Fuels and Society - Reformulated Gasolines

William Kovarik
Radford University
and
Matthew E. Hermes
Kennesaw State University

Fuels and Society C: 7. Reformulated Gasolines

Back to: Start

Economists and environmentalists have disagreed about the costs and benefits of air pollution regulations aimed at cutting ozone and smog by reducing hydrocarbons, CO and NOx.

While the overall costs of catalytic converters and other hardware is about $10 billion per year, few agreed on the benefits.

One economist put benefits at only $2 billion per year, relying on well-documented obvious health benefits extrapolated from air pollution related acute health emergencies. (Freeman, 1982)

On the other extreme, the American Lung Association estimated potential benefits of pollution control at as much as $93 billion per year. (Cannon, 1990) And the Natural Resource Defense Council saw benefits from pollution control of total car and light truck air pollution of from $120 to $220 billion per year (Miller, 1993).

Other studies have looked at more specific questions. For instance a 1988 OTA study looked at a 35% reduction in nationwide emissions of smog-forming volatile organic compounds (VOCs) in the nation’s 90 dirtiest cities. This modest reduction of VOCs by controlling vapor pressure would cost between $8.8 billion and $12 billion annually, yet the acute health improvements that could result from these changes were valued in a 1991 follow up study at only $250 million to $1 billion annually. (Krupnick, 1991).

Of course, the conclusions of all these studies depended a great deal on their assumptions about what counts as a benefit. If only a reduced incidence of asthma attacks and other acute health effects are measured, then the benefits will be seen as relatively low. On the other hand, if generalized health benefits, improvements in crop yields and reductions in acid rain and global warming are factored in, as is the case in the NRDC report, benefits of hundreds of billions are conceivable.

Clearly, not every risk can be eliminated and not every particle of pollution can be controlled. On the other hand, not every claim of economic damage from pollution control is credible. A common sense approach weighs the various estimates and methods along with broad policy goals.

When tetraethyllead was taken off the US market in the 1970s, oil refiners had a number of options to increase the octane value of gasoline. Outside of refinery operations (See Refining) oil companies could add blends of octane boosting compounds from external sources.

The external option involved adding "oxygenated" fuels, which include alcohols like methanol, ethanol and tertiary butyl alcohol (TBA) and ether combinations, especially MTBE (methyl tertiary butyl ether). Ethanol can be made from farm products or cellulosic biomass. Methanol, MTBE and TBA are usually made from natural gas. The oil industry usually preferred TBA and MTBE over alcohol blends because they were somewhat easier to handle. Ethanol was also seen as a competitor for profits and has long been resisted by the oil industry (See Back to Ethanol).

Along with boosting octane, oxygenated fuels have lower emissions of HC and CO, and have been used to fight city smog since the late 1980s, when Denver and Phoenix made them mandatory in city gasoline pumps. The idea of expanding the program by using ethanol blends became part of the 1990 Clean Air Act that President George Bush sent to Congress in 1990. The oil industry offered reformulated gasolines (RFG) as a substitute for most of the ethanol provisions in the Act.

The idea was to reduce pollutants such as hydrocarbons, toxics (from aromatics), and nitrogen oxides. When compared to typical gasoline , the EPA estimated that RFG reduced hydrocarbon emissions by at least 15% in major cities and cut back on the cancer risk from gasolines with high benzene content.

RFG was somewhat different from previous gasohol and MTBE blends because it evaporated less readily (it had lower vapor pressure) and lower benzene and sulfur content.

Gasoline, Gasohol, MTBE blends and RFG
(Source: EPA Office of Mobile Sources)

	Conventional Gasoline	Gasohol (Gasoline 10% ethanol blend)	MTBE Blend	RFG
Vapor Pressure: Summer	8.7	9.7	8.7	7.2
Vapor Pressure: Winter	11.5	11.5	11.5	11.5
Benzene(vol%)	1.6	1.6	1.6	1.0
Sulfur (ppm)	338	305	313	302
MTBE(vol%)*			15	11
Ethanol(vol%)*		10	7.7	5.7

* Oxygenate concentrations shown are for separate batches of fuel; combinations of both MTBE and ethanol in the same blend can never be above 15 volume percent total.

The MTBE Reformulated Gasoline dilemma is a good example of the law of unintended consequences. While solving air pollution problems, MTBE created serious water pollution problems and has been banned from at least 13 states. (see MTBE).

One solution is for the federal government to remove the requirement that RFG contain oxygenated fuels – In other words, to no longer require ethanol or MTBE. RFG would still have lower vapor pressure, benzene and sulfur, but the cost would be higher and the air pollution benefit of the oxygen would be lost.

The other solution is to require the use of ethanol rather than MTBE or ethanol. Although feasible, there are technical issues which need to be examined. (See Back to Ethanol).

EPA Information on RFG

About reformulated gasolines

http://www.epa.gov/otaq/consumer/fuels/oxypanel/epa/index.htm

Origin of RFG program

http://www.epa.gov/otaq/rfgorig.htm

Is RFG a new gasoline ?

http://www.epa.gov/otaq/rfgnew.htm

Air pollution and history of RFG

http://www.epa.gov/otaq/f99040.pdf

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