Physico-chemical properties of natural gas. Extraction and use of natural gas

Gaseous state of the substance - the most common in comparison with other aggregate parameters of compounds. After all, in this state are:

• stars;
• interstellar space;
• Planets;
• atmosphere;
• Cosmos whole.

The main distinguishing properties of gases are weak intermolecular interactions in the crystal lattice, because of which all the main characteristics of these substances are manifested. Gaza, of course, very much. However, we will consider the most important and the third most common on our planet - natural.

Natural gas: composition

If we characterize the qualitative composition of natural gas, we immediately need to distinguish the components of two groups: organic and inorganic. Since it is generally believed that it consists of methane, however, this is not entirely true.

The organic components include:

• Methane - CH ₄ ;
• Propane-C ₃ H ₈ ;
• Butane-C ₄ H ₁₀ ;
• Ethane - C ₂ H ₄ ;
• Heavier hydrocarbons with more than five carbon atoms.

Inorganic components include the following compounds:

• Hydrogen (in small amounts) - H ₂ ;
• Carbon dioxide - СО ₂ ;
• Helium - He;
• Nitrogen - N ₂ ;
• Hydrogen sulphide - H ₂ S.

What exactly will be the composition of a mixture, depends on the source, that is, the field. The same causes explain the various physical and chemical properties of natural gas. However, any of them is mined, and everyone also has value. Just some kind is used as fuel, and saturated with extraneous impurities is too fatly used in the chemical industry for compound synthesis.

Physico-chemical properties of natural gas

To specify such parameters in accuracy, it is necessary to know what the composition of the gas mixture is. After all, if it is predominantly methane (up to 97%), then the characteristics can be given, focusing on it.

If inorganic components or heavy hydrocarbons are in excess (up to several percent), then the physicochemical properties of natural gas change drastically.

Therefore, you can specify only approximate boundary indicators for physical characteristics.

1. The self-ignition temperature is 650-700 ^° C.
2. The octane number is 120-130.
3. It has no color, taste and smell.
4. Lighter than air is almost 2 times, it is easy to concentrate in the upper layers of the room.
5. The density in the form of a conventional state (gas) is 0.68-0.85 kg / m ³ .
6. Under standard conditions, always be in the gaseous aggregate state.
7. When mixed with air in volumes from 5-15% is explosive.
8. The heat of combustion is about 46 MJ / m ³ .

In addition, it should be noted and the chemical side of the parameters of natural gas.

1. It is a highly flammable substance, is capable of self-igniting when the spark is supplied and without it at a certain temperature.
2. Since the main component is methane, it has all its chemical properties.
3. Comes into the reaction of substitution, dehydrogenation, pyrolysis, is subjected to refraction.
4. It is compressed and liquefied at low temperatures and high pressure.

It is obvious that similar physical and chemical properties of natural gas determine a wide range of its use in industry.

A special property of natural gas

A special property of this compound is the ability to form gas hydrate deposits, that is, to be in a solid state. These structures are volumes of natural gas absorbed by the molecules of the reservoir water in the ratio 1/220. Therefore, such deposits are extremely rich in rocks. Places of their concentration in nature:

• Deep bottom layers of the World Ocean;
• Congestions of permafrost.

Conditions of existence - hydrodynamic pressure and low temperatures.

Natural gas fields

If we talk about the content of natural gas in nature, we can identify the main places of concentration:

1. It is a mountain sedimentary rock, a mineral that is formed many millennia by the anaerobic decomposition of organic matter in the deep layers of the earth's crust.
2. It is dissolved in underground waters.
3. It is part of the oil, forming over it an oil and gas cap.
4. It deposits in the form of gas hydrates in the layers of the seabed and the points of the extreme North.

If we denote the distribution of gas deposits territorially, then the leaders are the following countries:

• Russia.
• The countries of the Persian Gulf.
• USA.
• Canada.
• Iran.
• Kazakhstan.
• Azerbaijan.
• Uzbekistan.
• Norway.
• Turkmenistan.
• Netherlands.

The annual production in the world is approximately 3643 billion cubic meters per year. Of these, only Russia accounts for 673.46 billion cubic meters.

The temperature of the natural gas at which it burns is 650 ^° C. That is, it is the indicator at which it is capable of self-igniting. In this case, a greater amount of thermal energy is released than when any other type of fuel is burned. Naturally, this could not but affect the areas of use of this substance.

That is why many countries that do not have natural gas reserves are forced to import it from other states. Transportation is carried out in several ways:

• By pipeline in the gaseous state;
• In tanks along the sea route - in liquid form;
• In railway tank-wagons - liquefied.

Each of the ways has its advantages and disadvantages. In particular, sea and railway versions are safer, since the chemical activity of liquefied gas in refrigerated cylinders is much lower than in the gaseous state. By pipeline, however, the transmission distance and its volumes increase, in addition, this method is economically advantageous.

Methane in the composition of natural gas

Methane gas is the main raw material component of the natural mixture. Its content varies within the range of 70-98%. In itself, this is the third most common gas on the planet, which is a part of oil, interstellar space, the atmosphere of other planets.

From the point of view of chemistry, methane gas is the limiting hydrocarbon belonging to a number of saturated aliphatic compounds. The very first representative of alkanes or paraffins. His chemical activity is low, he is quite calm. Is able to react:

• Substitution;
• Full oxidation;
• Conversions.

It burns with a colorless, non-smoking flame, it does not smell.

Types of natural gas

There are three main types of substance in question.

1. Dry natural gas is one in which methane is more than 97%. That is, the content of impurities, including other hydrocarbons, is extremely low.
2. Skinny gas. This is the name of the mixture containing a small amount of heavy hydrocarbons.
3. Fatty natural gas is one that is rich in heavy hydrocarbons and inorganic components (nitrogen, hydrogen, helium, argon, carbon dioxide, hydrogen sulphide).

Such a concept as the dryness factor of gas allows us to evaluate the quality of raw materials, from which the products will be manufactured in the future. After all, natural gas itself is only a base. For different industries, you need your product, so it undergoes careful processing and cleaning in accordance with specific requirements.

Product Quality

The quality of natural gas depends on the composition. If methane prevails, then such a product will be the best as a source of fuel. If it is the most in fatty hydrocarbons, then for the chemical industry, such raw materials are the most suitable.

In order to supply natural gas of proper quality, there are special chemical plants where it is thoroughly cleaned and processed before being sent to the final destination. The methods of work will depend on the purpose for which the product is intended.

So, for example, if it is to be used for domestic purposes, special odorants, in particular mercaptans, are added to it. This is done to ensure that the gas began to smell, because then in the event of a leak it will be easy to detect. All mercaptans have a sharp unpleasant odor.

Use of natural gas

The consumption of natural gas is carried out by many industries and objects. For example:

• CHP.
• Boiler rooms.
• Gas engines.
• Chemical production (production of plastics and other materials).
• Fuel for cars.
• Heating of living quarters.
• Cooking food.

Therefore, the world production of this raw material is so great, and imports and exports are estimated at billions of dollars.

Ecological aspect

From the point of view of cleanliness for nature there is no better source of fuel than natural gas. Environmental organizations fully endorse its use. However, in recent years, the combustion of natural gas has led to the accumulation of one of the products of the reaction - carbon dioxide.

And since it refers to greenhouse gases, for the planet its congestions are very dangerous. Therefore, many works are being carried out, projects are being developed to protect the ecological state of the planet from the impending greenhouse effect.