Today there are many diverse gases. Any of them receives laboratory methods, from chemicals, some form themselves as a result of reactions as by-products. And what gases are born in nature? The main such gases of natural, natural origin includes four:
- natural gas whose formula CH 4;
- nitrogen, N 2;
- hydrogen, H 2;
- carbon dioxide, CO 2.
Of course, there are some other oxygen, hydrogen sulfide, ammonia, carbon monoxide. However, those listed above are practically significant for people and are used by them for different purposes, including fuel.
What is natural gas?
Natural is called such a gas that gives us nature. That is, the content of which in the bowels of the Earth is much higher and more than its quantity, which is obtained in industry as a result of chemical reactions.
Methane natural gas is generally accepted, but it is not quite so. If we consider the composition of such a gas according to fractions, you can see the following component composition:
- methane (up to 96%);
- ethane;
- propane;
- butane;
- hydrogen;
- carbon dioxide;
- nitrogen;
- hydrogen sulfide (small, trace amounts).
Thus, it turns out that natural gas is a mixture of several
Natural gas: Formula
From a chemical point of view, natural gas is a mixture of hydrocarbons of a linear simple structure - methane, ethane, propane and butane. But since the larger volume is still methane, then the general formula of natural gas is accepted to express the formula directly methane. So, it turns out that the chemical formula of natural gas methane is 4.
The remaining components have the following empirical formulas in chemistry:
- ethan - C 2 H 6;
- propane - with 3 H 8;
- bhutan - with 4 H 10;
- carbon dioxide - CO 2;
- nitrogen - N 2;
- hydrogen - H 2;
- hydrogen sulfide - H 2 S.
A mixture of such substances and is a natural gas. The formula of its main compound of methane shows that the carbon content is very small in it. This affects its physical properties, for example, such as the ability to burn with colorless, completely non-activating flame. While other representatives of its limit hydrocarbons or alkanov) for combustion form a black smoking flame.
Finding in nature
In nature, this gas is found deep underground, under thick and dense layers of sedimentary rocks. There are two main theories of origin of natural gas in nature.
- Theory of tectonic movements of rocks. Supporters of this theory believe that hydrocarbons are contained in the earth's depths always and rose as a result of tectonic movements and upward cuts. Upstairs high pressure and changing temperature turn them as a result of chemical reactions into two natural minerals - oil and gas.
- Biogenic theory speaks of another method, as a result of which natural gas was formed. The formula reflects its qualitative composition - carbon and hydrogen, which indicates that living organic beings took part in his education, the bodies of which were mostly built of these elements, like all living on our planet, existing so far. Over time, the dead remains of animals and plants descended all lower on the bottom of the ocean, where there was no oxygen, nor bacteria that could decompose and recycle this organic mass. As a result of the anaerobic oxidation, a biomass decreased, and for millions of years two sources of minerals - oil and gas were formed. In this case, the basis of both the same is the same - and partially low molecular weight substances. The chemical formula of gas and oil proves. However, various products are also formed using different conditions: high pressure and temperature - gas, low indicators - oil.
To date, countries such as Russia, USA, Canada, Iran, Norway and the Netherlands have the main deposits and gas reserves.
In terms of its aggregate state, natural gas cannot always be contained only in a state of gas. There are several options for its condensation:
- Gas is dissolved in oil molecules.
- Gas is dissolved in water molecules.
- Gas forms solid gas hydrates.
- Under normal conditions, a gaseous connection.
Each of these states has its own field and is very valuable for humans.
Getting in the laboratory and industry
In addition to natural gas formations, there are a number of ways to get it in laboratory conditions. However, these methods are definitely used only for small portions of the product, as it is not profitable to economically carry out the synthesis of natural gas in the laboratory.
Laboratory methods:
- Hydrolysis of low molecular weight compound - aluminum carbide: Al 4 C 3 + 12H 2 O \u003d 3CH 4 + 4AL (OH) 3.
- From sodium acetate in the presence of alkali: CH 3 COOH + NaOH \u003d CH 4 + Na 2 CO 3.
- From synthesis gas: CO + 3H 2 \u003d CH 4 + H 2 O.
- Of these substances - hydrogen and carbon - at elevated temperature and pressure.
The chemical formula of natural gas is reflected in the formula of methane, so everything for this gas.
In industry, methane is produced from natural deposits and further processing on factions. Also, the obtained gas must necessarily clean. After all, the formula of natural gas methane shows only some of those components that it contains. And for use in everyday life, clean gas is needed that does not contain other substances other than methane. Detachable ethane, propane, butane and other gases are also widely used.
Physical properties
Gas formula gives an idea of \u200b\u200bwhat physical properties he should possess. Consider what it is for the characteristics.
- Colorless substance that does not smell.
- Approximate density varies in the range of 0.7-1 kg / m 3.
- Burnage temperature 650 0 S.
- Almost two times lighter than air.
- The heat released during the combustion of a single cubic gas meter is 46 million Joule.
- In elevated concentrations (more than 15%) in the air, the gas is very explosive.
- When used as fuel, an octane number is 130.
Pure gas is obtained only after passing it through special sewage seats (installations), which are erected at the fossil production site.
Application
There are several basic areas of natural gas. After all, in addition to the main component, the gas formula of CH 4, all other components of the mixture are used.
1. Household sphere of people. This includes gas for cooking, heating residential buildings, fuel for boiler rooms and so on. Gas, which is used for cooking, add special substances belonging to the Mercptian group. This is done in order to in the event of a pipe or other omission of gas, people could feel his smell and take action. A mixture of household gas (and this mixture of propane and butane) is extremely explosive in large concentrations. Mercaptans are made by specific and unpleasant natural gas on the smell. The formula includes such elements like sulfur and phosphorus, which gives them such specifics.
2. Chemical production. In this area, one of the main primary substances for many reactions of obtaining important compounds is natural gas, the formula of which shows which synthesis it can take part:
- the basis for the production of plastics, which are the most common modern material for almost all fields of industry;
- raw materials during the synthesis of ethin, cyanide hydrogen and ammonia. The listed products themselves will continue to produce many synthetic fibers and tissues, fertilizers and insulation in construction;
- rubber, methanol, organic acids - are formed from methane and other substances. Find an application in almost all spheres of human life;
- polyethylene and many other synthetic nature compounds obtained thanks to methane.
3. Use as fuel. Moreover, for any type of human activity, ranging from refueling the appropriate type of table lamps and to the operation of thermal power plants. This type of fuel is considered environmentally correct and appropriate on the background of all alternative ways. However, during combustion, methane forms carbon dioxide as any other organic matter. And he, as you know, the cause of the greenhouse effect of the Earth. Therefore, there is a task of searching for an even cleaner and high-quality source of thermal energy.
While these are all major sources that natural gas use. The formula for it, if you take all the complex components, shows that it is almost a renewable resource, only time for this need a lot. Our country with gas reserves is extremely lucky, because this amount of natural fossil is enough for many hundreds of years not only by Russia itself, but also many countries in the world through export.
Nitrogen
It is an integral part of petroleum and gas natural deposits. In addition, this gas occupies most of the volume in the air (78%), and also occurs in the form of natural compounds Selitr in the lithosphere.
As a simple substance is practically not used by alive organisms of nitrogen. It has the form N 2, or, from the point of view of chemical ties, N≡n. The presence of such a strong bond speaks of high stability and chemical inertness of the molecule under normal conditions. This is exactly what explains the possibility of the existence of a large amount of this gas in free form in the atmosphere.
In the form of a simple substance, nitrogen is capable of fixed by special organisms - nodule bacteria. They are then processed into a more suitable plant shape this gas and thus make mineral nutrition of root vegetable systems.
There are several main compounds, in the form of which exists in the nature of nitrogen. The formulas are as follows:
- oxides - NO 2, N 2 O, N 2 O 5;
- acids - nitrogen HNO 2 and nitrogen HNO 3 (formed during thunder discharges from oxides in an air atmosphere);
- selitras - Kno 3, Nano 3 and so on.
A nitrogen man is used not only in but in liquid state. It has the ability to move into a liquid state at temperatures below -170 0 C, which allows it to be used to freeze plant and animal fabrics, many materials. That is why the widespread use of liquid nitrogen is found in medicine.
Nitrogen is also the basis for obtaining one of its main compounds - ammonia. The production of this substance is multinitory, as it is very widely used in everyday life and industry (obtaining rubber, dyes, plastics, synthetic fibers, organic acids, paintwork, explosives, and so on).
Carbon dioxide
What is the substance formula? Carbon dioxide is written as CO 2. Communication in a covalent molecule is weaklyolar, double durable chemical forces between carbon and oxygen. This indicates the stability and inertness of the molecule under normal conditions. This fact is confirmed by the free existence of carbon dioxide in the Earth's atmosphere.
This substance is an integral part of natural gas and oil, and also accumulates in the upper layers of the planet's atmosphere, causing the so-called greenhouse effect.
A huge amount of carbon dioxide is formed during the combustion of any kind of organic fuel. Whether it is coal, firewood, gas or other fuel, complete combustion leads to the formation of water and this substance.
From here it turns out that its accumulation in the atmosphere is inevitable. Therefore, the important task of modern society is to search for an alternative, which gives the minimum of the greenhouse fuel effect.
Hydrogen
Another associated compound, founding in natural minerals, is hydrogen. Gas, whose formula - H 2. The easiest substance from all known today.
Due to its special properties, there are two positions in the periodic system - among alkali metals and halogen. Having one electron is capable of how to give (metal properties, restorative), and take (non-metallic properties, oxidative).
The main area of \u200b\u200buse is environmentally friendly fuel, followed by scientists. The reasons:
- unlimited number of stocks of this gas;
- education as a result of burning only water.
However, the total technology for the development of hydrogen as a source of energy requires the revision of many other nuances.
Formulas for calculating mass, density and volume of gases
In physics and chemistry, several basic ways are used for calculations on gases. For example, if we are talking about one of the most basic parameters, such as the mass of gas, the formula for calculation will be as follows:
m \u003d V * þ, where þ is the density of the substance, and V is its volume.
For example, if we need to calculate the mass of natural gas with a volume of 1 meter cubic under normal conditions, then we take the standard average of its density in reference materials. It will be equal to 0.68 kg / m 3. Now that we know the volume and density of the gas, the formula for calculation quite satisfies the requirements. Then:
m (CH 4) \u003d 0.68 kg / m 3 * 1 m 3 \u003d 0.68 kg, since cubic meters are reduced.
The formula for the volume of gas, on the contrary, is made up of weight indicators and density. That is, we can express this value from the above configuration:
V \u003d M / þ, then under standard conditions, the volume of 2 kg of methane will be equal to: 2 / 0.68 \u003d 2.914 m 3.
Also in more complex cases (when the conditions are non-standard) to calculate the mass and volume of gases use the Mendeleev-Klapairone equation, which has the form:
p * V \u003d M / M * R * T, where p is the gas pressure, V is its volume, m and m - mass and molar mass, respectively, R is a universal gas constant, equal to 8.314, T - temperature in Kelvin.
Such a gas volume formula allows to obtain calculations are very close to the value of the ideal gas that exists is purely hypothetically and is used for abstract concept when solving problems in physics and chemistry. Also calculate the volume by the Boyle-Mariotta equation, which has the form:
V \u003d P H * V H * T / P * T n, where values \u200b\u200bwith the index n is values \u200b\u200bunder normal standard conditions.
In order for the calculation to be the most accurate and corresponded to reality, it is necessary to take into account such a parameter as a formula for calculating this parameter is still controversial. It is customary to use the most common simple, which has the form:
þ \u003d m 0 * n, where m 0 is the mass of the molecule (kg), and n is a concentration, a unit of measurement - 1 / m 3.
However, in some cases it is necessary to use other, more complex and complete calculations with several variables to obtain accurate and close to the ideal result.
Humanity knows about the existence of natural gas for a long time. According to the worst estimates, natural gas was used in China for heating and lighting already to the IV century BC. To obtain it, the boreholes are drilled, and the pipelines were made from bamboo. In addition, a long time, a bright flame, not leaving ash, was the subject of a mystical and religious cult for some nations. For example, on the Absheron Peninsula (modern territory of Azerbaijan) in the VII century was erected by the Temple of Fireplates of Ateshgi, the ministry in which they took up to the XIX century.
The word "gas" was invented at the beginning of the XVII century by the Flemish naturalist, Jan Helmont's Baptist, to designate the "dead air" (carbon dioxide). Helmont wrote: "I called such a couple, because it is almost no different from the chaos of the ancients." But in this case, we are dealing with one of the forms of the existence of a substance.
Regarding the origin of natural gas among scientists, there is still no uniform opinion. Two main concepts - biogenic and mineral - approve the various reasons for the formation of hydrocarbon minerals in the depths of the Earth.
- Mineral theory. The formation of minerals in the formations of rocks - part of the process of degassing the Earth. Due to the internal dynamics of the Earth, the hydrocarbons located at high depths rise to the low pressure zone, forming gas deposits as a result.
- Biogenic theory. Living organisms, dead and lowering on the bottom of the reservoirs, decomposed in airless space. Ring everything deeper due to geological movements, the remains of the decomposed organic organics turned under the influence of thermobaric factors (temperature and pressure) into hydrocarbon minerals, including in natural gas.
Regarding recently, a group of scientists from the Institute for Oil and Gas RAS Problems of the Russian Academy of Sciences, under the direction of Dr. Geological and Mineralogical Sciences, Azaria Barenbaum has developed a new concept of origin of oil and gas. According to this theory, major deposits of hydrocarbons may arise not for millions of years, as previously thought, but only over decades.
Natural gas can exist in the form of gas deposits that are in the formations of some rocks, as a gas cap (over oil), as well as in a dissolved or crystalline form. Also, natural gas may be in the form of gas hydrates (hydrates of natural gases are gas hydrates or clathrates - crystalline compounds formed under certain thermobaric conditions from water and gas).
Natural gas has a number of advantages compared to other types of fuel and raw materials.:
- the cost of extraction of natural gas is significantly lower than other types of fuel; labor productivity during its production is higher than during oil and coal mining;
- the absence of carbon oxide in natural gases prevents the possibility of poisoning people when gas leaks;
- with gas heating of cities and settlements, the air pool is much less polluted;
- when working on natural gas, the possibility of automating combustion processes is ensured, high efficiency is achieved;
- high temperatures in the process of burning (more than 2000 ° C) and the specific heat of the combustion make it possible to effectively apply natural gas as an energy and technological fuel.
Gas - younger fuel than oil. The era of natural gas, in fact, began with the discovery of the Groningen field in 1959 in the Netherlands and followed by the discoveries of the Gas reserves of the United Kingdom in the southern pool of the North Sea in the mid-60s.
According to the IEA, from the first 70s. Gas share in the world energy balance increased from 16 to 21% in 2008. According to BP Statistical Review of World Energy, this share in 2008-2010. In global energy consumption, it turned out to be even higher - about 24%. In the forecast study of BP on the development of world energy until 2030, it is said that natural gas will be the fastest growing type of fuel in the next 25 years. At the same time, experts of the International Energy Agency believe that the share of gas in the world energy balance will increase from 21% to 25%, gas will be the second after oil energy carrier, shifting coal to third place.
Chemical composition
The chemical composition of natural gas is quite simple. The bulk of this type of gas is methane (CH4) - the simplest hydrocarbon (organic compound consisting of carbon and hydrogen atoms), its share exceeds 92%.
Depending on the content of methane, two main groups of natural gas are distinguished:
- Natural gas group H (H gas, i.e. high-calorie gas) due to the high content of methane (from 87% to 99%) is the highest quality. Russian natural gas refers to a group H and differs by high calorific value. Due to the high content of methane (~ 98%), it is the highest quality natural gas of the world.
- Natural gas group L (L-Gas, i.e. low-calorie gas) is natural gas with a less high methane content - from 80% to 87%. If quality requirements are not fulfilled (11.1 kW / cubic meters), then often gas cannot be delivered directly to the final consumer without additional processing.
In addition to methane, heavier hydrocarbons, methane homologs may include: ethane (C2H6), propane (C3H8), butane (C4H10) and some inconspicuous impurities. At the same time, it is important that the composition of natural gas is not constant and varies from the deposit to the field.
Physical properties
Approximate physical characteristics (depend on the composition):
- Density: from 0.7 to 1.0 kg / m3 (dry gaseous, under normal conditions) or 400 kg / m3 (liquid).
- Separation temperature: T \u003d 650 ° C.
- The heat of combustion of one m3 of natural gas in a gaseous state at N.P.: 28-46 MJ, or 6.7-11.0 μal.
- Octane number when used in internal combustion engines: 120-130.
- Easier air is 1.8 times, so when leakage is not going to lowers, but rises up.
Application
Possessing such advantages over other energy carriers, such as economics and environmental friendliness, natural gas is becoming increasingly important in industry and households.
Natural gas as a fossil energy is mainly used for the heating of residential and industrial premises, for cooking, generating electricity, as well as in the industrial production sector to generate thermal energy.
In a small amount, natural gas is used as a motor fuel. In connection with the increase in gasoline prices in recent years and months have increased the number of private transport repaid on gas engines. In addition, the re-equipment of trucks and buses to work on natural gas is carried out. Along with the cost factor, an important argument in favor of natural gas is the lower level of harmful substances into the atmosphere.
20 leading countries of the world on proven gas reserves (according to 2010)
| Country | Stocks (trillion cubic meters) | Share from global (%) | |
| 1 | RF | 44,76 | 23,9 |
| 2 | Iran | 29,61 | 15,8 |
| 3 | Qatar | 25,32 | 13,5 |
| 4 | Turkmenistan | 8,03 | 4,3 |
| 5 | Saudi Arabia | 8,01 | 4,3 |
| 6 | USA | 7,71 | 4,1 |
| 7 | UAE | 6,43 | 3,4 |
| 8 | Venezuela | 5,45 | 2,9 |
| 9 | Nigeria | 5,29 | 2,8 |
| 10 | Algeria | 4,50 | 2,4 |
| 11 | Iraq | 3,16 | 1,7 |
| 12 | Indonesia | 3,06 | 1,6 |
| 13 | Australia | 2,92 | 1,6 |
| 14 | China | 2,80 | 1,5 |
| 15 | Malazia | 2,39 | 1,3 |
| 16 | Egypt | 2,21 | 1,2 |
| 17 | Norway | 2,04 | 1,1 |
| 18 | Kazakhstan | 1,84 | 1 |
| 19 | Kuwait | 1,78 | 1 |
| 20 | Canada | 1,72 | 0,9 |
A source
20 leading countries of the world on gas consumption (according to 2010)
| Country | Consumption (billion cubic meters) | Share from global (%) | |
| 1 | USA | 683,4 | 21,7 |
| 2 | RF | 414,1 | 13 |
| 3 | Iran | 136,9 | 4,3 |
| 4 | China | 109,0 | 3,4 |
| 5 | Japan | 94,5 | 3 |
| 6 | Great Britain | 93,8 | 3 |
| 7 | Canada | 93,8 | 3 |
| 8 | Saudi Arabia | 83,9 | 2,6 |
| 9 | Germany | 81,3 | 2,6 |
| 10 | Italy | 76,1 | 2,4 |
| 11 | Mexico | 68,9 | 2,2 |
| 12 | India | 61,9 | 1,9 |
| 13 | UAE | 60,5 | 1,9 |
| 14 | Ukraine | 52,1 | 1,6 |
| 15 | France | 46,9 | 1,5 |
| 16 | Uzbekistan | 45,5 | 1,4 |
| 17 | Egypt | 45,1 | 1,4 |
| 18 | Thailand | 45,1 | 1,4 |
| 19 | Netherlands | 43,6 | 1,4 |
| 20 | Argentina | 43,3 | 1,4 |
A source: BP Statistical Review of World Energy 2011
20 leading countries in the world's production (according to 2010)
| Country | Prey (billion cubic meters) | Share from global (%) | |
| 1 | USA | 611 | 19,3 |
| 2 | Russia | 588,9 | 18,4 |
| 3 | Canada | 159,8 | 5 |
| 4 | Iran | 138,5 | 4,3 |
| 5 | Qatar | 116,7 | 3,6 |
| 6 | Norway | 106,4 | 3,3 |
| 7 | China | 96,8 | 3 |
| 8 | Saudi Arabia | 83,9 | 2,6 |
| 9 | Indonesia | 82 | 2,6 |
| 10 | Algeria | 80,4 | 2,5 |
| 11 | Netherlands | 70,5 | 2,2 |
| 12 | Malaysia | 66,5 | 2,1 |
| 13 | Egypt | 61,3 | 1,9 |
| 14 | Uzbekistan | 59,1 | 1,8 |
| 15 | Great Britain | 57,1 | 1,8 |
| 16 | Mexico | 55,3 | 1,7 |
| 17 | UAE | 51 | 1,6 |
| 18 | India | 50,9 | 1,6 |
| 19 | Australia | 50,4 | 1,6 |
| 20 | Trinidad and Tobago | 42,4 | 1,3 |
A source: BP Statistical Review of World Energy 2011
There is a mixture of methane CH 4 with a small amount of nitrogen N 2 and carbon dioxide with 2 - that is, it is qualitatively identical in composition with a gas that is distinguished from the swamps.
Encyclopedic YouTube.
1 / 4
✪ Natural gas is interesting
✪ Natural gas. How it works?
✪ Natural gas and oil (riddle of origin and the problem of exhaustion)
✪ No. 53. Organic Chemistry. Theme 14. Sources of hydrocarbons. Part 1. Natural gas
Subtitles
Chemical composition
The bulk of natural gas is methane (CH 4) - from 70 to 98%. The composition of natural gas may include more heavy hydrocarbons - methane homologs:
- ethane (C 2 H 6),
- propane (C 3 H 8),
- bhutan (C 4 H 10).
Natural gas also contains other substances that are not hydrocarbons:
- helium (not) and other inert gases.
Pure natural gas has no color and smell. To facilitate the possibility of determining the gas leakage in it in a small amount, odorates are added - substances having a sharp unpleasant smell (rotten cabbage, heavy hay, rotten eggs). Most often, thiology (mercaptane) is used as a odorant, for example, ethyl mercaptan (16 g per 1000 m³ of natural gas).
Physical properties
Approximate physical characteristics (depend on the composition; under normal conditions, unless otherwise indicated):
Natural Gaza field
In the sedimentary shell of the earth's crust focuses huge deposits of natural gas. According to the theory of biogenic (organic) origin of oil, they are formed as a result of the decomposition of the remains of living organisms. It is believed that natural gas is formed in a sedimentary shell at high temperatures and pressures than oil. This is consistent with this fact that gas fields are often located deeper than oil fields.
Russia (Urengoyaskoye deposit), Iran, Most of the Persian Gulf, USA, Canada possess huge stocks of natural gas. From European countries worth noting Norway, the Netherlands. Among the former republics of the Soviet Union, Turkmenistan, Azerbaijan, Uzbekistan, as well as Kazakhstan (Karachaganak deposit) own large gas reserves.
Methane and some other hydrocarbons are widespread in space. Methane - the third largest gas in the universe, after hydrogen and helium. In the form of methane ice, it participates in the structure of many planets and asteroids removed from the Sun, however, such clusters, as a rule, do not belong to the deposits of natural gas, and they have not yet found practical applications. A significant amount of hydrocarbons is present in the land mantle, but they also do not represent interest.
Gas hydrates
In science, for a long time it was believed that the accumulations of hydrocarbons with a molecular weight of more than 60 are in the earth's crust in a liquid state, and more lungs in gaseous. However, in the second half of the 20th century, a group of employees A. A. Trofimuk, N. V. Chersky, F. A. Trebr, Yu. F. McOn, V. G. Vasilyev discovered the property of natural gas in certain thermodynamic conditions to move in the earth's crust in solid condition and form gas hydrate deposits. Later it turned out that the reserves of natural gas in this state are huge.
Gas goes into a solid state in the earth's crust, connecting with plastic water at hydrostatic pressures up to 250 atm and relatively low temperatures (up to +22 ° C). Gas hydrate deposits have an incomparably higher gas concentration in a unit of the volume of the porous medium than in conventional gas fields, since one volume of water during its transition to the hydrate state connects to 220 volumes of gas. Zones of gas hydrate deposits are focused mainly in the areas of distribution of many-neutral rocks, as well as at a small depth under the oceanic bottom.
Natural gas reserves
Mining and transportation
Natural gas is located in the ground at a depth of 1000 m to several kilometers. A superhong of the wells not far from the city of Novy Urengoy obtained a gas inflow from a depth of more than 6000 meters. In the depths of gas is in microscopic voids (pores). The pores are interconnected by microscopic channels - cracks, gas comes from high pressure to the pores with a lower pressure until it turns out to be in the well. The gas movement in the reservoir is subject to certain laws.
Gas mined from the depths of the earth with wells. Wells try to place evenly throughout the field of the field, for a uniform drop in the reservoir pressure in the deposits. Otherwise, gas flows are possible between areas of the deposit, as well as premature deployment of the deposit.
Gas comes out of the subsoil due to the fact that the formation is under pressure, many times exceeding atmospheric. Thus, the driving force is the pressure difference in the formation and the collection system.
The global natural gas production in 2014 was 3460.6 billion m 3. The leading position in the production of Gaza is occupied by Russia and the United States.
| Country | 2010 | 2006 | ||
| Mining billion m³. |
Share of world market (%) |
Mining billion m³. |
Share of world market (%) |
|
| Russia | 647 | 673,46 | 18 | |
| USA | 619 | 667 | 18 | |
| Canada | 158 | |||
| Iran | 152 | 170 | 5 | |
| Norway | 110 | 143 | 4 | |
| China | 98 | |||
| Netherlands | 89 | 77,67 | 2,1 | |
| Indonesia | 82 | 88,1 | 2,4 | |
| Saudi Arabia | 77 | 85,7 | 2,3 | |
| Algeria | 68 | 171,3 | 5 | |
| Uzbekistan | 65 | |||
| Turkmenistan | 66,2 | 1,8 | ||
| Egypt | 63 | |||
| Great Britain | 60 | |||
| Malaysia | 59 | 69,9 | 1,9 | |
| India | 53 | |||
| UAE | 52 | |||
| Mexico | 50 | |||
| Azerbaijan | 41 | 1,1 | ||
| Other countries | 1440,17 | 38,4 | ||
| World Gas mining | 100 | 3646 | 100 | |
Natural gas preparation for transportation
Gas coming from wells must be prepared for transportation to the end user - the chemical plant, boiler room, CHP, urban gas networks. The need to prepare gas is caused by the presence in it, besides the target components (targeted for various consumers are different components), also impurities that cause difficulties in transporting or use. Thus, the water pairs contained in the gas under certain conditions can form hydrates or condensing, accumulate in various places (for example, a pipeline bending), having a gas promotion; The hydrogen sulfide causes severe corrosion of gas equipment (pipes, heat exchanger capacitances, etc.). In addition to the preparation of the gas itself, the pipeline must be prepared. Widespread use here are nitrogen settings that are used to create an inert medium in the pipeline.
Gas is prepared according to various schemes. According to one of them, in the immediate vicinity of the field, the installation of comprehensive gas preparation (UKHPG) is built, on which the gas is cleaned and drying in absorption columns. Such a scheme is implemented in the Urengoy field. Also advocated the preparation of gas by membrane technology.
To prepare gas to transport, technological solutions are applied using a membrane gas separation, with the help of which heavy hydrocarbons can be isolated (C 3 H 8 and above), nitrogen, carbon dioxide, hydrogen sulfide, and significantly reduce the temperature of the dew point on water and hydrocarbons before feeding in GTS.
If the gas contains in a large number of helium or hydrogen sulfide, then the gas is treated at a gas processing plant, where it is isolated from the amine cleaning and settings of the Claus, and helium on cryogenic helium installations (KSU). This scheme is implemented, for example, on the Orenburg field. If there is less than 1.5% of the hydrogen sulfide gas, it is also advisable to consider the membrane natural gas preparation technology, since its use reduces capital and operating costs in 1.5-5
Transportation of natural gas
Currently, the main type of transport is pipeline. The gas under pressure of 75 atm is pumped through pipes with a diameter of up to 1.42 m. As the gas moves along the pipeline, it, overcoming friction forces both between the gas and the pipe wall, and between the gas layers, loses the potential energy that is dissipated as heat. Therefore, at certain intervals, it is necessary to build compressor stations (COP), on which the gas usually lives to pressure from 55 to 120 atm and then cooled. The construction and maintenance of the pipeline is quite expensive, but nevertheless it is the most cheapest from the point of view of initial investments and the organization method of transporting gas into small and medium distances.
In addition to pipeline transport, special tankers are widely used - gas carriers. These are special vessels on which the gas is transported in a liquefied state in specialized isothermal containers at temperatures from -160 to -150 ° C.
For liquefaction, the gas is cooled at elevated pressure. At the same time, the compression ratio reaches 600 times depending on the needs. Thus, to transport gas in this way, it is necessary to stretch the gas pipeline from the deposit to the nearest sea coast, to build a terminal on the shore, which is significantly cheaper than the usual port, for liquefying gas and download it to tankers, and tankers themselves. The usual capacity of modern tankers is from 150,000 to 250,000 m³. This method of transportation is significantly more economical than pipeline, starting with distances to the consumer of liquefied gas over 2000-3000 km, as the main cost is not transportation, but loading and unloading, but requires higher initial investments in the infrastructure than the pipeline. Its advantages also include the fact that liquefied gas is much safer during transportation and storage than compressed.
In 2004, international gas supplies on pipelines amounted to 502 billion m³, liquefied gas - 178 billion m³.
There are also other gas transportation technologies, such as railway tanks.
Terms of gas transportation projects are also developed using
Natural gas is called a mixture of such gases that were formed in earthly depths during the decomposition of various organic substances. Of course, the composition of natural gas is worth determining with a correction for specific samples. However, all natural gases have undoubtedly many common substances and chemical elements in the structure, as well as any natural gas has about the same physical composition and properties as others. We will talk about it about this.
General
Natural gas is one of the most important minerals that are actively used in industry and in everyday life. In conditions of occurrence (or, as Gasoviki say, in reservoir conditions) natural gas is exclusively in a gaseous state or in the form of the so-called "gas cap" in general fields of oil and gas, or in the form of gas deposits (that is, individual clusters), either dissolved in water or in oil. True, under certain conditions, natural gas can be located not only in gaseous, but also in solid state as crystals.
Chemical Composition of Natural Gas
As for the basic substances that are part of natural gas, they are methane (CH 4), carbon dioxide (CO 2) and nitrogen in the form of molecules (N 2). Of these substances and elements, almost any natural gas consists, be it mining or swamp. As for the composition of natural gas in percentage, the main substance that is part of natural gas is certainly methane. Its share ranges from 90 to 98% - depending on the gas field. Also, the composition of natural gas includes substances such as butane, propane, ethane (hydrocarbons, also called methane homologues, since they consist of the same chemical elements, differing only in the number of carbon and hydrogen atoms and, accordingly, according to the structure of molecules). From the inconsistency components of natural gas, it is noted, in addition to the nitrogen and carbon dioxide (carbon dioxide), hydrogen (H 2), helium (HE) and hydrogen sulfide (H 2 S).
Natural Gas Physical Properties
First of all, we note that natural gas, which is in its pure form, is blunt and has no smell. In order to determine the gas leakage, so-called odorants or substances that have sharp and sufficiently unpleasant smell are added in small quantities: for example, Tiol, among which the leading place occupies ethyl mercaptan. For 1000 cubic meters of natural gas, not more than 15-16 g of ethyl mercaptan are added. The density of natural gas in a gaseous state is an average of 0.75 kg per cubic meter. In the crystalline state, the density reaches 400 kg per m 3. Self-turn natural gas only at a very high temperature - about 650 degrees on the Celsius scale. At a certain concentration of natural gas in the air (approximately 5-15%) explosions may occur. Also known and the specific heat of the combustion of natural gas, which averages 35 MJ / m? or 9 μal / m?. When used in various internal combustion engines, the octane number of natural gas is from 120 to 130. Finally, natural gas is approximately 1.8 times easier than air, so when leucing it rises up, and not going to lowers.
Application of natural gas
First of all, natural gas in the modern world is used as fuel and fuel. So, in many apartment and private homes, people use natural gas for cooking, heating water, heating. As for the other use of natural gas in the form of fuel, it is recently actively used not only as fuel for various CHP and boiler rooms, but also as fuel for fuel systems of some cars. In addition, modern engineers and designers have established even the release of natural gas transport - for example, buses. In the chemical industry, natural gas is used as a raw material for the manufacture of various substances - for example, various plastics and plastics. And at the dawn of its prey in many European and North American cities, natural gas was used as street lighting and it was used even in the very first traffic lights.
Natural gas to which we are all so accustomed in your kitchen is a close relative of oil. It consists mostly from methane with impurities of heavier hydrocarbons (ethane, propane, butane). In natural conditions, it also often contains impurities of other gases (helium, nitrogen, hydrogen sulfide, carbon dioxide).
Typical composition of natural gas:
Hydrocarbons:
- Methane - 70-98%
- Ethan - 1-10%
- Propane - up to 5%
- Bhutan - up to 2%
- Pentan - up to 1%
- Hexane - up to 0.5%
Impurities:
- Nitrogen - up to 15%
- Helium - up to 5%
- Carbon dioxide - up to 1%
- Hydrogen sulfide - less than 0.1%
Natural gas is extremely widespread in the depths of the Earth. It can be found in the thickness of the earth's crust at a depth of several centimeters to 8 kilometers. As well as oil, natural gas, in the process of migration in the earth's crust, falls into traps (permeable layers limited impermeable thicknesses), as a result of which gas deposits are formed.
The five largest gas fields of Russia:
- Urengoy (gas)
- Yamburg (oil and gas condensate)
- Bovanenkovsky (oil and gas condensate)
- Shtokman (gas condensate)
- Leningrad (gas)
Natural (hydrocarbon) gas is a frequent satellite of oil fields. It is usually contained in oil dissolved, and in some cases accumulates in the upper part of the deposits, forming the so-called gas cap. For a long time, the gas that is released during oil production and called by associated gas was the undesirable component of the production process. Most often it was simply burned in torches.
Over the past few decades, mankind has learned enough to fully use all the advantages of natural gas. Such a delay in the development of this extremely valuable type of fuel is largely due to the fact that gas transportation and its use in industry and everyday life require a sufficiently high technical and technological level of development. In addition, natural gas, mixing with air, forms an explosive mixture, which requires increased security measures when used.
Gas use
Some attempts to use gas were taken back in the XIX century. Light gas, as it was then called, served as a light source. The development of gas fields at the time was not yet long, and for lighting used gas produced along with oil. Therefore, such gas was often called oil. Such petroleum gas, for example, has long been covered by Kazan. Used it for the lighting of St. Petersburg and Moscow.
Currently, gas plays an increasingly significant role in the energy industry. The spectrum of its application is very wide. It is used in industry, in everyday life, in boiler houses, CHP, as motor fuel for cars and as starting raw materials in the chemical industry.
Gas is considered a relatively pure fuel type. When burning gas, only carbon dioxide and water is formed. At the same time, carbon dioxide emissions are almost two times less than when burning coal and 1.3 times less than when oil burning. Not to mention the fact that when burning oil and coal, soot and ash remain. Due to the fact that from all fossil fuels of fuel gas is the most environmentally friendly view, in the energy sector of modern megacities it takes a dominant position.
How gas is mined
As well as oil, natural gas is mined with wells, which are distributed evenly throughout the gas field area. Mining takes place due to the pressure difference in the gas-mounted layer and on the surface. Under the action of reservoir pressure, the gas is pushed through well to the surface where it will fall into the collection system. Next, the gas is submitted to the installation of integrated gas preparation, where it is purified by impurities. If the impurities in the gas extracted minor quantity, then it can immediately be directed to the gas processing plant, bypassing the installation of comprehensive preparation.
How gas is transported
Gas transport is carried out mainly by pipelines. The main volumes of gas are transported by trunk gas pipelines, where gas pressure can reach 118 atm. Consumers of gas falls through distribution and domestic gas pipelines. First, the gas passes through the gas distribution station, where its pressure is reduced to 12 atm. Then, according to the distribution gas pipelines, it is fed to gas regulatory items, where its pressure is reduced again, this time is already up to 0.3 atm. After that, in the domestic gas pipelines, gas enters the kitchen.
All this huge gas distribution infrastructure is a truly large-scale picture. Hundreds and hundreds of thousands of kilometers of gas pipelines, enclosed by almost the entire territory of Russia. If all this web pipeline is pulled out in one line, then its length is enough to get from the ground to the moon and back. And this is only the gas transmission system of Russia. If we talk about the entire global gas transmission infrastructure, then it will be more about millions of kilometers of pipelines.
Since natural gas does not possess either a smell, neither color, so that it is possible to quickly detect gas leaks, it is artificially attached to the unpleasant odor. This process is called odorization and occurs on gas distribution stations. As odors, that is, unpleasant substances are commonly used sulfur-containing compounds, such as ethantiol (ETSH).
Gas consumption is seasonal. In winter, its consumption increases, and in the summer it decreases. To smooth out seasonal fluctuations in gas consumption, near large industrial centers, underground gas storage facilities (PCG) are created. It may be exhausted gas fields adapted to storing gas or artificially created underground salt caves. In the summer, the surplus of the transported gas is sent to the PCG, and in the winter, on the contrary, the possible lack of capacity of the pipeline system is compensated for gas selection from storages.
In international practice, in addition to gas pipelines, natural gas is often transported in liquefied by means of special vessels - gas carriers (methane carriers). In liquefied form, the volume of natural gas decreases 600 times, which is convenient not only for transportation, but also for storage. For liquefaction, the gas is cooled to condensation temperature (-161.5 ° C) as a result of which it turns into a liquid. In such a cooled form, it is transported. The main manufacturers of liquefied natural gas are Qatar, Indonesia, Malaysia, Australia and Nigeria.
Prospects and trends
Due to its environmental cleanliness and continuous improvement of technology and technologies, both in mining and in the use of gas, this type of fuel is becoming increasingly popular. BP, for example, predicts a leading increase in gas demand compared with other types of fossil fuels.
The growth in the need for gas leads to the search for new, often non-traditional, gas sources. Such sources can be:
- Gas from coal layers
- Shale gas
- Gas hydrates
♦ Gas from coal layers Began to extract only in the late 1980s. For the first time, it was made in the United States, where the commercial feasibility of such a type of production was proven. In Russia, Gazprom began to test this method since 2003, starting trial production of methane from coal layers in Kuzbass. Gas production from coal reservoirs is carried out in other countries - Australia, Canada and China.
♦ Shale gas. The shale revolution in the production of gas, which happened in the United States in the last decade, does not come down from the first strips of periodic press. The development of horizontal drilling technology and allowed mining gas from low-permeable shale in volumes paying for its extraction costs. The phenomenon of the rapid development of shale gas production in the United States spurs out other countries to the development of this direction. In addition to the United States, active work on the extraction of shale gas is carried out in Canada. Also, China has a significant potential for the development of large-scale mining of shale gas.
♦ Gas hydrates. A significant part of natural gas is in the crystalline state in the form of so-called gas hydrates (methane hydrates). Large reserves of gas hydrates exist in the oceans and in the zones of permafrost of continents. Currently, the estimated gas reserves in the form of gas hydrates are superior to the reserves of oil, coal and ordinary gas. The development of economically appropriate technologies for mining gas hydrates is stiguously engaged in Japan, USA and some other countries. A particularly this topic pays attention to Japan, devoid of traditional gas reserves and forced purchasing this type of resource in extremely high prices.
Natural gas as fuel and source of chemical elements has a great future. In the remote future, it is it that it is considered as the main type of fuel, which will be used during the transition of the world energy to cleaner renewable resources.