Saturday, February 13, 2010
ABSOLUTE PRESSURE
Pressure measured with respect to zero pressure, as distinct from pressure measured with respect to some standard pressure such as atmospheric pressure. Thus, 2 Bar gauge (i.e. atmospheric) is equivalent to 3 Bar absolute.  (Atmospheric pressure being 1 bar absolute).

ABSOLUTE TEMPERATURE
A temperature at which zero is a condition absolutely free of heat and equivalent to -459°F or  –273°C.  To convert temperature on Fahrenheit or centigrade scales to degrees absolute, add 459 or 273 respectively.

ABSORPTION PROCESS
A separation process, a weak chemical reaction, by which certain components of a gas are condensed in an absorption liquid (lean oil) with which the gas is brought into contact.  The absorption liquid with the absorbed components is called fat oil.  The fat oil leaves the bottom of the absorber and is separated from the absorbed components in a following fractionator (Regenerator) whence the fresh lean oil is returned to the absorber.  For example, Adip and Sulfinol Processes for H2S + CO2 removal.


ACCELERATOR
  1. A substance that hastens a reaction, usually by acting as a catalyst, as in the vulcanization of rubber.
  2. Any of several automobile attachments for increasing the speed at will, especially a foot-operated throttle.
ACCUMULATOR
A vessel for the temporary storage of a gas or liquid; usually used for collecting sufficient material for a continuous charge to some refining process.

ACETYLENE C2H2
A highly unsaturated hydrocarbon gas usually made by the action of water on calcium carbide and by pyrolysis of natural gas.  It is largely used in industry for cutting and welding metals.  Several important intermediates have been synthesised from acetylene but a cheaper route via ethylene has now been developed for many of them.

ACID
A member of an important and fundamental category of chemical substances characterised by having an available reactive hydrogen and requiring an alkali to neutralise them.  Acid solutions usually have a sour, biting and tart taste, like vinegar.

ADDITIVE
A substance added to a product in order to improve its properties.

ADIP
Shell trade name for aqueous DIPA solution.

ADIP TREATING
A process for removal of hydrogen sulphide from hydrocarbon gases and LPG by a specific regenerable solvent.
Carbon dioxide and, to a certain extent, carbonyl sulphide can be removed at the same time.  The solvent employed is an aqueous DIPA solution.

ADSORPTION PROCESS
A fractionation process based on the fact that certain highly porous materials preferentially adsorb certain types of molecules on their surface, e.g. PSA units.

AEROBIC
Existing in the presence of oxygen.

AEROMETER
An instrument for ascertaining the weight or density of air or other gases.

AGGREGATE
As applied to non-bituminous materials, the inert material, such as sand, gravel, or broken stone, with which cementing material is mixed to form a mortar or concrete.

AIR-BLOWN ASPHALT
Asphalt produced by blowing air through residual oils or similar mineral oil products at moderately elevated temperatures.


AIR HEAT EXCHANGER
A heat exchanger in which air is used as the cooling medium.

AIR SWEETENING
In this process sour gasoline fractions are sweetened by dissolving air in the hydrocarbon phase followed by contacting with a strong NaOH aqueous solution. The reaction products formed are disulphides which dissolve in the sweetened gasoline and water remaining in the aqueous phase.

ALCOHOLS
A class of organic compounds containing oxygen (as a hydroxyl), of which ethyl alcohol (the alcohol of potable spirits and wines) is the best known.  They can react with acids to form esters.  They are largely used as solvents.

ALGAE
Plants of the group comprising practically all seaweed’s and allied freshwater or nonaquatic forms, such as pond scum’s, stoneworts, etc.

ALIPHATIC HYDROCARBONS
Hydrocarbons in which the carbon atoms are arranged in open chains, which may be branched.  The term includes paraffins and olefins and provides a distinction from aromatics and naphthenes which have at least some of their carbon atoms arranged in closed rings.

ALKALI
In chemistry, any substance having marked basic properties.  In its restricted and common sense, the term is applied only to hydroxides of ammonium, lithium, potassium, and sodium.  They are soluble in water, they have the power of neutralising acids and forming salts with them and of turning red litmus blue.  In a more general sense, the term is also applied to the hydroxides of the so-called alkaline earth metals - barium, calcium, and strontium.

ALKALI TEST
A test to determine the presence or absence of free alkali in finished oils after chemical purification.

ALKALINE
Having the properties of an alkali; opposite to acidic.

ALKALINITY
The amount of free alkali in any substance.

ALKYLATION
A reaction in which a straight-chain or branched-chain hydrocarbons group, which is called an alkyl group or radical, is united with either an aromatic molecule or a branched-chain hydrocarbon. Used for detergent or petroleum manufacture.  Usually catalysed by Hydrofluoric or Sulphuric acid.

ALLOY
A substance composed of two or more metals, or of a metal and a nonmetal, intimately united, usually by being fused together and dissolved in each other when molten.

AMERICAN PETROLEUM INSTITUTE
An association incorporated in the United States, having as its object the study of the arts and sciences connected with the petroleum industry in all its branches and the fostering of foreign and domestic trade in American petroleum products.

AMERICAN SOCIETY FOR TESTING MATERIALS
An association incorporated in the United States for promoting knowledge of the properties of engineering materials and for standardising specifications and methods of testing.

AMINE
    Hydrocarbon with attached Ammonia group having absorbent properties, making it useful in treatment processes (ADIP, SULFINOL).

AMMONIA (NH3)
    Ammonia is manufactured by the direct combination of hydrogen and nitrogen under pressure over a catalyst.  Anhydrous ammonia is mainly used for the manufacture of nitrogenous fertilisers, but is used at NZRC for pH control in various processes.  A colourless, gaseous compound, NH3 is of extremely pungent smell and taste and is very soluble in water.

ANAEROBIC
    Existing in an oxygen free condition.

ANALYSIS
    The process of determining the composition of a substance by chemical or physical methods.

ANHYDROUS
    Free of water.

ANILINE POINT
    The minimum temperature for complete miscibility of equal volumes of the chemical aniline and a petroleum product.  In conjunction with API gravity the aniline point may be used to calculate the net heat of combustion of aviation fuels or the diesel index of diesel fuels.  The lower temperature at which an oil product is completely miscible with aniline in a 1:1 volumetric ratio.

ANNEALING
    Heating and slowly cooling to increase the ductility or remove internal stresses, as of metal or glass.

ANTIFOAM AGENT
    An additive used for controlling foam.  Antifoam agents are used in some lubricating oils.  At PIM, used
UCON or AMEREL

ANTI KNOCK
    An adjective signifying resistance to detonation (pinking) in spark ignited internal combustion engines.  Anti knock value is measured in terms of octane number of gasoline engines and of cetane number for diesel fuels.

ANTI KNOCK AGENT
    A chemical compound such as tetramethyl lead which, when added in small amounts to the fuel charge of an internal combustion engine, tends to lessen knocking.

ANTIOXIDANT
    A chemical added to gasoline, lubricating oil, etc. to inhibit oxidation.

ANTI STATIC ADDITIVE
    An additive for reducing static properties, notably in Kerosene.

AROMATIC BLEND
    A mixture made by the addition of a component or stock essentially aromatic in nature to impart to the mixture some property of the aromatic.

AROMATICS
    A group of hydrocarbons characterised by their having at least one ring structure of six carbon atoms, each of the latter having one valency outside the ring.  If these valencies are occupied by hydrogen atoms, hydrocarbon radicals, or inorganic groups one speaks of condensed aromatics.  These hydrocarbons are called aromatics because many of their derivatives have an aromatic odour.  They are of relatively high specific gravity and possess good solvent properties.  Certain aromatics have valuable anti knock characteristics.  Typical aromatics are: benzene, toluene, xylene, phenol (all mono aromatics) and naphthalene (a di aromatic).  Aromatics can cause smoke and freeze point problems in Kerosene.

ASH
    The solid residue left when combustible material is thoroughly burned.

ASH CONTENT
    The percent by weight of residue left after combustion of a sample of a fuel oil or other petroleum oil.

ASPHALT
    This term may have several meanings:
  1. It refers to a mixture of bitumen and mineral aggregate, as prepared for the construction of roads or for other purposes.
  2. In the United States it refers to the product which is known as bitumen elsewhere.  Black to dark brown solid or semisolid cementitious material which gradually liquefies when heated and in which the predominating constituents are bitumens.  These occur in the solid or semisolid form in nature: are obtainable by refining petroleum; or are combinations with one another or with petroleum or derivatives thereof.
ASPHALTENES
    Polyaromatic constituents of asphaltic bitumen characterised by being insoluble in aromatic free low boiling petroleum spirit, but soluble in carbon disulphide.

ASPHALTIC BASE CRUDE OILS
    Crude oils which contain little or no paraffin wax but usually contain asphaltic matter.  Now often referred to as naphthene base crude oils.

ASPHALTIC BITUMEN
    The full name for bitumen adopted by the Permanent International Association of Road Congresses.

ASPIRATOR
    An apparatus which serves to create a partial vacuum through pumping a jet of water, steam, or some other fluid or gas past an orifice opening out of the chamber in which the vacuum is to be produced.

ASSOCIATED NATURAL GAS
    Natural gas associated with oil accumulations by being dissolved in the oil under the reservoir temperatures and pressures (solution gas) and often also be forming a gas cap of free gas above the oil (gas cap gas).

ASTM DISTILLATION
    Any distillation made in accordance with an ASTM distillation procedure; and, especially, a distillation test made on such products as gasoline and kerosene to determine the initial and final boiling points and the boiling range.

ASTM GUM TEST
  1. An analytical method for determining the amount of existing gum in a gasoline by evaporating a sample from a glass dish on an elevated temperature bath with the aid of circulating air.
  2. Any gum test carried out in accordance with an ASTM gum test procedure.
ASTM MELTING POINT
The temperature at which wax first shows a minimum rate of temperature change, also known as the English melting point.

ATMOSPHERIC PRESSURE
  1. The pressure of air.
  2. More specifically, the pressure of the air at sea level.
  3. As a standard, the pressure at which the mercury barometer stands at 760mm, or 30in. (equivalent to approx. 14.7 psi).
ATOM
    The smallest complete particle of an element which can be obtained, yet retain all physical and chemical properties of the element.  According to present theory, the atom consists of a nucleus of neutrons and positively charged protons, surrounded by negatively charged particles called electrons.

ATOMISE
    To divide a liquid into extremely minute droplets, either by impact with a jet of steam or compressed air, or by passing through some mechanical device.

ATTEMPERATOR
    Same as Desuperheater,you can see in the desuperheater glossary (me2d will post it later) :)

ATTRITION
    The act of wearing out by rubbing or grinding, or the state of being so worn or ground.  Granular catalysts or absorbents may suffer such attrition as a result of movement.

AUTO IGNITION POINT
    The temperature at which the vapour given off by a sample will ignite in air without any ignition source.

AVERAGE BOILING POINT
    Unless otherwise indicated, the sum of the ASTM distillation temperatures in steps of 10C from the 10 percent point to the 90 percent point, inclusive, divided by 9.  Sometimes half the initial and half the maximum distillation temperatures are also added, and the sum then divided by 10.

AVGAS
    High octane aviation gasoline for piston type engine.

AVIATION GASOLINE
    Any of the special grades of gasoline suitable for use in certain aeroplane engines.

AVTAG
    Wide range aviation turbine fuel, gasoline type, about identical to the JP 4 type fuel.

AVTUR
    Kerosene type aviation turbine fuel, (Jet A1).

AZEOTROPE
    Two (or more) components are said to form an azeotrope if there is a mixture of those components which has no boiling range but whose boiling point and dew point are the same.

AZEOTROPIC DISTILLATION
    A distillation process characterised by the fact that the relative position of the components boiling points is influenced by the addition of a compound which selectively forms an azeotrope with one or a group of the components.  The added compound is called the azeotrope former.  E.g. furfural, used in the extraction of aromatics, forms an azeotrope with water.

1 Responses to Operator Dictionary (A)

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