Oil, the origin, properties and composition.
The oil is a mineral of organic origin, natural oily flammable liquid with a characteristic odor, consisting mainly of a complex mixture of hydrocarbons of various molecular weights and other chemical compounds.
Classification of oils according to density. Light oil. The average oil. Heavy oil.
The origin and formation of oil (theories and hypotheses)
Chemical (component, hydrocarbon and elemental) composition
Other fuels: biodiesel, biofuels, gas oil, oil shale, naphtha, fuel oil, oil, associated petroleum gas, natural gas, landfill gas, shale oil, shale gas, synthesis gas
Description of oil:
The oil is a mineral of organic origin, natural oily flammable liquid with a characteristic odor, consisting mainly of a complex mixture of hydrocarbons of various molecular weights and other chemical compounds.
Externally the oil is a flammable liquid whose color can be black, brown, light brown, dirty yellow, dark brown, light yellow-green or deep green. Found oil and without any color.
The oil has an odor, which can be different and varies from light to heavy nice and very unpleasant.
The color and smell of oil are due to the presence in it of nitrogen, sulfur and oxygen-containing impurities and components of aromatic hydrocarbons.
Oil is lighter than water, almost insoluble in it. But under certain conditions can form a water resistant emulsion. Soluble in organic solvents.
The composition of the hydrocarbons contained in the oilaffect its properties: starting from the fact that it is transparent and fluid as water, and to the fact that it is black, very viscous and sticky, not flowing from the vessel when turning.
Oil – the most important minerals that have a complex application (not only as a fuel and energy source, but also as a valuable chemical feedstock for the chemical and petrochemical industry). Modern world economy cannot do without oil. The demand for it increases every day and grows. No wonder oil is called “black gold”, underscores its value on a par with the usual gold. The price of oil on the commodity market the prices depend on different products, in General, the whole world economy.
Oil occurs together with natural gas at depths of several tens of meters to 5-6 km At a depth of more than 6 kilometers is found only gas, at depths of up to 1 mile, just oil, and at depths of from 1 to 6 kilometers of oil and natural gas in various combinations. The natural access to the earth’s surface, the oil is converted into a thick, Malta, the semi-solid asphalt and other entities – for example, tar Sands and bitumens.
Oil refers to non-renewable mineral resources.
Name of oil:
The word oil of foreign origin. From what language it came into Russian is not known. The word “oil” in various accents found in Turkish, Persian, Indian, Arab, Assyrian, Akkadian, ancient Iranian and Semitic languages.
In English, it is spelled “petroleum” is derived from Greek petra “rock” and the Latin oleum – “oil” and literally means “mountain oil”. This word the British and the Americans usually refer to crude oil.
In German language it is spelled “Еrdöl” which literally means “earth oil”, and, for example, in the Hungarian – кооlаj – “rock oil”.
Classification of oils according to density. Light oil. The average oil. Heavy oil.
Depending on the density of the oil is divided into types:
Oil the density of which is below 0,83 g/cm3, is called the light oil.
The 0,831 oil density is 0.86 g/cm3 – average oil.
A higher density of 0.86 g/cm3 – heavy oil.
The origin and formation of oil (theories and hypotheses):
There are two hypotheses – the theory of the origin (formation) oil: biogenic (organic) theory and abiogenic (inorganic, mineral, UC) theory.
For the first time biogenic theory of the origin of oil and natural gas in 1759, was expressed by M. V. Lomonosov. In the distant geological past of the Earth the dead the living organisms (plants and animals, mostly algae and zooplankton) fell to the bottom of ponds, forming muddy deposits. As a result of various chemical, physico-chemical and biochemical processes they decompose in the vacuum of space. Due to the movement of the earth’s crust these remains sank deeper and deeper – to a depth of 6 kilometers, where under the action of high temperature (250 ° C) and high pressure transformed into hydrocarbons: natural gas and oil. Low molecular weight hydrocarbons (i.e. natural gas) were formed at higher temperatures and pressures. High molecular weight hydrocarbons – oil – with less. The hydrocarbons up to the surface because of its lower density, migrated through the overlying sediments, penetrated into the porous sedimentary rock called reservoir, and, meeting on the way impermeable layers (where upward movement was not possible), fell into the trap, where they formed deposits (clusters) – oil and gas. The Deposit proper is not a place of birth and place of accumulation of oil and gas. If during this migration the hydrocarbons did not meet the thickness of the impermeable layers (i.e. do not fall into the trap), then, in the end, was left on the surface. On the surface they were exposed to various external factors, resulting in dissipated and destroyed.
Mineral theory of the origin of oil and natural gas formulated in 1877 by Mendeleev. He proceeded from the fact that hydrocarbons can be formed inside the earth under high temperatures and pressures resulting from the interaction of superheated steam and molten carbides of heavy metals (primarily iron). As a result of chemical reactions forming the oxides of iron and other metals, and various hydrocarbons in the gaseous state. The water falls deep in the bowels of the Earth in cracks-faults in the earth’s crust. The resulting hydrocarbons while in the gaseous state in turn according to the same fractures and faults climb up into the area of least pressure, forming eventually the gas and oil deposits. This process, according to D. I. Mendeleev and supporters of the hypothesis, is constant. Therefore, the reduction of hydrocarbon reserves in the form of oil and gas, humanity is not threatened.
Physical properties of oil:
| Parameter name: | Value: |
| Density, g/cm3
(depends on temperature and pressure) |
0,65-1,05 |
| Density, kg/m3
(depends on temperature and pressure) |
650-1050 |
| Aggregate state | liquid |
| Color | various: black, brown, light brown, dirty yellow, dark brown, light yellow-green, deep green, without color. |
| The smell | various: varies from light to heavy nice and very unpleasant. |
| Transparency | various |
| Flash (depends on the fractional composition and content of dissolved gases), °C | from +35 to +121 |
| Molecular weight, g/mol | 220-400 (rarely 450-470) |
| Temperature of boiling liquid hydrocarbons in the oil, °C | typically >28 °C, at least ≥100 °C in the case of heavy oil |
| The temperature of crystallization, °C
(depends mainly on the content in oil of paraffin and light fractions. The more paraffin, the crystallization temperature is higher. The more light fractions, the lower this temperature is.) |
from -60 to +30 |
| Viscosity, mm2/s
(as determined by the fractional composition of oil and its temperature as well as the content of resinous-asphaltenic substances. The higher the temperature and higher the amount of light fractions, the lower the viscosity of the oil. The more the content of resinous-asphaltenic substances, the viscosity of the above.) |
from 1,98 to 265,90 |
| Specific heat of combustion (lower), MJ/kg | 43,7-46,2 |
| Specific heat, kJ/(kg∙K) | Of 1.7-2.1 |
| Dielectric permittivity | 2.0 to 2.5 |
| Electrical conductivity, Ohm-1∙cm-1 | 2∙10-10 to 0.3∙10-18 |
Chemical (component, hydrocarbon and elemental) composition:
Oil is a complex mixture of various hydrocarbon and non-hydrocarbon components.
The composition of the oil includes about thousands of different individual chemical substances, of which:
– liquid hydrocarbonsthat constitute a large part (more than 500 substances, or usually 80-90% by weight);
– heteroatomic organic compounds (4-5 %): predominantly sulfur (about 250 substances), nitrogen (over 30 ingredients) and oxygen (about 85 compounds), ORGANOMETALLIC compounds (mainly Nickel and vanadium);
– other components: dissolved hydrocarbon gases (CH4 from methane to butane C4H10, inclusive, from a few tenths to 4 %), water (from traces to 10 %), mineral salts (mainly chlorides, 0,1-4000 mg/l and more), solutions of salts of organic acids, etc.;
– mechanical impurities (particles of sand, clay, etc.).
Liquid hydrocarbons represented by paraffin (usually 30-35 %, at least 40-50 %) and naphthenic compounds (25-75 %), compounds of the aromatic series (10-20, at least 35 %) and compounds of mixed or hybrid structure (for example, paraffin-naphthenic, naphtene-aromatic).
Paraffins (from the Latin. parum “little” + affinis “related”) is a waxy mixture of saturated hydrocarbons (alkanes) are predominantly normal structure of С18Н38 (octadecan) to С35Н72 (pentatriacontane), inclusive and a melting point of 45-65 °C.
Naftanaalso cycloalkane, polumetrovye hydrocarbons, Chiclana cycloparaffin or is a cyclic saturated hydrocarbons according to their chemical properties close to the limit hydrocarbons. Have the chemical formula CnH2n, and the cyclic structure (i.e. a closed ring of carbon atoms).
Aromatic compounds (arena) – cyclic organic compounds that are composed of the aromatic system.
Sulfur compoundscontained in oil: H2S, mercaptans, mono – and disulfides, tifany and tifany and polycyclic (heterocyclic) sulfur compounds, etc. 70-90% of the sulfur compounds concentrated in residual products such as fuel oil and tar.
Nitrogen compoundscontained in the oil mainly homologues of pyridine, quinoline, indole, and carbazole, of pyrrole and porphyrins. For the most part concentrated in the heavy fractions and residues.
The oxygen compoundscontained in oil: naphthenic acids, phenols, tarry-asphaltene and other substances. Usually concentrated in high boiling fractions of hydrocarbons.
From the point of view of the elemental composition of oil is present in more than 50 chemical elements. The content of these chemical elements, especially of the impurities varies widely. The following table shows the elemental composition of oil:
| The name of a chemical element: | %% content |
| Carbon, With | 82-87 |
| Hydrogen, N | 11-14,5 |
| Sulfur, S | 0.01 to 6 (rarely up to 8) |
| Nitrogen, N | Of 0.001 to 1.8 |
| Oxygen, O | 0,005-0,35 (rarely to 1.2) |
| Vanadium, V | 10-5-10-2 |
| Nickel, Ni | 10-4-10-3 |
| Chlorine, Cl | from traces to 2⋅10-2 |
| and other |
Other types of fuel:
– biodiesel,
– biofuels,
– gas oil,
– oil shale,
– naphtha,
– fuel oil,
– oil,
– associated petroleum gas,
– natural gas,
– landfill gas,
– shale oil,
– shale gas,
– synthesis gas.
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