Physical properties of hydrogen sulfide acid. Hydrogen sulfide acid

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When heated, sulfur reacts with hydrogen. A poisonous gas with a pungent odor is formed - hydrogen sulfide. Otherwise called hydrogen sulfide, hydrogen sulfide, dihydrosulfide.

Structure

Hydrogen sulfide is a binary compound of sulfur and hydrogen. The formula of hydrogen sulfide is H 2 S. The structure of the molecule is similar to the structure of the water molecule. However, sulfur forms not a hydrogen bond with hydrogen, but a covalent polar bond. This is due to the fact that, unlike the oxygen atom, the sulfur atom is larger in volume, has lower electronegativity and lower charge density.

Rice. 1. The structure of hydrogen sulfide.

Receipt

Hydrogen sulfide is rare in nature. In small concentrations it is part of associated, natural, volcanic gases. Seas and oceans contain hydrogen sulfide at great depths. For example, hydrogen sulfide is found at a depth of 200 meters in the Black Sea. In addition, hydrogen sulfide is released when proteins containing sulfur rot.

In industry it is obtained in several ways:

reaction of acids with sulfides:
FeS + 2HCl → FeCl 2 + H 2 S;
the effect of water on aluminum sulfide:
Al 2 S 3 + 6H 2 O → 2Al(OH) 3 + 3H 2 S;
by fusing sulfur with paraffin:
C 18 H 38 + 18S → 18H 2 S + 18C.

The purest gas is obtained by direct interaction of hydrogen and sulfur. The reaction takes place at 600°C.

Physical properties

Dihydrosulfide is a colorless gas with the smell of rotten eggs and a sweetish taste. This is a toxic substance, dangerous in high concentrations. Due to its molecular structure, hydrogen sulfide does not liquefy under normal conditions.

General physical properties of hydrogen sulfide:

poorly soluble in water;
exhibits superconductor properties at a temperature of -70°C and a pressure of 150 GPa;
flammable;
soluble in ethanol;
liquefies at -60.3°C;
turns into a solid at -85.6°C;
melts at -86°C;
boils at -60°C;
decomposes into simple substances (sulfur and hydrogen) at 400°C.

Under normal conditions, you can prepare a solution of hydrogen sulfide (hydrogen sulfide water). However, hydrogen sulfide does not react with water. In air, the solution quickly oxidizes and becomes cloudy due to the release of sulfur. Hydrogen sulfide water exhibits weak acid properties.

Rice. 2. Hydrogen sulfide water.

Chemical properties

Hydrogen sulfide is a powerful reducing agent. The main chemical properties of the substance are described in the table.

Reaction	Description	The equation
With oxygen	Burns in air with a blue flame producing sulfur dioxide. When there is a lack of oxygen, sulfur and water are formed	2H 2 S + 4O 2 → 2H 2 O + 2SO 2; 2H 2 S + O 2 → 2S + 2H 2 O
With oxidizing agents	Oxidizes to sulfur dioxide or sulfur	3H 2 S + 4HClO 3 → 3H 2 SO 4 + 4HCl; 2H 2 S + SO 2 → 2H 2 O + 3S; 2H 2 S + H 2 SO 3 → 3S + 3H 2 O
With alkalis	With an excess of alkali, medium salts are formed, with a ratio of 1:1 - acidic ones	H 2 S + 2NaOH → Na 2 S + 2H 2 O; H 2 S + NaOH → NaHS + H 2 O
Dissociations	Dissociates stepwise in solution	H 2 S ⇆ H + + HS – ; HS – ⇆H + + S 2-
High quality	Formation of black precipitate - lead sulfide	H 2 S + Pb(NO 3) 2 → PbS↓ + 2HNO 3

Rice. 3. Combustion of hydrogen sulfide.

Hydrogen sulfide is a toxic gas, so its use is limited. Most of the hydrogen sulfide produced is used in industrial chemistry for the production of sulfur, sulfide, and sulfuric acid.

What have we learned?

From the topic of the lesson we learned about the structure, production and properties of hydrogen sulfide or hydrogen sulfide. It is a colorless gas with an unpleasant odor. Is a toxic substance. Forms hydrogen sulfide water without interacting with water. In reactions it exhibits the properties of a reducing agent. Reacts with atmospheric oxygen, strong oxidizing agents (oxides, oxygen acids), and alkalis. Dissociates in solution in two stages. Hydrogen sulfide is used in the chemical industry to produce derivatives.

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If they say that he is weak, it means that illness or hunger has come, in general, adversity. In chemistry everything is different. Let's consider weak hydrogen sulfide. It is weak not because it is ready to fall apart or die, but, on the contrary, because of its unwillingness to dissociate.

This is the name given to the process of dissolution in water, separation into hydronium ion and anion. Hydrogen sulfide dissociates by only 0.011%, and in two stages. In the first of them, the degree of decay does not exceed 0.005%.

So, it is quite resistant, “takes a hit.” However, this is by human standards. In chemistry everything is different. Let's dive into its world by continuing to study the properties of hydrogen sulfide.

Properties of hydrogen sulfide acid

The heroine's resilience is relative. Not wanting to completely dissolve in water, the compound disintegrates under the influence of oxygen. It oxidizes hydrosulfide acid. Formula it looks like this: - Н 2 S. Н in it - , S - . So, the latter “breaks out” of the formula during oxidation. The connection breaks down.

In fact, hydrosulfide acid is an aqueous solution of gas. Hydrogen sulfide is known to smell like rotten eggs and is toxic. the substance does not. Nor do indicator papers that have been in hydrosulfide acid. Property this is another indicator of a weak connection. Strong ones color litmus in tones.

Characteristics of hydrogen sulfide acid comes down not only to slow dissolution in water. Other reactions with the heroine of the article also take place slowly. In relation to human character, this is rather laziness than weakness.

For example, hydrogen sulfide solution reacts reluctantly with metals. The explanation for this is the low concentration of positive hydrogen ions. Their deficiency is associated with a low degree of dissociation.

Of the metals, the heroine of the article interacts only with those that are up to H2 in the voltage series. Such elements are capable of displacing hydrogen from solution. Interaction can lead to the formation hydrosulfide salts.

It is completely insoluble in water. The replica concerns sulfides. This is one of the types formed with the participation of hydrogen sulfide compounds. The second type is hydrosulfides. They are formed during the reaction with alkaline and alkaline earth compounds and are soluble.

When interacting with alkaline earth metals, hydrogen sulfide also reacts with alkalis. The heroine of the article acts as a reducing agent, that is, she donates electrons. It turns out that the properties of the connection are typical for the weak type.

Ambiguously different. Being a solution of poisonous hydrogen sulfide, the heroine of the article is only relatively dangerous. Due to the low concentration of the original substance, it becomes a medicine. We will tell you where and how it is used in the next chapter.

Application of hydrogen sulfide acid

Dissociation of hydrosulfide acid to a solution with a saturation of thousandths of a percent allows the compound to be used for medicinal purposes. They are usually organized in areas where groundwater containing hydrogen sulfide emerges. The smell of rotten eggs is tolerated for the sake of getting rid of skin ailments, rehabilitation of the system, and treatment of insomnia.

Hydrogen sulfide baths improve blood flow, which means they have a beneficial effect on the entire body. Moving faster through the vessels, the blood does not stagnate and more quickly supplies the organs with the elements they need. Metabolism accelerates, leading to cleansing of toxins. For the overall effect of rejuvenation.

“On the face” is used in its literal meaning. Cosmetologists use hydrogen sulfide solution for lifting procedures. In addition to tightening, you can get rid of cellulite and acne. Local application of the solution has fewer contraindications than baths.

Doctors note that baths with hydrogen sulfide are not taken at home or, in general, in enclosed spaces. The concentration of vapors emanating from water may exceed permissible limits.

In sanatoriums, they try to place pools in the open air. Hot springs. Therefore, it is pleasant to swim in them even in winter. There are a number of hydrogen sulfide resorts, for example, near the city of Severobaikalsk.

Doctors supervising the guests also recommend the heroine of the article as a cure for ailments of the genitourinary system. True, the procedures are contraindicated for pregnant and lactating women. But for those who want to become a parent, baths with hydrogen sulfide will not harm.

In the west of the country, hydrogen sulfide is formed along the Black Sea shelf. True, there the compound forms at a depth of about 150 meters, emerging as bubbles into the shallow water.

If temporary procedures in a gas atmosphere are acceptable, then prolonged inhalation of hydrogen sulfide leads to a loss of the ability to smell. This is the result of paralysis of the olfactory nerve.

How to recognize hydrogen sulfide acid in the air at low concentrations, in the absence of obvious odor? Only it will help. She is also poisonous, but there is no other way. It is moistened in the reagent. In an atmosphere containing at least 0.0000001% hydrogen sulfide, the leaf will become coated.

Preparation of hydrogen sulfide acid

Since it is a solution of hydrogen sulfide, it is worth asking about its production. A popular way to use sulfide. Natural minerals are used as the latter. There are several sulfides in the interior of the planet. The most famous is perhaps. Its formula: - FeS 2.

The reaction between sulfide and is violent, with active gas evolution. Accordingly, interaction is carried out in isolated rooms, using protective clothing.

Industrialists often go the other way. Hydrogen sulfide is a by-product of many industries. All that remains is to extract the substance from industrial gases, the purification of which, anyway, is the direct responsibility of enterprises.

Then, hydrogen sulfide is dissolved in water. The liquid is heated. This makes dissociation more successful. The heroine of the article is ready for use or sale. Let's find out the price tags.

Hydrosulfide acid price

Since in everyday life the heroine of the article is needed only for water procedures, the form of sale of the compound is reduced to hydrogen sulfide baths. Example: - Matsesta product. It is sold in pharmacies, like other drugs in the group.

“Matsesta” is sold in bags and added to a bath of water at a temperature of 37-38 degrees Celsius. The drug is thoroughly stirred and immersed for 5-15 minutes. The pleasure costs about 300 per package, that is, one procedure.

The remark about the dangers of taking hydrogen sulfide baths at home has not been canceled. But manufacturers play it safe by selecting the optimal, safe concentration. With it, do not apply it within 15 minutes.

For laboratory needs and industrial production, it makes no sense to pay for water with a minimal proportion of hydrogen sulfide. It is more convenient to organize the supply of liquefied gas in cylinders and do it yourself. The product is specific, demand is limited. Therefore, there are few offers, and gas cylinders are usually negotiable.

DEFINITION

Hydrogen sulfide acid(hydrogen sulfide, monosulfane) under normal conditions is a colorless gas.

Thermally unstable. Poorly soluble in cold water. A saturated solution (0.1 M) is called “hydrogen sulfide water,” which becomes cloudy when exposed to air. Shows weak acidic properties. The OVR is a strong reducing agent.

Chemical formula of hydrosulfide acid

The chemical formula of hydrosulfide acid is H 2 S. It shows that this molecule contains two hydrogen atoms (Ar = 1 amu) and one sulfur atom (Ar = 32 amu). Using the chemical formula, you can calculate the molecular weight of hydrogen sulfide acid:

Mr(H 2 S) = 2×Ar(H) + Ar(S);

Mr(H 2 S) = 2×1 + 32 = 2 +32 = 34.

Graphic (structural) formula of hydrogen sulfide acid

The structural (graphic) formula of hydrogen sulfide acid is more clear. It shows how atoms are connected to each other inside a molecule (Fig. 1).

Rice. 1. The structure of the hydrogen sulfide molecule, indicating the bond angle between bonds and the length of chemical bonds.

Ionic formula

Hydrogen sulfide acid is an electrolyte, i.e. in an aqueous solution it is capable of dissociating into ions according to the following equation:

H 2 S ↔ 2H + + S 2- .

Examples of problem solving

EXAMPLE 1

Exercise

Determine the molecular formula of a compound containing 49.4% potassium, 20.2% sulfur, 30.4% oxygen, if the relative molecular mass of this compound is 3.95 times the relative atomic mass of calcium.

Solution

Let us denote the number of moles of elements included in the compound as “x” (potassium), “y” (sulfur) and “z” (oxygen). Then, the molar ratio will look like this (the values of relative atomic masses taken from D.I. Mendeleev’s Periodic Table are rounded to whole numbers):

x:y:z = ω(K)/Ar(K) : ω(S)/Ar(S) : ω(O)/Ar(O);

x:y:z= 49.4/39: 20.2/32: 30.4/16;

x:y:z= 1.3: 0.63:1.9 = 2: 1: 3.

This means that the simplest formula for a compound of potassium, sulfur and oxygen will be K 2 SO 3 and a molar mass of 158 g/mol.

Let's find the true molar mass of this compound:

M substance = Ar(Ca) × 3.95 = 40 × 3.95 = 158 g/mol.

To find the true formula of an organic compound, we find the ratio of the resulting molar masses:

M substance / M(K 2 SO 3) = 158 / 158 = 1.

This means that the formula for the compound of potassium, sulfur and oxygen is K 2 SO 3 .

Answer

K2SO3

EXAMPLE 2

Exercise

The substance contains 32.5% sodium, 22.5% sulfur and 45% oxygen. Derive the chemical formula of the substance.

Solution

The mass fraction of element X in a molecule of the composition NX is calculated using the following formula:

ω (X) = n × Ar (X) / M (HX) × 100%.

Let us denote the number of moles of elements included in the compound as “x” (sodium), “y” (sulfur) and “z” (oxygen). Then, the molar ratio will look like this (the values of relative atomic masses taken from D.I. Mendeleev’s Periodic Table are rounded to whole numbers):

x:y:z = ω(Na)/Ar(Na) : ω(S)/Ar(S) : ω(O)/Ar(O);

x:y:z= 32.5/23: 22.5/32: 45/16;

x:y:z= 1.4: 0.7: 2.8 = 2: 1: 4.

This means that the formula for the compound of sodium, sulfur and oxygen will be Na 2 SO 4. This is sodium sulfate.

Answer

Na2SO4

PART AND

GENERAL CHEMISTRY

CHEMISTRY OF ELEMENTS

OXYGEN. SULFUR

Hydrogen sulfide

The hydrogen sulfide molecule consists of a Sulfur atom and two Hydrogen atoms connected by a polar covalent bond. Angle between bonds

SH equal to 91°. The hydrogen sulfide molecule is polar.

Hydrogen sulfide is a natural component of volcanic and natural gases. Some mineral waters contain dissolved hydrogen sulfide, which gives them medicinal properties. Hydrogen sulfide is formed as a result of rotting products containing proteins. In the Black Sea at a depth of more than 40 meters there is no life due to the saturation of the waters with hydrogen sulfide.

Physical properties of hydrogen sulfide

Hydrogen sulfide is a colorless gas with the smell of rotten eggs. 3 volumes of hydrogen sulfide are dissolved in 1 volume of water, resulting in approximately 0.1 molar solution. The melting point of hydrogen sulfide is -83 °C, and the boiling point is -61 °C. Hydrogen sulfide affects the human nervous system, so it is necessary to work with it under a fume hood.

Chemical properties of hydrogen sulfide

Hydrogen sulfide is a compound that has a structure similar to a water molecule, but is less stable compared to it. When heated to high temperatures, hydrogen sulfide decomposes according to the reaction:

Combustion can occur in two different directions. In excess oxygen, water and sulfur (I) are formed

V) oxide:

Due to lack of oxygen, incomplete combustion of hydrogen sulfide occurs. This process is used to extract sulfur on an industrial scale from gases that are formed during the roasting of ores:

Bromine and iodine reduce hydrogen sulfide to the simple substance sulfur:

Hydrogen sulfide reacts with hexafluorsulfur at elevated temperatures:

When hydrogen sulfide is dissolved in water, a weak dibasic sulfide acid is formed (K a 1 = 10 - 7, K a 2 = 1.2 ∙ 10 - 13):

Medium salts of sulfide acid are called sulfides (for example, K 2 S is potassium sulfide). Acid salts of the corresponding acid are also known - hydrogen sulfides(K.H.S. - potassium hydrogen sulfide). Since sulfidic acid is a rather weak acid, solutions of sulfides and hydrogen sulfides undergo hydrolysis at the anion, and accordingly the solution environment is basic:

Sulfides of alkali and alkaline earth metals are soluble in water, while other sulfides are insoluble. Many sulfide acid salts have a characteristic color: HgS - red, Sb 2 S 3 - orange, CdS - yellow, MnS - pink, CuS - black.

Extraction and application of hydrogen sulfide

Hydrogen sulfide is usually produced by the action of mineral acids on metal sulfides:

Hydrogen sulfide can also be obtained from simple substances.

Hydrogen sulfide is used in the qualitative analysis of cations according to the sulfide classification. It also plays an important role in the sulfuric acid production process.

Qualitative reaction to hydrogen sulfide i sulfide ion

To determine sulfide ions in a solution, add any soluble Lead salt to the test solution (most often P b acetate (CH 3 COO) 2 or nitrate Pb (NO 3) 2). If after addition a black precipitate appears in the solution, then the test sample contained sulfide ions:

Properties of hydrogen sulfide acid

The heroine's resilience is relative. Not wanting to completely dissolve in water, the compound disintegrates under the influence of oxygen. It oxidizes hydrosulfide acid. Formula it looks like this: - Н 2 S. Н in it – , S – . So, the latter “breaks out” of the formula during oxidation. The connection breaks down.

Application of hydrogen sulfide acid

Dissociation of hydrosulfide acid to a solution with a saturation of thousandths of a percent allows the compound to be used for medicinal purposes. They are usually organized at places where groundwater containing hydrogen sulfide emerges. The smell of rotten eggs is tolerated for the sake of getting rid of skin ailments, rehabilitation of the system, and treatment of insomnia.

Doctors note that baths with hydrogen sulfide are not taken at home or, in general, in enclosed spaces. The concentration of vapors emanating from water may exceed the permissible limits.

In the west of the country, hydrogen sulfide is formed along the Black Sea shelf. True, there the compound forms at a depth of about 150 meters, emerging as bubbles into the shallow water.

How to recognize hydrogen sulfide acid in the air at low concentrations, in the absence of obvious odor? It will only help. She is also poisonous, but there is no other way. It is moistened in the reagent. In an atmosphere containing at least 0.0000001% hydrogen sulfide, the leaf will become coated.

Preparation of hydrogen sulfide acid

Since it is a solution of hydrogen sulfide, it is worth asking about its production. The method of using sulfide is also popular. Natural minerals are used as the latter. There are several sulfides in the interior of the planet. The most famous is perhaps. Its formula: - FeS 2.

The reaction between sulfide and is violent, with active gas evolution. Accordingly, interaction is carried out in isolated rooms, using protective clothing.

Then, hydrogen sulfide is dissolved in water. The liquid is heated. This makes dissociation more successful. The heroine of the article is ready for use or sale. Let's find out the price tags.

Hydrosulfide acid price

SECTION II. INORGANIC CHEMISTRY

9.3. ElementsVIAgroups

9.3.7. Hydrogen sulfide (hydrogen sulfide). Hydrogen sulfide (sulfide) acid. Sulfides 2

Hydrogen sulfide and hydrogen sulfide acid Hydrogen sulfide or hydrogen sulfide H 2 S , is a volatile compound of Sulfur with Hydrogen. In a hydrogen sulfide molecule, the Sulfur atom forms two covalent polar bonds with two Hydrogen atoms. The bond angle is 92.1°. Solution H2S in water is called hydrosulfide acid.

Prevalence of hydrogen sulfide in nature

In nature, hydrogen sulfide is found in natural and volcanic gases, is contained in the water of some mineral springs, and is also formed during the decomposition of organic substances (plant and animal residues), and therefore is found in small quantities in the air.

Huge reserves of hydrogen sulfide accumulated in the depths of the Black Sea: its layer starts from a depth of 150-200 m and reaches the bottom (maximum depth - 2210 m). Hydrogen sulfide concentration at a depth of 150 m - 0.19 mg/l of sea water, at a depth of 200 m - 0.83 mg/l, and at a depth of 2000 m it reaches 9.60 mg/l. Thus, with the exception of some specific microorganisms, there are almost no living creatures there.

Physical properties and physiological effects of hydrogen sulfide

Hydrogen sulfide is a colorless gas with a sharp, unpleasant odor of rotten eggs - hich water dissolves up to 2.5 liters of H 2 S. Hydrogen sulfide is very poisonous. The presence of a volume fraction of 0.1% in the air causes poisoning. Hydrogen sulfide binds hemoglobin, forming with the ion Fe 2+ , included in its composition, is a low-purity compound - ferrum(II) sulfide.

Hydrogen sulfide production

In the laboratory, to extract hydrogen sulfide, a reaction between the sulfide of a metal element and chloride acid or dilute sulfuric acid is used:

In industry, hydrogen sulfide is produced by passing hydrogen over molten sulfur:

Chemical properties of hydrogen sulfide and sulfide acid

Hydrogen sulfide

1. Hydrogen sulfide burns with a bluish flame:

When there is a lack of oxygen, sulfur is formed:

2. Hydrogen sulfide is classified as a strong reducing agent - it can be oxidized to sulfur, sulfur (And V ) oxide or sulfuric acid:

3. Hydrogen sulfide interacts with oxidizing acids:

4. Reacts with both strong and weak oxidizing agents:

Use of hydrogen sulfide

1. In the chemical industry for the production of sulfuric acid, elemental sulfur, sulfides.

2. In the organic synthesis of sulfur-containing substances (thiols 3).

3. As a reagent in analytical chemistry for the detection of ions of heavy metal elements (Ag +, Pb 2+, C u 2+).

4. In the future, it is possible to use the gigantic reserves of hydrogen sulfide contained in the Black Sea for the needs of hydrogen sulfide energy and the chemical industry.

5. In medicine, natural sources and artificial baths containing hydrogen sulfide are used to combat skin diseases.

Sulfide acid

A solution of hydrogen sulfide in water - hydrogen sulfide water, or hydrogen sulfide (sulfide) acid - a weak dibasic acid. It is weaker than sulfite acid H 2 SO 3. Dissociates in two steps (beyond degree II - to a slight extent):

Sulfide acid exhibits the general properties of acids. It reacts with basic oxides, bases, forming medium and acid salts, as well as with some salts and metals:

Salts of hydrosulfide acid

Hydrogen sulfide acid forms two series of salts: medium - sulfides (K 2 S, CaS) - and acidic - hydrogensulfides(KHS, Ca(HS ) 2). Water-soluble sulfides of alkali and alkaline earth metal elements, as well as ammonium sulfide(NH 4) 2 S. Some sulfides have a characteristic color: black - PbS and CuS, yellow - CdS, white - ZnS, MgS, pink - MnS.

Chemical properties of sulfides

1. Water-soluble sulfides slowly hydrolyze, that is, they decompose with water:

As a result of complete hydrolysis in solution, some sulfides cannot be obtained:

2. Sulfides react with some other salts:

These two reactions are qualitative for the detection of sulfide ion S 2- , because the formation of characteristic black deposits is observed - CuS and PbS.

3. Sulfides are decomposed by strong acids:

4. Sulfides, when interacting with oxidizing agents, exhibit reducing properties:

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1 The reaction is used to bind spilled mercury (demercurization). The area of the floor where the mercury thermometer broke must be sprinkled with sulfur powder. Cinnabar is a non-toxic compound. It does not evaporate (at room temperature) and can be easily collected.

2 Polysulfides are Sulfur compounds with the general formula X 2 S n , the structure of which contains chains of atoms - S - S (n -2) - S -, where, depending on the component X, n may vary: in Hydrogen polysulfides H2Sn (liquid polysulfides, depending on the Sulfur content, from yellow to red) n varies from 2 to 23, in ammonium polysulfides ( NH 4) 2 S n - from 2 to 9, alkali metals Me 2 S n - from 2 to 8. They are used in the leather industry to remove hair from the skin), in the production of dyes, polysulfide rubbers, and in analytical chemistry.

3 Thiols (or mercaptans) have a strong unpleasant odor. In particular, eganthiol C2H5SH added to natural gas (methane has no odor) before it is supplied to the domestic gas pipeline to detect gas leaks from the system.

What is hydrogen sulfide?

HYDROGEN SULPHIDE, H 2 S, (hydrogen sulfide, hydrogen sulfide) is a colorless flammable gas with a pungent odor, boiling point 60.35 °C. Aqueous solution - hydrosulfide acid. Hydrogen sulfide is often found in oil and gas fields.

Hydrogen sulfide H 2 S is toxic: acute human poisoning occurs at concentrations of 0.2–0.3 mg/m 3 , concentrations above 1 mg/m 3 are fatal. Hydrogen sulfide H 2 S is an aggressive gas that provokes acid corrosion, which in this case is called hydrogen sulfide corrosion. When dissolved in water, it forms a weak acid which can cause pitting in the presence of oxygen or carbon dioxide.

In this regard, without modern gas treatment stations and desulfurization modules, hydrogen sulfide can cause severe damage to people. The maximum permissible concentration of hydrogen sulfide in the air of the working area is 10 mg/m3, and in a mixture with C1–C3 hydrocarbons it is equal to 3 mg/m3.

Without hydrogen sulfide treatment stations, a variety of equipment in the oil, energy, transport and gas processing industries seriously suffers and fails.

What happens to metals if hydrogen sulfide is not removed?

Hydrogen sulfide - H 2 S - total metal corrosion

Hydrogen sulfide reacts with almost all metals, forming sulfides, which act as a cathode in relation to iron and form a galvanic couple with it. The potential difference of this pair reaches 0.2–0.48 V. The ability of sulfides to form microgalvanic pairs with steel leads to rapid destruction of process equipment and pipelines.

It is extremely difficult to combat hydrogen sulfide corrosion: despite the addition of acid corrosion inhibitors, pipes made from special grades of stainless steel quickly fail. And even sulfur obtained from hydrogen sulfide can be transported in metal tanks for a limited period of time, since the tanks are prematurely destroyed due to hydrogen sulfide dissolved in sulfur. In this case, the formation of polysulfanes HS n H occurs. Polysulfanes are more corrosive elements than hydrogen sulfide.

Hydrogen sulfide, when added to unsaturated compounds, forms mercaptans, which are an aggressive and toxic part of sulfur compounds - chemical poisons. It is they that significantly worsen the properties of catalysts: their thermal stability, intensify the processes of resin formation, loss and deposition of slag, sludge, and sediment, which causes passivation of the surface of the catalysts, and also enhance the corrosive activity of the material of technological devices.

H 2 S significantly enhances the process of hydrogen penetration into steel. If during corrosion in acidic environments the maximum proportion of hydrogen diffusing into steel is 4% of the total amount of reduced hydrogen, then in hydrogen sulfide-containing solutions this value reaches 40%.

The presence of oxygen in the gas significantly accelerates corrosion processes. It was experimentally found that the most corrosive gas is the one in which the ratio of oxygen to hydrogen sulfide is 114:1. This attitude is called critical.

The presence of moisture in the gas leads to corrosion of the metal, but the simultaneous presence of H 2 S, O 2 and H 2 O is the most unfavorable from the point of view of corrosion.

The corrosive effect of these impurities on metal increases sharply with increasing pressure.

The rate of corrosion of gas pipelines is directly proportional to the pressure of the gas passing through this gas pipeline. At pressures up to 20 atm. and wet gas, even traces of hydrogen sulfide 0.002–0.0002% vol. are enough to cause significant corrosion damage to the pipe metal, limiting the service life of the gas pipeline to 5–6 years.

Due to the corrosive effects of hydrogen sulfide present in gases, the service life of power generation equipment (GPES - GTU) and equipment during gas production, transportation, processing and use is significantly reduced.

In field conditions, pipes, valves, combustion chambers and pistons of power plants, gas meters, compressors, and refrigerators are subject to particularly high levels of corrosion.

A significant portion of hydrogen sulfide reacts with metal and can be deposited in the form of corrosion products on the valves of power plants, compressors, on the internal walls of equipment, communications and main gas pipelines.

Relevance of the problem of gas purification from hydrogen sulfide

The urgency of the problem of purifying gas from hydrogen sulfide is enhanced by the requirements to ensure environmental safety when developing sulfur deposits and reducing harmful emissions into the atmosphere.

At the same time, special attention is paid to improving existing and developing new desulfurization technologies that eliminate emissions of toxic hydrogen sulfide and its combustion products into the environment.

Despite all the listed disadvantages, hydrogen sulfide is a valuable chemical raw material, since a huge amount of inorganic and organic compounds can be obtained from it.