Auto industry paper supports UAI concerns on EPA ethanol testing
Source: By Urban Air Initiative, Ethanol Producer Magazine • Posted: Wednesday, November 5, 2014
The SAE Paper echoed concerns raised by Urban Air Initiative and the Energy Future Coalition in a recent analysis of EPA models that determine emissions from various fuel blends. The practice of “match blending” produces skewed results that the authors contend produces emission increases that are “incorrectly attributed to ethanol”.
The paper focuses on the fact that modification of gasoline blendstock composition in preparing ethanol-gasoline blends has a significant impact on vehicle exhaust emissions. In “splash” blending the blendstock is fixed, ethanol-gasoline blend compositions are clearly defined, and effects on emissions are relatively straightforward to interpret. In “match” blending the blendstock composition is modified for each ethanol-gasoline blend to match one or more fuel properties. The effects on emissions depend on which fuel properties are matched and what modifications are made, making trends difficult to interpret.
SAE papers are technical in nature, require exhaustive peer review, and are highly regarded. According to Steven VanderGriend, Urban Air Initiative technical director, this is critical to the argument UAI has made that splash blending higher volumes of ethanol on to finished E10 not only fails to raise any emissions but serves to improve emissions by diluting sulfur and aromatics, along with reducing the current non-regulated ultrafine particulates emissions. Also, by using ethanol’s octane potential, the greatest CO2 and mileage benefits can be achieved by the auto industry.
“This paper can serve as an important tool to correct the MOVES (Motor Vehicle Emissions Simulator) model that EPA requires states to use when estimating air quality impacts of motor fuels,” said VanderGriend. “As an independent source, the auto industry experts who were involved in this study are validating the concerns we have had for quite some time now.”
“In fact we are very excited with regard to the conclusion they reached that studies to evaluate the effects of ethanol should be conducted by adjusting the blendstock only as necessary to satisfy ASTM requirements. Blending ethanol at up to 30 percent volume with an E10 blendstock should generally require no change in composition to meet ASTM D4814.”
The Urban Air Initiaitive and the Energy Future Coalition have provided data to EPA supporting the use of E30 as a low carbon, high octane substitute for toxic aromatics in gasoline.