Petrochemistry - Properties of Petroleum and Natural Gas

CHEM 3010

Natural Gas

A naturally occurring mixture of light hydrocarbons, primarily methane (CH₄), and some non-hydrocarbon compounds.

Composition of Crude Oil

Crude oil consists of hydrocarbons, non-hydrocarbon compounds, organometallic compounds, and inorganic salts.

Distillation

A process used to separate liquids based on differences in boiling points through heating and cooling cycles.

Atmospheric Distillation

A method that separates crude oil into fractions according to boiling point at atmospheric pressure.

Vacuum Distillation

A distillation process that occurs under reduced pressure to prevent thermal cracking of heavier fractions.

API Gravity

A measure of how heavy or light a petroleum liquid is compared to water; higher values indicate lighter oils.

Pour Point

The lowest temperature at which an oil will flow; it indicates the ability of oil to be transported and handled.

Flash Point

The lowest temperature at which vapors of a material ignite when exposed to an ignition source.

Cloud Point

The temperature at which wax in the crude oil starts to solidify and form a cloudy appearance.

Viscosity

A measure of a fluid's resistance to flow; higher measure means a thicker oil.

Distillates

Products obtained from the distillation of crude oil, such as gasoline, kerosene, and diesel fuel.

LPG

a mixture of propane and butane used as a fuel or feedstock.

Gasoline

A complex mixture of hydrocarbons used primarily as fuel in internal combustion engines.

Kerosene

A distillate used for heating and jet fuel; it typically boils between 150°C and 300°C.

Diesel Fuel

A type of fuel derived from crude oil, used in compression engines, with a boiling range of 250°C to 360°C.

Lubricating Oils

Oils designed to reduce friction between surfaces, originating from vacuum distillates of crude oil.

Bitumen

A sticky, black, semi-solid form of petroleum, also known as asphalt, used in paving.

Aromatic Compounds

Hydrocarbons containing at least one aromatic ring, such as benzene, toluene, and xylene.

Napthenes

Cyclic hydrocarbons that are saturated, such as cyclopentane and cyclohexane.

Paraffins

Saturated hydrocarbons, including straight-chain and branched isomers.

Non-Hydrocarbon Compounds

Compounds in crude oil that are not hydrocarbons, including sulfur, nitrogen, and oxygen compounds.

Refinery Processes

Processes applied to crude oil to convert it into useful products, such as distillation, cracking, and reforming.

Cracking

A chemical process that breaks down large hydrocarbon molecules into smaller, more valuable products.

Reforming

A process to convert low-quality naphtha into high-octane gasoline components.

Alkylation

A chemical reaction that combines smaller hydrocarbons to form larger branched-chain alkanes.

Desalting

The removal of salt and other impurities from crude oil before refining.

Hydrodesulfurization

A chemical process used to remove sulfur from petroleum products to reduce environmental pollution.

Sulfur Content

The amount of sulfur present in crude oil, affecting its classification as sweet or sour.

Sweet Crude Oil

Crude oil with a low sulfur content, generally below 0.5%.

Sour Crude Oil

Crude oil with a high sulfur content, typically above 0.5%; requires more refining.

Petrochemical Feedstocks

Raw materials derived from petroleum used to produce chemicals and plastics.

Heavy Fractions

Petroleum components that boil at higher temperatures, typically less desirable and require more processing.

Light Fractions

Petroleum components that boil at lower temperatures, usually more desirable and sold at higher prices.

Naphtha

A light fraction of petroleum, typically used to make gasoline and as a solvent.

Refinery Yield

The percentage of each fraction produced compared to the total amount of crude oil processed.

Crude Oil Assay Report

A detailed analysis of the physical and chemical properties of crude oil used for classification and processing decisions.

Total Acid Number (TAN)

A measure of the acidity in crude oil that indicates potential corrosion issues during refining.

Carbon Residue

The amount of carbon remaining after crude oil is distilled, which can indicate its quality.

Hydrogen Sulfide (H₂S)

A toxic and corrosive gas often found in natural gas and crude oil that can pose hazards.

Carbon Dioxide (CO₂)

A gas that can reduce the heating value of natural gas and contribute to environmental concerns.

LNG (Liquefied Natural Gas)

Natural gas that has been cooled to liquid form for ease of storage and transport.

NGL (Natural Gas Liquids)

Liquid hydrocarbons recovered from natural gas processing; includes ethane, propane, and butanes.

Compounds present in Natural Gas

Mainly methane (CH₄), along with ethane (C₂H₆), propane (C₃H₈), and other light hydrocarbons.

Catalytic Reforming

A refining process that increases the octane rating of gasoline by rearranging the molecular structure of hydrocarbons.

Thermal Cracking

A process for breaking down large hydrocarbon molecules using high temperatures.

Catalytic Cracking

A refining process that uses a catalyst to break down large hydrocarbons into more valuable products.

Fossil Fuels

Natural fuels formed from the remains of ancient plants and animals; includes coal, oil, and natural gas.

Gas to Liquids (GTL) Technology

A method of converting natural gas into liquid hydrocarbons for easier transportation and storage.

primary fractions

What type fractions of petroleum include gasoline, kerosene, diesel, and lubricating oils.

kerosene

Petroleum fraction of petroleum typically used for jet fuel.

boiling point

A key property that determines the quality of different fractions in petroleum.

API gravity

measures how heavy or light petroleum is compared to water; higher values indicate lighter oils.

pour point

is the lowest temperature at which an oil will flow, affecting its transportability.

flash point

indicates the lowest temperature at which vapors of a petroleum product can ignite.

cloud point

the temperature at which wax in the crude oil begins to solidify, affecting its clarity and flow.

Distillates

Petroleum products obtained through distillation, including gasoline, kerosene, and diesel.

How do heavier fractions differ from lighter fractions in petroleum?

Heavier fractions boil at higher temperatures, are typically less desirable, and require more processing compared to lighter fractions.

Light Crudes

Fractions with an API gravity greater than 38 are classified as

Medium Crudes

Fractions with an API gravity between 29 and 38 are classified as

Heavy crudes

Fractions with an API gravity below 29 are classified as

Distillation

is used to separate crude oil into various fractions based on boiling points.

aromatic compounds

compounds are used in the production of plastics, dyes, and synthetic fibers.

heavy fractions

are components that boil at higher temperatures and generally require more refining to become marketable.

light fractions

boil at lower temperatures and are typically more valuable due to higher demand.

What role does refining play in petroleum processing?

Refining converts crude oil into usable products through processes like distillation, cracking, and reforming.

lubricating oils?

Petroleum fraction that generally boil between 350°C and 600°C.

What is the composition of diesel fuel?

Composed primarily of long-chain hydrocarbons with a boiling point between 250°C and 360°C.

How does the extraction of natural gas liquids occur?

Natural gas liquids are extracted from natural gas processing plants through the cooling and separation of gases.

What is the primary use of propane in the petroleum industry?

Propane is commonly used as a fuel and is also an important petrochemical feedstock.

sulfur content

What property provides information about its contribution to pollution when burned and requires additional processing to remove.

What does a crude oil assay report provide?

A crude oil assay report provides detailed analysis of crude oil's physical and chemical properties to inform refining processes.

What are non-hydrocarbon compounds found in crude oil?

Non-hydrocarbon compounds include sulfur, nitrogen, and oxygen compounds that affect oil quality and processing.

refinery yields

indicate the percentage of different fractions produced from crude oil, affecting profitability and efficiency.

pour point

What property of petroleum affects its transportability?

API gravity

helps classify petroleum liquids as light or heavy compared to water; higher values indicate lighter oils.

Catalytic cracking

Process that breaks down large hydrocarbon molecules into smaller, more valuable products using a catalyst.

Hydrodesulfurization

removes sulfur from petroleum products to reduce environmental pollution.

What is the relationship between viscosity and oil temperature?

Viscosity decreases with increasing temperature, making oil flow more easily at higher temperatures.

carbon residue

indicates the amount of carbon left after distillation; higher residue may suggest lower quality.

Paraffins

are saturated hydrocarbons, including both straight-chain and branched isomers.

flash point

It is important as it indicates the temperatures at which vapors can ignite, guiding safe handling practices.

gas-to-liquids (GTL) technology?

converts natural gas into liquid hydrocarbons, making transport and storage easier.

cracking

Thermal cracking uses heat alone to break down hydrocarbons, while catalytic cracking uses a catalyst to enhance reactions.

petrochemical feedstocks

They are essential raw materials for producing plastics and chemicals in the industry.

medium crudes

have an API gravity between 29 and 38, falling between light (greater than 38) and heavy (below 29) crudes.

boiling point range for naphtha?

Typically has a boiling point range between 30°C and 200°C.

total acid number (TAN)

What indicates the acidity level in crude oil, which can inform its corrosion potential during refining.

carbon dioxide

Can reduce the heating value of natural gas and contribute to greenhouse gas emissions when burned.