E85, which consists of nominally 85% fuel grade ethanol and 15% gasoline, must be used in flexible-fuel (or flexfuel) vehicles (FFVs) that can operate on fuel with an ethanol content of 0% to 85%. Published studies include measurements of the effect of E85 on tailpipe emissions for Tier 1 and older vehicles. Car manufacturers have also supplied a large body of FFV certification data to the U.S. Environmental Protection Agency, primarily on Tier 2 vehicles. These studies and certification data reveal wide variability in the effects of E85 on emissions from different vehicles. Comparing Tier 1 FFVs running on E85 to similar non-FFVs running on gasoline showed, on average, significant reductions in emissions of oxides of nitrogen (NOX; 54%), non-methane hydrocarbons (NMHCs; 27%), and carbon monoxide (CO; 18%) for E85. Comparing Tier 2 FFVs running on E85 and comparable non-FFVs running on gasoline shows, for E85 on average, a significant reduction in emissions of CO (20%), and no significant effect on emissions of non-methane organic gases (NMOGs). NOX emissions from Tier 2 FFVs averaged approximately 28% less than comparable non-FFVs. However, perhaps because of the wide range of Tier 2 NOX standards, the absolute difference in NOX emissions between Tier 2 FFVs and non-FFVs is not significant (P = 0.28). It is interesting that Tier 2 FFVs operating on gasoline produced approximately 13% less NMOGs than non-FFVs operating on gasoline. The data for Tier 1 vehicles show that E85 will cause significant reductions in emissions of benzene and butadiene, and significant increases in emissions of formaldehyde and acetaldehyde, in comparison to emissions from gasoline in both FFVs and non-FFVs. The compound that makes up the largest proportion of organic emissions from E85-fueled FFVs is ethanol.
Effect of E85 on tailpipe emissions from light-duty vehicles
Journal of the Air and Waste Management Association ; 59 , 2 ; 172-182
2009
11 Seiten, 4 Bilder, 4 Tabellen, 31 Quellen
Aufsatz (Zeitschrift)
Englisch
Non-Tailpipe Hydrocarbon Emissions from Motor Vehicles
British Library Conference Proceedings | 1997
|Evaluation of Utilizing Remote Sensing to Monitor Tailpipe Emissions from Heavy Duty Vehicles
British Library Conference Proceedings | 1997
|