Alternative Fuel Autos: Discover Alternative Fuels
Quick Facts About Alternatives to Gasoline
Biodiesel
Biodiesel can be used in blends up to 5% in most light-or heavy-duty diesel engines and in higher concentrations in some vehicles, depending on the manufacturer. It is a renewable fuel made by converting vegetable oils, animal fats, or recycled restaurant greases into mono alkyl esters, the chemical name for the substances that make up biodiesel. Unconverted oils, fats and greases, whether recycled or not, are not biodiesel and should be avoided as motor fuels because of performance issues.
Clean Diesel
"Clean Diesel" is a petroleum-based distillate fuel containing very low amounts of sulfur. The primary purpose of lower sulfur diesel fuel is to enable or improve the performance of emission control systems. Lower sulfur also reduces particulate emissions even without any emission control device. EPA requires refiners to produce ultra-low sulfur diesel fuel, which has a maximum sulfur level of 15 parts per million, beginning in 2006. Widespread availability of this fuel in the U.S. marketplace will enable automakers to introduce ultra-clean diesel vehicles that are capable of meeting the same emission standards as gasoline vehicles.
Ethanol
Ethanol, also known as grain alcohol, is blended with gasoline to create E-85 motor fuel for use in spark-ignited engines. E85 is a mixture of nominally 85% ethanol and 15% gasoline. Vehicles are specially designed to run on E85; those that can also run on any mixture of gasoline and ethanol up to E-85 are called flexible fuel vehicles. Ethanol is produced by fermenting and distilling starch crops (such as corn, barley and wheat) that have been converted into simple sugars. Ethanol also can be produced from "cellulosic biomass" such as trees and grasses. When this feedstock is used, the fuel is called bioethanol. Ethanol is most commonly used to increase octane and improve emissions.
GTL, BTL and CTL
Renewable biomass, natural gas or coal can be converted into a finished fuel product by using the Fischer-Tropsch process, which today represents a variety of similar processes. The resulting fuels—commonly referred to as BTL ("biomass-to-liquid"), GTL ("gas-to-liquid") or CTL ("coal-to-liquid")—are usable in any diesel engine either in pure form or blended with conventional diesel fuel. These fuels have zero sulfur, high cetane and low aromatic levels, which makes them extremely clean burning.
Hydrogen
Hydrogen is the simplest fuel because it is composed of only one type of atom. This fuel is expected to play an important role in developing sustainable transportation because it can be produced in virtually unlimited quantities using renewable resources. Hydrogen has been used successfully in a number of internal combustion engine vehicles as pure hydrogen mixed with natural gas. Pure hydrogen also is used to power fuel cells, which are being developed to power vehicles of the future.
Natural Gas
Natural gas, or methane, is readily available to consumers through a widespread infrastructure of pipelines. Natural gas is clean burning and emits a very small amount of pollutants compared to other types of fuels. Vehicles are specially designed to use it as a fuel and store it onboard either as compressed natural gas (CNG) or as liquefied natural gas (LNG). Natural gas also can be blended with hydrogen, which makes it especially useful as a transitional fuel for fuel cell vehicles.
Propane
Propane is produced as a by-product of natural gas processing and crude oil refining. Vehicles are specially designed for propane use. Like many other fuels, propane is produced and distributed through an infrastructure of processing facilities, pipelines and storage terminals.
Source: For more specific information on alternative fuels, log onto the Department of Energy's alternative fuels data web site: http://www.eere.energy.gov/afdc/altfuel/altfuels.html For more specific information on clean diesel, log onto the Diesel Technology Forum's web site: http://www.dieselforum.org/
