyde and unburned MTBE emissions from an EFI gasoline engine without modification were investigated. Meanwhile, the catalytic conversion efficiencies of these unregulated emissions were measured. The experimental results showed that with the increase of MTBE concentration in the blended fuels, the benzene emission was drastically reduced,especially for MTBE containing 20%(down to 50%). On the contrary, engine-out formaldehyde, acetaldehyde and unburned MTBE emissions were increased with high MTBE addition to gasoline. Three-way catalyst was effective to reduce benzene and formaldehyde emissions, while acetaldehyde and MTBE were hardly converted. The catalytic conversion rate of benzene reached about 86%, and it was difficult to detected formaldehyde in the tailpipe after the catalyst operation.