Reformulated Gasoline in Metro-Atlanta

1
Reformulated Gasoline in Metro-Atlanta

• An analysis of E10 Reformulation
• CEE/EAS 6792
• Burcak Kaynak
• Grant T. Michalski

2
Why Is This Issue Important?

• Court Orders New Fuel Mix AJC 10/8/04
• Result of Atlantas problems with ground-level
  ozone concentrations.
• 1999-2002 168 recorded violations of 0.085 ppm
  8-hour ozone standard.
• Federally-mandated reformulated gasoline (RFG)
  would contain 10 ethanol to act as an oxygenate
  and octane enhancer.
• 13 Metro-Atlanta counties required to switch to a
  federally designed fuel by mid-January.

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Why Is This an Issue?

• Clean Air Act, 1990 Amendments
• Title II, Section 211 (k) (1) the EPA
  Administrator shall promulgate regulations under
  this section establishing requirements for
  reformulated gasoline to be used in gasoline
  fueled vehicles in specified nonattainment
  areas.
• Atlanta recently designated as being in Severe
  Nonattainment for ozone.
• As of 1999, 29 areas in 18 states used
  reformulated gasoline.

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Why Is This an Issue?

• State of Georgia claims the new gasoline will
  cost more, and increase air pollution.
• Estimates predict reformulation could increase
  gasoline costs by 5 cents per gallon.
• Studies show that new gasoline would increase
  certain emissions while decreasing others.
• April 1999, California requests exemption for RFG
• EPA denies request in June of 2001

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1990 Clean Air Act Amendments

• Objectives
• Enhance octane rating
• Reduce air pollution
• Smog in summer months
• CO in winter months
• Air toxics year-round
• Enhance energy security by extending the gasoline
  supply through the use of oxygenates.
• Encourage the use of domestically-produced,
  renewable energy sources.

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1990 Clean Air Act Amendments

• Requirements for reformulated gasoline
• Must contain 2 (by weight) oxygen.
• Ethanol not specifically required.
• Limits benzene to 1 by volume.
• Non-RFG can contain as much as 5 benzene.
• Limits total aromatics to 25 by volume.
• Aromatics include benzene, ethylbenzene, toluene,
  xylene
• Non-RFG can contain as much as 50 aromatics.
• Limits NOx emissions to non-reformulated levels.

7
1990 Clean Air Act Amendments

• Options for meeting CAA requirements
• Addition of 11 (by volume) of methyl tert-butyl
  ether (MTBE)
• Addition of 5.7 (by volume) ethanol.

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1990 Clean Air Act Amendments

• Separated into 2 phases
• Phase 1 (January 1995)
• Reduce VOCs and Air Toxics by 15
• Phase 2 (January 2000)
• Reduce VOC and Air Toxic emissions by an
  additional 5-10 (to be determined by the EPA
  Adminstrator)

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Benefits of E10

• Enhanced Octane Rating
• Reduces knocking
• Reduces emissions of certain air pollutants by
  providing for more complete combustion.
• Reduced levels of harmful aromatics in gasoline.
• Reduce amount of crude oil needed for a gallon of
  gasoline.
• Provide additional use for domestically-grown
  corn in the production of ethanol.

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Benefits of E10

• Equivalence Ratio (amount of fuel)/(amount of
  oxygen)

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Benefits of E10

• PM2.5 from automobiles is primarily soot.
• Soot and Carbon Monoxide (CO) are both products
  of incomplete combustion.
• Adding oxygen (through the use of oxygenates)
  improves combustion efficiency.
• Hydrocarbon (HC) emissions are also reduced,
  largely due to the increased combustion
  efficiency.

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Benefits of E10

• Reduced Greenhouse Gas (GHG) emissions
• RFGs are more fuel efficient than
  non-reformulated options. Less GHSs are
  produced.
• Reduction of benzene emissions
• Dilution effect
• Reduced incidence of cancer due to benzene

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Issues with E10

• NOx
• Typically, engines operate at an equivalence
  ratio of F1 (stoichiometric amount of oxygen fed
  with fuel)
• Adding oxygenates decreases the equivalence
  ratio.
• NOx peaks at equivalence ratios just less than 1.
• Mixed data on effect on NOx emissions, though one
  study shows that with RFG, emissions from
  pre-1986 cars dropped 0.5, while increasing 5
  with post-1986 cars.

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Issues with E10

• Ethanol
• Increased permeation through polymer materials.
• Increased soil and groundwater contamination.
• Ethanol increases corrosion steel underground
  storage tanks.
• Increased risk of leakage to surrounding soil.
• Material incompatibility with several components
  of fueling systems.
• Inhibits bioremediation and natural attenuation
  of NAPL by affecting NAPL/water interface.

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Issues with E10

• Ethanol (continued)
• Toxicity of ethanol.
• Low (occasionally negative) Net Energy Value
  (NEV)
• Ethanol production occasionally requires more
  energy to produce than is released in its
  combustion.
• Energy used to produce ethanol typically comes
  from power plants, resulting in a relocation of
  combustion emissions.

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Issues with E10

• Evaporative losses
• Above 16 C (61 F), E10 exhibits a higher Reid
  Vapor Pressure (RVP) than standard gasoline (E0)
• Higher vapor pressure implies greater volatility,
  more evaporation.
• Evaporation causes release of additional air
  toxics, as well as VOCs.

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Issues with E10

• Ozone (O3)
• VOCs NOx sunlight O3

NOx (ppm)
ROG/NOx 5
0.25 0.10
A
O3
B
ROG (ppm C)
0.5 1.25
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Issues with E10

• Acetaldehyde
• RFG increases acetaldehyde emissions by 100-200
• Chemically similar to ethanol
• Ethanol (C2H5OH) vs Acetaldehyde (C2H4O)
• Precursor to Peroxy Acetyl Nitrate (PAN)
• Important chemical in long-range transport of NOx
• Probable carcinogen

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Issues with E10

• Acetaldehyde (continued)
• Cost-benefit analysis from 2000 compared decrease
  in incidence of cancer from benzene emissions to
  increase in cancer from acetaldehyde due to use
  of RFG
• Analysis predicted savings from reduction of
  benzene-related cancer of 2.4-65 million per
  year.
• Same analysis predicted annual cost due to
  acetaldehyde-related cancer to be 2.7-200
  million per year.

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Alternatives to E10

• Methyl Tertiary-Butyl Ether
• Provides better results for air quality, but has
  been found in groundwater since its use as an
  oxygenate.
• Generally discounted as an option
• Alkylates
• Highly-branched alkanes with low aromatic content
• Meet many of the objectives of RFG
• Do not contain oxygen
• Do not meet CAA requirements for RFG

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Conclusions

• E10 can be shown to reduce emissions of carbon
  monoxide (CO), hydrocarbons (HC), and
  particulates.
• Emissions of NOx are largely unaffected, with
  research suggesting a slight tendency towards
  increased NOx emissions.
• E10 use results in increased emissions of ethanol
  and acetaldhyde
• E10 causes an increased risk of soil and
  groundwater contamination.

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Conclusions

• Greatest issue appears in emissions of air
  toxics, where increased incidence of cancer could
  cost as much as 135 million per year.
• Conclusion The minor gains in CO, HC, and
  particulate emissions do not outweigh the costs
  associated with the numerous risks of E10 use,
  particularly the increased incidence of cancer
  due to increased acetaldehyde emissions.