Where is carbon dioxide found? Obtaining CO2. Artificial sources of carbon dioxide

Carbon dioxide (carbon dioxide, carbon dioxide) occupies the most important place among technical gases; it is widely used in almost all sectors of industry and the agro-industrial complex. CO 2 accounts for 10% of the total technical gas market, which puts this product on par with the main air separation products.

The uses of carbon dioxide in various states of aggregation are diverse - food industry, welding gases and mixtures, fire fighting, etc. Its solid phase, dry ice, is increasingly being used, from freezing, dry briquettes to surface cleaning (blasting).

Receipt

Carbon dioxide cannot be obtained from the outside due to the fact that there is almost no carbon dioxide in the atmosphere. Animals and humans receive it through the complete breakdown of food, since proteins, fats, and carbohydrates, built on a carbon basis, form carbon dioxide (CO 2) when burned with the help of oxygen in the tissues.

In industry, carbon dioxide is obtained from furnace gases, from decomposition products of natural carbonates (limestone, dolomite). The gas produced during alcoholic fermentation is used for food purposes. Carbon dioxide is also produced in air separation plants as a by-product of the production of pure oxygen, nitrogen and argon. In laboratory conditions, small amounts of CO 2 are obtained by reacting carbonates and bicarbonates with acids, for example, marble, chalk or soda with hydrochloric acid. Side sources of CO 2 production are combustion products; fermentation; production of liquid ammonia; reforming units; ethanol production; natural sources.

When producing carbon dioxide on an industrial scale, three main groups of raw materials are used.

Group 1- sources of raw materials from which pure CO 2 can be produced without special equipment to increase its concentration:

gases from chemical and petrochemical industries containing 98-99% CO 2;
gases of alcoholic fermentation in breweries, alcohol and hydrolysis plants with 98-99% CO 2;
gases from natural sources with 92-99% CO 2.

Group 2- sources of raw materials, the use of which ensures the production of pure CO 2:

gases from less common chemical industries containing 80-95% CO 2.

Group 3- sources of raw materials, the use of which makes it possible to produce pure CO 2 only with the help of special equipment:

gas mixtures consisting mainly of nitrogen and carbon dioxide (combustion products of carbon-containing substances containing 8-20% CO 2;
exhaust gases from lime and cement factories with 30-40% CO 2;
top gases of blast furnaces with 21-23% CO 2;
consisting mainly of methane and carbon dioxide and containing significant admixtures of other gases (biogas and landfill gas from bioreactors with 30-45% CO 2;
associated gases during the production of natural gas and oil containing 20-40% CO 2.

Application

According to some estimates, CO2 consumption on the world market exceeds 20 million metric tons per year. Such a high level of consumption is formed under the influence of the requirements of the food industry and oilfield enterprises, carbonation technologies for drinks and other industrial needs, for example, a decrease in the pH value of water treatment plants, problems of metallurgy (including the use of welding gas), etc.

The consumption of carbon dioxide is steadily growing as the scope of its application expands, which covers tasks from industrial purposes to food production - food preservation, in mechanical engineering from welding production and the preparation of protective welding mixtures to cleaning the surfaces of parts with dry ice granules, in agriculture for fertilizing plants, in the gas and oil industry for fire fighting.

Main applications of CO 2:

in mechanical engineering and construction (for welding, etc.);
for cold landing of machine parts;
in fine sharpening processes;
for electric welding, based on the principle of protecting molten metal from the harmful effects of atmospheric air;
in metallurgy;
blowing carbon dioxide gas through molds;
in the production of aluminum and other easily oxidized metals;
in agriculture to create artificial rain;
in ecology it replaces strong mineral acids to neutralize alkaline waste water;
in the manufacture of fire-fighting means;
used in carbon dioxide fire extinguishers as a fire extinguishing agent, effectively stopping the combustion process;
in perfumery in the manufacture of perfumes;
in the mining industry;
using the method of flameless rock explosion;
in the food industry;
used as a preservative and indicated on the packaging with code E290;
as a dough leavening agent;
for the production of carbonated drinks;

Carbonation of drinks can occur in one of two ways:

In the production of popular sweet and mineral waters, a mechanical carbonation method is used, which involves saturating a liquid with carbon dioxide. This requires special equipment (siphons, acratophores, saturators) and cylinders with compressed carbon dioxide.
With the chemical carbonation method, carbon dioxide is produced during the fermentation process. This way you get champagne wine, beer, bread kvass. Carbon dioxide in soda water is obtained as a result of the reaction of soda with acid, accompanied by the rapid release of carbon dioxide.

CO 2 as welding gas

Since 1960, welding of alloy and carbon steels in a carbon dioxide (CO 2) environment that meets the requirements of GOST 8050 has become widespread. Recently, the use of welding gas mixtures of argon and helium has become increasingly widespread in the welding technologies of machine-building enterprises, with many of the most popular gas mixtures include a small amount of active gases (CO 2 or O 2) necessary to stabilize the welding arc. However, when welding carbon and low-alloy steels of the main structural classes at Russian enterprises, the main shielding gas continues to be carbon dioxide CO 2, which is explained by the physical properties of this shielding gas and its availability.

It is equal to +4), called carbon dioxide (other names: carbon dioxide, carbonic anhydride, carbon dioxide). This substance is usually written with the molecular formula CO2. Its molar mass is 44.01 g/mol. In appearance, under normal conditions, carbonic anhydride is a colorless gas. At low concentrations it is odorless; at higher concentrations it acquires a pungent, sour odor.

For this chemical substance there are three possible states of aggregation, which are characterized by different density values:

solid (dry ice); at a pressure of 1 atm. and temperature -78.5 °C - 1562 kg/m³;
liquid (carbon dioxide); at a pressure of 56 atm. and temperature +20 °C - 770 kg/m³;
gaseous; at a pressure of 1 atm. and temperature 0 °C - 1.977 kg/m³.

The melting point of carbon dioxide is -78 °C, the boiling point is -57 °C. The substance dissolves in water: at 25 °C and a pressure of 100 kPa, its solubility is 1.45 g/l.

Carbon dioxide is a natural chemical compound in the molecule of which oxygen atoms are linked to a carbon atom by a covalent bond. The carbon dioxide molecule is linear and centrosymmetric. Both bonds between carbon and two oxygen atoms are equivalent (essentially double). The molecule is symmetrical about its center, so it has no electric dipole moment.

Carbon dioxide was one of the first gaseous chemical compounds that were no longer identified with air. In the seventeenth century, the Flemish chemist Jan Baptista van Helmont noticed that when he burned coal in a closed vessel, the mass of the resulting ash was much less than that of ordinary carbon dioxide. The properties of carbon dioxide were studied more carefully in 1750 by the Scottish physician Joseph Black.

Carbon dioxide at standard pressure and temperature is found in the Earth's atmosphere in an amount of approximately 0.04% by volume. As part of the carbon cycle, known as photosynthesis, carbon dioxide is absorbed by plants, algae, and cyanobacteria. As a result, water and carbohydrates are formed, but this process occurs only under the influence of light. Carbon dioxide is also produced by the combustion of coal or hydrocarbons, by the fermentation of liquids, and by the exhalation of air by humans and animals. In addition, it is emitted from volcanoes, hot springs, and geysers.

Carbon dioxide plays an important role (absorbs and emits radiation in the thermal infrared range). This chemical compound is also one of the main sources of decrease in ocean pH: when dissolved in water, it forms weak carbonic acid: CO2 + H2O ↔ H2CO3, which is unable to completely dissociate into ions.

Carbon dioxide does not support combustion or respiration. The lit splinter in its atmosphere goes out. Animals and humans suffocate at high concentrations of CO2. At 3% concentration in the air, breathing quickens, at 10%, loss of consciousness and rapid death occurs, and at 20%, it causes instant paralysis.

Carbon dioxide is a carbonic anhydride and therefore has the properties of an acidic oxide. In laboratory conditions, it is obtained by reacting chalk with hydrochloric acid in CaCO3 + 2HCl → CaCl2 + CO2 + H2O. In industry, it is produced by the thermal decomposition of limestone or chalk (less commonly magnesite or dolomite): CaCO3 → CaO + CO2. The production of carbon dioxide is a by-product of the low-temperature separation of air into nitrogen and oxygen. Nowadays, special generators are produced to produce carbon dioxide from the air. Such generators are used to supply CO2 to greenhouses in order to create a favorable environment for plants.

Carbon dioxide is widely used in chemical industries. It is used to produce soda, to synthesize organic acids, and to make soft drinks. used as a refrigerant, for example, in winemaking. A carbon dioxide atmosphere is created to prevent rotting of food products, including grapes after they are harvested and before wine production begins.

The production of carbon dioxide or liquefied carbon dioxide is carried out to fill it which is used to extinguish fires. However, they cannot extinguish a person, since a significant part of the stream of liquid CO2 evaporates, while the temperature drops sharply (which can cause frostbite) and the CO2 turns into dry ice. Carbon dioxide is usually used to extinguish electrical wiring. The mechanism is to stop the flow of air oxygen to the source of fire.

Structural formula

True, empirical, or gross formula: CO2

Chemical composition of carbon dioxide

Molecular weight: 44.009

Carbon dioxide (carbon dioxide, carbon dioxide, carbon (IV) oxide, carbonic anhydride) is a colorless gas (under normal conditions), odorless, with a chemical formula CO2. Density under normal conditions is 1.98 kg/m³ (heavier than air). At atmospheric pressure, carbon dioxide does not exist in a liquid state, changing directly from a solid to a gaseous state. Solid carbon dioxide is called dry ice. At elevated pressure and normal temperatures, carbon dioxide turns into liquid, which is used for its storage. The concentration of carbon dioxide in the Earth's atmosphere averages 0.04%. Carbon dioxide easily transmits ultraviolet rays and rays of the visible part of the spectrum, which come to the Earth from the Sun and heat it. At the same time, it absorbs infrared rays emitted by the Earth and is one of the greenhouse gases, as a result of which it takes part in the process of global warming. A constant increase in the level of this gas in the atmosphere has been observed since the beginning of the industrial era.

Carbon monoxide (IV) - carbon dioxide, an odorless and colorless gas, heavier than air, upon strong cooling it crystallizes in the form of a white snow-like mass - “dry ice”. At atmospheric pressure it does not melt, but evaporates; the sublimation temperature is −78 °C. Carbon dioxide is formed when organic matter rots and burns. Contained in the air and mineral springs, released during the respiration of animals and plants. Soluble in water (1 volume of carbon dioxide in one volume of water at 15 ° C).

According to its chemical properties, carbon dioxide is classified as an acidic oxide. When dissolved in water, it forms carbonic acid. Reacts with alkalis to form carbonates and bicarbonates. It undergoes electrophilic substitution reactions (for example, with phenol) and nucleophilic addition (for example, with organomagnesium compounds). Carbon monoxide (IV) does not support combustion. Only some active metals burn in it. Interacts with oxides of active metals. When dissolved in water, it forms carbonic acid. Reacts with alkalis to form carbonates and bicarbonates.

The human body produces approximately 1 kg (2.3 lb) of carbon dioxide per day. This carbon dioxide is transported from the tissues, where it is formed as one of the end products of metabolism, through the venous system and is then excreted in the exhaled air through the lungs. Thus, the content of carbon dioxide in the blood is high in the venous system, and decreases in the capillary network of the lungs, and is low in the arterial blood. The carbon dioxide content of a blood sample is often expressed in terms of partial pressure, that is, the pressure that a given amount of carbon dioxide contained in a blood sample would have if it alone occupied the entire volume of the blood sample. Carbon dioxide ( CO2) is transported in the blood in three different ways (the exact proportion of each of these three transport methods depends on whether the blood is arterial or venous).

Most of the carbon dioxide (70% to 80%) is converted by the enzyme carbonic anhydrase in red blood cells into bicarbonate ions.
About 5% - 10% of carbon dioxide is dissolved in blood plasma.
About 5% - 10% of carbon dioxide is bound to hemoglobin in the form of carbamine compounds (carbohemoglobin).

Hemoglobin, the main oxygen-transporting protein of red blood cells, is capable of transporting both oxygen and carbon dioxide. However, carbon dioxide binds to hemoglobin at a different site than oxygen. It binds to the N-terminal ends of globin chains rather than to heme. However, due to allosteric effects, which lead to a change in the configuration of the hemoglobin molecule upon binding, the binding of carbon dioxide reduces the ability of oxygen to bind to it, at a given partial pressure of oxygen, and vice versa - the binding of oxygen to hemoglobin reduces the ability of carbon dioxide to bind to it, at a given partial pressure of carbon dioxide. In addition, the ability of hemoglobin to preferentially bind with oxygen or carbon dioxide also depends on the pH of the environment. These features are very important for the successful uptake and transport of oxygen from the lungs into the tissues and its successful release into the tissues, as well as for the successful uptake and transport of carbon dioxide from the tissues into the lungs and its release there. Carbon dioxide is one of the most important mediators of autoregulation of blood flow. It is a powerful vasodilator. Accordingly, if the level of carbon dioxide in tissue or blood increases (for example, due to intense metabolism - caused by, say, exercise, inflammation, tissue damage, or due to obstruction of blood flow, tissue ischemia), then the capillaries dilate, which leads to increased blood flow and accordingly, to increase the delivery of oxygen to the tissues and the transport of accumulated carbon dioxide from the tissues. In addition, carbon dioxide in certain concentrations (increased, but not yet reaching toxic values) has a positive inotropic and chronotropic effect on the myocardium and increases its sensitivity to adrenaline, which leads to an increase in the strength and frequency of heart contractions, cardiac output and, as a consequence, , stroke and minute blood volume. This also helps to correct tissue hypoxia and hypercapnia (increased carbon dioxide levels). Bicarbonate ions are very important for regulating blood pH and maintaining normal acid-base balance. Respiration rate affects the carbon dioxide content in the blood. Weak or slow breathing causes respiratory acidosis, while rapid and excessively deep breathing leads to hyperventilation and the development of respiratory alkalosis. In addition, carbon dioxide is also important in regulating respiration. Although our body requires oxygen for metabolism, low oxygen levels in the blood or tissues usually do not stimulate breathing (or rather, the stimulating effect of low oxygen on breathing is too weak and “turns on” late, at very low levels of oxygen in the blood, at which a person often is already losing consciousness). Normally, breathing is stimulated by an increase in the level of carbon dioxide in the blood. The respiratory center is much more sensitive to increased levels of carbon dioxide than to a lack of oxygen. As a consequence, breathing very thin air (with a low partial pressure of oxygen) or a gas mixture containing no oxygen at all (for example, 100% nitrogen or 100% nitrous oxide) can quickly lead to loss of consciousness without causing a feeling of lack of air (because the level of carbon dioxide does not increase in the blood, because nothing prevents its exhalation). This is especially dangerous for pilots of military aircraft flying at high altitudes (if an enemy missile hits the cockpit and the cockpit depressurizes, the pilots can quickly lose consciousness). This feature of the breathing regulation system is also the reason why flight attendants on airplanes instruct passengers in the event of depressurization of the aircraft cabin, first of all, to put on an oxygen mask themselves, before trying to help anyone else - by doing this, the helper risks quickly losing consciousness himself, and even without feeling any discomfort or need for oxygen until the last moment. The human respiratory center tries to maintain the partial pressure of carbon dioxide in arterial blood no higher than 40 mmHg. With conscious hyperventilation, the content of carbon dioxide in arterial blood can decrease to 10-20 mmHg, while the oxygen content in the blood will remain virtually unchanged or increase slightly, and the need to take another breath will decrease as a result of a decrease in the stimulating effect of carbon dioxide on the activity of the respiratory center. This is the reason why, after a period of conscious hyperventilation, it is easier to hold your breath for a long time than without previous hyperventilation. This deliberate hyperventilation followed by breath holding can lead to loss of consciousness before the person feels the need to take a breath. In a safe environment, such a loss of consciousness does not threaten anything special (having lost consciousness, a person will lose control over himself, stop holding his breath and take a breath, breathing, and with it the oxygen supply to the brain will be restored, and then consciousness will be restored). However, in other situations, such as before diving, this can be dangerous (loss of consciousness and the need to take a breath will occur at depth, and without conscious control, water will enter the airways, which can lead to drowning). This is why hyperventilation before diving is dangerous and not recommended.

In industrial quantities, carbon dioxide is released from flue gases, or as a by-product of chemical processes, for example, during the decomposition of natural carbonates (limestone, dolomite) or during the production of alcohol (alcoholic fermentation). The mixture of the resulting gases is washed with a solution of potassium carbonate, which absorbs carbon dioxide, turning into bicarbonate. A solution of bicarbonate decomposes when heated or under reduced pressure, releasing carbon dioxide. In modern installations for the production of carbon dioxide, instead of bicarbonate, an aqueous solution of monoethanolamine is more often used, which, under certain conditions, can absorb CO2 contained in the flue gas, and release it when heated; This separates the finished product from other substances. Carbon dioxide is also produced in air separation plants as a by-product of the production of pure oxygen, nitrogen and argon. In the laboratory, small quantities are obtained by reacting carbonates and bicarbonates with acids, such as marble, chalk or soda with hydrochloric acid, using, for example, a Kipp apparatus. Using sulfuric acid to react with chalk or marble results in the formation of slightly soluble calcium sulfate, which interferes with the reaction, and which is removed by a significant excess of acid. To prepare drinks, the reaction of baking soda with citric acid or sour lemon juice can be used. It was in this form that the first carbonated drinks appeared. Pharmacists were engaged in their production and sale.

In the food industry, carbon dioxide is used as a preservative and leavening agent and is indicated on the packaging with code E290. Liquid carbon dioxide is widely used in fire extinguishing systems and fire extinguishers. Automatic carbon dioxide fire extinguishing systems differ in their starting systems, which can be pneumatic, mechanical or electrical. The device for supplying carbon dioxide to the aquarium may include a gas reservoir. The simplest and most common method of producing carbon dioxide is based on the design for making the alcoholic drink mash. During fermentation, the carbon dioxide released may well provide nutrition for aquarium plants. Carbon dioxide is used to carbonate lemonade and sparkling water. Carbon dioxide is also used as a protective medium in wire welding, but at high temperatures it dissociates and releases oxygen. The released oxygen oxidizes the metal. In this regard, it is necessary to introduce deoxidizing agents such as manganese and silicon into the welding wire. Another consequence of the influence of oxygen, also associated with oxidation, is a sharp decrease in surface tension, which leads, among other things, to more intense metal spattering than when welding in an inert environment. Carbon dioxide in cans is used in air guns (in gas-cylinder pneumatics) and as an energy source for engines in aircraft modeling. Storing carbon dioxide in a steel cylinder in a liquefied state is more profitable than in the form of gas. Carbon dioxide has a relatively low critical temperature of +31°C. About 30 kg of liquefied carbon dioxide is poured into a standard 40-liter cylinder, and at room temperature there will be a liquid phase in the cylinder, and the pressure will be approximately 6 MPa (60 kgf/cm²). If the temperature is above +31°C, then carbon dioxide will go into a supercritical state with a pressure above 7.36 MPa. The standard operating pressure for a regular 40-liter cylinder is 15 MPa (150 kgf/cm²), but it must safely withstand pressure 1.5 times higher, that is, 22.5 MPa, so working with such cylinders can be considered quite safe. Solid carbon dioxide - “dry ice” - is used as a refrigerant in laboratory research, in retail trade, during equipment repair (for example: cooling one of the mating parts during a press-fit), etc. Carbon dioxide is used to liquefy carbon dioxide and produce dry ice. installations.

Measuring the partial pressure of carbon dioxide is required in technological processes, in medical applications - analysis of respiratory mixtures during artificial ventilation and in closed life support systems. Concentration Analysis CO2 in the atmosphere is used for environmental and scientific research, to study the greenhouse effect. Carbon dioxide is recorded using gas analyzers based on the principle of infrared spectroscopy and other gas measuring systems. A medical gas analyzer for recording the carbon dioxide content in exhaled air is called a capnograph. For measuring low concentrations CO2(as well as CO) in process gases or in atmospheric air, you can use the gas chromatographic method with a methanator and registration with a flame ionization detector.

Annual fluctuations in the concentration of atmospheric carbon dioxide on the planet are determined mainly by the vegetation of the middle latitudes (40-70°) of the Northern Hemisphere. Vegetation in the tropics is practically independent of the season, the dry desert belt of 20-30° (in both hemispheres) makes a small contribution to the carbon dioxide cycle, and the strips of land most covered with vegetation are located asymmetrically on Earth (in the Southern Hemisphere there is an ocean in the middle latitudes). Therefore, from March to September, due to photosynthesis, the content CO2 in the atmosphere it decreases, and from October to February it increases. Contributions to winter growth come from both the oxidation of wood (heterotrophic respiration of plants, rotting, decomposition of humus, forest fires) and the combustion of fossil fuels (coal, oil, gas), which increases noticeably in the winter season. A large amount of carbon dioxide is dissolved in the ocean. Carbon dioxide makes up a significant part of the atmospheres of some planets in the solar system: Venus, Mars.

Carbon dioxide is non-toxic, but due to the effect of its increased concentrations in the air on air-breathing living organisms, it is classified as asphyxiating gases (English) Russian. Slight increases in concentration up to 2-4% indoors lead to the development of drowsiness and weakness in people. Dangerous concentrations are considered to be levels around 7-10%, at which suffocation develops, manifesting itself in headache, dizziness, hearing loss and loss of consciousness (symptoms similar to those of altitude sickness), depending on the concentration, over a period of several minutes up to one hour. When air with high concentrations of gas is inhaled, death occurs very quickly from suffocation. Although, in fact, even a concentration of 5-7% CO2 is not lethal, already at a concentration of 0.1% (this level of carbon dioxide is observed in the air of megacities) people begin to feel weak and drowsy. This shows that even at high oxygen levels, high CO2 concentrations have a significant impact on well-being. Inhalation of air with an increased concentration of this gas does not lead to long-term health problems, and after removing the victim from the polluted atmosphere, complete restoration of health quickly occurs.

Colorless and odorless. The most important regulator of blood circulation and respiration. Non-toxic. Without it, there would be no rich buns and pleasantly tart carbonated drinks. From this article you will learn what carbon dioxide is and how it affects the human body...

Most of us do not remember well the school course in physics and chemistry, but we know: gases are invisible and, as a rule, intangible, and therefore insidious. Therefore, before answering the question of whether carbon dioxide is harmful to the body, let's remember what it is.

Earth Blanket

CO2 is carbon dioxide. It is also carbon dioxide, carbon monoxide (IV) or carbonic anhydride. Under normal conditions, it is a colorless, odorless gas with a sour taste.

Under atmospheric pressure, carbon dioxide has two states of aggregation: gaseous (carbon dioxide is heavier than air and poorly soluble in water) and solid (at –78 °C it turns into dry ice).

Carbon dioxide is one of the main components of the environment. It is found in the air and underground mineral waters, is released during the respiration of humans and animals, and is involved in plant photosynthesis.

Carbon dioxide actively influences the climate. It regulates the heat exchange of the planet: it transmits ultraviolet radiation and blocks infrared radiation. In this regard, carbon dioxide is sometimes called the Earth's blanket.

O2 - energy. CO2 - spark

Carbon dioxide accompanies a person throughout his life. Being a natural regulator of respiration and blood circulation, carbon dioxide is an integral component of metabolism.

Inhaling about 30 liters of oxygen per hour, a person emits 20–25 liters of carbon dioxide.

By inhaling, a person fills the lungs with oxygen. At the same time, a two-way exchange occurs in the alveoli (special “bubbles” of the lungs): oxygen passes into the blood, and carbon dioxide is released from it. The man exhales. CO2 is one of the end products of metabolism. Figuratively speaking, oxygen is energy, and carbon dioxide is the spark that ignites it.

Carbon dioxide is no less important for the body than oxygen. It is a physiological stimulant of respiration: it affects the cerebral cortex and stimulates the respiratory center. The signal for the next breath is not a lack of oxygen, but an excess of carbon dioxide. After all, metabolism in cells and tissues is continuous, and its end products must be constantly removed.

In addition, carbon dioxide affects the secretion of hormones, enzyme activity and the speed of biochemical processes.

Gas exchange equilibrium

Carbon dioxide is non-toxic, non-explosive and absolutely harmless to people. However, the balance of carbon dioxide and oxygen is extremely important for normal life. Lack and excess of carbon dioxide in the body leads to hypocapnia and hypercapnia, respectively.

Hypocapnia - lack of CO2 in the blood. It occurs as a result of deep, rapid breathing, when more oxygen enters the body than needed. For example, during too intense physical activity. The consequences can vary: from mild dizziness to loss of consciousness.

Hypercapnia - excess CO2 in the blood. A person inhales (together with oxygen, nitrogen, water vapor and inert gases) 0.04% carbon dioxide, and exhales 4.4%. If you are in a small room with poor ventilation, the concentration of carbon dioxide may exceed the norm. As a result, headache, nausea, and drowsiness may occur. But most often hypercapnia accompanies extreme situations: a malfunction of the breathing apparatus, holding one’s breath under water, and others.

Thus, contrary to the opinion of most people, carbon dioxide in the quantities provided by nature is necessary for human life and health. In addition, it has found wide industrial application and brings many practical benefits to people.

Sparkling bubbles at the service of chefs

CO2 is used in many fields. But, perhaps, carbon dioxide is most in demand in the food industry and cooking.

Carbon dioxide is formed in yeast dough under the influence of fermentation. It is its bubbles that loosen the dough, making it airy and increasing its volume.

With the help of carbon dioxide, various refreshing drinks are made: kvass, mineral water and other sodas loved by children and adults. These drinks are popular with millions of consumers around the world, largely due to the sparkling bubbles that burst so funny in the glass and “prick” the nose so pleasantly.

Can the carbon dioxide contained in carbonated drinks contribute to hypercapnia or cause any other harm to a healthy body? Of course not!

Firstly, the carbon dioxide used in the preparation of carbonated drinks is specially prepared for use in the food industry. In the quantities in which it is contained in soda, it is absolutely harmless to the body of healthy people.

Secondly, most of the carbon dioxide evaporates immediately after opening the bottle. The remaining bubbles “evaporate” during the drinking process, leaving behind only a characteristic hiss. As a result, a negligible amount of carbon dioxide enters the body.

“Then why do doctors sometimes prohibit drinking carbonated drinks?” - you ask. According to the candidate of medical sciences, gastroenterologist Alena Aleksandrovna Tyazheva, this is due to the fact that there are a number of diseases of the gastrointestinal tract for which a special strict diet is prescribed. The list of contraindications includes not only drinks containing gas, but also many food products. A healthy person can easily include a moderate amount of carbonated drinks in his diet and allow himself a glass of cola from time to time.

Conclusion

Carbon dioxide is necessary to support the life of both the planet and an individual organism. CO2 affects the climate, acting as a kind of blanket. Without it, metabolism is impossible: metabolic products leave the body with carbon dioxide. It is also an indispensable component of everyone’s favorite carbonated drinks. It is carbon dioxide that creates playful bubbles that tickle your nose. At the same time, it is absolutely safe for a healthy person.

Carbon dioxide (carbon dioxide, carbon dioxide, CO 2) is formed by the interaction of two elements - oxygen and carbon. Carbon dioxide is produced by the combustion of hydrocarbon compounds or coal, as a result of fermentation of liquids, and also as a product of animal and human respiration. It is found in the atmosphere in small quantities. Plants absorb carbon dioxide from the atmosphere and convert it into organic compounds. When this gas disappears from the atmosphere, there will be virtually no rain on Earth and it will become noticeably cooler.

Properties of carbon dioxide

Carbon dioxide is heavier than air. It freezes at -78 °C. When carbon dioxide freezes, it forms snow. In solution, carbon dioxide forms carbonic acid. Due to certain properties, carbon dioxide is sometimes called the “blanket” of the Earth. It easily passes ultraviolet rays. Infrared rays are emitted from the surface of carbon dioxide into outer space.

Carbon dioxide is released in liquid form at low temperature, liquid form at high pressure, and gaseous form. The gaseous form of carbon dioxide is obtained from waste gases during the production of alcohols, ammonia, and also as a result of fuel combustion. Carbon dioxide gas is a non-toxic and non-explosive gas, odorless and colorless. In liquid form, carbon dioxide is a colorless and odorless liquid. When the content is more than 5%, carbon dioxide accumulates in the floor area in poorly ventilated areas. A decrease in the volume fraction of oxygen in the air can lead to oxygen deficiency and suffocation. Embryologists have found that human and animal cells need about 7% carbon dioxide, and only 2% oxygen. Carbon dioxide is a nervous system tranquilizer and an excellent anesthetic. The gas in the human body is involved in the synthesis of amino acids and has a vasodilating effect. A lack of carbon dioxide in the blood leads to spasm of blood vessels and smooth muscles of all organs, to an increase in secretion in the nasal passages, bronchi and to the development of polyps and adenoids, and to thickening of membranes due to cholesterol deposition.

Production of carbon dioxide

There are several ways to produce carbon dioxide. In industry, carbon dioxide is obtained from dolomite, limestone - products of the decomposition of natural carbonates, as well as from furnace gases. The gas mixture is washed with a solution of potassium carbonate. The mixture absorbs carbon dioxide and turns into bicarbonate. The bicarbonate solution is heated and it decomposes, releasing carbon dioxide. In the industrial production method, carbon dioxide is pumped into cylinders.

In laboratories, the production of carbon dioxide is based on the interaction of bicarbonates and carbonates with acids.

Applications of carbon dioxide

In everyday practice, carbon dioxide is used quite often. In the food industry, carbon dioxide is used as a leavening agent for dough and also as a preservative. It is indicated on the product packaging under the code E290. The properties of carbon dioxide are also used in the production of sparkling water.

Biochemists have found that to increase the yield of various crops, it is very effective to fertilize the air with carbon dioxide. However, this method of fertilization can only be used in greenhouses. In agriculture, gas is used to create artificial rain. When neutralizing an alkaline environment, carbon dioxide replaces potent mineral acids. In vegetable storage facilities, carbon dioxide is used to create a gaseous environment.

In the perfume industry, carbon dioxide is used in the manufacture of perfumes. In medicine, carbon dioxide is used for antiseptic effects during open operations.

When cooled, carbon dioxide turns into “dry ice.” Liquefied carbon dioxide is packaged in cylinders and sent to consumers. Carbon dioxide in the form of “dry ice” is used to preserve food. When heated, such ice evaporates without leaving a residue.

Carbon dioxide is used as an active medium in wire welding. When welding, carbon dioxide decomposes into oxygen and carbon monoxide. Oxygen interacts with the liquid metal and oxidizes it.

In aircraft modeling, carbon dioxide is used as an energy source for engines. Carbon dioxide canisters are used in air guns.