December 26, 2013 | 5 Comments
This week saw a team at Ford Motor Company’s Research and Innovation Center in Dearborn release a detailed study of the effect of ethanol blend levels in emissions. The study wasn’t done with the latest and greatest products, rather they used a 2006 model, an age about midway through most of the working U.S. private fleet. The choice was a large car, a 2006 model Mercury Grand Marquis flexible fuel vehicle (FFV).
The Ford team report was published in the American Chemical Society’s Environmental and Science & Technology journal. While it’s behind a paywall, the surprise is that proprietary research has been made public at all. If consumers were to believe the mass media and the competitor’s pressures points there is no useful point in ethanol at all.
The Ford team just killed that.
The Mercury Grand Marquis was operated on E0, which would be no ethanol, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer. The study thus included the current predominant market fuel (E10); a range of possible future midlevel ethanol blends (E20−E40); and the new range for high-level ethanol blends (E55, E80).
Here’s the graph:
The number of blends studied is about twice that of previous studies, and shows a more detailed picture of the effect of ethanol blend level on emissions. Further, they reported data for engine-out emissions and tailpipe emissions; operating temperatures (engine-out and catalyst); and ethanol concentrations used in the engine control strategy. Comparing these data allows for differentiation between fuel chemistry and engine calibration effects – the two general mechanisms by which increased ethanol content in fuel affects the emissions.
Both the environmentalists and farmers should be thrilled. And the EPA chagrinned by the recent suggestion to back out of its job to supplement the U.S. gasoline supply with ethanol.
Ethanol is standing in for about 900,000 barrels of oil per day or at today’s price nearly $90,000,000 of daily imports, almost a dollar per day per car.
In a nutshell, the higher ethanol content in the fuel, the Ford team found that the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx (mono-nitrogen oxides NO and NO2) and NMHC (nonmethane hydrocarbons ) decreased; while CO (carbon monoxide), ethene, and N2O (nitrous oxide) emissions were not discernibly affected.
The main polluters of concern nowadays are NOx and organic compounds that have the main role in ozone reduction in highly polluted urban areas that generally requires reduction of the emissions for human health.
NMOG (nonmethane organic gases) and THC (total hydrocarbon) emissions displayed a pronounced minimum with midlevel (E20–E40) ethanol blends; 25–35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30–E40, with no further decrease seen with E55 or E80.
All that is technical, and in general points to a sensible assessment of the dominant role of engine calibration on the tailpipe emissions of NOx. Upon sensing greater ethanol content in the fuel, the calibration prescribed different engine operating conditions that yielded higher engine-out and catalyst temperatures during the critical cold-start period, which improved the NOx conversion efficiency of the exhaust after-treatment system.
Higher engine-out and catalyst temperatures from the cold start are very good things.
The Ford crew doesn’t address the politics and public relations war over the fuel market. Instead they speak straight to the engineering on engines declaring, “It is important to recognize the importance of both fuel chemistry and engine calibration in determining tailpipe emissions and to consider the fuel and vehicle together as a system. There are important differences in the nature of the fuel chemistry and engine calibration effects. The fuel chemistry effect is fundamental and the same qualitative emissions trend of increased ethanol, acetaldehyde, and CH4 emissions and decreased NMHC emissions will be seen for all FFVs from all manufacturers.”
Continuing they said, “In contrast, the impacts of engine calibration on emissions depend on the calibration strategy and will be specific for specific vehicle models. Different manufacturers adopt different strategies and even the same manufacturer can adopt different strategies for different models.”
The conclusion includes an important point for alternative and fuel extension proponents, “ . . . the minimum in NOx and NMOG emissions for midlevel ethanol blends for the FFV tested in the present work points to future opportunities for emission reductions from FFVs.”
The point for today in short form is ethanol can be a large and beneficial fuel resource far into the future. Ford put hard research up again discrediting many myths about ethanol.
Most of these kinds of things are kept under wraps for sound business reasons. Congratulations and appreciation is earned for the managerial courage to put the data right out where everyone can see it. Go Ford. Thanks for looking out for the consumers.