Oil - This oil and flammable liquid that is prevalent in the area of the sedimentary shell of the Earth's crust.She is one of the most important minerals for humans.Oil is a very complex mixture cyclanes, arenes and alkanes.Also, it contains oxygen, sulfur and nitrogen compounds.The oil composition revealed over thousands of specific organic compounds which comprise about ninety percent of carbon, hydrogen fifteen percent, five percent of sulfur, nitrogen and one percent to three percent oxygen.Also includes oil and a small admixture of mineral compounds nature.The ash content of the oil is very low, it does not exceed one tenth of a percent.Oil is of three kinds:
1. Easy.
2. Average.
3. Heavy.
Burns oil when the heat of about 43,7-46,2 MJ / kg, which is a great advantage among other combustibles.
The composition may include oil and lighter fractions which boil at about two hundred degrees Celsius.They consist mainly of methane hydrocarbons, i.e. alkanes.The content of light fractions of oil products produced at different localities, may be very different.Cycloalkanes, and aromatic hydrocarbon type, that is the arena in the oil composition are essential.
most toxic components that make up the oil and oil products, are justly considered aromatic hydrocarbons (arena).They are called chronic toxicants.The most active among them fast include benzene, toluene and xylene, as they are low boiling substances.A large number of various arenes considered dangerous carcinogens and mutagens.The most dangerous group stage - a group of polyaromatic hydrocarbons.
chemical composition of the oil also includes a large share of solid methane hydrocarbons - the so-called paraffins.Their content in it can exceed fifteen percent.
According to the content of paraffinic oil products divided into several groups:
1. Oil maloparafinovogo composition.They are no more than fifteen percent of paraffins in the composition.
2. Oil sredneparafinovogo composition.This oil contains six percent paraffin.
3. Vysokoparafinovaya oil.Here wax contains more than 6 percent.
The oil contains such substances as chrysene, phenanthrene, benzopyrene, pyrene, tetrafeny.It also has non-hydrocarbon components - resins and asphaltenes, which play an important role in the activity of this mineral.
From an environmental point of view, important components of the oil are sulfur compounds.On the content of the products of oil also divided into three groups:
1. sweet crude.It contains up to half a percent of sulfur.
2. sour crude.Here, the sulfur content does not exceed two percent.
3. sour crude oil.This all oil products containing more than two percent of sulfur.
properties of oil, which is the basic definition of the height of its quality include:
1. Density.Regarding oil often mean its density relative to distilled water.The density of the oil typically ranges from 0.8 to 0.9 g / cm3, but there are also types of oil, the density of which may reach 0.98 g / cm3.
2. Viscosity.There are conditional, kinematic and dynamic viscosity.
3. Molecular weight.It is the most important indicator of the quality of petroleum products.The molecular weight of most of the oil is less than 300 g / mol.
4. The refractive index.This is a very important indicator for the oil, which is a complex mixture of various substances.
5. Fractional composition.All substances, which even in small amounts included in the oil are essential for its quality.
