Aftermarket Conversion A standard, conventionally fueled, factory-produced vehicle to which
equipment has been added that enables the vehicle to operate on an alternative
Alcohols (CH3-(CH2)n-OH) The family name of a group of
organic chemical compounds composed of carbon, hydrogen, and oxygen. The series
of molecules vary in chain length and are composed of a hydrocarbon, plus a
hydroxyl group (for example, methanol, ethanol, and tertiary butyl alcohol).
Aldehydes One of several families of compounds formed as
products of incomplete combustion in engines using gasoline, methanol, ethanol,
propane, or natural gas as fuels. As a general rule of thumb, the presence of
methanol or methyl ethers in the fuel will lead to formaldehyde as the primary
aldehyde in the exhaust, while ethanol or ethyl ethers will lead to
acetaldehyde as the primary aldehyde in the exhaust. In both cases, other
aldehydes are present, but in much smaller quantities. Formaldehyde and
acetaldehyde are toxic and possibly carcinogenic.
Fuel As defined pursuant to the EPACT, methanol, denatured ethanol, and
other alcohols, separately or in mixtures of 85 percent by volume or more (or
other percentage not less than 70 as determined by DOE rule) with gasoline or
other fuels, CNG, LNG, LPG, hydrogen, coal-derived liquid fuels, fuels other
than alcohols derived from biological materials, electricity, or any other fuel
determined to be substantially not petroleum and yielding substantial energy
security benefits and substantial environmental benefits.
Alternative-Fueled Vehicle A vehicle either designed and manufactured
by an original equipment manufacturer or a converted vehicle designed to
operate in either dual-fuel, flexible-fuel, or dedicated modes on fuels other
than gasoline or diesel. This does not include a conventional vehicle that is
limited to operation on blended or reformulated gasoline fuels.
Alternative-Fueled Vehicle Converter An organization
(including companies, government agencies, and utilities), or an individual who
performs conversions involving alternative fueled vehicles. An AFV converter
can convert (1) conventionally fueled vehicles to AFV's, (2) AFV's to
conventionally fueled vehicles, or (3) AFV's to another alternative fuel.
Bi-Fuel Vehicle A vehicle with two separate fuel systems
designed to run on either an alternative fuel or conventional fuel using only
one fuel at a time.
Biodiesel Any liquid biofuel suitable as
a diesel fuel substitute or diesel fuel additive or extender. A diesel
substitute made from transesterification of oils of vegetables such as
soybeans, rapeseed, or sunflowers (end product known as methyl ester) or from
animal tallow (end product known as methyl tallowate). Biodiesel can also be
made by transesterification of hydrocarbons produced by the Fisher-Tropsch
process from agricultural byproducts such as rice hulls.
Cycle All reservoirs and fluxes of carbon; usually thought of as a
series of the four main reservoirs of carbon interconnected by pathways of
exchange. The four reservoirs, regions of the Earth in which carbon behaves in
a systematic manner, are the atmosphere, terrestrial biosphere (usually
includes freshwater systems), oceans, and sediments (includes fossil fuels).
Each of these global reservoirs may be subdivided into smaller pools ranging in
size from individual communities or ecosystems to the total of all living
organisms (biota). Carbon exchanges from reservoir to reservoir by various
chemical, physical, geological, and biological processes.
Dioxide (CO2) A colorless, odorless, nonpoisonous gas that is a normal
part of the ambient air. Carbon dioxide is a product of fossil fuel combustion.
Although CO2 does not directly impair human health, it is a greenhouse gas that
traps the earth's heat and contributes to the potential for global warming.
Carbon Monoxide (CO) A colorless, odorless gas slightly
lighter than air. It is poisonous if inhaled, in that it combines with blood
hemoglobin to prevent oxygen transfer. It is produced by the incomplete
combustion of fossil fuels with a limited oxygen supply (as in automobiles). It
is a major component of urban air pollution, which can be reduced by the
blending of an oxygen-bearing compound such as alcohols and ethers into
Chlorofluorocarbons (CFC's) A family of
inert, nontoxic, and easily liquified chemicals used in refrigeration, air
conditioning, packaging, and insulation, or as solvents or aerosol propellants.
Because they are not destroyed in the lower atmosphere, they drift into the
upper atmosphere where their chlorine components destroy ozone.
Clean Alternative Fuel Any fuel (including methanol,
ethanol, or other alcohols (including any mixture thereof containing 85 percent
or more by volume of such alcohol with gasoline or other fuels), reformulated
gasoline, diesel, natural gas, liquefied petroleum gases, and hydrogen) or
power source (including electricity) used in a clean fuel vehicle that complies
with the standards and requirements of the Clean Air Act Amendments of 1990.
Compressed Natural Gas (CNG) Natural gas compressed to a
volume and density that is practical as a portable fuel supply (even when
compressed, natural gas is not a liquid).
Nonattainment Area Areas with carbon monoxide design values of 9.5
parts per million or more (generally based on data for 1988 and 1989).
Converted Vehicle A vehicle originally designed to operate
on gasoline that has been modified or altered to operate on an alternative
Criteria Pollutant A pollutant determined to be
hazardous to human health and regulated under the Environmental Protection
Agency's National Ambient Air Quality Standards. The 1970 amendments to the
Clean Air Act require the Environmental Protection Agency to describe the
health and welfare impacts of a pollutant as the criteria for inclusion in the
Dedicated Vehicle A vehicle designed to
operate solely on one alternative fuel.
Diesel Fuel A
complex mixture of hydrocarbons with a boiling range between approximately 350
and 650 degrees Fahrenheit. Diesel fuel (simply referred to as "diesel") is
composed primarily of paraffins and naphthenic compounds that auto-ignite from
the heat of compression in a diesel engine. Diesel is used mainly by heavy-duty
road vehicles, construction equipment, locomotives, and by marine and
Dual-Fuel Vehicle A vehicle designed to
operate on a combination of alternative fuel, such as LNG or LPG, and
conventional fuel, such as gasoline or diesel. These vehicles have two separate
fuel systems which inject both fuels simultaneously into the engine combustion
E85 A fuel containing a mixture of 85 percent
ethanol and 15 percent gasoline.
E95 A fuel containing a
mixture of 95 percent ethanol and 5 percent gasoline.
Efficiency The inverse of energy intensiveness: the ratio of energy
outputs from a process to the energy inputs (for example, miles traveled per
gallon of fuel).
Environmental Protection Agency (EPA) A
government agency, established in 1970. Its responsibilities include the
regulation of fuels and fuel additives.
Ethyl Tertiary Butyl Ether
(ETBE), (CH3)3COC2H5 A colorless, flammable, oxygenated hydrocarbon
blend stock formed by the catalytic etherification of isobutylene with ethanol.
Ethanol (C2H5OH) Otherwise known as ethyl alcohol, alcohol,
or grain-spirit. A clear, colorless, flammable oxygenated hydrocarbon with a
boiling point of 78.5 degrees Celsius in the anhydrous state. However, it forms
a binary azeotrope with water, with a boiling point of 78.15 degrees Celsius at
a composition of 95.57 percent by weight ethanol. It is used in the United
States as a gasoline octane enhancer and oxygenate (10 percent concentration).
Ethanol can also be used in high concentrations in vehicles optimized for its
Ether The family name applied to a group of organic
chemical compounds composed of carbon, hydrogen, and oxygen, and which are
characterized by an oxygen atom attached to two carbon atoms (for example,
methyl tertiary butyl ether).
Flexible-Fuel Vehicle A
vehicle with the ability to operate on alternative fuels (such as M85 or E85),
100 percent traditional fuels, or a mixture of alternative fuel and traditional
Global Warming The theoretical escalation of global
temperatures caused by the greenhouse effect.
Effect A popular term used to describe the roles of water vapor, carbon
dioxide, and other trace gases in keeping the Earth's surface warmer than it
would be otherwise. These radiatively active gases are relatively transparent
to incoming shortwave radiation, but are relatively opaque to outgoing long
wave radiation. The latter radiation, which would otherwise escape to space, is
trapped by these gases within the lower levels of the atmosphere. The
subsequent reradiation of some of the energy back to the Earth maintains the
surface at temperatures higher than they would be if the gases were absent.
Greenhouse Gases Those gases, such as water vapor, carbon
dioxide, tropospheric ozone, nitrous oxide, and methane, that are transparent
to solar radiation but opaque to long wave radiation. Their action is similar
to that of increased humidity in a greenhouse. Gross Vehicle Weight Rating: The
weight of the empty vehicle plus the maximum anticipated load weight.
Heavy Duty Vehicles Pursuant to the EPACT, trucks and buses
having a gross vehicle weight rating of 8,500 pounds or more.
Hydrogen (H2) The lightest of all gases, the element
(hydrogen) occurs chiefly in combination with oxygen in water. It also exists
in acids, bases, alcohols, petroleum, and other hydrocarbons.
Duty Vehicles Automobiles and trucks having a gross vehicle weight
rating of less than 8,500 pounds.
Liquefied Natural Gas (LNG) Natural gas that has been refrigerated to temperatures at which it exists
in a liquid state.
Liquefied Petroleum Gases (LPG) Propane,
propylene, normal butane, butylene, isobutane, and isobutylene produced at
refineries or natural gas processing plants (includes plants that fractionate
raw natural gas plant liquids).
Lower Heating Value (LHV)
The Btu content per unit of fuel excluding the heat from the condensation of
water vapor in the fuel.
M85 A fuel containing a mixture of
85 percent methanol and 15 percent gasoline. M100 100 percent (neat) methanol.
Methane (CH4) The simplest of the hydrocarbons and the chief
constituent of natural gas. Methane, a gas at normal temperatures and
pressures, boils at -263 degrees Fahrenheit.
(CH3OH) A colorless liquid with essentially no odor and very little
taste. The simplest alcohol, it boils at 64.7 degrees Celsius. It is miscible
with water and most organic liquids (including gasoline) and is extremely
flammable, burning with a nearly invisible blue flame. Methanol is produced
commercially by the catalyzed reaction of hydrogen and carbon monoxide. It was
formerly derived from the destructive distillation of wood, which caused it to
be known as wood alcohol.
Methyl Tertiary Butyl Ether (MTBE),
(CH3)3COCH3 A colorless, flammable, liquid oxygenated hydrocarbon that
contains 18.15 percent oxygen and has a boiling point of 55.2 degrees Celsius.
It is a fuel oxygenate produced by reacting methanol with isobutylene.
Motor GasolineBlending of Oxygenates Blending of
gasoline and oxygenates under the Environmental Protection Agency's
"Substantially Similar" Interpretive Rule (56 FR [February 11, 1991]).
Natural Gas A mixture of hydrocarbon compounds and small
quantities of various nonhydrocarbons existing in the gaseous phase or in
solution with crude oil in natural underground reservoirs at reservoir
conditions. The primary constituent compound is CH4. Gas coming from wells also
can contain significant amounts of ethane, propane, butanes, and pentanes, and
widely varying amounts of carbon dioxide and nitrogen. Pipeline-quality natural
gas has had most, but not all natural gas liquids and other contaminants
removed. On board a vehicle, it is stored under high pressure at 2,500 to 3,600
pounds per square inch (psi). A gallon of natural gas at 2,000 psi contains
about 20,000 Btu; at 3,600 psi, a gallon contains about 30,000 Btu.
Neat Alcohol Fuels Straight alcohol (not blended with
gasoline) that may be either in the form of ethanol or methanol. Ethanol, as a
neat alcohol fuel, does not need to be at 200 proof; therefore, it is often
used at 180 to 190 proof (90 to 95 percent). Most methanol fuels are not
strictly "neat," since 5 to 10 percent gasoline is usually blended in to
improve its operational efficiency.
Nitrogen Oxides (NOx)
Air-polluting gases contained in automobile emissions, which are
regulated by the Environmental Protection Agency. They comprise colorless
nitrous oxide (N2O) (otherwise known as dinitrogen monoxide, or as the
anaesthetic "laughing gas"), colorless nitric oxide (NO), and the
reddish-brown-colored nitrogen dioxide (NO2). Nitric oxide is very unstable,
and on exposure to air it is readily converted to nitrogen dioxide, which has
an irritating odor and is very poisonous. Nitrogen dioxide contributes to the
brownish layer in the atmospheric pollution over some metropolitan areas. Other
nitrogen oxides of less significance are nitrogen tetroxide (N2O4) and nitrogen
pentoxide (N2O5). Nitrogen oxides are sometimes collectively referred to as
"NOx" where "x" represents any proportion of oxygen to nitrogen.
Nonattainment Area A region that exceeds minimum acceptable
National Ambient Air Quality Standards (NAAQS) for one or more criteria
pollutants, in high population density areas, in accordance with the U.S.
Census Bureau population statistics. Such regions (areas) are required to seek
modifications to their State Implementation Plans, setting forth a reasonable
timetable using means (approved by the Environmental Protection Agency) to
achieve attainment of NAAQS by a certain date. Under the Clean Air Act, if a
nonattainment area fails to attain NAAQS, the Environmental Protection Agency
may superimpose a Federal Implementation Plan with stricter requirements or
impose fines, construction bans, or cutoffs in Federal grant revenues until the
area achieves applicable NAAQS.
Original Equipment Manufacturers
(OEM's) Vehicle manufacturers that provide the original design and
materials for assembly and manufacture of their product. They are directly
responsible for manufacturing and modifying vehicles, making the vehicles
commercially available, and providing a warranty for the finished product.
Oxygenated Fuel Any fuel substance containing oxygen
(includes oxygen-bearing compounds such as ethanol and methanol). Oxygenated
fuel tends to give a more complete combustion of its carbon into carbon dioxide
(rather than monoxide), thereby reducing air pollution from exhaust emissions.
Oxygenated Gasoline Gasoline with an oxygen content of 1.8
percent or higher, by weight, that has been formulated for use in motor
Ozone (O3) An oxygen molecule with 3 oxygen atoms
that occurs as a blue, harmful, pungent-smelling gas at room temperature. The
stratospheric ozone layer, which is a concentration of ozone molecules located
at 6 to 30 miles above sea level, is in a state of dynamic equilibrium.
Ultraviolet radiation forms the ozone from oxygen, but can also reduce the
ozone back to oxygen. The process absorbs most of the ultraviolet radiation
from the sun, shielding life from the harmful effects of radiation.
Tropospheric ozone is normally present at the ground level in low
concentrations. In cities where high levels of air pollutants are present, the
action of the sun's ultraviolet light can, through a complex series of
reactions, produce a harmful concentration of ozone in the air. The resulting
air pollution is known as photochemical smog. Certain air pollutants (e.g.,
chlorofluorocarbons) can drift up into the atmosphere and damage the balance
between ozone production and destruction, resulting in a reduced concentration
of ozone in the layer.
Ozone Precursor A chemical compound
(such as nitrogen oxides, methane, nonmethane hydrocarbons and hydroxyl
radicals) that, in the presence of solar radiation, reacts with other chemical
compounds to form ozone.
Petroleum A generic term applied to
oil and oil products in all forms (such as crude oil, lease condensate,
unfinished oil, refined petroleum products, natural gas plant liquids, and
finished petroleum products).
Propane (C3H8) A normally
gaseous straight-chain hydrocarbon, it is a colorless paraffinic gas that boils
at a temperature of -43.67 degrees Fahrenheit. It is extracted from natural gas
or refinery gas streams.
Reformulated Gasoline (RFG)
Gasoline whose composition has been changed (from that of gasolines sold in
1990) to 1) include oxygenates, 2) reduce the content of olefins and aromatics
and volatile components, and 3) reduce the content of heavy hydrocarbons to
meet performance specifications for ozone-forming tendency and for release of
toxic substances (benzene, formaldehyde, acetaldehyde, 1,3-butadiene, and
polycyclic organic matter) into the air from both evaporation and tailpipe
Replacement Fuel The portion of any motor fuel
that is methanol, ethanol, or other alcohols, natural gas, liquefied petroleum
gases, hydrogen, coal derived liquid fuels, electricity (including electricity
from solar energy), ethers, or any other fuel the Secretary of Energy
determines, by rule, is substantially not petroleum and would yield substantial
energy security benefits and substantial environmental benefits.
Incentives In general, a means of employing the tax code to stimulate
investment in or development of a socially desirable economic objective without
the direct expenditure from the budget of a given unit of government. Such
incentives can take the form of tax exemptions or credits.