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Nanda's Page
Peggy's Corner
Charles 803
Still Location
Robert Warren Wrote
'Questions from Mars'
Phase separation
Raoult's Law and Phase Diagrams
Castor Oil Process
Tables & Forms
Alphabetic Listing
Reverse Osmosis

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Aldehyde: Created from the combustion of alcohols (ethanol).

American Society for Testing and Materials (ASTM): A non-profit organization that
provides specifications and procedures that are recognized as guidelines for
gasoline quality.

Anti-icer: Typically, an alcohol (such as ethanol, isopropyl alcohol, or methanol)
added to gasoline in small amounts to eliminate water; thereby, reducing the
chance for fuel line freeze-up.

Antiknock Index (AKI): Measures the ability of a gasoline to resist engine knock/
ping.  AKI is the average of Research and Motor Octane or (R+M)/2.  Commonly
referred to as pump octane.

Anti-oxidant: A stabilizing compound used to inhibit gum formation from oxidation of

Aromatic: High octane blending components that have a benzene ring in their
molecular structure (benzene, toluene, xylene).

Benzene: Basic aromatic usually of higher value as a chemical feedstock.  A known
cancer causing agent.

British Thermal Unit (BTU): One British thermal unit represents the amount of heat
required to raise one pound of water one degree Fahrenheit.

Butane:  A light hydrocarbon used to raise octane and increase fuel volatility.

Carbon dioxide: A normal byproduct of combustion.  A food for plants.

Carbon monoxide: A deadly toxic gas produced from the tail pipe when cars burn

Clean Air Act Amendments-1990:  A series of amendments to the original Clean Air Act
which includes requirements for oxygenated fuel programs in CO non-attainment
areas and reformulated gasoline programs in certain ozone non-attainment areas.

Corrosion inhibitors: An additive used to reduce the corrosion properties of

Deposit control additive: Performs same functions as detergent plus minimizes
deposit buildup in intake manifold, intake ports, and underside of intake valves.

Detergent: Additive used to prevent and/or clean up carburetor and fuel injector

E-10:  A mixture of 10% ethanol and 90% gasoline based on volume.

E-85:  A mixture of 85% ethanol and 15% gasoline based on volume.

Elastomer: The rubber-like compounds used in fuel lines, evaporative canister
lines, and carburetor parts.

Environmental Protection Agency (EPA): A federal agency charged with monitoring
and creating standards for air and water quality.  Determines standards for vehicle
emissions and testing procedures. 

Ethanol (ethyl alcohol, grain alcohol): Typically fermented from grain.  An octane
enhancer added at a rate of up to 10 percent in gasoline.  Will increase octane
2.5 to 3.0 numbers at 10 percent concentration.  Ethanol is a fuel oxygenate.  Also
can be used "neat" (pure) as a fuel in specially designed vehicles.

ETBE (ethyl tertiary butyl ether): An ether similar to MTBE.  This fuel oxygenate is
manufactured by reacting isobutylene with ethanol.  The resulting ether is high
octane and of low volatility.  Can be added to gasoline up to a level of
approximately 17%.

Fermentation: A chemical decomposition which takes place in an organic substance
exposed to the air, due to the action of microscopic organisms.

Flexible Fuel Vehicle (FFV): A vehicle designed to burn gasoline or any blend of
ethanol/gasoline up to 85% ethanol and 15% gasoline (E-85).

Fluidizer oils: Oils typically used with deposit control additives to control
deposit formation on intake valves.

Gasohol: In the U.S., the term gasohol refers to gasoline which contains 10%
ethanol.  This term was used in the late 1970's and early 1980's but has been
replaced by terms such as Super Unleaded Plus Ethanol or Unleaded Plus. 

Ground level ozone: A reaction of hydrocarbons, nitrogen oxides, and sunlight
creating a brown haze in the lower atmosphere.  Also referred to as photochemical

Hydrocarbon (HC): Vapors formed from products made from crude oil.  Usually vapors
created from incomplete combustion or from vaporization of liquid gasoline. A
pollutant that contributes to ground level ozone.

Isobutylene: A chemical that is reacted with methanol to form MTBE or with ethanol
to form ETBE.

Lead (Tetraethyl lead): A metallic octane enhancer. One gram of lead increases the
octane of one gallon of gasoline about six numbers.  Not permitted in U.S. gasoline
after 1995, except for certain racing or aviation uses.

Metal deactivator:  Gasoline additive used to neutralize the effects of copper

Methanol (methyl alcohol, wood alcohol): Typically manufactured from natural gas. 
In the 1980's, methanol was used in combination with heavier alcohols as an octane
enhancer in gasoline.  Also is being considered for use as a "neat" (pure) fuel in
specially designed vehicles.  Typically not blended with today's gasoline.

MTBE (methyl tertiary butyl ether): An ether manufactured by reacting methanol and
isobutylene.  The resulting ether is high octane and of low volatility.   Is a fuel
oxygenate and is permitted in unleaded gasoline up to 15%.

National Energy Policy Act of 1992: Legislation requiring phasing in of alternative
fuel vehicles in fleets.

Nitrogen Oxides (NOx): Produced when high combustion temperatures (2300F-2500F)
exist.  Contributes to ground level ozone.

Non-attainment areas: Those areas of the country which have excessive rates of
carbon monoxide and/or ozone in their air.

Octane: General term for a gasoline's ability to resist engine knock.
     Pump Octane: A term used to describe the octane as posted on the retail
       gasoline dispenser as (R+M)/2 and is the same as Antiknock index
     Motor Octane:  The octane as tested in a single cylinder octane test engine
       at more severe operating conditions.  Affects high speed and part throttle
       knock and performance under load, passing, etc.   Abbreviated M and is the
       lower number in (R+M)/2
     Research Octane: The octane as tested in a single cylinder octane test engine
       operated under less severe operating conditions.  Affects low to medium
       speed knock and engine run-on.  Abbreviated R and is the higher number
       in (R+M)/2.

Octane enhancer: Common term designating components that are added to gasoline to
increase octane and reduce engine knock.  Toluene, ethanol, and MTBE.

Octane Number Requirement (ONR): The octane level required to provide knock-free
operation in a given engine.

Olefins: A gasoline component resulting from several refining processes --
ethylene, butylene.  Often contributes to the formation of gum and deposits in

Oxygenate:  A term used to denote octane components containing hydrogen, carbon, and
oxygen in their molecular structure.  Includes ethers such as MTBE and alcohols
such as ethanol and methanol.

Oxygenated gasoline: Gasoline containing an oxygenate such as ethanol or MTBE.
Provides chemical enleanment of the air fuel charge, thereby improving combustion
and reducing tailpipe emissions of CO.

Ozone: Is formed when oxygen and other compounds react in sunlight.  In the upper
atmosphere, ozone protects the earth from the sun's ultraviolet rays.  Though
beneficial in the upper atmosphere, at ground level, ozone is a respiratory
irritant and considered a pollutant.

Photochemical Smog (ground level ozone): A reaction of hydrocarbons, nitrogen
oxides, and sunlight, creating a brown haze in the lower atmosphere.

Reformulated gasoline: Gasolines which have had ether composition and/or
characteristics altered to reduce vehicular emissions of pollutants.  Specifically,
those gasolines which meet RFG requirements of the 1990 Clean Air Act

Reid Vapor Pressure (RVP): A method of determining vapor pressure of gasoline.  Used
as an indicator of volatility (vaporization characteristics) of gasoline.

Toxics:  As defined in the 1990 Clean Air Act Amendments, toxics include benzene,
1,3 butadiene, formaldehyde, acetaldehyde, and polycyclic organ matter.

Vapor Liquid Ratio:  A measurement of the ratio of vapor to liquid at a given
temperature used to determine a gasoline's tendency to contribute to vapor lock
in an automotive fuel system.

Volatility: A term used to describe a gasoline's tendency to change from liquid to
a vapor.

Volume Percent: A percentage measurement based solely on volume without regard
to differences in weight or density. Typically used to measure the concentration
of alcohols and ethers in gasoline.

Weight Percent:  A percentage measurement based on weight. Typically used to measure
the oxygen content of gasoline.