Petroleum and Its Distillation Products

8/3/2019 Petroleum and Its Distillation Products

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Petroleum And Its Distillation Products

Petroleum:

Petroleum is a complex mixture of organic liquids called crude oiland natural gas, which occurs naturally in the ground and was

formed millions of years ago. Crude oil varies from oilfield to

oilfield in colour and composition, from a pale yellow low viscosity

liquid to heavy black 'treacle' consistencies.

Crude oil and natural gas are extracted from the ground, on land

or under the oceans, by sinking an oil well and are then

transported by pipeline and/or ship to refineries where their

components are processed into refined products.

How Ol Was Formed?

Oil was formed from the remains of animals and plants that lived

millions of years ago in a marine (water) environment before the

dinosaurs. Over the years, the remains were covered by layers

of mud. Heat and pressure from these layers helped the remainsturn into what we today call crude oil . The word "petroleum"

means "rock oil" or "oil from the earth."


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Crude Oil:

Crude oil comes from the well and it contains a mixture ofhydrocarbon compounds and relatively small quantities of other

materials such as oxygen, nitrogen, sulphur, salt and water.

Oil Refinery:

An oil refinery is an organised and coordinated arrangement of

manufacturing processes designed to produce physical and

chemical changes in crude oil to convert it into everyday productslike petrol, diesel, lubricating oil, fuel oil and bitumen. In the

refinery, most of these non - hydrocarbon substances are

removed and the oil is broken down into its various components,

and blended into useful products.

Petroleum Hydrocarbon Structures:

Petroleum consists of three main hydrocarbon groups:

Paraffins:

These consist of straight or branched carbon rings saturated with

hydrogen atoms, the simplest of which is methane (CH4) the main

ingredient of natural gas. Others in this group include ethane

(C2H6), and propane (C3H8).


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Hydrocarbons:

With very few carbon atoms (C1 to C4) are light in density and are

gases under normal atmospheric pressure. Chemically paraffins

are very stable compounds.

Naphthenes:

Naphthenes consist of carbon rings, sometimes with side chains,

saturated with hydrogen atoms. Naphthenes are chemically

stable, they occur naturally in crude oil and have properties

similar to paraffins.


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Aromatics:

Aromatic hydrocarbons are compounds that contain a ring of sixcarbon atoms with alternating double and single bonds and six

attached hydrogen atoms. This type of structure is known as a

benzene ring. They occur naturally in crude oil, and can also be

created by the refining process.

The more carbon atoms a hydrocarbon molecule has, the"heavier" it is (the higher is its molecular weight) and the higher is

its the boiling point.

Small quantities of a crude oil may be composed of compounds

containing oxygen, nitrogen, sulphur and metals. Sulphur content

ranges from traces to more than 5 per cent. If a crude oil contains

appreciable quantities of sulphur it is called a sour crude; if it

contains little or no sulphur it is called a sweet crude.


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The Refining Process:

Every refinery begins with the separation of crude oil into different

fractions by distillation.

The fractions are further treated to convert them into mixtures of

more useful saleable products by various methods such as

cracking, reforming, alkylation, polymerisation and isomerisation.

These mixtures of new compounds are then separated using

methods such as fractionation and solvent extraction. Impurities

are removed by various methods, e.g. dehydration, desalting,

sulphur removal and hydrotreating.

Two types of processes have been developed:

Breaking down large, heavy hydrocarbon molecules

Reshaping or rebuilding hydrocarbon molecules.


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Distillation:

Distillation separates chemicals by the difference in how easily

they vaporize. The two major types of classical distillation include

continuous distillation and batch distillation. Continuous

distillation, as the name says, continuously takes a feed and

separates it into two or more products. Batch distillation takes on

lot (or batch) at a time of feed and splits it into products by

selectively removing the more volatile fractions over time.

Other ways to categorize distillation are by the equipment type

(trays, packing), process configuration (distillation, absorption,

stripping, azeotropic, extractive, complex), or process type

(refining, petrochemical, chemical, gas treating).

Distillation Categories:

System composition

System refers to the chemical components present in the mixture

being distilled. The two main groups are binary distillation and

multicomponent distillation.

Binary distillation is a separation of only two chemicals. A

good example is separating ethyl alcohol (ethanol) from

water. Most of the basic distillation teaching and a lot oftheoretical work starts with looking at binary distillation; it's a

lot simpler.

Multicomponent distillation is the separation of a mixture

of chemicals. A good example is petroleum refining. Crude


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oil is a very complex mixture of hydrocarbons with literally

thousands of different molecules. Nearly all commercial

distillation is multicomponent distillation. The theory and

practice of multicomponent distillation can be very complex.Processing Sequence:

Fractionation systems have different objectives. The major

processing objectives set the system type and the equipment

configuration needed. The common objectives include

removing a light component from a heavy product, removing a

heavy component from a light product, making two products, or

making more than two products. We will call these major

categories are called stripping, rectification, fractionation, and

complex fractionation.

Stripping systems remove light material from a heavy

product.

Rectification systems remove heavy material from a light

product.Fractionation systems remove a light material from a

heavy product and a heavy material from a light product at

the same time.

Reaction:

Reactive distillation uses a reaction in the distillation equipmentto help the separation. The reaction may or may not use a

catalyst. DMT manufacture uses reactive distillation without a

catalyst. One process to make methy-tert-butyl-ether uses a


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catalyst inside the distillation tower. The reaction changes the

composition, allowing the distillation to work better

Equipment Type:

Distillation equipment includes two major categories, trays and

packing.

Trays force a rising vapor to bubble through a pool of

descending liquid.

Packing creates a surface for liquid to spread on. The thin

liquid film has a high surface area for mass-transfer

between the liquid and vapor.

Trays Packing


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Oil Refining Production Process:

Desalting and Dewatering

Distillation

Reforming

Cracking

Alkylation

Isomerisation

Polymerisation

Hydrotreating

Petroleum Products:

Petroleum products are usually grouped into three categories:

light distillates (LPG, gasoline, naphtha), middle distillates

(kerosene, diesel), heavy distillates and residuum (heavy fuel oil,

lubricating oils, wax, asphalt). This classification is based on the

way crude oil is distilled and separated into fractions (called

distillates and residuum).

Liquified petroleum gas (LPG)

Gasoline (also known as petrol)

Naphtha

Kerosene and related jet aircraft fuels

Diesel fuel

Fuel oils

Lubricating oils

Paraffin waxAsphalt and tar

Petroleum coke


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Oil refineries also produce various intermediate products such as

hydrogen, light hydrocarbons, reformate and pyrolysis gasoline.

These are not usually transported but instead are blended or

processed further on-site. Chemical plants are thus often adjacentto oil refineries. For example, light hydrocarbons are steam-

cracked in an ethylene plant, and the produced ethylene is

polymerized to produce polyethene.

Specialty end products:

These will blend various feedstocks, mix appropriate additives,

provide short term storage, and prepare for bulk loading to trucks,

barges, product ships, and railcars.

y Gaseous fuels such as propane, stored and shipped in

liquid form under pressure in specialized railcars to

distributors.

y Liquid fuels blending (producing automotive and aviation

grades of gasoline, kerosene, various aviation turbine fuels,

and diesel fuels, adding dyes, detergents, antiknockadditives, oxygenates, and anti-fungal compounds as

required). Shipped by barge, rail, and tanker ship. May be

shipped regionally in dedicated pipelines to point consumers,

particularly aviation jet fuel to major airports, or piped to

distributors in multi-product pipelines using product

separators called pipeline inspection gauges ("pigs").

y

L

ubricants (produces light machine oils, motor oils, andgreases, adding viscosity stabilizers as required), usually

shipped in bulk to an offsite packaging plant.


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y Wax (paraffin), used in the packaging of frozen foods,

among others. May be shipped in bulk to a site to prepare as

packaged blocks.

y

Sulfur (or sulfuric acid), byproducts of sulfur removal frompetroleum which may have up to a couple percent sulfur as

organic sulfur-containing compounds. Sulfur and sulfuric

acid are useful industrial materials. Sulfuric acid is usually

prepared and shipped as the acid precursor oleum.

y Bulk tar shipping for offsite unit packaging for use in tar-

and-gravel roofing.

y

Asphalt unit. Prepares bulk asphalt for shipment.y Petroleum coke, used in specialty carbon products or as

solid fuel.

y Petrochemicals or petrochemical feedstocks, which are

often sent to petrochemical plants for further processing in a

variety of ways. The petrochemicals may be olefins or their

precursors, or various types of aromatic petrochemicals.


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ASSIGNMENT

TOPIC: Petroleum And Its Distillation Products

Submitted To:

Mam Shazia Naz Malik.

Submitted By:

M.Muavia

2k10-Che-115 (Sec: B)

Department:

Chemical Engineering.

NFC_ Institute Of Engineering And Technological

Training,Multan.


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REFERENCES:

GOOGLE SEARCH

y http://www.aip.com.au/industry/fact_refine.htm

y http://en.wikipedia.org/wiki/Petroleum_product

y http://science.howstuffworks.com/environmental/ener

gy/oil-refining2.htm

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Petroleum and Its Distillation Products

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