Ozone-Forming Potential of Reformulated Gasoline (1999) / Chapter Skim
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1 Introduction
1 Introduction
Pages 11-22
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From page 11... ...
On-road gasoline fueled motor vehicles are estimated to account for about 26% of the VOC emissions from all source categories, about 56% of the CO emissions, and about 22% of the NOx emissions in 1997 (EPA 1998~. As a result, motor vehicles have been a primary target for emission controls in the iAn organic compound is a compound containing carbon combined with atoms of other elements, commonly hydrogen, oxygen, and nitrogen.
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From page 12... ...
12 A, ~ ~ 1 i' \ ~ it\ \ + NO 11 ~- CO E c~ E o ~ ~ ..
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From page 14... ...
Should some oxygenated additives be allowed to be used in RFG whereas others should not be allowed? In the traditional approach to ozone mitigation in the United States, these questions are addressed in a straightforward and simple manner: the mass of precursor emissions from the use of various RFG blends in motor vehicles are assessed; and, 2EPA estimates that non-road gasoline-fueled motor vehicles account for about 9% of the VOC emissions from all source categories, about 19% of the CO emissions, and about 19% of the NOX emissions in 1997 (EPA 19983.
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From page 15... ...
sin this report, the abundance or concentration of atmospheric ozone will be expressed in terms of its volume mixing ratio; that is, the number of ozone molecules per unit volume of air divided by the total number of atmospheric molecules per unit volume of air. Thus, an ozone concentration of 1 ppb denotes an ozone abundance of 1 ozone molecule for each billion atmospheric molecules, and an ozone concentration of 1 ppm (i.e., parts per million by volume)
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From page 16... ...
In retrospect, it appears that the ozone mitigation policies our nation has embarked upon over the past 3 decades have had a positive impact. On average, peak ozone concentrations in urban areas of the United States appear to be on a downward trend (Figure I-3)
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From page 17... ...
Of the 29 urban areas required by the Clean Air Act Amendments of 1990 to submit State Implementation Plans, 27 were unable to submit plans that showed attainment by the mandated date of 1998. Moreover, the promulgation of a new 8-hr, 80-ppb NAAQS for ozone in 1997 is expected to approximately triple the number of non-attainment counties
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From page 18... ...
Source: Adapted from EPA 1998. and lead to widespread non-attainment in rural as well as urban areas of the eastern United States (Wolff 1996; Chameides et al.
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From page 19... ...
Can a metric based on ozone-forming potential be reliably and robustly used to quantify the relative impacts of different RFG blends with different oxygenates on ozone pollution in the United States? As outlined above, these are the questions that motivated the formation of the National Research Council Committee on Ozone-Forming Potential of Reformulated Gasoline and this report.
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From page 20... ...
Factors to be considered include assessment of effects of the fuel blending method (i.e., splash blending versus match blending) , "distillation impact" and/or the "commingling effect," variability in fuel composition, engine operating conditions as they pertain to emissions, and changes in the exhaust-to-evaporative emissions ratio.6 The committee was asked to identify any gaps in the existing scientific and technical information, recommend how such gaps might be 6"Splash blending" refers to a method of oxygenating gasoline by adding an oxygenate to the gasoline blend stock without any systematic control over the resulting Reid Vapor Pressure (RVP)
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From page 21... ...
Therefore, the committee has not addressed issues such as balance of trade, energy and cost requirements for fuel production, domestic sources of fuel versus foreign sources, human health and global environmental impacts, and use of renewable fuels versus nonrenewable fuels. In addition, it should be noted that this report is limited to the scientific and technical aspects ofthis issue; the possible design or implementation of regulations based on ozone-forming potential are not within the scope of this study.
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From page 22... ...
Appendix B contains a letter from Senator Richard G Lugar suggesting that EPA establish a procedure to certify ethanol blends of RFG as equivalent to methanol blends based on ozoneforming potential.
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