Impact of Higher Alcohols Blended in Gasoline on Light-Duty Vehicle Exhaust Emissions

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• 作者：Matthew A. Ratcliff ; Jon Luecke ; Aaron Williams ; Earl Christensen ; Janet Yanowitz ; Aaron Reek ; Robert L. McCormick
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：December 3, 2013
• 年：2013
• 卷：47
• 期：23
• 页码：13865-13872
• 全文大小：339K
• 年卷期：v.47,no.23(December 3, 2013)
• ISSN：1520-5851

文摘

Certification gasoline was splash blended with alcohols to produce four blends: ethanol (16 vol%), n-butanol (17 vol%), i-butanol (21 vol%), and an i-butanol (12 vol%)/ethanol (7 vol%) mixture; these fuels were tested in a 2009 Honda Odyssey (a Tier 2 Bin 5 vehicle) over triplicate LA92 cycles. Emissions of oxides of nitrogen, carbon monoxide, non-methane organic gases (NMOG), unburned alcohols, carbonyls, and C₁鈥揅₈ hydrocarbons (particularly 1,3-butadiene and benzene) were determined. Large, statistically significant fuel effects on regulated emissions were a 29% reduction in CO from E16 and a 60% increase in formaldehyde emissions from i-butanol, compared to certification gasoline. Ethanol produced the highest unburned alcohol emissions of 1.38 mg/mile ethanol, while butanols produced much lower unburned alcohol emissions (0.17 mg/mile n-butanol, and 0.30 mg/mile i-butanol); these reductions were offset by higher emissions of carbonyls. Formaldehyde, acetaldehyde, and butyraldehyde were the most significant carbonyls from the n-butanol blend, while formaldehyde, acetone, and 2-methylpropanal were the most significant from the i-butanol blend. The 12% i-butanol/7% ethanol blend was designed to produce no increase in gasoline vapor pressure. This fuel鈥檚 exhaust emissions contained the lowest total oxygenates among the alcohol blends and the lowest NMOG of all fuels tested.