Petroleum Chemistry - Practice Flashcards

Comprehensive practice flashcards covering petroleum alteration processes, exploration, refining methods, product properties, and engine knocking chemistry.

Petroleum

A complex mixture of organic compounds with high energy content that is thermodynamically metastable under geological conditions.

Thermal Maturation

A process where generated hydrocarbons are subjected to higher temperatures, breaking them down into smaller components, eventually resulting in methane and solid pyrobitumen.

Water Washing

An alteration process where moving water removes lower molecular weight hydrocarbons, aromatic compounds, and polar compounds like fatty acids, making the oil heavier.

Magnetic Surveying

A predrilling exploration method that measures the earth's geomagnetic field strength variations to identify oil-bearing sedimentary rocks.

Field Balance

A type of magnetic instrument used on the earth's surface to measure magnetism in specific locations.

Airborne Magnetometer

An instrument used to measure the magnitude of the earth's total magnetic field over a large area, typically from a low-flying aircraft.

Fractionation

The separation of crude oil in atmospheric and vacuum distillation towers into groups of hydrocarbon compounds with differing boiling-point ranges called "fractions" or "cuts."

Conversion Processes

Refining steps that change the molecular size or structure of hydrocarbons through decomposition (cracking), unification (alkylation/polymerization), or alteration (isomerization/reforming).

Blending

A physical refining operation where accurately weighed quantities of two or more components are mixed to form a homogenous phase conforming to customer specifications.

Continuous (in-line) Blending

A process where all required components are pumped simultaneously into a common header at specified rates proportioned by control valves.

Desalting

The first step in refining used to remove water, inorganic salts, sand, and other impurities to reduce corrosion and fouling of equipment.

Cottrell’s method

A water removal technique where crude oil flows between highly charged electrodes to cause colloidal water droplets to coalesce into large drops.

Vacuum Distillation

A low-pressure distillation process that recovers additional liquid from atmospheric residue at the top of a tower pulling a vacuum.

Ligroin

A petroleum fraction containing normal and branched isomers of pentane and hexane with a boiling range from room temperature to $70\,^{\circ}\text{C}$.

Light Gasoline

All components of crude oil which boil below $100\,^{\circ}\text{C}$, containing paraffins and aromatics up to gaseous reservoir conditions.

Gasoline

A petroleum fraction with a boiling range of $70-180\,^{\circ}\text{C}$ consisting of $C_7-C_{11}$ hydrocarbons.

Kerosene

A fraction with a boiling range of $180-270\,^{\circ}\text{C}$ consisting of compounds between $C_{11}$ and $C_{15}$, often used in jet fuels.

Gas Oil (Diesel Oil)

Molecules composed of $C_{15}-C_{25}$ with a boiling range of $275-320\,^{\circ}\text{C}$ used for jet and diesel engines.

Lubricating Oil

A fraction containing compounds from $C_{26}-C_{40}$ (sometimes $C_{20}-C_{50}$) with boiling points exceeding $350\,^{\circ}\text{C}$.

Pitch

A black, hard, and highly ductile material with viscoelastic properties left as residue after the removal of heavy oil or distillate.

Natural Gas

A gaseous fuel consisting of over $85\,\text{vol \%}$ methane, along with ethane, propane, and butane.

Liquefied Petroleum Gases (LPG)

A fraction consisting of propane and butane isomers (up to $C_4$) that can be liquefied by an increase in pressure at room temperature.

Coal Gas

A colourless gaseous mixture of $H_2$, $CO$, $CO_2$, and $CH_4$ formed by the destructive distillation of bituminous coal at approximately $1300\,^{\circ}\text{C}$.

Knocking

The premature explosion of compressed liquid fuel vapour and air in internal combustion engines, resulting in a metallic rattling sound and loss of efficiency.

Compression Ratio

The ratio of the volume ($V_1$) of reactant gases at the maximum induction point to the volume ($V_2$) just prior to ignition, calculated as $\frac{V_1}{V_2}$.

Self-Ignition Temperature (SIT)

The temperature above which an air-fuel mixture will ignite without a spark plug or external igniter.

Tetraethyllead (TEL)

The principal antiknock compound for gasolines, prepared by the action of ethyl chloride on a $PbNa$ alloy.

Ethyl Fluid

An antiknock mixture containing $61.45\,\%$ $TEL$, $17.85\,\%$ ethylene dibromide, and $18.80\,\%$ ethylene dichloride.

Octane Number

An arbitrary scale where $n-heptane$ is assigned $0$ and $iso-octane$ ($2,2,4-trimethylpentane$) is assigned $100$ to measure antiknock fuel characteristics.

CFR Engine

Cooperative Fuel Research engine; a standardized single-cylinder engine used worldwide to measure octane ratings.

Fuel Sensitivity (FS)

The difference between Research Octane Number ($RON$) and Motor Octane Number ($MON$), calculated as $FS = RON - MON$.

Top Dead Centre (TDC)

The topmost position of the piston inside the engine cylinder.

Power Alcohol

A mixture of $5-25\,\%$ ethyl alcohol with petrol used as an internal combustion engine fuel.

Gasoline Gum

A resinous, non-volatile product formed by the oxidation and polymerization of certain hydrocarbons during fuel storage.