Physicochemical properties of natural gas. Natural gas production and use

The gaseous state of a substance is the most common in comparison with other aggregate parameters of compounds. After all, in this state are:

• stars;
• interstellar space;
• planets;
• atmosphere;
• space in general.
  

The main distinguishing properties of gases are weak intermolecular interactions in the crystal lattice, due to which all the main characteristics of these substances are manifested. There are certainly a lot of gases. However, we will consider the most important and the third most prevalent on our planet - natural.

Natural Gas Composition

If you characterize the qualitative composition of natural gas, then you must immediately distinguish the components of two groups: organic and inorganic. Since although it is generally accepted that it consists of methane, this is not entirely true.

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 quantities) - H ₂ ;
• carbon dioxide - CO ₂ ;
• helium - Not;
• nitrogen - N ₂ ;
• hydrogen sulfide - H ₂ S.

What exactly will be the composition of a particular mixture depends on the source, that is, the field. The same reasons explain the various physicochemical properties of natural gas. However, any of them is mined, and each also has value. It’s just that some kind is used as fuel, and saturated with extraneous impurities it is too oily used in the chemical industry for compound synthesis.

Physicochemical Properties of Natural Gas

To indicate such parameters exactly, you should know what exactly is the composition of the gas mixture. After all, if methane predominates in it (up to 97%), then the characteristics can be cited based on it.

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

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

1. Auto-ignition temperature - 650-700 ⁰ .
2. The octane number is 120-130.
3. It has no color, taste or smell.
4. Almost 2 times lighter than air, it is easily concentrated in the upper layers of the room.
5. The density in the form of a normal state (gas) is 0.68-0.85 kg / m ³ .
6. Under standard conditions, always be in a gaseous state of aggregation.
7. When mixed with air in volumes of 5-15% it is explosive.
8. The calorific value is about 46 MJ / m ³ .

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

1. It is a highly combustible substance, capable of self-igniting when a spark is supplied and without it at a certain temperature.
2. Since the main component is methane, it has all its chemical properties.
3. It enters into the reactions of substitution, dehydrogenation, pyrolysis, undergoes refraction.
4. Compresses and liquefies at low temperatures and high pressure.
   

Obviously, such physicochemical properties of natural gas determine a wide range of its use in industry.

The 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 formation water molecules in a ratio of 1/220. Therefore, such deposits are extremely rich rocks. Places of their concentration in nature:

• deep pallets of the oceans;
• accumulations of permafrost.

The conditions of existence are hydrodynamic pressure and low temperatures.

Natural gas deposits

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

1. This is a sedimentary rock, a mineral that has been formed for many millennia by 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 oil, forming an oil and gas cap over it.
4. It occurs in the form of gas hydrates in the layers of the seabed and points of the far North.

If the distribution of gas deposits is designated territorially, the following countries are leaders:

• Russia.
• Gulf countries.
• USA.
• Canada.
• Iran.
• Kazakhstan.
• Azerbaijan.
• Uzbekistan
• Norway.
• Turkmenistan
• Netherlands.

Worldwide production is approximately 3,643 billion m ³ per year annually. Of these, only Russia accounts for 673.46 billion m ³ .

The temperature of natural gas at which it burns is 650 ⁰ C. That is, this is the indicator at which it is capable of self-ignition. In this case, a greater amount of thermal energy is released than when burning any other type of fuel. 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:

• through the pipeline in a gaseous state;
• in tanks on the sea - in liquid form;
• in railway tank cars - liquefied.

Each of the ways has its advantages and disadvantages. In particular, sea and rail options are safer, since the chemical activity of liquefied gas in refrigerated cylinders is much lower than in the gaseous state. The pipeline also increases the transmission range and its volumes, in addition, this method is economically viable.

Natural gas methane

Methane gas is the main raw material component in the composition of the natural mixture. Its content ranges from 70-98%. By itself, this is the third most abundant gas on the planet, which is part of oil, interstellar space, and the atmosphere of other planets.

From the point of view of chemistry, methane gas is a saturated hydrocarbon belonging to a number of saturated aliphatic compounds. The very first representative of alkanes or paraffins. Its chemical activity is small, it is quite calm. Able to react:

• substitution;
• complete oxidation;
• conversions.

It burns with a colorless non-smoky flame, has no smell.

Types of Natural Gas

There are three main types of the 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 sulfide).
   

Such a concept as the coefficient of dryness of gas allows us to evaluate the quality of the raw materials from which the products will be manufactured in the future. Indeed, natural gas itself is only a base. Different industries need their own product, so it undergoes thorough processing and cleaning in accordance with specific requirements.

Product quality

The quality of natural gas directly depends on the composition. If methane prevails, then such a product will be the best as a fuel source. If it is most of all in the composition of 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 undergoes thorough purification and processing before further shipment to the final destination. The working methods will depend on the purpose for which the product is intended.

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

Natural gas use

Natural gas consumption is carried out by many industries and facilities. For instance:

• CHP.
• Boiler rooms.
• Gas engines.
• Chemical production (manufacturing of plastics and other materials).
• Fuel for cars.
• Heated residential premises.
• Cooking food.

Therefore, world production of this raw material is so great, and import and export are estimated at billions of dollars.

Environmental aspect

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

And since it belongs to greenhouse gases, its accumulations are very dangerous for the planet. Therefore, numerous work is underway, projects are being developed to protect the ecological state of the planet from the impending greenhouse effect.