Alternative Fuels

Alternative fuels, as defined by the Energy Policy Act of 1992 (EPAct), include ethanol, natural gas, propane, hydrogen, biodiesel*, electricity, methanol, and p-series fuels. These fuels are being used worldwide in a variety of vehicle applications.

Using these alternative fuels in vehicles can generally reduce harmful pollutants and exhaust emissions. In addition, most of these fuels can be domestically produced and derived from renewable sources.

* Pure biodiesel (B100) is considered an alternative fuel under EPAct. Lower-level biodiesel blends are not considered alternative fuels, but covered fleets can earn one EPAct credit for every 450 gallons of B100 purchased for use in blends of 20% or higher.

* Natural gas is domestically produced and readily available to end-users through the utility infrastructure. It is also clean burning and produces significantly fewer harmful emissions than reformulated gasoline or diesel when used in natural gas vehicles. In addition, commercially available medium - and heavy - duty natural gas engines have demonstrated over 90% reductions of carbon monoxide (CO) and particulate matter and more than 50% reduction in nitrogen oxides (NOx) relative to commercial diesel engines. Natural gas can either be stored onboard a vehicle as compressed natural gas (CNG) at 3,000 or 3,600 psi or as liquefied natural gas (LNG) at typically 20-150 psi. Natural gas can also be blended with hydrogen.
(fonte: http://www.eere.energy.gov/afdc/altfuel/altfuels.html)

Vocabulary:
Policy: politica.
Act: decreto.
Applications: solicitação; aplicação.
Generally: geralmente.
Harmful: nocivo, prejudicial.
Pollutants: poluentes.
Exhaust: fumaça de escapamento.
Addition: além disso.
Renewable: renovável.
Sources: fontes.
Lower-level: baixo nível.
Blends: misturas. (blended: misturado.)
Covered: disfarçadas.
Fleets: frotas.
Readily: prontamente; facilmente.
Available: disponível.
End-users: usuários.
Duty: dever.
Engines: motores.
Stored: armazenado.



1. Usar combustíveis alternativos pode diminuir poluentes prejudiciais liberados na atmosfera. O que mais podemos fazer para diminuir esses poluentes?

2. Biodisel puro é considerado um combustível alternativo, enquanto o biodisel com baixo nível de misturas não é. Qual a razão disso?

3. Quais os combustíveis alternativos definidos pelo EPAct?

4. Como pode ser armazenado o gás natural?

5. O gás natural poder ser misturado com o quê?


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