The prospective development of the largest industries is impossible without the most valuable raw materials and high-quality energy carrier - natural gas. Its use not only automates many technological processes, but also significantly improves the living conditions of the population.
What is natural gas?
There is no single chemical formula for natural gas - in each field it has a composition with a different ratio of its constituent components.
Natural gas is a mixture of hydrocarbons, most of which is methane. The remaining components are: butane, propane, ethane, hydrogen, hydrogen sulfide, helium, nitrogen, carbon dioxide.
Natural gas has no color and odor; its presence in air cannot be determined without the help of special devices. The smell familiar to every person is given to the gas by artificial means (odorization). Thanks to this process, it is possible to sense the presence of gas in the air and prevent life-threatening situations.
Origin
Regarding the origin of gas, there is no unified theory, scientists adhere to two versions:
- Once upon a time there was an ocean in the place of the continents. Killing, living organisms accumulated in a space in which there was no air and bacteria that started the decomposition process. Thanks to geological movements, the accumulated masses plunged deeper into the bowels of the Earth, where, under the influence of high pressure and temperature, they entered into chemical reactions with hydrogen, forming hydrocarbons.
- Earth's dynamics contribute to the rise of hydrocarbons located at great depths, where there is a lower level of pressure. As a result, gas or oil fields are formed.
Production
Contrary to popular belief, natural gas can be underground not only in voids, extraction from which does not require significant material and energy costs. Often it is concentrated inside rocks with such a small porous structure that the human eye can not see it. Depth of deposits may be small, but sometimes reaches several kilometers.
The gas production process includes several stages:
- Geological work, as a result of which the location of deposits is accurately determined.
- Production wells drilling. It is carried out throughout the field, which is important for uniform reduction of gas pressure in the reservoir. The maximum depth of the wells is 12 km.
- Production. The process is carried out due to different levels of pressure in the gas-bearing formation and the earth's surface. Through the wells, the gas rushes out - to where the pressure is less, immediately falling into the collection system. In addition, associated gas is produced, which is a by-product of oil production. It is also of value to many industries.
- Preparing for transportation. The produced gas contains numerous impurities. If their quantity is insignificant, gas is transported by tankers or pipeline to the plant for further processing. Natural gas is purified from a significant amount of impurities at the complex treatment facilities, which are being built next to the field.
Why natural gas processing is needed
Natural gas production occurs during the formation of layers of porous rocks containing oil and coal seams. In addition to components important for the needs of industry, it contains impurities that impede the process of transportation and use by end users.
Immediately after production, the gas in the complex treatment plants is drained, during which water and sulfur fumes are extracted. Further processing of natural and associated gas is carried out at chemical and gas processing plants.
The basic principle of the processing plants
The main task of an enterprise engaged in the processing of natural gas is the maximum possible extraction of all components of the fossil and bringing them to marketability. At the same time, the environment and the earth's interior should not be harmed, and financial costs should be minimized.
By fulfilling all aspects of this rule, natural gas processing products are considered high quality and economical.
Recycling methods
The following gas processing methods are available:
- physical and energy;
- chemical catalytic;
- thermochemical.
Physico-energetic methods are used to compress gas and separate it into components using cooling or heating plants. This technology of natural gas processing is most often used directly in the fields.
Initially, the compression and separation process was carried out using compressors. To date, less financially expensive equipment has been successfully used - ejectors and oil pumps.
The chemical-catalytic method of processing natural gas involves the conversion of methane into synthesis gas for its subsequent processing. This can be done in three ways: steam or carbon dioxide conversion, partial oxidation.
The methane partial oxidation method is often used. This is due to the convenience of carrying out the process in an autothermal mode (when the raw material heats up due to incomplete oxidation of hydrocarbons), the reaction rate and the absence of the need to use a catalyst (as in the case of steam and carbon dioxide conversion).
The resulting synthesis gas is not further subjected to a separation process.
Thermochemical methods involve thermal exposure to natural gas, resulting in the formation of unsaturated hydrocarbons (e.g. ethylene, propylene). The process is possible only at very high temperatures (about 11 thousand degrees Celsius) and a pressure of several atmospheres.
Processed products
For many people, the word "gas" is associated with fuel and a gas stove. In fact, the use of its components is more extensive:
- helium is a valuable raw material used in high technology, for example, in the manufacture of medical equipment and magnetic pads for long trips in public transport, in the design of nuclear reactors and space satellites;
- formaldehyde, one of the methane derivatives, is a raw material that plays an important role in the production of phenolic plastics (brake linings, billiard balls) and resins, which are an important component of building construction materials (plywood, fiberboard), paint and varnish and thermal insulation products;
- ammonia - used in the pharmaceutical (aqueous solution), agricultural (fertilizers) and food (flavor enhancer) industries;
- ethane - the raw material from which polyethylene is produced;
- acetic acid - is widely used in the textile industry;
- methanol - fuel for vehicles.
Natural gas production and processing are the processes by which the most important industries are effectively developed. The end consumer receives gas after careful processing, its use significantly improves the living conditions.