Barrel (bbl) – Standard measure for oil and oil products. One barrel = 35 imperial gallons, 42 US gallons, or 159 litres.

Base Oil – a fully refined oil which is blended with other oils and additives to produce a finished product, a lubricating oil.

BDEP – Basic design and engineering package. The step subsequent to the BOD whereby the BOD is translated into physical components, including the specification of each of the components.

BDU – Deasphalting unit that uses butane as the solvent, c.f. PDU.

Benchmarking – A means by which to measure a process, organisation or strategy against those of others, with the purpose of improving performance cf Solomon Associates.

BFE – Brightstock Furfural Extract, the by-product from the FEU operation on DAO.

Biodegradable – Material that can be decomposed or rotted by bacteria or other natural agents. Biodegradability for base oils and lubricants is defined according to specific test methods (CEC, Sturm test, etc.)

Bitumen – A non-crystalline semi-solid material which is the end product from distillation or extraction of selected petroleum oils. It gradually softens on heating. Bitumens are black or brown in color.

Black Oil – Intermediate stream in the HVU between the MMO and SR. To minimise contamination of the heaviest distillate by short residue components.

Black Products – Diesel oils and fuels oils, i.e. products from the low or heavy end of the distillation process. See also: white products.

Blocked-Out Operation – Operation of a unit e.g. MDU, with periodic changes of feedstock (e.g. SPO, MMO, LMO) and therefore conditions.

BO – Black oil from the HVU (between MMO and Short residue).

BOD – Basis of design, the first step in the construction of a new unit defining the overall operating conditions and modes or Biological Oxygen Demand (a water analysis).

BOMP – Base oil manufacturing plant, comprising HVU, FEU, MDU in a Solvex plant.

BPD or B/D – Barrels per day.

Brightstock – High viscosity, fully refined base oil produced from short residue by propane deasphalting (in the PDU) to DAO, solvent extraction in the FEU and dewaxed in the MDU.

BSSW – BrightStock Slack Wax.

BTU – British Thermal Unit: The quantity of heat required to raise the temperature of 1 lb. of water through 1°F. 1000 BTU = 252 kcal.

C&F – Cargo and Freight: A pricing standard which includes these things but excludes insurance. Not to be confused with CIF.

Calorie – The amount of heat required to raise the temperature of  1 gram of water through 1°C (from 14.5 to 15.5°C). In calculations, the kilocalories, equal to 100 calories, is most often used. 1000 kcal = 3968 BTU.

Catalysis – The alteration of the rate of a chemical reaction by the presence of a ‘foreign’ substance (catalyst) that remains relatively unchanged at the end of the reaction.

Catalyst – A substance which aids or promotes a chemical reaction without forming part of the final product. It enables the reaction to take place faster or at a lower temperature and remains relatively unchanged at the end of the reaction. In industrial processes, nevertheless, the catalyst must be replaced periodically to maintain economic production.

Catalytic Cracking – Process of converting vacuum distillates to mogas using a catcracking catalyst – typically at temperatures above 500°C.

Catalytic Dewaxing – A catalytic hydrocracking process which uses molecular sieves to selectively hydrocrack the waxes present into hydrocarbon fractions. Often abbreviated to ca.dewaxing.

Catalytic Partial Oxidation – Oxidation of hydrocarbons to syngas precursors using a catalytic process.

Catalytic Reforming – Catalytic process of dehydrogenation and ring closure of gasoline components to raise the RON and MON of the resulting gasoline. The hydrogen by-product often used in the refineries for hydroprocessing e.g. in an LHT.

CCMC – Comité de Constructeurs d’Automobiles du Marche Commun, European automobile constructors association.

CCR (or) CCT – Conradson Carbon Residue test.

CCS – Cold Cranking Simulator Determination of the dynamic viscosity at low temperatures.

CCU – Catalytic Cracker Unit.

CDU – Catalytic Dewaxing Unit, the first distillation step in a refinery separating the crude oil into naphtha, kerosene, gas oil and LR.

CDW – Catalytic Dewaxer (or) Catalytic Dewaxing Unit.

CEC – Coordinating European Council for the development of performance tests for lubes and engine fuels.

Centipoise – A Centipoise (cP) is 1/100th of a poise (P) which is the fundamental unit of dynamic viscosity in the CGS (centimetre-gram-second) system of units. The viscosity of water at 20°C is approx. 1 cP.

Centistoke – A Centistoke (cSt) is 1/100th of a stoke (S) which is the fundamental unit of kinematic viscosity in the CGS system. The two viscosities (dynamic and kinematic) are related by the density: centistoke = centipoise/liquid density (in g/cm3).

CFPP – Cold Filter Plugging Point, standard test for gas oils.

CIF – Cargo Insurance and Freight. cf C&F and fob.

Clay Treating – Process improving the quality of a (base oil) product by contacting it with an activated clay whereby minor contaminants are absorbed on to the clay.

Cloud Point – The temperature at which the first signs of wax precipitation appear.

COA – Certificate of Analysis that is associated with a batch of product when sold.

COC – Cleveland open cup flash point determination method.

COD – Chemical Oxygen Demand (a water analysis).

COED – Crude Oil Evaluation Data.

Color – An ASTM test converting the color of an oil into a unitary scale.

• Pale = 4.5 ASTM color or lighter
• Red = Darker than 4.5 ASTM
• Dark = Darker than 8.0 ASTM

CONCAWE – The oil companies’ European organisation for environment, health and safety. The emphasis of its work lies on technical and economic studies relevant to oil refining, distribution and marketing in Europe. CONCAWE was established in 1963 in The Hague, and in 1990 its Secretariat was moved to Brussels.

COSHH – Control of Substances Hazardous to Health (UK legislation).

Crystallisation – Formation of a solid phase, or e.g. wax in the MDU, often prior to separation by filtration.

Cylinder Oil – The residuum remaining in a still after the lighter parts of the crude have been vaporised.

DACO – Deasphalted cylinder oil (or BFE with specifications).

DCS – Distributed control system, computerised control system for refineries e.g. made by Honeywell, Foxboro and Yokagawa.

Deasphalted Oil – DAO the residual oil from which asphalt and resins have been removed by an extractive precipitation process called deasphalting.

Deasphalting – Separation of the asphaltenes from a short residue by contacting with (typically) propane or butane.

Decanter – Vessel in the refinery, e.g. in the solvent recovery section of an FEU permitting the separation into furfural-rich and water-rich phases.

Demulsibility – Ability of an oil to separate from water with which it is mixed. Standard test (ASTM D1401) for base oils at 54°C (82° for BS) with units of the time required to result in 3 ml or less emulsion. Typically 10-30 minutes (max).

Density – Mass per unit volume of a substance at a given temperature.

Deoiling – Reduction in quantity of liquid oil entrained in solid wax, i.e. conversion of slackwax into wax.

Dewaxing – The removal of wax from the processed oil stream (the waxy raffinate) by use of a solvent (MDU, physical separation) or a catalyst (CDW, conversion).

Dewaxing Aid – Additive introduced into the MDU prior to cooling the waxy raffinate – solvent mixture to aid the crystallisation and so to reduce the oil content of the slackwax, thus increasing the yield of base oil over the MDU.

Dewaxing Filter – Rotary vacuum filters in the MDU of typically 93 m2 (100 ft2) to separate the crystallised wax from the wax-slurry mixture producing the dewaxed base oil and slackwax. Typically manufactured by Eimco (Italy), Dorr-Oliver and TSK (Sumitomo, Japan).

Dewaxing Unit – See MEK dewaxing unit.

Dielectric Strength – Measure of the ability of an insulating fluid to withstand electric stress (voltage) without failure. A specification for electrical/transformer oils which depends, in part, on the base oil properties.

Diesel Fuel – See gas oil, a general term covering light fuel oil derived from gas oil used in diesel engines. Sometimes called diesel engine road vehicle (Derv) fuel.

Dilchill – An Exxon technology for cooling the waxy raffinate-solvent mixture in an MDU.

Distillates – Products of condensation during the fractional distillation process (gaseous fuels, naphtha, kerosene, gas oils and fractions used for the manufacture of base oils (SPO, LMO and MMO).

Distillation – Process in the CDU and HVU, based on the difference in boiling point of the liquids in the mixture that are to be separated. Successive vaporisation and condensation over trays (bubble cap, sieve tray, etc.) in a fractionating column permits the different components to exit the column at different heights. Produces distillates and short residue. Distillation is carried out in such a way as to avoid any cracking.

DO – Dewaxed Oil.

Double Effect – Recovery of solvent in the FEU (furfural) and MDU (MEK/toluene) by the successive flashing, heating and pressurising and reflashing. c.f. triple effect.

DPHE – Double pipe heat exchanger in MDU, also known as scraped surface heat exchangers. Internal scrapers in the h/e prevent deposition of wax on the walls of the h/e inhibiting heat transfer. Manufactured by Borsig (and Armstrong in US).

DU – Distillation unit: either CDU for crude distillation unit of HVU for high vacuum (distillation) unit.

DWD – Dewaxed Distillate.

Dynamic Viscosity – The ratio between the applied shear stress and the rate of shear of a liquid, i.e. a measure of the resistance to flow or deformation of a liquid, symbol n, c.f. kinematic viscosity.

Electrical Oil – Lubricating oil (base oil with additives) meeting specifications regarding electrical conductivity, amongst others, for use in e.g. transformers.

Engine Oil – Subdivided into GEOs (gasoline engine oils) or DEO, (diesel engine oils).

Entrainment – Unintentional carry over of a heavier contaminants into the distillate fractions of distillation/fractionation/separation column.

Equipment – Term denoting hardware which may be individually tracked (e.g. using a serial number) and which fulfils a function in a facility. The number of equipment is indicative of a unit’s complexity.

Extract – In solvent refining processes, that portion of the oil/distillate which is dissolved in and removed by the selective solvent, a by-product from the solvent extraction unit (FEU or SEU).

Extraction – The process of addition of a solvent to a liquid stream, followed by separation into two phases, the solvent-rich stream and the raffinate-rich stream, followed by recovery, for recycle within the unit, of the solvent. Extraction results in an upgraded raffinate (the waxy raffinate) and the highly aromatic extract phase. see FEU.

F1 – Formula 1 grand prix (car) racing.

FCC – Fluidised catalytic cracking.

FD – Flashed distillate.

Feedstock – Material which is fed into a processing unit. The term covers both raw materials and crudes and intermediates. It can also cover base oil and additives, although these could be the output product from some processes.

FEU – Furfural extraction unit.

FIFO – First in first out, a stock management procedure for handling stock on refineries. See also CCS, LIFO.

Filter Cloth – Special filter-cloths are used in MDU’s to separate the wax from the oil-solvent mix and which are resistant to the MEK andtoluene solvent.

Flare – When the unexpected happens in a refinery and units need to shut-down rapidly, the (hot) hydrocarbon and gas stream can be redirected to the flare permitting them to be safely burned.

Flash Point – The flash point of an oil is the temperature to which it must be heated to give off sufficient vapour to form momentarily a flammable mixture with air when a small flame is applied under specific conditions, either Pensky-Maartens or Cleveland open Cup standard tests.

FOB – Free on board: a pricing standard which makes no allowance for freight, etc.

Foots Oil – Oil and low melting point wax removed from a slack wax in the manufacture of a hard wax.

Formulation – Specification of a lubricant, including the base oils and additives to be used, blending and packing, and final product specs. Also known as product formulation. see also LOBP.

Fractional Distillation – See distillation.

Fractionation – The general name for the process of separating a mixture into its constituents or fractions. See also: absorption, adsorption, distillation.

FT – Fischer-Tropsch. A method and process for the conversion of monomers into polymers, c.f. SMDS.

Fuel Oils – Heavy fuel from refining process used for fuel for power stations, industry, ships. Use for long residue when in excess of BOMP requirements.

Functional-Value Analysis (FVA) – A multi-disciplinary method for enhancing product value by identifying and reducing any unnecessary project costs.

Furfural – C5H4O2 the solvent used in the FEU.

Furfural Extraction – A widely used solvent extraction process used to reduce aromatics contents thereby increasing the oxidation stability of a base oil.

Gas Liquefaction – The process of cooling natural gas to a temperature of 162°C, thereby reducing its volume by a factor of 600, and making it liquid, transportable by ships (LNG carriers). Alternative, larger volume application than SMDS.

Gas Oil – Synonym for diesel fuel, a medium oil from refining process, sub-categories are VGO (vacuum gas oil), straight-run gas oil. By-product from base oil hydroprocessing units.

Gas Processing – The separation of oil and gas, and the removal of impurities and natural gas liquids from natural gas.

Gasification – The production of gaseous fuel from solid or liquid fuel or gas.

GATO – Gas Absorbing Transformer Oil.

GO – Gas Oil.

Grimmer Analysis – Standard analysis method to determine the concentrations of specific polynuclear aromatics occurring in a material. Specifications exist on the maximum concentration of species, e.g. benzo-a -pyrene, see PNA.

GtL – Gas to Liquids.

HCU – Hydrocracking Unit.

HDN – Hydrodenitrogenation, i.e. removal of the nitrogen species which are present in waxy distillates, a crucial step in the hydrocatalytic route to the preparation of base oils.

HDS – Hydrodesulphurisation, i.e. the removal of sulphur by their reaction with hydrogen under high pressure and temperature and in the presence of a catalyst.

HF – Hydrofinished, the improvement of the colour, and some sulphur removal, by processing a base oil under ‘mild’ (temperature and pressure) conditions.

HFU – Luboil hydro-finishing unit.

Hot Oil – In the base oil manufacturing plant it is important to avoid excessive temperatures otherwise this can lead to deterioration of the base oil properties and/or unit fouling.

HPC – Heavy paraffin conversion – part of the SMDS process.

HPS – Heavy paraffin synthesis – part of the SMDS process.

HR – Hydroraffinate (ex HTU in hydrex/hycat), or human resources.

HSE – Health, Safety and Environment.

HSFO – High-Sulphur Fuel Oil, typically 3% sulphur, a benchmark, internationally traded grade.

HTU – Hydrotreating unit, a generic term encompassing hydrocracking, hydrotreating, hydrofinishing, etc.

HVI – High VI oil.

HVU – High vacuum (distillation) unit. After the CDU the long residue feed is separated under elevated temperatures and vacuum conditions to make ‘distillates’ and a short (or vacuum) residue. Into a single waxy distillate stream (when used as a feed-prep unit for a hydrocracker or catcracker) or separate waxy distillate cuts (SPO, LMO, MMO when used as the feed-prep unit in a base oil manufacturing complex.

Hydraulic Oil – An oil (base oil plus additives) specially designed for use as a power transmission medium in hydraulically operated equipment.

Hydrex –  A sub-set of the hybrid technology.

Hydrocracking – Process converting a vacuum distillate into transportation fuels, e.g. gas oil, over a catalyst and under a high temperature and hydrogen partial pressure.

Hydroprocessing – Process converting vacuum distillates into base oils using hydrogen, c.f. Hycat.

Hydroskimming Refinery – Refinery with a configuration including only distillation, reforming and some hydrotreating.

Hydrotreating – Process which converts or removes undesirable components with the use of a catalyst and hydrogen, see HDN, HDS.

Hydrowax – The bottom product from a hydrocracker. May be used as the feed for a base oil manufacturing plant.

Incident – An unplanned event or chain of events which has caused or could have caused injury, illness and/or damage (loss) to assets, the environment or third parties.

Incineration – The combustion of, generally, waste streams under conditions to render them harmless (> 2 seconds at 1300°C according to EU regulations).

Inert Gas – Chemically inert gas (e.g. nitrogen), resistant to chemical reactions with other substances, used to exclude oxygen/air from units and tanks to prevent oxidation and/or fire risks.

Inhibitor – A chemical additive used to inhibit reactions, often oxidation, which would otherwise lead to undesired products, e.g. acids.

Integrated Solutions – Solutions requiring contributions from more than one discipline, a area of excellence.

Intermediate – A product which has been produced from raw materials or feedstock but will be used again as part of the production of an end product.

IP – Intellectual Property.

ISO – International Standards Organisation.

ISO 9000 – An international standard dealing with quality systems, which can be used for external quality-assurance purposes.

ISO 9001 – An international standard for design, execution and delivery of activities or products. The ISO 9001 standard (paragraph 4.8) states: ‘the product should be identifiable through all stages of production and delivery to the customer. Individual products or batches shall have a unique identification.

IsoDewaxing – A Chevron trademarked term for a process to reduce the pour point of waxy raffinates.

ISO-Grade – Grades for the classification of certain lubricating oil products. The number is equivalent to the viscosity in cSt at 40°C.

JV – Joint Venture; A new company created by two parent companies.

Kerosine (kerosene) – A medium-light oil from the oil refining process intermediate between gas oil and gasoline; used for lighting and heating and as fuel for jet and turbo-prop aircraft engines.

Kinematic Viscosity – The resistance to flow of a fluid under gravity, i.e. the viscosity usually measured in the lab, e.g. with an Ostwald viscometer. It is directly proportional to the dynamic viscosity via the density, i.e.: n = h /r , cf. dynamic viscosity.

Know-How – The intrinsic technical knowledge within.

LHT – Luboil Hydrotreater.

Licence Agreement – An agreement under which one party (the ‘licenser’) grants the right to use its technology (which may or may not be patented) to another party (the ‘licensee’) for a particular scope of activities, either on an exclusive or non-exclusive basis, and undertakes to make relevant documentation or services available.

LIFO – Last In First Out: a stock-management procedure using the newest stock first. See also CCS, FIFO.

LMO – Light Machine Oil distillate from HVU (mid range distillate).

LNG – Liquified Natural Gas: naturally generated gas liquefied by compression or temperature equivalent to cooling to -161°C at atmospheric pressure. has this technology available for licensing.

LOBP– Lubricant Oil Blending Plant. Base oils, from the refineries’ base oil manufacturing plants/complex are combined with other base oils and additives to make lubricants which are packaged and sold to customers.

LOC – Local grade base oil quality.

Long Residue – The undistilled product from the crude distiller.

LPG – Liquified Petroleum Gas: A mixture of propane and butane, liquefied by compression to facilitate transport and storage. Used for cooking and heating or as an automotive fuel.

LR – Long Residue.

LTI – Lost time injury:  measure of safety performance, indicating the person involved in an accident is unable to attend work on the subsequent day.

Luboil – Lubricating oil used to grease and ease the working of mechanical joints and moving parts.

Lubricant – Any substance interposed between two surfaces in relative motion for the purpose of reducing the friction between them.

LVI – Low viscosity index base oils manufactured from naphthenic crudes, below 40 VI units.

LVIN – Low viscosity index naphthenic base oil.

LVIP – Low viscosity index paraffinic base oil made from extracts in HTU.

L-wax – LMO slack wax.

MAC – Maximum acceptable concentration, see TLV.

Market Segment – A market grouping based on consumer attitudes, usage and behaviour. See also market segmentation.

Market Segmentation – The process of understanding and interpreting the structure and dynamics of a market, on the basis of groupings (segments) of different consumer attitudes, usage and behaviour. See also market segment.

Master Plan – Offerings providing a long-term plan for an area of business, which describes the activities required to implement a crucial aspect of a strategy in a business or activity segment:

• ensures that short-term plans are compatible with long-term requirements.

• is related to a particular aspect of the business.

• covers the totality of a resource base, including visible and invisible assets.

• ensures that the relevant resources are managed profitably and in a manner consistent with overall strategy, both currently and into the future.

• allows communication vertically in the organisation, leading to consistency between top-down strategy and bottom-up understanding of the business.

• is a vehicle for interfunctional discussion and consistency across the organisation.

Maxwell Bonnell – The authors of a paper presenting formulas for represent the temperature of distillation under vacuum of petroleum products as an equivalent temperature under atmospheric pressure conditions.

Maxwell Bonnell Temperature – The ‘temperature’ at atmospheric pressure corresponding to the lower temperature at reduced pressure (under vacuum) of distillation

MDS – Middle Distillate Synthesis – see SMDS.

MDU – methyl-ethyl ketone/toluene dewaxing unit.

Medicinal Oil – ultra-pure base oils which are suitable for applications coming into contact with humans (i.e. extremely low sulphur and aromatics contents).

MEK – Methyl-ethyl ketone (dewaxing) solvent.

Middle Distillate – atmospheric distillation unit fractions boiling in the range 250-370°C.

MLDW – Mobil Luboil Catalytic Dewaxing process.

MMO – Medium machine oil distillate from HVU.

Mogas – motor gasoline, ‘gasoline’ in the USA, ‘petrol’ in the UK, ‘essence’ in France, ‘benzine’ in Germany. Satisfies both RON and MON specifications.

Monomers – Molecules that become the building blocks for oligomers or polymers.

MSDS – Material Safety Ddata Sheet summarising the risks associated with a material, preventative actions to be taken and TLVs.

MSDW – Mobil Selective Dewaxing process.

MVIN – Medium VI Naphthenic base oil.

MVIP – Medium VI Paraffinic base oil.

M-Wax – MMO Slack Wax.

MWI – Mobil Wax Isomerisation catalyst.

Naphtha – Range of distillates lighter than kerosene – used as feedstock for motor gasoline or ethylene (C2=) production.

Naphthenic Crudes – Class designated of crude oils containing predominantly naphthenes or asphaltic compounds.

Net sales Proceeds – Sales proceeds measured after deducting: sales taxes and sales-based discounts given to buyers, rebates, allowances and dealer margins. See also gross margin and net margin.

NMP – N-Methyl Pyrrolidone – A solvent used for upgrading distillates, c.f. furfural.

NND – Neutralised naphthenic distillate.

Noack Volatility – A standard test for base oils to simulate the loss of base oil in an engine. The Noack volatility of an oil, according to test method CEC L-40-A-93 (IP 421) is defined as that mass of oil which is lost when the oil is heated at 250°C and 20 mmHg (2.67 kPa; 26.7 mbar) below atmospheric in a test crucible through which a constant flow of air is drawn for 60 minutes.

Non-Condensables – The sum of the gases which cannot be readily condensed, i.e. methane, ethane, propane, etc.

Normal Paraffin – A straight chain hydrocarbon in which no carbon atom is united with more than two other carbon atoms, the main component of light waxes.

NPV – Net Present Value, a financial calculation of the earning power of a project, adjusted for inflation and cost of money.

NS – Solvent neutral luboil grade.

NSR – Naphthenic SO2 extracted Raffinate.

OECD – Organisation for Economic Cooperation and Development.

OEM – Original equipment manufacturer, e.g. an automobile manufacturer.

Oil Gasification – The conversion of petroleum into syngas to be used as a fuel or chemical feedstock.

Oligomer – di-mers, tri-mers or tetra-mers, i.e. the molecules formed from the bonding of 2, 3 or 4 monomers.

OpCo – Operating company. Also known as company.

Opex – Operating expenditure. Also known as revex – revenue expenditure.

Optimisation – The process of maximising the economic benefit from a unit or complex of units. May be performed online in an optimiser.

Outlet – A location where products (and other goods or services) are supplied and payment is made in cash or cash equivalent (cheque, credit card, voucher) at the time of product collection.

Oxidation – The act of reaction with oxygen of, e.g., a base oil forming acids and often associated with a degradation of color.

Oxidation Stability – When exposed to air over time base oils react with oxygen and degrade. When used in engines the high temperature can cause base oils with poor oxidation stability to form corrosive acids, insoluble sludge etc.

P & L – Profit and loss account. Also known as income statement (when applied to a single year).

PA – Propane asphalt – from PDU.

Paraffin – Saturated hydrocarbons sub-divide into iso-paraffins and normal paraffins.

PCA – Polycyclic aromatics, the mass of aromatics that are soluble in DMSO according to the standard test IP-346. According to EU legislation no label is required for a product provided the PCA content is less than 3 %. Products containing more than 3% PCAs must be labelled as potential dermal carcinogens, cf. PNA.

PDU – Propane deasphalting unit.

Petrolatum – A jelly-like product obtained from petroleum and having a microcrystalline structure.

Petroleum – The general name for hydrocarbons, including crude oil, natural gas and NGLs. The name is derived from the Latin oil, oleum, which occurs naturally in rocks, petra.

PFD – Process flow diagram, scheme of the vessels, lines, columns, valves, pumps, etc. in a plant.

pH – A log scale measure of the acidity of water pH = log [H+].

Plant – A configuration of processing, blending and storage facilities which make up a composite facility.

Platforming – A catalytic reforming process using a platinum catalyst.

PNA – polynuclear aromatics, aromatics detected by GCMS (gas chromatography-mass spectrometry) methods, e.g. the Grimmer method c.f. PCA.

Polymer – A complex compound in which single molecules (monomers) are chemically joined together in long chains. Desired products sometime, e.g. plastics, and undesired other times, e.g. coke, polymerised hydrocarbons, depositing on the surfaces of heat exchangers, etc. in refineries.

Pour point – The temperature at which a lubricant or base oil will pour or flow when it is chilled without disturbance under specified conditions.

Pour Point Depressant – Additive that retards wax crystallisation and lowers the pour point.

Pour Point Differential (ppd) – The difference between the temperature at which the dewaxing occurs in the MDU and the pour point of the resulting base oil.

PPM – Parts Per Million.

Predilution – The dilution in an MDU before it starts to be cooled.

Process Model – Equations to calculate yields and selectivities for the conversion of a feedstock over a continuous range of operating modes of a plant.

Process Oil – A base oil or lubricating oil that is wholly consumed in another process, e.g. the manufacture of car tyres.

Product – Any hydrocarbons or related substances, i.e. feedstock, intermediate products or components, end products, additives, mixtures of the above. This term is often used synonymously with finished product (i.e. the product in its final state after all processing and blending has been completed).

Product Formulation – See Formulation – As applied in the LOBP.

Product Properties – The basic thermodynamic and other physical and chemical properties of a product.

Product Slate – Total set of products resulting from one specific process in a production facility.

Production Plan – Plan of production operations for lumped time periods and for lumped operations.

Production Schedule – Plan for production operation runs, based on the production plan but with added detail about events, time instants and operating modes. The schedule includes technical and economic constraints and the driving forces for further (on-line) optimisation of the operation.

Project – The design, engineering, procurement and construction or installation of property, plant, facility or equipment or

• The development of new products or 

• A structured series of activities carried out on behalf of a customer in order to develop and define the technical requirements of the customer’s capital-investment proposals for an oil-refining and gas-processing plant and their associated facilities.

Project specification (PS) – a project-definition package which consists of:

• General project information, scope of work and local information. 

• Design information.

• Basic engineering information.

• Project procedures including standards, specifications and drawings.

Propane (C3H8 or C3) – Hydrocarbon, consisting of three carbon atoms and eight hydrogen atoms; a gas under normal conditions. Used as the solvent in the PDU to remove the asphalt components from short residue making the de-asphalted oil (DAO). Propane liquefies at -42°C. See also: LPG.

PSA – Pressure Swing Absorption. Process used in BOMPS for manufacture of inert gas (N2 with < 0.5% O2) from air by absorption on molecular sieves.

PSE – Propane asphalt/short residue/extract route for bitumen.

PSFS – Process Safety Flow Scheme, the PFD containing details of the safety schemes mplemented in a plant.

PSS – Product Supply Specification.

PTO – Paraffin Transformer Oil.

QMI – Quality Measuring Instrument, An on-line instrument determining a measure of the stream quality (pour point, oxygen content, etc.) as opposed to its temperature, pressure or flow rate.

Quality – Meeting agreed customer requirements. This has been derived from the international standard on quality vocabulary (ISO 8402) which defines quality as the totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs.

Quality Giveaway – The difference between the quality of a product delivered to a customer and the quality of the product ordered by the customer, where the quality received is higher than the quality ordered, and producing the higher quality may have incurred some cost to the manufacturer.

R & B – Ring and ball temperature (for residues).

Raffinates – In solvent refining, the portion of the oil which remains undissolved and is not removed by the selective solvent (furfural or NMP), i.e. waxy raffinate. In hydroprocessing routes, the product from the HTU, i.e. hydro-raffinate.

RCR/RCT – Ramsbottom carbon residue test.

RDC – The rotating disc contactor used in the (furfural) extraction unit to increase the contact between the feed and solvent.

RDU – Redistilling unit, normally downstream of a (luboil) hydrotreater to correct the viscosity, flashpoint, Noack volatility of the product.

Redistillation – See RDU.

Refinery – A complex of facilities where crude oil is separated into light and heavy fractions which are then converted into usable products or feedstocks.

Refractive Index – An indicator of the optical density of a material. Often used as a quality indicator in base oil plants.

Replenishment – The physical acquisition of product (in its broadest sense) in order to restore stocks to their required levels.

Repulp – The second stage of a two-stage dewaxing unit.

Re-Refining – The process of converting used luboil back into a base oil substitute. Processes such as acid-clay treating or distillation and hydrotreating may be used.

Residue – Heavy, non-volatile components of crude oil that flow from bottom of fractionating column during fractional distillation, see long residue and short residue.

Revamping – The process of updating a unit to improve the quality of the plant or to return it to its original state. May involve debottlenecking.

RI – Refractive Index.

ROACE – Return On Average Capital Employed: A well-accepted financial performance ratio.

RON – Research Octane Number: A grade applicable to petrol and gasoline.

RRBO – Re-Refined Base Oil.

RTEP – Real-Terms Earning Power. Also known as IRR: internal rate of return

Run – Plan or actual data on the operation of a facility, including a specification of 

• Facility operating mode 

• Events and time instants at which operation starts, stops or changes.

• See also ‘Test run’

SAE – Society of Automotive Engineers (USA).

Safeguarding – The systems, processes, operating procedures for a refinery unit to ensure its safe operation, see PSFS.

Saybolt Universal Viscosity (SUS) – The time in seconds for 60 ml of fluid to flow through a standard Saybolt universal viscometer at a specified temperature.

SCD – Synthetic crude distillation – part of the SMDS technology.

Scenarios – A set of possible future business environments which challenges decision-makers within the Group. Each scenario is internally consistent, fundamentally different and relevant to the business. Scenarios are used for testing objectives, strategies and investment proposals. Although containing numerical data, they are conceptual and descriptive rather than quantitative.

SCF – Standard Cubic Feet.

Scouting phase – The development of a project description and evaluation, including all relevant aspects of the project. This phase culminates in a scouting phase report.

Scrubbing – The process of purifying a gas by washing it with a liquid.

SDU – Solvent Dewaxing Unit also know as the MDU.

Selectivity – The fraction of desired product occurring in the total product slate.

Service Contracts – Contracts between buyers and its customers for the provision of specified services.

Settler – Vessel in a base oil manufacturing plant (and refinery) designed to have a sufficient residence time to permit the separation under gravity of two liquid phases.

SEU – Sulfolane extraction unit for the removal of benzene from light refinery streams, e.g. platformate or solvent extraction unit where the solvent may be furfural (FEU) or NMP for the upgrading of waxy distillates.

Short residue – The undistilled, bottom product from an HVU. Also known as vacuum residue.

Shutdown – Planned shutdowns of refinery units occur on a regular basis for maintenance of the unit; unplanned shutdowns are controlled operations to take the unit out of service that were not originally envisaged in the annual planning of the unit.

Slack wax – The soft, oily crude wax obtained from the solvent dewaxing of paraffin distillates or lube base stocks. Slack waxes contain varying amounts of oil and must be deoiled to produce hard or finished waxes.

Solubility – The maximum amount of a solvate that may be fully dissolved in a solvent.

Solvent extraction – The process of using a solvent to extract the undesired components from a feed stream: addition of the solvent to the feed, mixing (in the RDC), separation into two phases (in settlers) and recovery of the solvent for recycling within the unit. Typical solvent extraction units in refineries use furfural and NMP.

Solvent Neutral Oil – A paraffinic base oil which has been solvent refined, dewaxed and finished.

Solvent Ratio – The mass of solvent divided by the mass of feed (needed to effect a desired extraction).

Solvent – Common name for a liquid which is capable of dissolving or dispersing other substances.

Solvex Process – Luboil solvent extraction process, i.e. solvent (furfural/NMP) extraction and MEK dewaxing.

SOx – Sulphur Oxides, i.e. SO2 – sulphur dioxide and SO3 – sulphur trioxides, one of the products from the combustion of fuels containing sulphur.

Space Velocity – The mass/volume of feed per unit of catalyst per unit of time (WHSV = weight hourly space velocity = x kg-feed/kg-catalyst/hour; LHSV = liquid hourly space velocity = litres-feed/litre-catalyst/hour).

Specific Gravity – The ratio of the density of a substance at a particular temperature to the density of water at 4°C.

Specifications – See PSS.

SPO – Spindle oil distillate from the HVU.

SPOSW – Slack Wax.

Spot Market – An international market in which oil or oil products are traded for immediate delivery at the current price (the ‘spot price’).

SR – Short residue also known as vacuum residue, the bottom product of a vacuum distillation unit (HVU).

SR – Straight run, solvent ratio or short residue.

Stability – The ability of a refinery product to resist changes with time.

Standard – A document providing rules, guidelines or characteristics for activities or their results, aimed at achieving the optimum degree of order in a given context.

Start Up – Opposite of shutdown. A process that requires care and detailed procedures.

Steam – Refineries generally have boilers to generate steam from highly purified ( ‘boiler feed’) water which is then released into the HP (high pressure) circuit. Units in the refinery use the steam for their operations letting it down to MP (medium pressure) and/or LP (low pressure) steam circuits. The latter has little energy value and is either released into the environment of used for local heating (including district (home) heating in some cases).

Straight-Run – A description applied to a product of crude oil that has been made by distillation with no chemical conversion.

Strategy – A framework for the plans designed to achieve company objectives. A strategy may be used as a screen for possible plans.

Sulphur Content – Specifications on the sulphur content of finished refinery products are continually decreasing. The ‘auto-oil”‘programme in Europe will gradually reduce the sulphur contents of both gasoil and mogas.

SW – Slack Wax – by-product of dewaxing process from the MDU and used as the feed for the manufacture of base oils.

S-Wax – Slack wax.

SWOT – (analysis of) Strength, weaknesses, opportunities and threats.

Syngas – A mixture of methane and CO usually resulting from a gasification process.

Tank – Used for storage of large quantities (thousands of tons) of refinery products, as opposed to ‘vessels’.

TBP-GLC – True boiling point – gas liquid chromatography. The process (ASTM-D2887) for simulating the distillation of a small sample of a product using a gas chromatograph.

Technical White Oil – Hydrofinished base oils meeting specific maximum UV absorbance specifications.

Test run – Run in a refinery unit for a specific, generally non-standard purpose (e.g. maximum capacity, new feedstock, etc.) in which detailed input, output and operational data are measured, a mass balance determined and the results reported.

TLV-STEL – Threshold limit value – short time exposure limit. A 15 minute TWA exposure which should not be exceeded at any time during a workday even if the 8-hour TWA is within the TLV-TWA.

TLV-TWA – Threshold limit value – time-weighted average – the time-weighted average concentration for a normal 8-hour work day and a 40-hour work week, to which all workers may be repeatedly exposed, day after day, without adverse effects. A definition of the ACGIH, the American Conference of Governmental and Industrial Hygienists.

TO – Transformer Oil

TOR – Terms Of Reference. The basis for a project.

TOST – Turbine Oil Stability Test. A standard test to oxidise an oil resulting in the formation of acids.

TOST life – The time (in hours) that an oil takes to oxidise in the TOST until a specific acidity is reached.

TPA – Tonnes Per Annum.

TPC – Total Polar Content in % wt.

TQ – Turbine Quality.

Triple Effect – A highly efficient system for the recovery of a solvent involving three successive steps of flashing, heating and pressuring, cf. double effect.

Trunion Head – The flat end of a rotary vacuum filter used in a MEK dewaxing unit (MDU) which is in contact with the stationary side/casing of the filter. There are different connections in the trunion head permitting successive partial, then full, suction (to remove the dewaxed base oil-solvent mixture), suction (to remove the solvent-rich phase from washing the filter cake) and blowing (with nitrogen to push the slackwax cake off from the filter cloth).

TWO – Technical white oil, a base oil that has been purified by hydroprocessing to reduce the concentrations of aromatics in the product to a lower level of specifications.

UND – Unneutralised Naphthenic Distillate.

Used Luboil – When a lubricating oil has reached the end of its effective life it has to be replaced. The resulting ‘used’, sometimes also referred to as ‘waste’, oil may contain non-negligible amounts of acids, halogens and polycyclic aromatics. It should be collected to permit its re-use to recover its hydrocarbon value and to prevent pollution of the environment. It may then be burned to recover the energy content or rerefined.

Utilities – The generic term for the refinery plants and units that are not directly connected with the manufacture of products (e.g. steam generation, water treatment, etc.)

Vacuum – Less than one atmosphere.

Vd – Dynamic Viscosity in centipoise.

VDU – Vacuum Distillation Unit synonym of HVU.

Vessel – In a refinery a vessel generally has a volume of less than 20 m3, about the same size as a road tanker.

VGO – Vacuum Gas Oil from the HVU (top prods).

VHVI – Very High Viscosity Index base oils.

VI or Viscosity Index – An arbitrary system which has been devised for indicating the relative rate of change of viscosity of a fluid with temperature.

Viscosity – The measure of the internal friction or the resistivity to flow of a liquid more.

Vk – kinematic viscosity in cSt

Volatile – term used to describe substances with low molecular weight that will evaporate at normal atmospheric temperatures and pressures, c.f. Noack volatility.

Waste water – The result of a (refinery) process requiring treatment before it is returned to the environment.

Wax – Plastic, fusible and viscous or solid substance having a characteristic lustre. Wax present in crude oil belongs to two major varieties: paraffin wax and petrolatum. It has to be removed from a waxy distillate to improve its pour point.

Waxy Distillate – The products from the HVU prior to further treatments to improve their qualities, c.f. SPO, LMO, MMO and SR.

Waxy Raffinate – The products from the FEU prior to dewaxing.

White Oil – A colourless and odourless mineral oil used in medicinal and pharmaceutical preparations and as a lubricant in food and textiles.

White Products – Gasoline, naphtha, kerosine and gas oil, i.e. products from the high or light end of the distillation process. See also: black products, light fractions.

WR – Waxy Raffinate ex FEU prior to dewaxing in the MDU

Yield – The mass of the desired product(s) divided by the mass fed to the unit or process, c.f. selectivity.