Industry Glossary

The definitions contained in this "Chemical Glossary" are merely generic definitions that may prove helpful to those using this Web site. They do not supercede, nor are they intended to supercede, the definitions or specifications that may apply to various technical terms as they are used in specific Chevron Phillips Chemical documents, agreements, proposals or offerings, or in Chevron Phillips Chemical or third party patents.

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ABS resin Acrylonitrile-Butadiene-Styrene copolymer.  A group of tough, rigid thermoplastics derived from the monomers in the name. Uses include automobile and boat parts and fittings, business machines, packaging and other articles.
Absorbent A substance that penetrates the inner structure of another, used to remove or extract one of the compounds of a mixed stream.  The component is subsequently separated from the absorbent, usually by distillation.

A compound, usually organic, that greatly reduces the time for a reaction to take place.

Acetylene A colorless gas derived by cracking hydrocarbons with steam or by partial oxidation of natural gas.  In the chemical industry, it is a by-product of ethylene. It is used as an industrial gas and to produce vinyl chloride, acrylonitrile, and carbon black.
Acrylonitrile A monomer derived mainly from the reaction of propylene or acetylene with HCN.  This is a key raw material used in the fiber, plastics, and rubber industries.
Additive A substance, added to a base material, in low concentrations, to perform a specific function such as to preserve, thicken, disperse or color. Chevron Phillips Specialty Chemicals and PAO organizations sell a range of additives and additive feedstocks that are used in industries such as mining, drilling, fuels, food, and personal care

A substance that can trap molecules of other substances on its surface.


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; CH3-(CH2)n-OH (e.g., methanol, ethanol, and tertiary butyl alcohol).


The product of an alkylation reaction. It usually refers to the high octane product from alkylation units. This alkylate is used in blending high octane gasoline.

Alkylation A petrochemical process in which an alkyl radical is introduced to another molecule. Chemicals produced using alkylation chemistry include cumene, dodecylbenzene, and ethylbenzene. In the oil industry, alkylation refers to a process for making a high-octane blending component for gasoline.
Alpha Olefins

A range of highly linear terminal olefins formed by oligomerization of ethylene.  Examples include 1-butene (C4=), 1-hexene (C6=), and 1-octene (C8=). A.k.a. NAO (Normal Alpha Olefins) or LAO (Linear Alpha Olefins). Alpha olefins are major petrochemical building blocks, which serve as polyethylene co-monomers and as reagents to form surfactants, plasticizers, and additives. NAO’s and NAO derivatives are used in a wide range of applications including: synthetic motor oils for jet engines and automobiles, synthetic lubricants, synthetic drilling fluids, additives for lube oil and the upstream oil industry, paper sizing, flavors, candles, PVC lubes, detergents, and a number of personal care items. Chevron Phillips Chemical is one of the largest producers in the world.

API Gravity

An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it may be calculated in terms of the following formula:
The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity.


A highly reactive group of hydrocarbons with unsaturated rings of carbon atoms, enabling the production of a wide variety of products.   As the name suggests, aromatics have a distinctive odor.

Aromax® process A Chevron Phillips Chemical proprietary process for production of benzene.

A dark-brown-to-black cement-like material containing bitumens as the predominant constituent obtained by petroleum processing; used primarily for road construction. It includes crude asphalt as well as the following finished products: cements, fluxes, the asphalt content of emulsions (exclusive of water), and petroleum distillates blended with asphalt to make cutback asphalts. Note: The conversion factor for asphalt is 5.5 barrels per short ton.


The acronym for the American Society for Testing and Materials.

Atmospheric Crude Oil Distillation

The refining process of separating crude oil components at atmospheric pressure by heating to temperatures of about 600 degrees Fahrenheit to 750 degrees Fahrenheit (depending on the nature of the crude oil and desired products) and subsequent condensing of the fractions by cooling.

Aviation Gasoline (Finished)

A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifications are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note: Data on blending components are not counted in data on finished aviation gasoline.

Aviation Gasoline Blending Components

Naphthas which will be used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates.