**Clean Alternative Fuels:** Fischer-Tropsch

United States Environmental Protection Agency

The majority of heavy-duty vehicles on our nation's highways today are
powered by diesel fuel. This presents enormous opportunities for
clean-burning diesel substitutes such as Fischer-Tropsch liquids.
Although they have been used to some degree since the 1920s,
Fischer-Tropsch fuels are not widely used today---but this could change.

From Africa to South America, extensive research and development efforts
are under way to commercialize the fuels for vehicle use. More auto
manufacturers are viewing Fischer-Tropsch liquids as a viable way to use
alternative fuels in diesel engines without compromising fuel efficiency
or impacting infrastructure or refueling costs.

Fischer-Tropsch technology converts coal, natural gas, and low-value
refinery products into a high-value, clean-burning fuel. The resultant
fuel is colorless, odorless, and low in toxicity. In addition, it is
virtually interchangeable with conventional diesel fuels and can be
blended with diesel at any ratio with little to no modification.
Fischer-Tropsch fuels offer important emissions benefits compared with
diesel, reducing nitrogen oxide, carbon monoxide, and particulate
matter.

Availability

Currently, several oil companies are researching large-scale production
of Fischer- Tropsch fuels. At least four major companies have announced
plans to build pilot plants to produce synthetically derived
Fischer-Tropsch diesel fuels. Plants are currently planned for
Indonesia, Africa, South America, and the United States.

In addition, while many alternative fuels require completely separate
distribution systems, Fischer-Tropsch fuels can use the existing fuel
distribution infrastructure. This means the fuels can be transported in
the same ships and pipelines as crude oil. A limited investment will be
required, however, to maintain the fuel's purity during distribution.
According to the California Energy Commission, Fischer-Tropsch fuels'
superior quality, cost, and ease of distribution could lead to
production of 2 to 3 million barrels per day, or 2 to 3 percent of
worldwide refinery output, by 2005.

Affordability

According to the California Energy Commission, Fischer-Tropsch fuels can
cost up to 10 percent more than conventional diesel, depending on market
fluctuations.

Performance

Based on available research, there are no significant differences in
Fischer-Tropsch fuels' performance versus petrodiesel fuels. In fact,
the higher cetane number of Fischer-Tropsch diesel fuel might result in
improved combustion; the cetane number is a primary measure of diesel
fuel quality. In addition, many alternative fuels require major changes
in vehicle engines, but Fischer-Tropsch fuels require no engine
modifications. Fischer-Tropsch fuels, however, are slightly less energy
dense than petrodiesel, which might result in lower fuel economy and
power. Further investigations of fuel compatibility issues need to take
place, as well.

Safety

There are no reported safety issues with Fischer-Tropsch fuels. They can
boost safety by using excess gas from oil production, thereby avoiding
its disposal. Ingestion, absorption through skin, or other exposure
effects are likely to be similar to that of diesel fuel.

For More Information

**EPA Alternative Fuels Web Site**

www.epa.gov/otaq/consumer/fuels/altfuels/altfuels.htm

**California Energy Commission**

Web site: www.energy.ca.gov/afvs/synthetic_diesel.html

**Alternative Fuels Data Center**

Web site: www.afdc.nrel.gov

**National Alternative Fuels Hotline**

Phone: 800 423-1DOE

Emissions Characteristics

Actual emissions will vary withengine design; these numbers reflect the
potential reductions offered by Fischer-Tropsch liquids, relative to
conventional diesel.

• Nitrogen oxide reductions due to the higher cetane number and even
further reductions with the addition of catalysts.

• Little to no particulate emissions due to low sulfur and aromatic
content.

• Expected reductions in hydrocarbon and carbon monoxide emissions.

\*Estimates based on Fischer-Tropch's inherently "cleaner" chemical
properties with an engine that takes full advantage of these fuel
properties.