PETROCHEMICAL, OIL & GAS DICTIONARY (E-K)

DIFFERENT TERMS & ABBREVIATIONS USED IN OIL & GAS INDUSTRY (REFINERIES) & IN PETROCHEMICAL INDUSTRY INCLUDING MOST COMMONLY USED CHEMICAL INDUSTRY TERMS.

E

EARNINGS PER SHARE (CENTS)

Net profit after tax and before extraordinary items

Number of shares.

ECONOMISER

Equipment for preheating boiler feed water by use of low grade flue gas.

EJECTOR

A device that uses the venturi effect to pull a partial vacuum. Usually driven by steam and associated with condensing plant.

ELASTOMER

A synthetic polymer with rubber‑like characteristics. Examples of commercial products are styrene‑butadiene rubbers, butyl rubber, chloroprene rubber, nitrile rubber, polyurethane rubber and silicone rubber.

ELECTRICAL ISOLATION CERTIFICATE

Permit required to isolate or de‑isolate any electrical equipment.

ELECTROLYSIS

Chemical decomposition by the action of an electric current.

EMULSIFIER

A substance used to promote or aid the emulsification of two liquids and to enhance the stability of the emulsion.

EMULSION

A dispersion of fine droplets of a liquid (the disperse phase) in the bulk of another liquid (the continuous phase) with which it is immiscible. A third substance, the emusifier, is sometimes necessary to keep the droplets dispersed as a stable emulsion.

END POINT

The point indicating the end of some operation or at which a certain definite change is observed. In titration, this change is frequently a change in colour of an indicator which has been added to the solution, or the disappearance or excess of one of the reactants which is coloured. In the distillation of liquids, such as gasoline, the end point is the maximum temperature which occurs during the test (F.B.P).

ENDOTHERMIC

Relating to or designating a reaction which occurs with the absorption of heat, so that the temperature of the reacting bodies is lowered (i.e. heating is required).

ENGINE OIL

A term applied to oils used for the bearing lubrication of all types of engines, machines, and shafting, and for cylinder lubrication in other than steam engines.

ENGLER DISTILLATION

A standard test for determining the volatility characteristics of a gasoline by measuring the percent distilled at various specified temperatures.

ENTRAINMENT

See CARRYOVER

EROSION

To gradually wear away e.g. Catalyst circulation causes erosion.

ETHANE C₂H₆

A colourless, odourless gas of the methane series. Along with methane one of the main constituents of natural gas.

ETHENE

The normalised name for ethylene. A hydrocarbon gas and first member of the olefin series.

EVACUATION

Act of pulling a vacuum on a vessel at atmospheric pressure ‑ thus evacuating the air/gas present.

EVAPORATION

The conversion of a liquid into vapour, usually by means of heat.

EVAPORATOR

A vessel which receives the hot discharge from a heating coil, and by a reduction in pressure, flashes off overhead the light products and allows the heavy residue to collect in the bottom.

EX SITU REGEN

Where catalyst is removed from a reactor and regenerated elsewhere (usually at a catalyst specialists own plant).

EXOTHERMIC

Relating to or designating a reaction which occurs with the evolution of heat, so that the temperature of the reacting bodies is raised (i.e. cooling is required).

EXPANSION JOINT

A joint or coupling designed so as to permit an endwise movement of its parts to compensate for expansion or contraction.

EXTRACT

The portion of an unrefined petroleum product (often a kerosene or a lubricating oil) resulting from a solvent extraction process and consisting mainly of those components which are best soluble in the solvent. Generally the extract, after removal of the solvent consists largely of aromatic hydrocarbons.

EXTRACTION

A fractionation process based upon the difference in solubility, in a given solvent, of the various constituents of the mixture to be fractionated. The process is, for example, used in the separation of de‑asphalted oil from short residue (see butane de‑asphalting).

EXTRACTION DEPTH

Depth to which DAO may be extracted from short residue on BDU unit ‑ the greater the extraction depth, the higher the DAO yield, although too deep an extraction may affect DAO specification.

EXTRACTOR

Column in which an extraction process (e.g. BDU) is carried out.

EXTRAORDINARY ITEMS

Items of expenses or income that are not related to the main activities/operations of the company.

EXTREME PRESSURE LUBRICANTS

A term applied to lubricating oils or greases which contain a substance or substances specifically introduced to prevent metal‑to‑metal contact in the operation of highly loaded gears and bearings. In some cases this is accomplished by the substances reacting with the metal to form a protective film.

 

F

FAECAL COLIFORM (F. COLI.)

Bacteria found in intestines of humans and animals. Indicative of sewage contamination.

FATIGUE

The tendency of a metal to become brittle and fracture under conditions of repeated cyclic stressing at stress levels below its tensile strength.

FEED PREPARATION UNIT

High vacuum unit to split a long residue into a short residue and waxy distillate fraction with a low metal content; the latter fraction is used as Hydrocracker feed.

FEEDSTOCK

Stock from which material is taken to be fed (charged) into a process unit.

FILTER

A porous material on which solid particles are largely caught and retained when a mixture of liquids and solids is passed through it.

FILTRATE

The liquid which has passed through a filter; the product from a filtration process.

FIN FAN

See air heat exchanger.

FIRE WALL

An earth bank or cement wall built around an oil storage tank compound to prevent the spread of the oil in case of fire or bursting of the tank. Height normally calculated to contain contents of largest tank within compound.

FIXED‑BED OPERATION

A type of operation in which the catalyst remains stationary in the reactor. The catalyst may be regenerated insitu or exsitu periodically. To be contrasted with fluid‑bed operation.

FLAME ARRESTOR

An assembly of perforated plates or screens enclosed in a case and attached to the breather vent on petroleum storage tanks, and on bitumen or sour water gas lines prior to burning the gas in a furnace.

FLAMMABLE

Capable of being easily set on fire; combustible.

FLASH

1. A sudden release in pressure resulting in partial or complete vapourisation.

A sudden burst of light; a momentary blaze.

FLASH DISTILLATION

The process of heating a liquid to a temperature within the boiling range of the liquid which causes the evaporation of part of the liquid. The vapour may then be taken off and condensed.

FLASH POINT

The lowest temperature under closely specified conditions at which a combustible material will give off sufficient vapour to form an inflammable mixture with air in a standardised vessel. Flash point tests are used to assess the volatilities of petroleum products.

FLEXIBLE VOLATILITY INDEX

A measure of the volatility of gasoline’s calculated by the formula

RVP +( 0.7 x E70 ) E70 = Evaporation at 70 ⁰C

FLOATING HEAD

An end of a heat exchanger into which tubes are fitted, constructed to allow for the expansion and contraction of the exchanger tubes.

FLOATING ROOF

A special tank roof which floats upon the oil. Applied to do away with the vapour space in storage tanks and thus reduce losses by breathing and hazards of explosions.

FLOC

Any small, tufted, or flake‑like mass of matter floating in a solution, e.g. as produced by precipitation. Used in water treatment for removal of impurities.

FLOCCULATION

Process of forming and removing floc and associated impurities.

FLOODING

In a fractionating column, the filling up with a liquid.

FLUE GAS

Gas from the combustion of fuel, the heating effect of which has been substantially spent and which is, therefore, discarded to the flue or stack. Its constituents are principally CO₂, CO, 0₂, N₂ and H₂0.

FLUID

Non rigid substance consisting of particles that move freely amongst themselves (includes particulate, liquids and gases).

FLUID BED OPERATION

Where catalyst is continually moved from the reactor to a regenerator and back again, as in the continuously regenerated platformer or cat cracker processes.

FOAM

A preparation designed to smother oil fires. It consists of a solution which, on mixing with water, produces a mass of foam many times the volume of the original liquids.

FOAMING

1. The formation of froth or foam on lubricating oils or other oils as a result of aeration or release of gas dissolved in the oil.

2. The formation of bubbles on the surface of boiled water. The foam may entirely fill the steam space of the boiler or may be of minor depth; in either case, it causes appreciable entrainment of boiler water with steam.

3. Caused in Adip systems by presence of liquid hydrocarbons or fines affecting surface tension of solution.

FORCED DRAUGHT

Air forced into a furnace by means of a fan or blower to improve combustion (compare induced draught).

FRACTION

A portion of petroleum separated from other portions in the fractionation of petroleum products. It is often characterised by a particular boiling range.

FRACTIONAL CONDENSATION

A separation of the components of vapourised oil coming off during distillation by condensing the vapours in stages (partial condensation). The oil of highest boiling point will condense first and may be removed in the liquid stage, allowing the portion still in the vapour state to pass on to the next stage condenser.

FRACTIONATING COLUMN

An apparatus in which fractionation is carried out. It consists of a vertical cylindrical metal vessel, containing equipment for the proper contacting of flashed liquid and vapour. heat is often supplied at the bottom of the column in a reboiler, whereas heat is withdrawn at the top in a condenser. Heat can also be supplied or withdrawn at intermediate heights of the column, if beneficial to the process (inter‑heaters or inter‑coolers). The oil to be fractionated is fed into the column at one or more predetermined locations throughout the height of the column. The contacting equipment is formed by fractionating trays in the oil and chemical industry in general, although for some applications various packing materials are used.

FRACTIONATING TRAYS

Equipment aimed at promoting contact between vapour and liquid for fractionation. The flow can be of a single type (i.e. vapour and liquid are arranged to use separate aperatures) or of the dual type (i.e. vapour and liquid may use the same aperature). The former type is promoted by the provision of downcomers for the liquid. Various arrangements of downcomers lead to various systems of trays. Analogously there may be different provisions for the vapour passage, again leading to various possibilities of trays. For further information see bubble cap trays, calming section trays, grid trays, sieve trays and valve trays.

FRACTIONATION

The general name for a physical process of separating a mixture into its constituents, or into groups of these constituents, called fractions. Examples are: absorption, azeotropic distillation, crystallisation, decanting, distillation, extraction, extractive distillation and flotation.

FREE ON BOARD (FOB)

The unit price at the loading port.

FREE WATER

Water which is not dissolved (ie not chemically bound in solution) in a fuel or feedstock.

FREEZE POINT

An important characteristic of aviation fuels. The test for Jet A1 is to cool until solid then reheat, the temperature at which the solid MELTS is called freeze point.

FREEZING POINT

The temperature at which crystals first appear when a liquid is cooled under specified conditions.

FRESH GAS

In the HYDROCRACKER, Fresh H₂ from the reformer to replace H₂ used up in the process. Otherwise any imported gas as distinct from recycle gas.

FRICTION

Resistance to the motion of one surface against another.

FUEL AIR RATIO

The ratio of the weights of fuel to air supplied to an engine, furnace or boiler at any time.

FUEL CELL

An electrochemical device to convert chemical energy directly into electricity. It is similar in some respects to a storage battery or a dry cell. Like a battery, the fuel cell produces electricity by a chemical reaction. Unlike a storage battery, however, the fuel cell continues to produce electricity as long as fuel is added. In a fuel cell chemical energy is directly converted to electrical energy by a process that is the reverse of electrolysis. A fuel gas is fed into one or two hollow porous electrodes in a liquid electrolyte whilst oxygen or air is supplied to the other electrode.

FUEL GAS

Any gas used for heating by combustion.

FUEL OIL

Any liquid or liquefiable petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine, exclusive of oils with a flash point below 100^oF.

FUNCTIONAL LOGIC SCHEME

Diagrams used to show the interaction of plant trips, both cause and effect.

FUNCTIONAL LOGIC SYSTEM

System of plant protection whereby loss of a signal indicates a failure or trip of part of the unit. This trip will then shutdown all or part of the unit.

FURNACE

That section of the refinery process in which the combustion of fuel and air takes place.

FURNACE PASS

For more even heat transfer, the product to be heated is usually split into 4 or more individual pipes (passes) and then recombined at the furnace exit.

 

G

GAP

1. In adjacent fractions, the temperature difference between the initial boiling point of the higher boiling fraction and the end point of the lower boiling fraction. Specifically, the term 'gap' is only used when this difference is positive (c.f. overlap).

2. The mid‑position where a pair of gap‑acting split range controllers are both closed.

GAS HOLDER

A tank for the storage of gas. It usually floats on a liquid seal, buoyed up by the pressure of the stored gas.

GAS OIL

Another common name for diesel fuel (A.G.O.)

GAS/OIL RATIO

The volume of gas at atmospheric pressure produced per unit volume of oil produced (from oil wells).

GASOLINE

Light petroleum fraction, with a boiling range between the approximate limits of 30 and 200^oC.

GAS TURBINE

An engine in which gas (as distinct from steam) is directed, under pressure, against a series of turbine blades. The energy contained in the rapidly expanding gas is converted into rotary motion.

GATHERING STATION

Oilfield installation which receives the production from several wells in its vicinity. It provides facilities to separate the gas and the water, to gauge the production of oil, gas and water, and to transport the oil to the main storage tanks.

GEAR OIL

A lubricating oil for use in standard transmissions, most types of differential gears, and gears contained in gear cases.

GLAND

The outer portion of a stuffing box, consisting of a tubular projection which embraces the rod and extends into the bore of the box, thus bearing against the packing.

GOVERNOR

A device used to control the speed of a turbine, the best known example being the Woodward Governor.

GRAVITOMETER

Instrument used for measuring changes in the specific gravity of oil flowing in a pipeline.

GRID TRAYS

Fractionating trays consisting of parallel bars of flat or round section. The flow is essentially of the dual type, but this character may be reduced by the provision of downcomers (see Fractionating trays).

GUM

Oxidation of gasoline's may produce a sticky substance known as "gum". When unstable gasoline’s are stored for long periods, the gum content may increase. Gum forming is retarded or prevented by using certain inhibitors, e.g. Topanol.

 

H

HAMER LINE BLIND

A spectacle blind‑type blanking device which has only 3 retaining bolts, these are a type of wing not.

HEADER

A common manifold in which a number of pipelines are united. Also used in reference to the U‑bend connection between two consecutive tubes in a coil.

HEAT CAPACITY

Amount of heat per kg per ^oC change in temperature.

HEAT EXCHANGER

An apparatus for transferring heat from one fluid to another. Specifically, a piece of equipment having a tubular piping arrangements which affects the transfer of heat from a hot to a relatively cool material by conduction through the tube walls.

HEAT OF COMBUSTION

The heat created when a substance is burned in oxygen. The calorific, thermal, or heating value of a fuel is the total amount of heat developed by the complete combustion of a unit quantity of fuel; it is reported as calories per gram or Btu per pound.

HEATER

The furnace‑and‑tube arrangement which normally furnishes the principal heating element in a processing unit.

HI‑FI TRAYS

Similar to calming section trays, except there is a greater downcomer area.

HIGH VACUUM UNIT

A unit for the production of vacuum gas oil and waxy distillate from long residue, by means of distillation at very low pressures, i.e. high vacuum.

HORSEPOWER

A unit of rate of operation; one mechanical horsepower equals 33,000 ft‑lb per minute, or 550 ft‑lb per second. This is just one form of Horse Power there are more.

HORTON SPHERE

A spherical tank used to store volatile liquids under high pressure, e.g. butane.

HOT OIL

Any oil used for the transfer of heat, as in the 700 Unit.

HOT SPOT

1. A finite area in the combustion zone of an engine which remains at a temperature higher than that of the immediate surrounding, thus aggravating detonation or pre ignition.

2. An area on the wall of a vessel or line which is appreciably above normal operating temperature. Often as a result of the deterioration of an internal insulating liner which exposes the line or vessel shell to the temperature of its contents.

HUMIDITY

A measure of the moisture contained in the atmosphere.

HYDRATE

A compound formed by the chemical union of water with a molecule of some other substance such as gypsum, from which water may be separated by a simple readjustment of the molecular structure. Gas hydrates, formed from water and, for example methane, may cause plugging of the tubing and flow lines of gas wells.

HYDRATION

The addition of water to a double bond, no breakdown of the molecular structure being involved.

HYDRAULIC FLUIDS

Fluids used in the hydraulic systems of aircraft and industrial equipment etc.

HYDROCARBON

A compound containing only hydrogen and carbon. The simplest hydrocarbons are gases at ordinary temperatures; but with increasing molecular weight, they change to the liquid form and, finally, to the solid state. They form the principal constituents of petroleum.

HYDROCHLORIC ACID

A strong mineral acid, HCL. It is also called muriatic acid.

HYDROCRACKING

A process in which hydrocarbons are converted under hydrogen pressure into products of lower molecular weight, in the presence of an acidic catalyst.

HYDRODEALKYLATION

A process to remove side‑chains on aromatic molecules, either thermally or catalytically, under hydrogen pressure.

HYDRODESULPHURIZATION

The elimination of sulphur containing molecules in crude’s or distillates by the action of hydrogen under pressure over a catalyst.

HYDROGEN

The lightest of all gases, occurring chiefly in combination with oxygen in water, also in acids, bases, alcohol’s, petroleum and other hydrocarbons.

HYDROGEN BLISTERING

A form of corrosion. Blistering of steel is caused by trapped molecular hydrogen formed as atomic hydrogen during attack of steel by hydrogen sulphide.

HYDROGEN SULPHIDE

A compound of hydrogen and sulphur, specifically the monosulphide; a colourless, flammable, poisonous gas, H₂S, having a disagreeable odour; also called sulphureted hydrogen.

HYDROGENATION

The filling of the "free" places in unsaturated structures by hydrogen atoms. The chemical addition of hydrogen to a material. In non‑destructive hydrogenation, hydrogen is added to a molecule only if, and where, unsaturation with respect to hydrogen exists. In destructive hydrogenation, the operation is carried out under conditions which result in rupture of some of the hydrocarbon chains (cracking); hydrogen is added where the chain breaks have occurred. This process is known as hydrocracking.

HYDROLYSIS

The decomposition of a molecular structure by the action of water. A chemical decomposition in which a compound is broken up and resolved into other compounds by reaction with water. In many cases, it is induced by the presence of a small amount of dilute acid.

HYDROMETER

A graduated instrument for determining the gravity of liquids, usually made of hollow glass and weighted at one end so as to float upright. On immersion, the lighter the liquid, the lower the instrument sinks because the buoyancy force is less. Some hydrometers are marked to read percentage of constituent, or some other property related to gravity. The instruments used in measuring petroleum products usually read degress API or specific gravity directly.

HYDROSTATIC HEAD

The pressure exerted by a column of fluid, equalling the height of the column times the fluid density times the acceleration of gravity. An expression of the pressure existing at a certain point, in terms of weight of a superimposed column of fluid.

HYDROSTATIC TEST

A pressure test using water to check the reliability of equipment prior to being bought into service.

HYDROTREATING

A vapour phase process used to treat petroleum fractions boiling up to approximately 250C. The process involves passage over a fixed bed of catalyst (usually prepared by depositing the metals COBALT and MOLYBDENUM on an alumina base) in a hydrogen atmosphere. The process achieves:

1. Hydrogenation of the sulphurous contaminants in the feedstock to hydrogen sulphide.

2. Saturation of unsaturated component compounds such as olefins.

 

I

IGNITION POINT

The point or temperature at which a substance takes fire.

IGNITION QUALITY

A measure of the ignition delay of a fuel in a diesel engine.

IMMISCIBLE

Not capable of mixing; tending to form two layers, e.g. oil and water.

INCOMPATIBLE

Applied to a substance which, for chemical, physical, or physiological reasons, cannot be mixed with another without changing its nature or affect.

INDIGENOUS FEEDSTOCK

Local (i.e. NZ) crude’s or condensates e.g. Maui, Kapuni etc.

INDUCED DRAUGHT

Air drawn into a furnace by means of a fan to improve combustion (compare forced draught).

INERT ENTRY

Specialised entry into a vessel under N₂ atmosphere, by use of B.A. and special safety precautions. Used e.g. in hydrocracker catalyst change operation.

INERT GAS

Nitrogen on the refinery, scrubbed flue gas on the tankers. Used for air (oxygen) exclusion to reduce fire/explosion risk.

INERT FILLER

Non reactive packing/support material, e.g. ceramics, stainless steel etc.

INFLAMMABLE

Very flammable ‑ not to be confused with non‑flammable.

INHIBITOR

A substance, the presence of which in small amounts in a product prevents or retards undesirable changes in the quality of the product, or in the condition of the equipment in which the product is used. In general, the essential function of inhibitors is to prevent or retard oxidation. Examples of uses include the delaying of gum formation in stored gasoline’s and of colour change in lubricating oils; also the prevention of corrosion, e.g. rust prevention by inhibitors in turbine oils and fuels.

INITIAL BOILING POINT

According to ASTM Method D 86 the recorded temperature when the first drop of liquid falls from the end of the condenser.

INJECTOR

A mechanism which may be used in different forms for spraying fuel oil into the combustion chamber, or for feeding water into steam boilers.

IN‑LINE BLENDING

A system in which all components are pumped simultaneously into a common discharge pipe (header) at rates of flow corresponding to the required proportions, the rates of flow being controlled. Blending takes place in the lines between the header and the storage tank into which the blend is discharged.

INORGANIC

Pertaining to substances not organic, nonliving, i.e. which are not carbon compounds, with the possible exception of the oxides and sulphides of carbon.

INSITU REGEN

Catalyst regeneration carried out within the reactor. Carbon is burned off under controlled conditions of heat/air. Less effective, but cheaper and usually quicker than ex‑situ.

INSTITUTE OF PETROLEUM

The organisation in Great Britain primarily responsible for the advancement of the study of petroleum and its allied products in all their aspects. It is the recognised British standardisation authority for methods of testing petroleum products.

INTERCEPTOR

Equipment to remove oil from water either for process separation or pollution control. Weir, parallel and tilted plate types are used.

INTERNAL‑COMBUSTION ENGINE

An engine which operates by means of combustion of a fuel within its cylinder.

ION EXCHANGE RESINS

Preparation used in water softening ‑ Anion and Cation resins are used.

ISOLATE

Any means of positive separation from a risk source:‑

1. To electrically disconnect.

2. To valve/spade isolate a piece of linework/equipment.

ISOMER

Two substances composed of equal amounts of the same elements but differing in properties owing to variation in structure are called isomers.

ISOMERISATION

The conversion of a compound into its isomer. For example, butane may be converted into isobutane. A reaction which alters the fundamental arrangement of the atoms in the molecule without adding or removing anything from the original compound. In the petroleum industry, straight‑chain hydrocarbons are converted catalytically to branched‑chain hydrocarbons of substantially higher octane number by isomerisation.

ISO‑OCTANE C8H18 (2,2,4‑TRIMETHYLPENTANE)

A colourless liquid used with n‑heptane to prepare standard mixtures to determine anti‑knock properties of gasoline.

ISOTOPE

Any one of a number of atomic species differing in atomic weight but having the same atomic number.

Used in some Refinery instruments and for radiography.

J

JET A1

See Avtur.

JET ENGINE (see also Gas Turbine)

An engine which converts fuel and air into a fast‑moving stream of hot gases which effect propulsion of the device of which the engine is a part.

JET FUEL

Fuel meeting the required properties for use in jet engines and aircraft turbine engines. It is subject to intense testing and quality control as laid down in DERD and AFQRJOS documents internationally.

JETTY HOSE

Large bore counterbalanced heavy rubber hose used for loading/unloading ships.

 

K

KELVIN

The unit used as the Absolute temperature scale, i.e. zero Kelvin is absolute zero, 273K is 0^oC. The Kelvin degree has the same dimensions as the Celsius degree. The ^o symbol is not used on the Kelvin scale.

KEROSENE

Any petroleum product with a boiling range between the approximate limits of 140 ^oC and 270^oC which satisfies certain quality requirements (for lamp oil or jet fuel).

KETTLE REBOILER

A reboiler with facilities for separation of liquid and vapour.

KNOCK

Related to internal combustion engines the noise associated with detonation of a portion of the fuel‑air mixture in a cylinder ahead of the advancing flame front.

KNOCKOUT (DRUM OR VESSEL)

A vessel, constructed with baffles, through which a mixture of gas and liquid is passed to disengage one from the other. As the mixture comes in contact with the baffles, the impact frees the gases and allows them to pass overhead; the heavier substance falls to the bottom of the drum.