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Senin, 01 Oktober 2012


Oil Fraction

Crude oil is mostly composed of compounds of saturated hydrocarbons (alkanes). The unsaturated hydrocarbons (alkenes, alkynes and alkadiena) very little dkandung by oil, because susceptible addition to alkanes.

Because petroleum berasl of fossil organisms, petroleum compounds containing sulfur (0.1 to 7%), nitrogen (0.01 to 0.9%), oxygen (0.6 to 0.4%) and compound metal in very small quantities. Crude oil is separated into a number of fractions through a distillation process.


Separation of crude oil into the pure components (single compound) is not possible and also not prakstis because too many compounds present in the oil and hydrocarbons have isomers with close boiling points. Fractions obtained from the distillation of crude oil is a mixture of hydrocarbons that boil at a certain temperature trajectory. For example, the fraction of kerosene (kerosene) is composed of a mixture of compounds boiling between 180 0 C-250 0 C. Distillation process is done by using a distillation column or tower.

Boiling point (oC)
Number of C
< 30
1 - 4
Fraction of gas
Fuel gas
30 - 180
5 -10
Car fuel
180 - 230
11 - 12
Cooking fuel
230 - 305
13 - 17
Light gas oil
Diesel fuel
305 - 405
18 - 25
Heavy gas oil
Heating fuel

The first process in petroleum processing is the fractionation of crude oil distillation using a multilevel process, while the results obtained are as follows: 
1. Oil can evaporate: lubricating oils, wax, paraffin and vaseline. 
2. Materials that can not evaporate: asphalt and petroleum 

cokeOil Uses by fractions are as follows:

Name Number of
Carbon Atoms
Boiling Point
Refinery Gas 3 or 4 below 30 Bottled Gas
(propane or butane).
Petrol 7 to 9 100 to 150 Fuel for car
Naphtha 6 to 11 70 to 200 Solvents
and used in petrol.
Kerosene (paraffin) 11 to 18 200 to 300 Fuel for aircraft
and stoves.
Diesel Oil 11 to 18 200 to 300 Fuel for road vehicles
and trains.
Lubricating Oil 18 to 25 300 to 400 Lubricant for engines
and machines.
Fuel Oil 20 to 27 350 to 450 Fuel for ships
and heating.
Greases and Wax 25 to 30 400 to 500 Lubricants
and candles.
Bitumen above 35 above 500 Road surface
and roofing.


Gasoline is a fuel transport still plays an important role to date.  
Gasoline containing more than 500 types of hydrocarbons having chain C5-C10. Levels vary depending on the composition of the crude oil and desired quality. So, how exactly is the use of gasoline as a fuel? 

Gasoline as a motor vehicle fuel 

Because gasoline only burns in the vapor phase, the gasoline must be vaporized in the carburetor before being burned in the engine cylinder. The energy generated from the combustion of gasoline is converted into motion through the following steps. 

Burning gasoline is desired that produces a smooth impetus to the decline of the piston. It depends on the timeliness of combustion so that the amount of energy transferred to a maximum piston. Timeliness combustion depending on the type of hydrocarbon chains which in turn will determine the quality of gasoline. Straight-chain Alkanes in gasoline such as n-heptane, n-octane, and n ¬-nonana highly flammable. This causes the combustion occurs too early before the piston reaches the right position. That places an explosion known as the knock (knocking). Burning too early also means that there is residual unburned gasoline components so that energy is transferred to the piston is not the maximum. Branched-chain Alkanes / alicyclic / aromatic in gasoline as isooctane not very flammable. Thus, fewer beats are generated, and the energy is transferred to the larger piston. 

Therefore, with a good quality gasoline should contain more branched chain alkane / alicyclic / aromatic than straight-chain alkanes. The quality is expressed by the gasoline octane number. 

Octane (octane number) is a measure of the ability of the fuel to overcome a knock when burned in the engine. Octane value of 0 is set to n-heptane, a highly flammable, and the value of 100 for isooctane is not flammable. A mixture of 30% n ¬ isooctane and 70% heptane would have an octane number: 

= (30/100 x 0) + (70/100 x 100) 
= 70 

A gasoline octane number can be determined through the test sample burning gasoline to obtain the characteristics of combustion. The characteristics are then compared with the combustion characteristics of various mixtures of n-heptane and isooctane. If no appropriate characteristics, the levels of isooctane in a mixture of n-heptane and isooctane is used to declare the value of the octane number of the gasoline being tested. 

Gasoline fractions from distillation towers generally have ~ 70 octane. To raise the octane number, there are some things you can do: 

-Change the straight chain hydrocarbons in the gasoline fraction into branched chain hydrocarbon reforming for example through changing n-octane into isooctane. 

-    Adding alicyclic hydrocarbon / aromatic fraction into the final mix of gasoline. 

- Adding anti-knock additive in gasoline to slow burning gasoline. First use of a compound of lead (Pb). Because Pb is toxic, its use has been banned and replaced with organic compounds, such as ethanol and MTBE (Methyl Tertiary Butyl Ether). 

Components of Petroleum

Petroleum is a complex mixture of hydrocarbons plus organic compounds of sulfur, oxygen, nitrogen and compounds containing metal constituents, especially Nickel, Iron and Copper. 

Oil itself is not a uniform material, but berkomposisi highly variable, depending on location, the age of oil and also the depth of the well. 

In light paraffinic petroleum hydrocarbons containing less than 97%, while in the type of weight asphaltik least 50%. 

Hydrocarbon Components

Comparison of the elements contained in the oil varies greatly. Based on the analysis, the data obtained as follows: 

class of paraffinic
class naphthenik
aromatic groups
while the olefinic groups are generally not found in crude oil, as well as hydrocarbons asetilenik very rare.

Crude oil contains a number of non-hydrocarbon compounds, especially sulfur compounds, nitrogen compounds, oxygen compounds, compounds Organo Metallic (in small amounts / trace as a solvent) and inorganic salts (as a colloidal suspension).

1. Sulfur compounds
 Crude oil densitynya higher sulfur content have more tinggu anyway. The presence of sulfur in petroleum are many consequences, for example in gasoline can cause corrosion (especially in the cold or runny), due to the formation of acid produced from sulfur oxides (as a result of burning gasoline) and water.

2. Oxygen compounds
Total oxygen content of the oil is less than 2% and rising with increasing boiling point fractions. Oxygen content can be ascending when the product was long associated with the air. Oxygen in the oil is in the form of a bond as carboxylic acids, ketones, esters, ethers, anhydrides, and disiklo monosiklo compounds and phenols. As the carboxylic acid form Naphthenat acid (alicyclic acid) and aliphatic acids.

3. Nitrogen compounds

 Generally, the nitrogen content in the oil is very low, from 0.1 to 0.9%. The content contained on the type Asphalitik highest. Nitrogen has toxic properties of the catalyst and can form a gum / sap on fuel oil. Highest nitrogen content contained in a high boiling point fractions. Nitrogen base class that has a relatively low molecular weight that can be extracted with dilute mineral acids, while having a high molecular weight can not be extracted with dilute mineral acids.

4. Metallic Constituents

 Metals such as iron, copper, particularly nickel and vanadium in catalytic cracking processes affect catalyst activity, because it can lower gasoline product, produce a lot of gas and coke formation. At high temperatures power generators, such as oil-fired gas turbine, the constituent metals, especially vanadium can form a crust on the turbine rotor. Ash produced from burning fuel containing mainly sodium and vanadium can react with refactory furnace (refractory bricks), resulting in lower melting point refractory mix so damaging it.

In order to be processed into products, crude oil from wells to refineries transported using ships, pipelines, tank cars or trains. In the refinery, crude oil is processed into products that we know the physics based route boiling point (distillation), where the gas is at the top of the column fractionation and residue (asphalt) at the bottom of the fractionation column.

Each route boiling point is called "Faction", eg:

0-50 ° C: Gas
50-85 ° C: Gasoline
85-105 ° C: kerosene
105-135 ° C: Solar
> 135 ° C: Residue (Feedback processes more)

So-called petroleum or crude oil is often called is a mixture of hundreds of hydrocarbons from the smallest ranges, such as methane, which has one carbon atom to the greatest type of hydrocarbon containing 200 carbon atoms or more. 
Broadly petroleum grouped by chemical composition into four types, namely:

1. Paraffin2. Olefin3. Naften4. Aromat

But because the universe can be said to have never found minnyak earth in the form of olefin, then petroleum then be grouped into three types, namely Paraffin, Naften and Aromat.

The main content of the hydrocarbon mixture or compound is paraffin isomers. Isomers itself is another form of a hydrocarbon compound that has the same chemical formula. Suppose the normal-butane in the following figure has isomer 2-methyl propane, or sometimes referred to as iso-butane. Both have the same chemical formula, the formula C4H10 but have different wake as shown in the picture.

If the carbon atom (C) is denoted as a black ball and a hydrogen atom (H) is denoted as a red ball then the picture of normal-butane and iso-butane will look like the following picture:

Hydrocarbons 'normal' is also known as straight-chain hydrocarbons, while the compound isomers or 'iso' is also known as branched-chain hydrocarbons. Both are types of types of paraffin oil.

While the rest of the content of other hydrocarbons in petroleum are cyclo-paraffin compounds called naften and / or compounds Aromat. Here is an example of the cyclo-paraffins and Aromat.

'Family hydrocarbons' stretcher above called homologous, because most of the content is in the oil can be separated into different types of purity for commercial purposes. In general, in a petroleum refinery, separation purity comparisons made to the hydrocarbons that have a smaller carbon content than C7. In general, the content can be separated and identified, but only for the purposes in the laboratory.

Mixture of paraffin and cyclo Aromat the long hydrocarbon chains in petroleum making petroleum are classified as petroleum aspaltin types.

Petroleum is never found in nature in the form of pure paraffin and aspaltin pure, but always in the form of a mixture of paraffin and aspaltin. Grouping petroleum into petroleum and petroleum paraffin types aspaltin by many types of oil or paraffin or aspaltin dominance in petroleum. That is to say the type of paraffin oil if the compound parafinnya more dominant than Aromat and / or cyclo parafinnya. And vice versa.

In industry, from petroleum products grouped by ranges of boiling point, boiling point or by route. Grouping of products based on the boiling point is more often than grouping based on its composition.

Petroleum is not entirely composed of pure hydrocarbons. In the oil also contained impurities (impurities) in the form of sulfur (sulfur), nitrogen and metals. In general, there is lots of impurities in petroleum is an organic sulfur compound called mercaptan. Mercaptan is similar to hydrocarbons in general, but there is the addition of one or more sulfur atoms in the molecule.

More complex sulfur compounds in petroleum are in the form of tiofen and disulfide. Tiofen and disulfide is widely present in the hydrocarbon chain length or the middle distillate products (middle distillate).Besides other impurities contained in petroleum is in the form of organic halogen compounds, especially chloride, and organic metals, namely sodium (Na), Vanadium (V) and nickel (Ni).

The boiling point of paraffin oil and aspaltin can not be determined with certainty, because it varies, depending on how the composition of the hydrocarbon chain. If the oil contains a lot of short-chain hydrocarbons which have a number of carbon atoms less then a lower boiling point, whereas if you have a long-chain hydrocarbons which have a number of carbon atoms more then a higher boiling point.

Question :

  1. One of the properties is the lack of alkane solution in water. It deals with the interactions between the molecules. When the oil tanker Exxon Valdez ruptured near the coast of Alaska, oil (mostly consisting of Alkanes) spill was not soluble in water but float on the surface. Explain this fact from the interaction between molecules and molecular properties of alkanes and water!

Video : How petroleum exploration and refining process

5 komentar:

  1. some people use to used the kerosene in traditional medicine , especially when having the stomachache and then they smear it around it . but whether there will be a negative impact if used it continuously?

    1. I think for it if it is done on a continuous basis then it will have a negative impact also on the outside of our skin or the epidermis, the negative effects can be mild such as allergies or redness of the skin, which I think is due to compounds present in the oil to contract continuously with compounds in the skin epidermis, and to a large negative impact in my opinion could be skin cancer.

  2. Excuse me, I want to ask the oil formation process theory known to date there are two major theories, namely the theory of inorganic and organic theory. Inorganic theory is now rarely used in oil and gas exploration. One of the developers of an organic theory are the followers of creationist - or adherents of the principle of creation, it is anti-evolutionary theory :). An-organic theory is also often known abiotic or abiogenic. I ask what the difference between the theory of petroleum pembentukn inorganic with organic theory

  3. I think there is difference between the two, but it needs further study to the material that I learned yet.
    however I can explain in terms of general and C atoms, which are as follows, although between organic compounds and inorganic compounds are essentially no differences as chemical compounds, but that makes it different is the study raised, the study raised is still seen to be separated in a special branch of chemistry. Broadly speaking, the reasons underlying the separation of the study of organic chemistry and inorganic chemistry are:
    • the amount of organic compounds is much more than inorganic compounds
    • all organic compounds containing carbon atoms, which has a unique in its ability to form chains with other carbon atoms, and have distinctive properties.
    To more clearly be seen from the table below:
    Organic Carbon Compounds Inorganic Carbon Compounds I
    1. Melting point and a low boiling point. I 1. Boiling point and high melting point.
    2. Not resistant to heating. I 2. Resistant to heating.
    3. Covalent binding. I 3. Some are associated with covalent ions.
    4. Generally insoluble in water. I 4. Generally soluble in water
    5. The reaction between the molecules slow. I 5. The reaction between the ions is rapid.

  4. hello derio, i have 1 question for you
    with the number of massive consumption in developed countries or developing it will allow oil runs out. of course, we know on this earth everything related to human life can not be separated from the use of petroleum. you think through a chemical process whether oil can be updated?