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DEFINITIONS OF MOTOR FUELS AND REFINED PRODUCTS

Types of Motor Fuel Consumed in California:

The state's air quality standards limit the types of motor fuels sold for vehicles to:

  • EPA Low Sulfur Diesel: Diesel fuel with sulfur content less than .05% by weight. EPA diesel cannot be sold within California. EPA diesel produced in California is exported to neighboring states.


  • CARB Low Sulfur Diesel: Diesel fuel which meets specifications set by the California Air Resources Board (CARB). This fuel is widely available throughout California


  • CARB Ultra Low Sulfur Diesel: Diesel fuel which meets the CARB specifications for ultra low sulfur diesel. This fuel will become required in California as CARB Low Sulfur Diesel is phased out in June of 2006


  • CARB Reformulated Gasoline (CARB RFG): An oxygenated reformulated gasoline which meets the most recent specifications set forth by the California Air Resources Board (CARB). This gasoline contains 5.7% ethanol as an oxygenate.
(For more detail please see the definitions for these fuels below.)

Definitions/Glossary of Terms

Aviation Fuels: Includes aviation gasoline and aviation jet fuel.

Aviation Gasoline (Finished Aviation Gasoline): All special grades of gasoline for use in aviation reciprocating or piston engines. This category includes both leaded and unleaded grades of aviation gasoline. Also includes blending components which will be used in blending or compounding into finished aviation gasoline.

Aviation Jet Fuel: A quality kerosene based fuel. This fuel is used primarily for turbojet and turboprop aircraft engines. Jet fuel is typically categorized as for use in either military or commercial aircraft.

Bio-Diesel: A diesel fuel substitute or diesel fuel additive or extender. Bio-Diesel fuels are typically made from oils such as soybeans, rapeseed, or sunflowers, or from animal tallow that is blended with traditional diesel fuel or used as a replacement for traditional diesel fuel. There are three standard blends: Bio-Diesel B5, B20 and B100 where the number indicates the percentage of bio-diesel in the finished fuel. Bio-Diesel can also be made from hydrocarbons derived from agricultural products such as rice hulls.

BOB (Blendstock for Oxygenate Blending): An acronym for unfinished gasoline which will later be blended with an oxygenate such as MTBE or ethanol.

Butane: A flammable, colorless, easily liquefied gas that is used extensively as a fuel for cigarette lighters and portable stoves. Chemical formula: C4H10.

Crude Oil: A mixture of hydrocarbons that existed in liquid phase in underground reservoirs and remains liquid at atmospheric pressure after passing through surface separating facilities. This category includes synthetic crude such as those derived from shale oil and tar sands.

Distillate Fuel Oil: A general classification for one of the petroleum fractions produced in conventional distillation operations. It includes diesel fuels and fuel oils. Products known as No. 1, No. 2, and No. 4 diesel fuel are used in on-highway diesel engines, such as those in trucks and automobiles, as well as off-highway engines, such as those in railroad locomotives and agricultural machinery. Products known as No. 1, No. 2, and No. 4 fuel oils are used primarily for space heating and electric power generation.

  • Distillate with sulfur <0.05%: Diesel fuel that has a sulfur level no higher than 0.05 percent by weight. This fuel does not meet California specifications and cannot be sold in California but may be exported to neighboring states.


  • Distillate with sulfur >0.05%: Diesel fuel that has a sulfur level above 0.05 percent by weight. This fuel does not meet California specifications and cannot be sold in California. This fuel may be further processed to meet CARB or EPA standards for sulfur content or used as fuel for some marine vessels.


  • EPA Low Sulfur No. 2 Diesel Fuel (EPA Highway Diesel): No. 2 diesel fuel that has a sulfur level no higher than 0.05% by weight (500 ppm). This fuel was introduced in October of 1993 and meets specifications adopted by the United States Environmental Protection Agency (USEPA). It is used primarily in motor vehicle diesel engines for on-highway use. EPA diesel produced in California may be exported to neighboring states.


  • EPA Off-Road No. 2 Diesel Fuel (EPA Off-Road Diesel): No. 2 diesel fuel that has a sulfur level no higher than 0.05% by weight (500ppm). This fuel meets specifications adopted by the United States Environmental Protection Agency.


  • CARB Low Sulfur No. 2 Diesel Fuel (CARB Diesel): No. 2 diesel fuel that has a sulfur level no higher than 0.05% by weight (500ppm) and the aromatic hydrocarbon content is limited to 10% by volume or alternative formulations that are approved by the California Air Resources Board (CARB). These alternative formulations may have an aromatic hydrocarbon content that exceeds the 10% volume limit. This fuel was introduced in October of 1993 and meets specifications adopted by the CARB. It is used primarily in motor vehicle diesel engines for on-highway and off-highway use. This diesel will be phased out in June of 2006 in favor of a 15ppm sulfur fuel.


  • EPA Ultra Low Sulfur No. 2 Diesel Fuel (EPA Highway ULS Diesel): No. 2 diesel fuel that has a sulfur level no higher than 0.0015% by weight (15ppm). This fuel meets specifications adopted by the United States Environmental Protection Agency. It is used primarily in motor vehicle diesel engines for on-highway use.


  • CARB Ultra Low Sulfur No. 2 Diesel Fuel (CARB ULS Diesel): No. 2 diesel fuel that has a sulfur level no higher than 0.0015% by weight (15ppm) and the aromatic hydrocarbon content is limited to 10% by volume. This fuel meets specifications adopted by the California Air Resources Board in 2003. It is used primarily in motor vehicle diesel engines for on-highway and off-highway use. This fuel will replace CARB Low Sulfur Diesel (500ppm sulfur) in June 2006.


  • High Sulfur No. 2 Diesel Fuel: No. 2 diesel fuel that has a sulfur level above 0.05% by weight (500ppm). This fuel may be further processed to meet CARB or EPA standards for sulfur content or used as fuel in some marine vessels.


  • No. 2 Fuel Oil (Heating Oil): This fuel is used in atomizing type burners for domestic heating or for moderate capacity commercial/industrial burner units.


No. 4 Fuel: A distillate fuel oil made by blending distillate fuel oil and residual fuel oil stocks. This fuel is used extensively in industrial plants and in commercial burner installations that are not equipped with preheating facilities.

Isobutane: Also known as i-butane, isobutane is an isomer of butane with the formula CH3CH(CH3)2. Recent concerns with depletion of the ozone layer by freon gases have led to increased use of isobutane as a gas for refrigeration systems, especially in domestic refrigerators and freezers. When used as a refrigerant, isobutane is also known as R600a.

Finished Motor Gasoline: A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in spark-ignition engines. Finished Motor Gasoline includes conventional gasoline; all types of oxygenated gasoline, and all types of reformulated gasoline, but excludes aviation gasoline.

Reformulated Gasoline: Finished motor gasoline that is formulated to reduce emissions of various criteria pollutants from motor vehicles.

  • California Reformulated Gasoline (CA RFG): Finished motor gasoline formulated for use in motor vehicles, the composition and properties of which meet the requirements of the reformulated gasoline regulations promulgated by the California Air Resources Board (CARB). This type of finished gasoline usually contains 5.7% ethanol as an oxygenate or in a few areas may contain no oxygenate (CARB RFG Non Oxy). This category excludes California reformulated gasoline blendstock for oxygenate blending (CA RBOB).


  • EPA Reformulated Gasoline (RFG): Finished motor gasoline formulated for use in motor vehicles, the composition and properties of which meet the requirements of the reformulated gasoline regulations promulgated by the EPA to meet requirements of the Clean Air Act. This category excludes reformulated gasoline blendstock for oxygenate blending (RBOB).


  • Arizona Cleaner Burning Gasoline (Arizona CBG): Finished motor gasoline formulated for use in motor vehicles, the composition and properties of which meet the requirements of the cleaner burning gasoline regulations promulgated by the state of Arizona. This type of finished gasoline may contain MTBE (Arizona CBG - MTBE) or no oxygenate (Arizona CBG Non Oxy). This category excludes Arizona reformulated gasoline blendstock for oxygenate blending (AZ RBOB).


  • Nevada Cleaner Burning Gasoline (LVCBG): Finished motor gasoline formulated for use in motor vehicles, the composition and properties of which meet the requirements of the cleaner burning gasoline regulations promulgated by the state of Nevada. This category excludes Nevada's cleaner burning gasoline blendstock for oxygenate blending (CBGBOB).




Oxygenated Gasoline (not classified as reformulated gasoline outside of California, Arizona or Nevada): Finished motor gasoline that contains an oxygenate. This type of finished gasoline is primarily used during the winter months in regions of the United States that are not in compliance with carbon monoxide standards. Other areas may mandate the use of oxygenates during a portion of the year to help control other types of air pollutants. Oxygenates can also be mandated for use to achieve compliance with minimum use goals.

  • EPA Winter Oxygenated Gasoline: A finished gasoline that contains a minimum of 1.8% oxygen by weight. This type of finished gasoline is mandated for use during the winter months in areas of the United States (other than California, Arizona and Nevada) that are not in compliance with federal carbon monoxide standards.


  • Arizona Winter Gasoline: A finished gasoline that contains ethanol at a concentration of 10% by volume. This type of finished gasoline is mandated for use during the winter months (November through March) in certain areas of Arizona. Prior to blending with ethanol, the unfinished base gasoline is referred to as Arizona Blendstock for Oxygenate Blending (AZBOB).


  • Nevada Winter Gasoline: A finished gasoline that contains ethanol at a concentration of 10% by volume. This type of finished gasoline is mandated for use during the winter months (October through March) in Clark County. Prior to blending with ethanol, the unfinished base gasoline is referred to as Nevada Blendstock for Oxygenate Blending in Las Vegas (LVBOB).


Conventional Gasoline (not classified as oxygenated or reformulated gasoline): These types of finished gasoline do not contain any oxygenates.

  • Arizona Conventional Gasoline: Finished motor gasoline formulated for use in motor vehicles. This type of finished gasoline is for use in areas of Arizona not required to use Arizona Cleaner Burning Gasoline.


  • Nevada Conventional Gasoline: Finished motor gasoline formulated for use in motor vehicles. This type of finished gasoline is for use in areas of Nevada not required to use Nevada Cleaner Burning Gasoline.


  • Other Conventional Gasoline: Finished motor gasoline formulated for use in motor vehicles. This type of finished conventional gasoline is for use in areas outside of California, Arizona and Nevada or for use as an exempt fuel in California.


Kerosene is a petroleum distillate with a boiling point between 300°F and 500°F boiling and generally having a flash point higher than 100°F.

Lease Condensate: A mixture consisting primarily of pentanes and heavier hydrocarbons which is recovered as a liquid from natural gas in lease separation facilities. This category excludes natural gas plant liquids, such as butane and propane, which are recovered at downstream natural gas processing plants or facilities.

Liquefied Petroleum Gases: A group of hydrocarbon-based gases derived from crude oil refining or natural gas fractionation. They include ethane, ethylene, propane, propylene, normal butane, butylene, isobutane, and isobutylene. For convenience of transportation, these gases are liquefied through pressurization.

Lubricants:

  • Naphthenic: Includes all lubricating oil base stocks with a Viscosity Index <75.


  • Paraffinic: Includes all grades of bright stock and neutrals with a Viscosity Index >75.


Marine Fuels: A general classification of diesel fuel oil for marine use. Marine fuels are generally used by ocean-going marine vessels for bunkering to use with their primary and auxiliary compression ignition engines, by local tugboats and harbor ships, and by boats for recreational marine purposes. Marine fuel types may be categorized as distillate, intermediate or residual per the following grades and names.

  • Marine Fuels - Distillate Type: Referred to as Gas Oil or Marine Gas Oil. Examples of various fuel grades include DMX, DMA, DMB, and DMC.


  • Marine Fuels - Intermediate Type: Referred to as Marine Diesel Fuel or Intermediate Fuel Oil (IFO). Examples of various fuel grades include IFO 180 and IFO 380.


  • Marine Fuels - Residual Type: Referred to as Fuel Oil or Residual Fuel Oil. Examples of various fuel grades include RMA and RML.




Definitions of Gasoline Grades (classification of gasoline by octane ratings): Each type of gasoline (conventional, oxygenated and reformulated) is classified by three grades - Regular, Midgrade, and Premium.

Note: Gasoline sales are reported by grade in accordance with their classification at the time of sale. In general, automotive octane requirements are lower at high altitudes. Therefore, in some areas of the United States, such as the Rocky Mountain States, the octane ratings for the gasoline grades may be 2 or more octane points lower.

  • Regular Gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 85 and less than 88. Note: Octane requirements may vary by altitude.


  • Midgrade Gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 88 and less than or equal to 90. Note: Octane requirements may vary by altitude.


  • Premium Gasoline: Gasoline having an antiknock index, i.e., octane rating, greater than 90. Note: Octane requirements may vary by altitude.

Motor Gasoline Blending Components: Components used for blending or compounding into finished motor gasoline. These components include reformulated gasoline Blendstock for Oxygenate Blending (CA RBOB and RBOB), oxygenates (alcohols, ethers) and gasoline blending components.

Reformulated Gasoline Blendstocks for Oxygenates Blending:
  • California Reformulated Gasoline Blendstocks for Oxygenate Blending (CARBOB): Unfinished motor gasoline that meets the requirements of the CA RBOB regulations promulgated by the California Air Resources Board. This base gasoline is designed to be blended with an oxygenate (ethanol) in order to comply with California's finished reformulated gasoline regulations.


  • EPA Reformulated Gasoline Blendstocks for Oxygenate Blending (RBOB): Unfinished motor gasoline that meets the requirements of the RBOB regulations promulgated by the U.S. Environmental Protection Agency. This base gasoline is designed to be blended with an oxygenate in order to comply with EPA's finished reformulated gasoline regulations.


  • Arizona Reformulated Gasoline Blendstocks for Oxygenate Blending (AZ RBOB): Unfinished motor gasoline that, when blended with the correct percentage of oxygenate, will meet the requirements of the Arizona Cleaner Burning Gasoline regulations promulgated by the state of Arizona.


  • Cleaner Burning Gasoline Blendstock for Oxygenate Blending (CBGBOB): Unfinished motor gasoline that, when blended with the correct percentage of oxygenate, will meet the requirements of the Nevada Cleaner Burning Gasoline in Las Vegas (LVCBG) regulations promulgated by the state of Nevada.


Oxygenates: Alcohols and ethers which, when added to gasoline, increase the amount of oxygen in that gasoline blend. Common ethers in use as oxygenates include ETBE, MTBE and TAME. A common alcohol in use as an oxygenate is fuel ethanol.

  • ETBE (Ethyl Tertiary Butyl Ether): An oxygenate blendstock, formed by the catalytic etherification of isobutylene with ethanol, intended for gasoline blending.


  • MTBE (Methyl Tertiary Butyl Ether): An oxygenate blendstock, formed by the catalytic etherification of isobutylene with methanol, intended for gasoline blending.


  • TAME (Tertiary Amyl Methyl Ether): An oxygenate blendstock, formed by the catalytic etherification of isoamylene with methanol, intended for gasoline blending.


  • Fuel Ethanol (Ethyl Alcohol): An anhydrous denatured aliphatic alcohol intended for gasoline blending.


Gasoline Blending Components:

  • Alkylate: A branched paraffin compound formed by the catalytic reaction of isobutane with light olefins, such as ethylene, propylene, butylenes, and amylenes. Alkylate is a desirable gasoline blending component due to its high octane and relatively low volatility properties.


  • Hydrocrackate:A high-octane product made in a catalytic hydrocracking unit.


  • Isomerate: A high-aromatics, high-octane product made in an isomerization unit.


  • Isooctane: The pure hydrogenated form of diisobutylene, with a blending octane of 100, not commingled with other types of alkylates. Used as a gasoline blending component.


  • Natural gasoline: A term used in the gas processing industry to refer to a mixture of liquid hydrocarbons (mostly pentanes and heavier hydrocarbons) extracted from natural gas. It includes isopentane.


  • Reformate: A high-aromatics, high-octane product made in a reformer and used to blend motor gasoline or aviation gasoline.


  • Toluene: An aromatic hydrocarbon that can be used as a high octane gasoline blendstock.


  • Other Gasoline Blending Components: Includes all gasoline blending components not specifically listed above. Specifically, such petroleum products as: butane, butenes, catalytically cracked gasoline, coker gasoline, hexane, mixed xylene, pentane, pentane mixture, polymer gasoline, raffinates, straight-run gasoline, straight-run naphtha, thermally cracked gasoline and transmix containing gasoline.


Naphtha Jet Fuel: A naphtha based fuel used for turbojet and turboprop aircraft engines, primarily by the military. Excludes ram-jet and petroleum rocket fuels which should be reported with "Other Finished Products--fuel use."

Natural Gas Liquids: A general term for all liquid products separated from natural gas in gas processing or cycling plants. They include natural gas plant liquids and lease condensate.

Natural Gas Plant Liquids: Those hydrocarbons in natural gas that are separated as liquids at downstream gas processing plants or at fractionating and cycling plants. Products obtained include liquefied petroleum gases and pentanes plus.

Pentanes Plus: A mixture of hydrocarbons, mostly pentanes and heavier hydrocarbons, extracted from natural gas. Included are isopentane, natural gasoline, and plant condensate.

Petrochemical Feedstocks: Chemical feedstocks derived from petroleum principally for the manufacture of chemicals, synthetic rubber and a variety of plastics. There are two categories: “naphtha less than 401°F" and “other oils equal to or greater than 401°F."

Petroleum Coke:

  • Marketable Coke: Those grades of coke produced in delayed or fluid cokers which may be recovered as relatively pure carbon. This “green" coke may be sold as is or further purified by calcining. Calcination of petroleum coke can yield almost pure carbon or artificial graphite suitable for production of carbon or graphite electrodes, structural graphite, motor brushes, dry cells, etc. Marketable coke may also be used as fuel for power plants.


  • Catalyst Coke: In many catalytic operations (e.g., catalytic cracking) carbon is deposited on the catalyst, thus deactivating the catalyst. The catalyst is reactivated by burning off the carbon, which is used as a fuel in the refining process. This carbon or coke is not recoverable in a concentrated form


Petroleum Products: Includes finished motor gasoline, distillate, kerosene, biodiesel, aviation gasoline, aviation jet fuel, reformulated blendstocks for oxygenate blending, gasoline blending components, residual fuel oil, petroleum coke, liquefied petroleum gases, liquefied natural gas, synthetic fuel and unfinished oil.

Propane: Propane is sometimes derived from other petroleum products during oil or natural gas processing. Chemical formula: C3H8. When commonly sold as fuel, it is also known as liquified petroleum gas (LPG or LP gas) and is a mixture of propane with smaller amounts of propylene, butane and butylene, plus an ethyl mercaptan odorant to allow the normally odorless propane to be smelled. It is used as fuel in cooking on many barbecues and portable stoves and in motor vehicles.

Residual Fuel Oil:A general classification for the heavier oils, known as No. 5 and No. 6 fuel oils, that remain after the distillate fuel oils and lighter hydrocarbons are distilled away in refinery operations. No. 5, a residual fuel oil of medium viscosity, is also known as “Navy Special" and is used in steam-powered vessels in government service and as fuel for power plants. No. 6 fuel oil includes Bunker C fuel oil and is used for the production of electric power, space heating, vessel bunkering (marine vessel fuel), and various industrial purposes.

Road Oil (Asphalt Oil): Any heavy petroleum oil, including residual asphaltic oil used as a dust palliative and surface treatment on roads and highways. It is generally produced in six grades from 0, the most liquid, to 5, the most viscous.

Still Gas (Refinery Gas): Any form or mixture of gases produced in refineries by distillation, cracking, reforming and other processes. The principal constituents are methane, ethane, ethylene, butane, butylene, propane, propylene, etc. Still gas is used as a refinery fuel and a petrochemical feedstock. The conversion factor is 6 million BTU's per fuel oil equivalent barrel.

Synthetic Fuel: A fuel derived from feedstock such as coal, oil shale, tar sands, biomass, or natural gas. Specifically, include gas-to-liquid (GTL) fuels produced using Fischer-Tropsch or similar processes. Fischer-Tropsch Distillate refers to products that consist of neat blends of Fischer-Tropsch synthetic fuels.

ULS Diesel refers to ultra low sulfur diesel fuel.

Unfinished Oils: Includes all oils requiring further processing at a refinery. Oils which require only mechanical blending are not reported as unfinished oil. Unfinished oils include naphthas and lighter oils, kerosene and light gas oils, heavy gas oils, and residuum.

Wax: A solid or semi-solid material consisting of a mixture of hydrocarbons obtained or derived from petroleum fractions, or through a Fischer-Tropsch type process, in which the straight chained paraffin series predominates. This includes all marketable wax, whether crude or refined, with a congealing point between 100°F and 200°F and a maximum oil content of 50% by weight.

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