Argument: Corn ethanol has a positive effect on air quality

Issue Report: Corn ethanol


  • “The Benefits of Biofuels”. Energy Future Coalition. Retrieved 1.28.08 – “The effect of E85 on air quality is almost uniformly positive, with the exception of increased emissions of aldehydes, such as acetaldehyde. Conventional catalytic converters control these emissions in ethanol blends of up to 23%, and it is expected that they could be readily adapted to E85 blends. A test of advanced emission control systems in three conventional gasoline vehicles found that advanced systems reduced formaldehyde emissions by an average of 85% and acetaldehyde by an average of 58%.
Even without advanced controls, the benefits of reducing other toxic emissions outweigh the effects of aldehydes. The National Renewable Energy Laboratory tested a 1998 Ford Taurus FFV running on E85 and reported: ‘Emissions of total potency weighted toxics (including benzene, 1,3-butadiene, formaldehyde, and acetaldehyde) for the FFV Taurus tested on E85 were 55% lower than that of the FFV tested on gasoline.'”
  • “Clean Alternative Fuels: Ethanol”. Transportation and Regional Programs Division, U.S. Environmental Protection Agency. Mar. 2002 – “Actual emissions will vary with engine design; these numbers reflect the potential reductions offered by ethanol (E85), relative to conventional gasoline.

    • Fewer total toxics are produced.
    • Reductions in ozone-forming volatile organic compounds of 15%.
    • Reductions in carbon monoxide of 40%.
    • Reductions in particulate emissions of 20%.
    • Reductions in nitrogen oxide emissions of 10%.
    • Reductions in sulfate emissions of 80%.
    • Lower reactivity of hydrocarbon emissions.
    • Higher ethanol and acetaldehyde emissions.
    • Estimates based on ethanol’s inherently “cleaner” chemical properties with an engine that takes full advantage of these fuel properties.”
  • “The Benefits of Biofuels”. Energy Future Coalition. Retrieved 1.28.08 – “How can biofuels reduce toxic compounds in gasoline? The principal contributor to toxic air pollution from gasoline is a class of chemical compounds called aromatics, which make up an average of 26% of every gallon of gasoline. Blended with gasoline to increase octane, aromatics have the potential to cause cancer, and they also result in emissions of fine particulates and smog-forming gases that harm lung function and worsen asthma.
The EPA was required by the Clean Air Act Amendments of 1990 to seek ‘the greatest degree of emission reduction achievable’ of air toxics in automobiles. In response to recent litigation, the EPA issued a rule to reduce one of these hazardous air pollutants, benzene, but the agency did not address the two other aromatic compounds, toluene and xylene, which form benzene during combustion. Using biofuels instead of aromatics to improve octane would result in public health benefits worth tens of billions of dollars from the reduction in emissions of small particles alone.”