Influence of Ethanol and MTBE Proportion in China ⅥB Gasoline on Vehicle Particulate Emissions 2021-01-0540
With the implementation of China Ⅵ gasoline standards, the use of ethanol is expanding in China. The addition of ethanol in China Ⅵ gasoline is to further reduce emissions of gaseous and particulate matter. However, due to the constrain of biomass ethanol production, MTBE (Methyl tert-Butyl Ether) is still being used in addition of ethanol to improve fuel octane and maintain oxygen content. The impact of mixed oxygenates in fuel to vehicle emissions are studied in this paper. The correlation of fuel characteristics to vehicle particulate emission has been investigated, in particularly to well known fuel indices. Those include Honda’s particulate matter index (PMI), General Motor’s Particulate evaluation Index (PEI), and Toyota’s simplified particulate index (sPMI), etc.. The results from this study suggest some alternatives to existing fuel indices due to oxygenates contribution. In this paper, three direct-injection turbocharged models were used as the test vehicles. The particulate emissions from vehicles were investigated under Worldwide Harmonized Light Vehicles Test Cycle (WLTC). The test fuels are China Ⅵb gasoline with different mixture ratio of ethanol and MTBE. The results show that the uncorrected PMI has no correlation to vehicle PM emission due to oxygenates impact and results show correlations of oxygenates content to vehicle particulate emissions. Nevertheless, the sensitivities of PM/PN emission from the three vehicles are different due to content variation of oxygenates mix and fuel indices. Two out of three vehicle show positive correlation to ethanol and negative correlation to MTBE. With the addition of MTBE and ethanol mix in one blend, minimum impact to particulate emissions are observed.
Huanyu Tian, Lu Han, Xin Guo, Pat Geng, Wen Sun, Susan Zhang, Haitao Zhou, Xiaoshuang Kong, Ni Zhang
Sinopec RIPP, General Motors LLC, DONGFENG Motor Corporation, Pan Asia Technical Automotive Center Co, China FAW Group CO., Ltd