In the city of Revda with rails, 15 wagons with sulfuric acid came up. The cargo belonged to the Middle Ural copper smelter.

PE occurred on departmental railways in the 2013th year. Acid spilled on an area of \u200b\u200b1000 square kilometers.

This indicates the scale of the needs of industrialists in the reagent. In the Middle Ages, for example, only tens of liters of sulfuric acid were required per year.

In the 21st century, the global production of matter per year is tens of millions of tons. In terms of production and application, judge the development of chemical industries of countries. So, the reagent is worthy of attention. Description Let's start with the properties of the substance.

Properties of sulfuric acid

Externally 100 percent sulfuric acid - Oil liquid. It is colorless and severe, it is extremely hygroscopic.

This means that the substance absorbs the water pair of water from the atmosphere. At the same time, the acid highlights heat.

Therefore, to the concentrated form of the substance, water is added with low doses. Wlill a lot and quickly, splashes of acid.

Considering its property to erod matter, including alive fabrics, the situation is dangerous.

Concentrated sulfuric acidcalled a solution in which the reagent is more than 40%. This is capable of dissolving.

Sulfuric acid solutionup to 40% - non-concentrated, chemically manifests itself differently. Water to it can be addressed enough quickly.

Palladium C will not dissolve, but they will disintegrate, and. But the acid concentrate all three metal is subject to.

If you look at, sulfuric acid in solutionreacts with active metals facing hydrogen.

The saturated substance interacts with inactive. Exception - noble metals. Why does the concentrate not "touches" the iron, copper?

Cause in their passivation. So called the process of coating metals with protective film oxides.

It prevents the dissolution of surfaces, however, only under normal conditions. When heated, the reaction is possible.

Diluted sulfuric acidmore like water, rather than oil. Concentrate, distinguishes not only on tightness and density, but also the smoke emanating from the substance in the air.

Unfortunately, in the Dead Lake on Sicily, the acid content is less than 40%. In the appearance of the reservoir, you can not say that it is dangerous.

However, the dangerous reagent formed in the rocks earth crust. Raw materials can serve, for example,.

This mineral is also called sulfur. When contacting with air and water decays to 2 and 3-EXs valence iron.

The second product of the reaction - sulfuric acid. Formulaheroine, respectively: - H 2 SO 3. There is no specific color, no smell.

Lowering, by ignorance, hand in the water of the Sicilian lake of death for a couple of minutes, people are deprived.

Given the corrosive ability of the reservoir, local criminals undertook to dump the corpses into it. A few days, and there are no trace from the organic.

The product of sulfuric acid reaction with organica is often often. The reagent clears water from the organic matter. So the carbon remains.

As a result, the fuel can be obtained from the "raw" wood ,. Human fabrics are no exception. But, this is the plot for the horror movie.

The quality of the fuel obtained from the treated organic organic. Acid in the reaction is an oxidizing agent, although it can be a reducing agent.

In the last role, the substance stands, for example, interacting with halogens. These are elements of the 17th Mendeleev table group.

All these substances themselves are not strong reducing agents. If the acid is found with those, it acts only as an oxidizing agent.

Example: - reaction with hydrogen sulfide. And what reactions give the sulfuric acid itself, how is it mined and produced?

Sulfuric acid extraction

In previous centuries, the reagent was mined not only from iron ore, called pyrite, but also from iron mood, as well as alum.

Under the last concept, sulfate crystalline hydrides, double.

In principle, all listed minerals are sulfur-containing raw materials, therefore, can be applied to production of sulfuric acidand in modern times.

Mineral base is different, but the total of its treatment is one - sulfuric anhydrite with the formula SO 2. It is formed when reactions with oxygen. It turns out, you need to burn the foundation.

The resulting anhydrite passes with water absorption. The formula of the reaction is as follows: SO 2 + 1 / 2O 2 + H 2) -ÀH 2 SO 4. As can be seen, oxygen is involved in the process.

Under normal conditions, the sulfuric anhydride interacts with it slowly. Therefore, industrialists oxidize raw materials on catalysts.

The method is called contact. There is also a nitrous approach. This is oxidation oxide.

The first mention of the reagent and its production contains work dating from the 940s.

These are the records of one of the Persian alchemists named Abubeker al-time. However, Jafar Al-Sufi said about the acid gases obtained by calcining al-sufi.

This Arabic alchemist lived in the 8th century. However, judging by the records, he did not receive sulfuric acid in its pure form.

Sulfuric acid use

More than 40% of acids go to the production of mineral fertilizers. In the course of superphosphate, ammonium sulfate, ammophos.

All this complex feeding, which make rates farmers and large manufacturers.

A monohydrate is added to the fertilizer. This is a clean, 100 percentic acid. Crystallizes at 10 degrees Celsius.

If the solution is used, take 65 percent. Such, for example, add to the superphosphate obtained from the mineral.

The production of only one ton of fertilizer leaves 600 kilos of acid concentrate.

About 30% of sulfuric acid is spent on the purification of hydrocarbons. The reagent improves the quality of lubricating oils, kerosene, paraffin.

Mineral oils and fats are adjacent to them. They are also cleaned with a sulfur concentrate.

The ability of the reagent dissolve metals is used in the processing of ores. Their decomposition is just as fiscal as the acid itself.

Not dissolving iron, it does not dissolve and contain it. So you can use the equipment from it, and not expensive.

Suitable, as cheap, also made on the basis of Ferrum. As for dissolved produced by sulfuric acid of metals, it is possible to obtain

The ability of acid absorb water from the atmosphere, makes a reagent with an excellent dryer.

If air is influenced by air 95 percent solution, the residual moisture is only 0.003 milligrams of water vapor per liter of dried gas. The method is used in laboratories and industrial production.

It is worth noting the role not only clean substance, but also its connections. They are taught mainly in medicine.

Barium porridge, for example, delays X-ray radiation. Doctors fill the hollow organs by substance, facilitating the research of radiologists. Bariyeva Porridge formula: - Baso 4.

Natural, by the way, also contains sulfuric acid, and also needed physicians, but already when fixing fractures.

Mineral and builders are needed, using it as a binder, fastening material, as well as for decorative finishes.

Sulfuric acid price

Pricethe reagent is one of the reasons for its popularity. A kilogram of technical sulfuric acid can be purchased for only 7 rubles.

So much for its products are asked for example, managers of one of Rostov enterprises on Don. Split the canes of 37 kilos.

This is the standard volume of containers. There are also canisters in 35 and 36 kilograms.

Buy sulfuric acidspecialized Plan, for example, rechargeable, few more expensive.

For a 36 kilogram canister as a rule, as a rule, from 2000 rubles. Here, by the way, another scope of the reagent.

It is no secret that the acid diluted with distilled water is electrolyte. It is needed not only for ordinary batteries, but also machine batteries.

They are discharged, because sulfuric acid is consumed, at the same time, lighter water is distinguished. The density of the electrolyte falls, which means its effectiveness.

Sulfuric acid is a rather heavy liquid, its density is 1.84 g / cm³. It has the ability to pull water from gases and. When sulfuric acid dissolves in water, a huge amount of heat is distinguished, resulting in splashing of acid. In case of human skin, even in small quantities causes strong burns. To avoid this, you need to add acid into water, and not vice versa.

Obtaining sulfuric acid

The method by which sulfuric acid is obtained on an industrial scale is called contact. First, in a special furnace, a wet (bivalent iron sulfide) occurs. As a result of such a reaction, sulfur gas (sulfur dioxide), oxygen and water vapor dioxide, as wet pyrite was used. The distinguished gases go into the drying compartment, where the water vapor is getting rid of the vapor, as well as in a special centrifuge to remove all possible impurities of solid particles.

Next, sulfur gas is obtained from sulfur oxide (IV) with the help of oxidation reaction. At the same time use five-channel as a catalyst. The reaction can go to both sides, it is reversible. So that it flows in only one direction, certain temperatures and pressure are created in the reactor. Sulfur gas is dissolved in pre-prepared sulfuric acid to produce oleum, which is then sent to the finished product warehouse.

Chemical properties of sulfuric acid

Sulfuric acid has the ability to receive electrons, it is a strong oxidizing agent. Concentrated and diluted sulfuric acid have different chemical properties.

Diluted sulfuric acid is able to dissolve metals that cost the left of the hydrogen in the row of stresses. Among them: zinc, magnesium, lithium and others. Concentrated sulfuric acid may decompose some halogen acids (except salt, since it is not capable of restoring the chlorine ion of chlorine).

Sulfuric acid use

Due to its unique ability to pull water, sulfuric acid is often used to dry out gases. With it, it produces dyes, mineral fertilizers (phosphoric and nitrogen), smoke-forming substances, various synthetic detergents. It is often used as an electrolyte for, since sulfuric acid cannot dissolve lead.

Introduction

Physical chemical solo acid technologies

Kinetics and process mechanism

1 Equilibrium degree of transformation

2 S02 reaction speed in S03

3 oxidation S02 on a catalyst in a boiling layer

Sulfuric acid technology

1 raw material for technology

2 Technological scheme for production of sulfuric acid and its description

3 Waste in Sulfuric Acid Technologies and Methods for their disposal

4 Maximum permissible concentrations of gases, vapors and dust in the production of sulfuric acid

Construction of the main apparatus

1 Olemy absorber

2 monohydrate absorber

3 Technological characteristics of absorber

Technical and economic indicators of technology

BIBLIOGRAPHY

Introduction

Sulfuric acid is one of the main products of the chemical industry. It is used in various sectors of the national economy, since it has a complex of special properties that facilitate its technological use. Sulfuric acid does not smoke, does not have colors and odor, at normal temperature is in a liquid state, in concentrated form does not corrodies ferrous metals. At the same time, sulfuric acid refers to the number of strong mineral acids, forms numerous stable salts and cheap.

The chemical composition of sulfuric acid is expressed by the H2SO4 formula.

In a sulfuric acid technique, any mixtures of sulfur oxide are understood. If 1 mol of SO3 accounts for more than 1 mol of water, then the mixtures are aqueous solutions of sulfuric acid, and if less - solutions of sulfuric anhydride in sulfuric acid (oleum) or smoking sulfuric acid.

Among mineral acids, sulfuric acid in terms of production and consumption ranks first. The world production over the past 25 years has grown more than three times and is currently more than 160 million tons per year.

Sulfuric acid is used to produce fertilizers - superphosphate, ammonium, ammonium sulfate, etc. Its consumption is significant when cleaning petroleum products, as well as in non-ferrous metallurgy, when etching metals. Particularly clean sulfuric acid is used in the production of dyes, varnishes, paints, medicinal substances, some plastic masses, chemical fibers, many of the pesticides, explosives, esters, alcohols, etc.

Concentrated sulfuric acid is a strong oxidizing agent. Oxides Hi and partially nvg to free halogens, carbon - to CO2, S - to SO2, oxidizes many metals. Conducting redox reactions involving H2SO4 usually requires heating. Often the recovery product is SO2:

S + 2 H2SO4 \u003d 3SO2 + 2H2O (1) + 2 H2SO4 \u003d 2SO2 + CO2 + 2H2O (2) S + H2SO4 \u003d SO2 + 2H2O + S (3)

Strong reducing agents are converting H2SO4B S or H2S.

Concentrated sulfuric acid when heated reacts with almost all metals (excluding AU, PT, BE, BI, FE, MG, CO, RU, RH, OS, IR), for example:

Cu + 2 H2SO4 \u003d CUSO4 + SO2 + 2H2O (4)

Sulfuric acid forms salts - sulfates (Na2SO4) and hydrosulfate (NaHSO4). Insoluble salts - PBSO4, Caso4, Baso4, etc.:

H2SO4 + BACL2 \u003d BASO4 + 2HCL (5)

Cold sulfuric acid passivates iron, so it is transported in the iron container. Anhydrous sulfuric acid is well dissolved by SO3 and reacts with it, forming pyrosic acid, resulting in reaction:

H2SO4 + SO3 \u003d H2S2O7 (6)

SO3 solutions in sulfuric acid are called oleum. They form two compounds: H2SO4 · SO3 and H2SO4 · 2SO3

According to standards, technical and accumulator sulfuric acids are distinguished.

Sulfuric acid Acid GOST 2184-77

Technical sulfuric acid is designed for the production of fertilizers, artificial fiber, caprolactam, titanium dioxide, ethyl alcohol, aniline dyes and a number of other production. According to GOST 2184-77, the following types of technical sulfuric acid distinguish:

· Contact (improved and technical);

· Oleum (improved and technical);

· The tower;

· Regenerated.

According to physico-chemical indicators, it is necessary that sulfuric acid correspond to the standards:

Name of the indicator
	Contact					Tower	Regenerated
	improved	technical		improved	technical
1. Mass fraction of monohydrate (H2SO4),%		not less than 92.5		not normalized		at least 75.	not less than 91.
2.Mass fraction of free sulfur anhydride (SO3),% not more than
3. Mass fraction of iron (Fe),%, no more					not normalized
4. Mass fraction of the residue after calcination,%, no more			not normalized
5. Mass fraction of nitrogen oxides (N2O3),%, no more		not normalized			not normalized
6. Mass fraction of nitro compounds,%, no more	not normalized
7. Mass fraction of arsenic (AS),%, no more		not normalized			not normalized
8. Mass fraction of compound chloride (CL),%, no more		not normalized
9. Mass fraction of lead (PB),%, no more		not normalized			not normalized
10.Rerability	transparent without loss.	not normalized
11.The bed, cm3 comparison solution, no more			not normalized

Sulfuric acid accumulator GOST 667-73

Concentrated accumulatory sulfuric acid is specialized as an electrolyte for pouring lead batteries after diluted with distilled water. In physical and chemical indicators, it is necessary that rechargeable sulfuric acid correspond to the standards specified in the table.

Name of the indicator
	High Sort
1. Mass fraction of monohydrate (H2SO4),%
2. Mass fraction of iron (Fe),%, no more
3. Mass fraction of residue after calcination,%, no more
4. Mass fraction of nitrogen oxides (N2O3),%, no more
5. Mass fraction of arsenic (AS),%, no more
6. Mass fraction of compound chloride (CL),%, no more
7. Mass fraction of manganese (Mn),%, no more
8. Mass fraction of the amount heavy metals In terms of lead (PB),%, no more
9. Mass fraction of copper (CU),%, no more
10. Mass fraction of substances restoring KmnO4, cm3 solution with (1/5 kmnO4) \u003d 0.01 mol / dm3, no more

In this work is considered the most important task Workers of the sulfuric acid industry, which is to further improve production by using best practices. The introduction of progressive techniques and methods of work, as well as in the development of fundamentally new methods for production of sulfuric acid based on the latest achievements of science and technology.

sulfuric acid absorber

1.
Physico-chemical bases of solo acid technology

In the modern production of sulfuric acid, the raw material is sulfur dioxide (sulfur arhydride), oxygen and water, the interaction between them proceeds under the total stoichiometric equation:

SO2 + 1 / 2O2 + NN2O H2SO4 + (N-1) H2O + Q (7)

This process is carried out in two ways - nitrosis and contact.

The nitrous method of oxidation SO2 to SO3 occurs mainly in the liquid phase and is based on the transmission of oxygen using nitrogen oxides. Nitrogen oxides, oxidizing SO2 to SO3, restored to NO, which is again oxidized by the oxygen of the gas mixture both in the liquid and gas phases.

The essence of the nitrose method is that the burf gas after purification from dust is treated with sulfuric acid, in which nitrogen oxides, so-called nitrosis dissolved. Sulfur dioxide is absorbed by nitrose and then oxidized by nitrogen oxides for the reaction

SO2 + N2O3 + H2O \u003d H2SO4 + 2NO (8)

Forming NO is poorly soluble in nitroles and therefore is released from it, and then partially oxidized by oxygen in the gas phase to NO2 dioxide. A mixture of nitrogen oxides NO and NO2 is again absorbed by sulfuric acid, etc. Nitrogen oxides are essentially not spent in the nitrous process and returned to the production cycle. However, due to the incomplete absorption of their sulfuric acid, they are partially carried out by outgoing gases; This is irrevitable oxide losses.

The processing of SO2 in sulfuric acid according to the nitrosis method is carried out in the production towers - cylindrical tanks (15 m or more) tanks filled with a nozzle from clay rings. From above, the "nitroz" is sprinkled to the gas bunch - diluted sulfuric acid containing NOOSO3H nitrosyl heroic acid obtained by reaction:

O3 + 2 H2SO4 \u003d 2 Nooso3h + H2O (9)

The oxidation of SO2 nitrogen oxides occurs in solution after its absorption nitrosis. Water nitro is hydrolyzed:

H + H2O \u003d H2SO4 + HNO2 (10)

Sulfurous gas, entered in the tower, with water forms sulfuric acid:

H2O \u003d H2SO3 (11)

The interaction of HNO2 and H2SO3 leads to obtaining sulfuric acid:

2 hnO2 + H2SO3 \u003d H2SO4 + 2 NO + H2O (12)

The released NO is converted to the oxidative tower in N2O3 (more precisely into the consistency of NO + NO2). From there, the gases come to the absorption towers, where sulfuric acid is supplied to the top. Nitrose appears, which is pumped into the production towers. Such is the continuity of production and cycle of nitrogen oxides. The inevitable losses of them with exhaust gases are filled with the addition of HNO3.

Sulfuric acid obtained by a nitrose method has a sufficiently higher concentration and contains harmful impurities (for example, AS). Its creation is accompanied by an emission of nitrogen oxides ("fox tail", called the color of NO2).

In the lower part of the towers, 76% sulfuric acid accumulates, naturally, more than it was spent on the preparation of nitrose (because the "newborn" sulfuric acid is added).

The shortcomings of the tower method is that the acquired acid has a concentration of only 76% (with a larger concentration, the nitrosyl and acid hydrolysis is poorly.). The concentration of sulfuric acid by evaporation is additional difficulty. The advantage of this method is that impurities in SO2 do not affect the course of the process, so that the initial SO2 is pretty clean from dust, i.e. Mechanical pollution.

Previously, the nitrous process was carried out in lead chambers, and therefore it was called a chamber method, currently this method, as a small-performance, does not apply. Instead, a taper method is used in which all the main and intermediate processes of SO2 processing are not in the chambers, but in towers filled with nozzle and irrigated with sulfuric acid.

Contact method. The opening of the Phillips in England in 1831 the possibilities of oxidation SO2 oxygen on the surface of the solid platinum catalyst was widely used only in the 70s of the XIX century. Such a later development is explained, firstly, the fact that the platinum catalyst quickly lost its activity; And, secondly, the fact that at that time there were no consumers of oleum.

In the 70s, thanks to the work of the book, the reason for the decline in platinum activity was established: the presence of arsenic in sulfur gas under the cchedan firing; They also found a method for cleaning the fuggous gas from the catalyst poison.

Currently, most of the sulfuric acid in the world is produced by the contact method. The growth of sulfuric acid production is determined higher, technical level, due to the need for clean and concentrated acid, the ability to automate the process, as well as reduced the content of sulfur oxides in exhaust gases to maximum permissible concentrations (MPC). The contact process for obtaining sulfuric acid in the world is carried out by two methods:

· The method of single contact (OK) with the oxidation degree of S02 in S03, equal to 97.5-98%, and emissions into the atmosphere of exhaust gases containing SO2 and SO3, above the maximum permissible concentration (MPC), which demanded additional costs of construction in such cleaning separation systems;

· Double contact (DC) and double absorption (yes). In DC systems, the degree of oxidation SO2 in SO3 is 99.7-99.8%, which corresponds to the achievement of the maximum permissible concentration of SO2 and SO3 in exhaust gases.

Production of sulfuric acid contact method according to the DC system consists of stages:

) preparation of raw materials;

) Obtaining sulfur dioxide

4fes2 + 11O2 → 2Fe2O3 + 8SO2 + 3415 Q (T \u003d 800 ° C) (13)

either 3fes2 + 8o2 → Fe3O4 + 6SO2 + Q (14)

or burning sulfur S + O2 → SO2 (15)

)
gas purification;

) Oxidation of sulfur anhydride

2SO2 + O2 ↔2SO3 + Q (400-500 ° C, cat-p V2O5) (16)

) SO3 absorption

H2O → H2SO4 + Q (17)

) Cleaning exhaust gases.

When obtaining sulfuric acid on the DC system - yes the sixth stage is absent.

I liked the contact method of sulfuric acid technology, as the most efficient (a high degree of transformation is achieved) and more favorable from the point of view of ecology (emissions comply with MPC standards and PDV.)

Kinetics and process mechanism

Chemical process:

· Sulfur burning

· Oxidation SO2 to SO3

· Absorption SO3

The most important task in the production of sulfuric acid is to increase the degree of transformation of SO2 in SO3. In addition to increasing sulfuric acid performance, this task allows you to solve and environmental problems - reduce emissions into the environment of the harmful component of SO2.

Increasing the degree of transformation of SO2 can be achieved by different paths. The most common of them is the creation of double contact schemes.

In the production of sulfuric acid, the contact method of SO2 oxidation by the SO2 + 1 / 2O2↔SO3 + Q reaction occurs in the presence of a catalyst. The ability to accelerate the oxidation of SO2 has various metals, their alloys and oxides, some salts, silicates and many other substances. Each catalyst provides a certain, characteristic degree of transformation. In factory defense, it is more advantageous to use catalysts, with which the highest degree of transformation is achieved, since the residual amount of non-oxidized SO2 is not captured in the absorption department, but is removed into the atmosphere along with outgoing gases.

Long time with the best catalyst this process They considered platinum, which in a finely studed state was applied to fibrous asbestos, silica gel or magnesium sulfate. However, platinum, although it has the highest catalytic activity, is very expensive. In addition, its activity is greatly reduced if there are the most minor quantities of arsenic, selenium, chlorine and other impurities in Gaza. Therefore, the use of a platinum catalyst led to a complication of hardware design due to the need for careful gas purification and increased the cost of finished products.

Among non-payment catalysts, a vanadium catalyst (based on vanadium pentoxide V2O5) has the greatest catalytic activity, it is cheaper and less sensitive to impurities than a platinum catalyst.

In the production of sulfuric acid as a catalyst, contact masses based on vanadium oxide (V) BAV and SVD grades, named as the initial letters of the elements included in their composition are used.

Bav (Barium, Aluminum, Vanadium) Composition:

There are other inventions of catalysts. The invention relates to catalysts for oxidation of sulfur dioxide and can be used in the production of sulfuric acid in the processing of gas mixtures with the usual and elevated content of sulfur dioxide.

The catalyst for the oxidation of sulfur dioxide consisting of pentoxide vanadium with additives of alkaline promoters of sodium compounds, potassium, rubidium and (or) cesium on a diatom carrier containing SiO2, CAO. The mixture of alkaline promoters in terms of oxides contains, wt. Na2O 5-30; RB2O and (or) CS2O 15-35; K2O 8-35.

Catalyst activity at 485 ° C. 90.2-91% at 420 ° C. 57.8-59.7% when testing under the following conditions: v 4000 h-1, sulfur dioxide content in the original gas mixture 7 vol. The rest of the air. Mechanical durability of crushing 1-2 MPa

S02 oxidation reaction is exothermic; the thermal effect of it, like any chemical reactiondepends on temperature.

In the range of 400-700 ° with the thermal effect of the oxidation reaction (in KJ / mol) with sufficient accuracy for technical calculations can be calculated by the formula

Q \u003d 10 142 - 9.26T or 24205 - 2.21T (in kcal / mol) (18)

where T - Temperature, K.

The oxidation reaction S02 in S03 is reversible. The equilibrium constant of this reaction (in PA-0,5) is described by the equation

where PSO2, PSO3, PO2 equilibrium partial pressure SO2, SO3 and O2, PA. The value of the KD depends on the temperature:

Table 1. Dependence Constant equilibrium on temperature

390 400 425 450 475 500	1,801 1,410 0,768 0,437 0,258 0,159	525 575 600 625 650	0,100 0,044 0,030 0,021 0,015

The values \u200b\u200bof the KR in the range of 390-650 ° C can be calculated by the formula

(20)

or more exactly

2.1 Equilibrium degree of transformation

The degree of conversion S02, achieved on the catalyst depends on its activity, the composition of the gas, the duration of the contact of gas with a catalyst, pressure, etc. For the gas of this composition, theoretically possible, i.e. the equilibrium degree of conversion depends on temperature and is expressed by the equation:

(22)

where PSO2, PSO3 is the equilibrium partial pressure SO2 and SO3.

Substituting into equation (6-5) the ratio PSO3 / PSO2 from equation (23), we obtain:

(24)

If I designate the P - the total gas pressure (in PA), A is the initial content of S02 in the gas mixture (volume.%), B is the initial oxygen content in the gas mixture (volume%), the equation (6-6) will take the form:

(25)

The determination of the equilibrium degree of conversion according to this equation is carried out by the method of consecutive approximations. The right-hand part of the equation is substituted by the expected value of XP and conduct calculations. If the value found differs from previously accepted, the calculation is repeated.

With a decrease in temperature and increasing gas pressure, the value of XP increases. This is due to the fact that the oxidation reaction proceeds with heat release and a decrease in the total number of molecules. Below are the values \u200b\u200bof XP at different temperatures of the pressure of 0.1 MPa for a gas containing 7% S02, 11% 02 and 82% N2:

Table 2. Dependence of the degree of transformation on temperature

390 400 410 420 430 440 450 460	99,4 99,2 99,0 98,7 98,4 98,0 97,5 96,9	470 480 490 500 510 520 530 540	96,2 95,4 64,5 93,4 92,1 90,7 89,2 87,4	550 560 570 580 590 650 700 1000	85,5 82,5 80,1 77,6 75,0 58,5 43,6 5,0

The equilibrium degree of conversion depends on the ratio of SO2 and O2 in the gas, which in turn depends on the type of raw materials and the amount of air supplied. The larger the air was introduced, the less S02 and more than 02 are contained in the gas mixture and, therefore, the higher the equilibrium degree of transformation.

Table 3. Dependence of the equilibrium degree of transformation from pressure

	Xp * 100 at pressure (in MPa)
400 450 500 550 600	99,2 97,5 93,4 85,5 73,4	99,6 98,9 96,9 92,9 85.8	99,7 99,2 97,8 94,9 89,5	99,9 99,5 98,6 96,7 93,3	99,9 99,6 99,0 97,7 95,0	99,9 99,7 99,3 93,3 96,4

Table 4. Dependence of the equilibrium degree of the conversion of XP from the composition of the gas mixture (at 475 ° C and a pressure of 0.1 MPa)

		18,4 16,72 15,28 13,86 12,43	97,1 97,0 96,8 96,5 96,2		11,0 9,58 8,15 6,72	95,8 95,2 94,3 92,3

2.2 S02 reaction rate in S03

In production conditions, the oxidation rate S02 is essential.

The speed of the oxidation process S02 in S03 on the vanadium catalyst (in a fixed layer) is expressed by the equation

(26)

where the X-degree of transformation, the shares of the unit; τ - contact time, C; A-initial concentration of SOA, part of the unit; xp is the equilibrium degree of transformation, share; b - the initial concentration of oxygen, shares; T-temperature, k; P - general pressure, PA; Kr - equilibrium constant [equation (6-4)], pa-0,5; k - reaction rate constant, C-1-pa-1:

(28)

k0 - coefficient; E-Energy Activation, J / Mol;

The activation energy of sulfur oxidation oxide (IV) oxygen reaction in sulfur oxide (VI) is very large. Therefore, in the absence of a catalyst, the oxidation reaction even high temperatures Practically does not go. The use of the catalyst allows to reduce the activation energy and increase the oxidation rate.

3 oxidation S02 on a catalyst in a boiling layer

In a boiling layer, there is a very intense stirring of gas with catalyst particles, as a result of which the temperature and composition of the gas is almost the same in the entire volume of the catalyst. At the same time, the rate of external diffusion S02 and O2 to the surface of the catalyst is significantly increased.

The hydraulic resistance of the boiling layer does not depend on the grain size, therefore, very small spherical granules are used for the catalytic oxidation S02 (radius 0.5-2 mm), which ensures almost complete use of the inner surface of the catalyst.

The kinetics of the process of oxidation of sulfur dioxide on a suspended catalyst layer is largely determined by hydrodynamic factors, since in addition to intensive radial and axial stirring, gas is possible in the form of bubbles. All factors take into account very difficult. However, the pilot industrial and industrial tests show that the conditions of complete mixing are achieved in large-diameter reactors. Therefore, the speed of oxidation S02 in this case can be taken the same in all points of the boiling layer and, therefore, the calculated equation (6-19) can be represented in this form:

(29)

Where X is the degree of transformation at the outlet of the gas from the boiling layer (it is the same in the entire catalyst layer)

The dependence of XP on temperature, pressure and content of sulfur oxide (IV) in the firing gas is presented in Fig. one.

Fig. 1. Dependence of the equilibrium degree of conversion of sulfur oxide (IV) into sulfur oxide (VI) on temperature (a), pressure (b) and sulfur oxide content (IV) in gas (B).

For gas obtained by cchedan firing and burning sulfur in air, the achievement of the degree of transformation is more than 98% inexpedient, as this is due to a sharp increase in the amount of catalyst. Meanwhile, with high performance of the sulfuric acid settings (currently under construction) and the degree of conversion of 98%, the sanitary value of the S02 content in the atmosphere can only be achieved in the event of a construction of a very high (and therefore expensive) pipes for waste gases or during additional sanitary cleaning of exhaust gases. From S02, for example, when installing 5000 T / day, the amount of SO2 emitted into the atmosphere (at one point) is 100 t / day (in terms of H2S04).

To increase the final degree of conversion S02, double contacting (DC) is used. The essence of it is that the oxidation of S02 (contacting) is conducted in two stages, in the first stage, the degree of conversion of 90% is ensured. Then, S03 is separated from the reaction mixture, after which the second step of contacting is carried out, in which it is achieved in \u003d 95% of the remaining S02; The total degree of transformation is 99.5%.

The oxidation reaction S02 is reversible, so the total speed of the process W is expressed as:

where, - the rates of direct and reverse reactions; , -Constants of the direct and reverse reaction; CSO2, CO2, CSO3 - concentrations in Gaza SO2, O2, SO3; L, M, N-Oddock appropriate reaction.

It follows from equation (30) that if SO3 is derived from the reaction mixture after the first step of contacting, then before the second stage CSO3 \u003d 0 and R2 \u003d 0. Consequently, the speed of the process increases. In this case, the final degree of transformation is expressed by the equation

(31)

where x1, x2, the CP-degree of the transformation on the first, second (from the remaining after the first stage) and at the final stages, shares.

Thus, xp \u003d 0.9+ (1-0.9) 0.95 \u003d 0.995.

The contradiction between the kinetics and the thermodynamics of the sulfur oxide oxidation process (IV) is sufficiently successfully removed by the design and temperature mode of the contact apparatus. This is achieved by the breakdown of the process at the stage, each of which meets the optimal conditions of the contact process.

Table 5. The degree of transformation at each stage of the contact apparatus

3 Sulfuric Acid Technology

3.1 Raw materials for technology

The initial reagents for obtaining sulfuric acid can be element sulfur and sulfur-containing compounds from which it is possible to obtain either sulfur or sulfur dioxide. Such compounds are iron sulphides, non-ferrous metal sulphides (copper, zinc, etc.), hydrogen sulfide and a number of other sulfuric compounds.

Traditionally, the main sources of raw materials - sulfur and iron (sulfur) cchedan. Gradually, the fraction of the cchedan as a raw source decreases, which is connected with large transport costs for its transportation (except for sulfur in it, the share of other components is very large), and with the inability to get rid of waste - the flag. A significant place in the raw material balance of sulfuric acid production occupies exhaust gases of non-ferrous metallurgy containing sulfur dioxide.

For protection ambient All over the world, measures are taken on the use of waste industry containing sulfur. The atmosphere with waste gases of thermal power plants and metallurgical plants is discharged sulfur dioxide is much larger than it is used for the production of sulfuric acid. For example, in the 1980s, the global sulfur consumption was approximately 65 million tons / year, and 50 was lost, with outgoing gases (in terms of sulfur) mail 100 million tons. At the same time, due to the low concentration of SO2, in such deplents Gas recycling them is not always realized yet.

Iron Vchend.

Natural iron cchend is a complex breed consisting of FES2 iron sulfide, other metals sulphides (copper, zinc, lead, nickel, cobalt, etc.), metal carbonates and empty breed. In the territory of the Russian Federation there are rings of coledan, in the Urals and the Caucasus, where it is mined in the mines in the form of an ordinary cockeda.

The process of preparing an ordinary spelling to production aims to extract valuable non-ferrous metals from it and increasing the concentration of iron disulfide. The increase in the content of iron disulfide in the raw material by flotation of the cchedan, as well as the enrichment of air with oxygen increases the driving force of the roasting process.

In physical and chemical indicators, the flotation sulfur chemge must comply with the standards specified in Table 6.

Table 6.

The name of indicators	Norms for marks
1. Appearance	Bulk powder Do not allow foreign inclusions (pieces of breed, ore, wood, concrete, metal, etc.)
3. Total lead and zinc content,%, no more	Do not normal
7. Mass fraction of chlorine,%, no more

The sulfur is in nature in the form of metal sulphides and metals sulfates, is part of coal, oil, natural and associated gases. About 50% of the produced sulfur is used for the production of sulfuric acid.

Elementary sulfur can be obtained from sulfur ores or gases containing hydrogen sulfide or sulfur oxide SO2. In accordance with this, the sulfur native and sulfur gas (commission) is distinguished.

The thermal method of obtaining sulfur from native ores is to be placed using water vapor and cleaning raw sulfur with distillation. Obtaining gas sulfur from hydrogen sulfide, extracted during the purification of combustible and technological gases, is based on the process of incomplete oxidation of it above the solid catalyst:

H2S + O2 \u003d 2H2O + S2 (32)

Significant amounts of sulfur can be obtained from copper-smelting products containing various sulfur compounds. In this case, in the process of smelting, reactions flow, leading to the formation of elementary sulfur:

2fes2 \u003d 2fes + S2 (33) + C \u003d S + CO2 (34)

In physical and chemical parameters, the technical sulfur must comply with the standards specified in Table 7

Table 7.

Name of the indicator
1. Mass fraction of sulfur,%, not less
2. Mass fraction of ash,%. no more
3. Mass fraction organic substances, %, no more
4. Mass fraction of acids in terms of sulfuric acid,%, no more
5. Mass fraction of arsenic,%, no more
6. Mass fraction of Selena,%, NE more
7. Mass fraction of water,%, no more
8. Mechanical pollution (paper, tree, sand, etc.)	Not allowed

3.2 Technological scheme for production of sulfuric acid and its description

The largest amount of sulfuric acid production facilities uses sulfur as a raw material. Sulfur is lowered by a by-product of natural gas processing and some other industrial gases (generator, oil refining lawn). Such gases always contain some amount of sulfur compounds. The burning of the natural gas of the sulfuric gas will lead to environmental pollution by sulfur oxides. Therefore, sulfuric compounds are usually first removed and the form of hydrogen sulfide, which is then partially burned to SO2, after which a mixture of hydrogen sulfide and sulfur dioxide interacts on the bauxite layer at 270-300 ºС, turning as a result of this interaction in S and H2O. The sulfur resulting is called "gas". In addition to "Gas", native sulfur can be used as a raw material.

Sulfur as raw materials for the production of sulfuric acid has several advantages. First, it, in contrast to the sulfur cheeredan, almost does not contain impurities that could be catalytic poisons at the stage of contact oxidation of sulfur dioxide, for example, arsenic compounds. Secondly, it does not form solid and other waste, which would require storage or searching for methods for their further processing (with the cchedan firing, almost as many solid waste is formed by 1 t. Thirdly, the sulfur is much cheaper to transport than cchedan, as it is concentrated raw materials.

Consider a "short" scheme of obtaining sulfuric acid from sulfur using the DKDA method (Fig. 2).

Fig. 2. The scheme of production of sulfuric acid from sulfur according to the dual contact method and double absorption:

Furnace for burning sulfur; 2 - recycler boiler; 3 Economyzer 4 - Startup: 5. 6 - heat exchangers heat exchangers. 7 - Contact apparatus: 8 - heat exchangers 9 - drying tower. 10, 11 - the first and second monohydrate absorbers. 12 - acid collections: 13 - exhaust pipe.

The molten sulfur is passed through the mesh filters for cleaning from possible mechanical impurities (sulfur melts at a temperature. Slightly above 100 ºС, so this method of cleaning it is the easiest simple) and sent to the furnace 1, into which air is supplied as an oxidizer pre-drained with production sulfuric acid. In the drying tower 9. Outside from the furnace, the frying gas is cooled in the boiler-utilizer 2 from 1100-1200 ºС to 440-450 ºС and sent with this temperature equal to the ignition temperature of industrial catalysts based on pentoxide vanadium, on the first layer of the shelf contact apparatus 7 .

The temperature regime necessary to approximate the working line of the process to the optimal temperature line is regulated by passing the streams of partially entered into the reaction of the roasting gas through heat exchangers 8, where it is cooling with heated gas flows after absorption (or dried air). After the third step of contacting, the burgggous gas is cooled in the heat exchangers 8 and sent to the intermediate monohydrate absorber 10, irrigated circulating through a collection of acid 12 sulfuric acid with a concentration close to 98.3%. After extraction in the absorber, the sulfur trioxide and achieved due to this deviation from almost the equilibrium gas reached again heated to the ignition temperature in the heat exchangers 8 and sent to the fourth level of contact.

In this scheme for cooling gas after the fourth stage and additional mixing of equilibrium, part of the dried air is added to it. The gases reacted in the contact apparatus are passed for cooling through economizer 3 and sent to the final 11 monohydrate absorber 11, from which non-sulfur-sulfur oxides are emitted through the exhaust pipe 13 into the atmosphere.

To start the installation (withdrawing it to a given technological, in particular, the temperature, mode) is provided by the launcher 4 and the heat transfer heat exchangers 5 and 6. These devices are disconnected after the installation is output to the operating mode.

3 Waste in Sulfuric Acid Technologies and Methods for their disposal

In the production of sulfuric acid into atmospheric air due to the leakage of equipment and the incompleteness of the conversion of sulfur dioxide into the sulfuric anhydride, significant amounts of sulfur oxides are ejected. For example, with single contacting, the conversion of SO2 in SO3 reaches 98% and the content of sulfur dioxide in exhaust gases exceeds the allowable emission standards to the atmosphere of 5 or more times. Therefore, such systems provide special installations for cleaning outgoing gases. Preparation of sulfuric acid by double contacting ensures conversion to 99.8%, while SO2 emissions into the atmosphere are reduced in 2-3 times compared with single-stage contacting and no additional gas purification is required. The performance of the system increases by 20-25%, the raw materials use coefficient increases.

Inorganized emissions of sulfuric acid anosol from oleum sets range from 0.5 to 5 kg / tons of finished products.

Ammonia methods are most widely used to clean the exhaust gases of sulfuric acid production: ammonary sulfate to obtain ammonium commodity sulfate or its solutions and ammonary-cyclic to obtain 100% sulfur dioxide and ammonium commercial bisulfite. These methods of cleaning gases allow you to dispose of sulfur dioxide and at the same time get valuable products. Thus, sulfuric acid production gradually becomes non-frequensed. Currently, air pollution is usually captured using one of the following methods:

· Modification of the technological process in order to prevent or minimize the formation of polluting product.

· Installing new more efficient devices.

· Electrofilters, cyclones, wash towers, etc.

· Use of chemical or physical processes, such as adsorption, absorption, afterburning, double contact, catalytic neutralization, etc.

· Constructive decisions, for example, double, not single valves, closed valve systems, capturing emissions.

· The design of the installation should ensure reliable and safe operation of the devices, the possibility of inspection and cleaning, washing, purge and repair, as well as the necessary tests.

· Pipelines, cylinders, tanks are stained in colors corresponding to their contents, and provide an inscription with the name of the stored or transportable substance. To observe the mode of the process of production of sulfuric acid, automatic control means are installed.

Upon receipt of sulfur dioxide from the sulfur pyritan, pyrite dishar is formed. Pyrite flats consist mainly of iron (40-63%) with small sulfur impurities (1-2%), copper (0.33-0.47%), zinc (0.42-1.35%), lead ( 0.32-0.58%), precious (10-20 g / t) and other metals.

The gas exitting from the roasting furnace is contaminated with flaggy dust and other impurities. The concentration of dust in sulfur dioxide, depending on the design of furnaces, the quality and degree of raw materials, is from 1 to 200 g / m3. The volume of cubizing gases is hundreds of thousands of cubic meters per day. Before recycling, these gases are purified in cyclones and dry (agricultural) electrostilifers to residual dust content of about 0.1 g / m3. The furnace gases are subjected to further purification by a sequential washing with a cooled 60-75% (in hollow towers) and 25-40% (in the nozzle towers) with sulfuric acid with the capture of the resulting fog in wet electrostilifers. The process of additional purification of furnace gases from dust is accompanied by the formation of sludge accumulating in the equipment of the washing separation and wet electrostilifers.

Thus, the solid waste of production of sulfuric acid from the sulfur cochedane are pyrite dishes, dust of cyclones and dry electrostilifers, the sludges of washing towers that are assembled in sumps, collections and acid refrigerators, and sludge wet electrostilifers.

When firing sulfur cchedan, the waste of pyrite dishes are ~ 70% of the mass of the pitchdan. On 1 ton of the acid produced, the outage of the flack at best is 0.55 tons. Since the raw material for obtaining sulfuric acid, along with a sulfuric chest extracted specifically for this purpose, are waste generated by the enrichment of sulfide ores with a flotation method and waste formed during enrichment Stone coal, then there are three types of pyrite flats (spars from cropdans, spars from flotation tails of enrichment of sulfide ores, angry flats), significantly different from each other both by chemical composition and physical characteristics. The spars of the first two types are characterized by a significant content of copper, zinc, silver, gold and other metals.

Disposal of pyrite flames is possible in several directions: to extract non-ferrous metals and the production of cast iron and steel, in the cement and glass industry, in agriculture, etc.

4 Maximum permissible concentrations of gases, vapors and dust in the production of sulfuric acid

Substances	In the air of the working area of \u200b\u200bindustrial premises, mg / m3	Atmospheric locations
		maximum single, mg / m3	average daily, mg / m3
Mineral and vegetable dust that does not contain SiO2 and the current of the sickens
Arsenic and arsenovakovynagnridrida
Arsenic hydrogen
Nitrogen oxides (in terms of NN2O3)
Carbon oxide
Cement dust, clay, minerals and their mixtures that does not contain free SiO2
Dust Pentoxide Vanadia
Metal mercury
Lead and its inorganic connections
Selenia Amorphous
Selenite anhydride
Sulfuric acid, sulfuric anhydride
Sulfurian anhydride
Hydrogen sulfide
Phosphoric hydrogen
Hydrogen fluoride
Hydrogen chloride and hydrochloric acid (in terms of NS1)

Construction of the main apparatus

In absorbers, sulfuric acid removes from the gas mixture only sulfur trioxide, the rest of the gas, passing absorbers, is removed into the atmosphere. Usually, SO3 is absorbed in two consecutively connected absorbers: in the first - oleum and in the second - monohydrate.

The main indicator of the operation of the absorption department is the completeness of the absorption of SO3; With the optimal mode of the monohydrate absorber, the exhaust gases are practically transparent, they contain only sulfuric acid traces. At a concentration of acid, irrigating monohydrate absorber, less and more than 98.3% H2 SO4 is formed fog and exhaust gases become visible. In the monohydrate absorber, the fog is also formed with high humidity. Typically, 0.01% of water vapor remains in the gas after drying towers. Since the gas after the contact apparatus contains a large amount of SO3, then when cooled gas, the water pair is fully converted to the H2SO4 pairs, the concentration of which is also 0.01%, or 0.437 g / m3.

Sulfuric acid pairs are condensed on the surface of the absorber nozzle. At a very low temperature of irrigating acid or with increased gas humidity (sulfuric acid content in a gas of more than 0.437 g / m3), part of the sulfuric acid vapors is condensed in the volume with the formation of a fog that does not precipitate in absorbers and is ejected to the atmosphere.

When producing commercial products in the form of technical contact acid, it is usually derived from drying towers. To do this, in one of the drying towers, the concentration of acid is maintained in accordance with the standard requirements for contact technical sulfuric acid, and as it is accumulated from the collection to the warehouse. In such cases, in the absorption department (where the dilution occurs) significantly more heat is released than when the oleum is released, since the monohydrate has to be diluted with water.

1
Olemy absorber

Fig. 3 Oleum Absorber Design

Steel shelter; 2 - hatches; 3 - fence on the lid; 4 - Pipe for the supply of kis-lot; 5 - pressure tank; 6 - traction for suspension plates; 7 - steel stove with cups for acid distribution; 8 - nozzle (from below for the bottom of the rings of 150x150, 120x120, 100x100, 80x80 mm, from above 143 rows of rings 50x50 mm); 9 - grate and grate; 10 - rack (steel pipe); 11 is a steel grid with acid-resistant coating: 12 - bottom (acid-resistant brick); 13 - support beams; 14 - gas box.

At the old plants of the walls of the absorber lounge with acid-resistant brick, and the grate of the grate is mounted from Andesite or other acid-resistant plates. On the new contact plants, the steel walls of the ouhylic absorber are not lounge, the grille is mounted from steel beams.

For a uniform acid distribution along the absorber nozzle, various devices and devices are applied - steel plates in which steel or porcelain tubes are inserted, distribution gutters, sprayers, etc. In new contact plants, steel acid distributors are installed, according to the design of similar devices for the distribution of drying acid. Since even 1/3 of the sulfur trioxide, only 1/3 of the sulfur trioxide should be absorbed in the oleum absorber, the surface of contacting gas with irrigating oleum can be small, as a result of which oleum absorbers are installed in some factories without nozzle. The required surface of the contact of gas with liquid is created by splashing oleum.

The dimensions of the oleum absorber and the amount of oleum supplied to irrigation depends on the performance of the sulfuric acid system. Typically, 1 t / h of products requires the surface of the nozzle in the absorber from 600 to 1000 m2 at a gas velocity in the nozzle to 1 m / s and the density of irrigation 10-12 m3 / m2 of the ouxier cross section.

2 monohydrate absorber

Monohydrate absorber is irrigated by 98.3% sulfuric acid. In the acid absorber absorbs SO3 and its concentration increases. In the collection of acid monohydrate is diluted with water or drying acid to the initial concentration and through the refrigerator again enters the irrigation of the monohydrate absorber; The density of irrigation is about 20m3 / (m2 * h).

Fig. 4 Construction of monohydrate absorber

Steel shell: 2 - acid-resistant brick; 3 - asbestos; 4 - hatches; 5 - traction for plates suspension; 6 - pressure tank; 7 - a pipe for the feeding of an acid; 8 - fence on the lid; 9 - lid; 10 - an acid distributor on the stove; 11 - viewing window; 12 - nozzle (from below two rows of rings 150 x 150. 120x 120. 100x100 80x 80mm, above 144 rows of rings 60x 50 mm, from above Ring 80x80 mm in bulk); 13 - gas box; 14 - steel support beam; 15- Support design with brick arches; 16 - brick grate grille.

On some installations, the olemic absorber is connected to the monohydrate absorber in the shunt. In this case, the gas after an angidride refrigerator is divided into two streams, one of which is sent directly to the monohydrate absorber, and the second one comes into the outhic absorber, and from it to the monohydrate. Such a scheme allows you to include outhic absorber only when it is necessary to produce oleum.

A different design of the absorption tower is proposed, which includes (RY5): a lined with acid-resistant brick housing (1), tangentially performed inlet nozzle for the input of a gas or air mixture (2), laid out of acid-resistant bricks with a cylindrical gas distribution grille (3) having through channels Different lengths for gas pass at each level. On the gas distribution lattice, the cylindrical body of the same diameter (4) is laid out of acid-resistant bricks. The housing of the tower is filled with a nozzle (5) and is equipped with an acid distribution device (6).

The absorption tower works as follows:

The gas mixture or air flows through the input tangentially performed nozzle (2) in the annular space between the housing (1) and the inner, laid out of the acid-resistant brick, the cylindrical body (4) on the gas distribution grid (3), is distributed throughout the perimeter of the annular space and evenly arrives. Through the gas channels of the gas distribution grille on the nozzle of the absorption tower (5), on which heat exchange and mass transfer processes occur. The nozzle is irrigated by concentrated sulfuric acid through acid distribution devices (6)

For power system 120 tons per day Absorbers are installed with a diameter of 3.3 m. The distribution of irrigatory acid is produced With system Steel or cast iron grooves located under the lid of the absorber. Height of oleum absorber 12 m, and monohydrate - 13.5 m.

The schemes of absorption branches on the factories differ little from each other, the technological modes used are also similar. Below are approximate norms of the technological regime of the absorption unit at one of the contact plants:

The temperature at the outlet of the absorber, ° C, no more oleum ...................................... .................................................. ................. 60.

monohydrate ............................................................. ......................................... 60.

The concentration of irrigation acid in the absorber

in oleum,% SO3 (free) .......................................... ........................... 20 ± 1

in the monohydrate,% h2so4 ............................................. ............... 98.6 ± 0.2

The degree of absorption,%, not less ........................................... ............ 99,95

3 Technological characteristics of absorber

Factory performance, t / h

H2S04 ............................................................................10

The degree of transformation x ............................................................... 0.98 Completeness of the absorption SO3

in oleum absorber Y ...................................................... .0.5

general Z ..........................................................................................................

Concentration

oleum, irrigating olemic absorber CO,% SO3 (free) ... 20

monohydrate cm,% h2so4 ............................................... 98

tumbler SP,% H2SO4 ......... ... ................................. 93

Consumption of the roasting gas, m3 / h .......................................... 26820.

including:

sO2 .............................................................................. 2350

O2 ... ............................................................................................ .2220

N2 ........................................................................... ... 21460

couples H2O ............................................................... ... ...... 660

SO3 ................................................................................................ 130.

Barometric pressure P, PA .................................... ..1.01 * 105

Village in front of the drying tower PP, Pa ........................, 9 * 103

Gas temperature at the entrance to the drying tower, ° С .....................32

Pressure vapor water in this gas pH2O, Pa .................. .4.75 * 103

Technical and economic indicators of sulfuric acid technology

The cost of sulfuric acid significantly depends on the type of recyclable raw materials, since the cost of sulfur in various raw materials is not the same. For example, the cost of 1 tons of sulfur in the chedane is 2 times lower than in natural gray; The cost of sulfur in the exhaust gases of the metallurgical industry is not taken into account at all.

The influence of the type of raw material at the cost is also affected by the fact that the technological scheme and its instrumentation are different when working on various raw materials. Thus, when using natural sulfur, it disappears the need for gas washing, and when burning hydrogen sulfide, flushing and gas drying are not needed, thereby decreasing the costs of raw materials. The cost of sulfuric acid depends on many other factors: the remoteness of the sulfuric acid plant from the sources of raw materials, the cost of water, electricity, etc.

With an increase in the productivity of the sulfuric acid system, the cost of production is reduced, since the depreciation costs are reduced, the productivity of labor is reduced, the cost of equipment maintenance is reduced, etc. The cost of sulfuric acid is also reduced by increasing the intensity of the equipment.

An important indicator of the process of production of sulfuric acid is the cost of processing raw materials, it includes all costs with the exception of the value of raw materials. The cost of processing is continuously declining as the technological scheme of production improves, improve its hardware design, reducing consumables, increasing the performance of the system, etc. The cost of processing is the main indicator that characterizes the technical equipment and organization of production.

Table 8. Average consumable coefficients in the production of contact sulfuric acid, depending on the type of raw materials used (per 1 kg of H2S04)

Table 9. Expendable coefficients for the production of 1 ta of sulfuric acid from pure sulfur method DC-yes

CONCLUSIONS

In this abstract, the physical, chemical properties of sulfuric acid were considered. The main areas of its use are studied. The existing methods of obtaining acid are given. It was revealed that the most effective method of obtaining sulfuric acid is the method of dual contact and double absorption. The required reference data is given. Upon receipt of the roasting gas by burning sulfur, there is no need to purify the impurities, unlike the burning of the iron polegan. At this time, the development of effective catalysts continues to obtain sulfur trioxide with a maximum degree of transformation, as well as the development of installations for obtaining oleum in order to prevent emissions that do not apply to the standards of MPC and PDV. On the other hand, regardless of the type of sulfur-containing raw materials, it is advisable to apply acid-made waste in other industries (for example, cchedan flats in metallurgy). Since sulfur and pyrite reserves are exhausted, obtaining raw materials for waste gases, also decides environmental problem. Thus, sulfuric acid technology tends to waste production.

BIBLIOGRAPHY

1. Amelin A. G., Sulfuric acid technology, 2 ed., M., 1983.- 360 C.

GOST 2184-77 Sulfuric acidic acid. Technical conditions

GOST 667-73 Sulfuric accumulator acid. Technical conditions

4. Melnikov E.I, Saltanova V.P., Naumova A.M., Blinova Zh.S. Technology of inorganic substances and mineral fertilizers. Tutorial for technical schools. M.: Chemistry, 1983. - 432 p.

5. Borestkov G.K. Catalysis in the production of sulfuric acid M.-L.: Goshimzdat, 1954. - 348 p.

RF patent №94025148 / 04 Dobkin E.I.; Kuznetsova SM.; Larionov A.M. Catalyst for oxidation of sulfur dioxide // Patent of Russia №2080176, 05/27/1997

GOST 444-75 Pedagine sulfur flotation. Technical conditions

8. GOST 127.1-93. Technical sulfur. Technical conditions

Kutepov A.M., Bondareva T.I., Berengartan M.G. Common chemical technology. 3rd ed. Studies. For universities. - 3rd ed., Pererab. - M.: Academkniga, 2004. - 528 s.: Il.

10. O.A. Fediaeva Industrial Ecology . Lecture notes. - Omsk: Publishing House of OMGTU, 2007. - 145 c.

Handbook of the sulfurist / under. ed. KM Raspberries. - M.: Chemistry, 1971.

12. Syromyatnikov V.D. , Igin V.V. , Filatov Yu.V., Sostvev VS , Goloby V.I. Patent RU 2240976 Absorption tower.

13. Sokolovsky A.A., Yashka E.V. Mineral fertilizer technology and acids. - M.: Chemistry, 1979. - 384 p.

14. Reference magazine "Chemistry".

Sulfuric acid is the most important product of the chemical industry. Sulfuric acid formula H 2 SO 4. Colorless oily liquid, heavier than water. When mixed with water, hydrates are formed, a strong heating occurs, therefore it is strictly forbidden to pour water into concentrated sulfuric acid. Sulfuric acid should be poured into the water with a thin flowing with constant stirring.

Sulfuric acid takes water from organic substances, charring them. In industry, the ability of concentrated sulfuric acid binding water is used to dry out gases.

Sulfuric acid is a strong electrolyte, dissociates completely in aqueous solution. Collects Lacmus Indicators and Methyloranzh in red.

Strictly speaking, one hydrogen ion is cleaved (dissociation over the second stage is very small):

H 2 SO 4 \u003d H + + HSO 4 -

Metals located in a row of voltage to the left of hydrogen are displaced from hydrogen sulfuric acid solutions:

Zn + H 2 SO 4 \u003d ZNSO 4 + H 2 (Salt - zinc sulfate)

The oxidizer in this reaction is hydrogen acid:

Zn 0 + H 2 +1 SO 4 \u003d Zn +2 SO 4 + H 2 0

Concentrated sulfuric acid interacts when heated and with metals to the right of hydrogen, except gold and platinum. The oxidant will be sulfur. The reaction with copper is restored to sulfur oxide (IV):

CU + 2H 2 SO 4 \u003d CUSO 4 + SO 2 + 2H 2 O (colorless gas stands out)

indicating oxidation degrees:

Cu 0 + 2H 2 S +6 O 4 \u003d Cu +2 SO 4 + S +4 O 2 + 2H 2 O

At a concentration close to 100% sulfuric acid passivates iron reaction does not go.

With metal oxides, the reaction proceeds with the formation of salt and water:

MGO + H 2 SO 4 \u003d MgSO 4 + H 2 O

in ion form (oxides on ions do not expand!):

MGO + 2H + + SO 4 2- \u003d Mg 2+ + SO 4 2- + H 2 O

MGO + 2H + \u003d Mg 2+ + H 2 O

Sulfuric acid reacts with bases, with the formation of salt and water:

2NAOH + H 2 SO 4 \u003d Na 2 SO 4 + 2H 2 O

in ion form:

2NA + + 2OH - + 2H + + SO 4 2- \u003d 2NA + + SO 4 2- + 2H 2 O

OH - + H + \u003d H 2 O

A high-quality reaction to sulfate ion is the interaction with bary salts - the white crystalline precipitate of barium sulfate is falling out, insoluble in nitric acid:

H 2 SO 4 + BACL 2 \u003d BASO 4 ↓ + 2HCl

2H + + SO 4 2- + Ba 2+ + 2Cl - \u003d Baso 4 ↓ + 2H + + 2Cl -

SO 4 2- + Ba 2+ \u003d Baso 4 ↓

Sulfuric acid is used to obtain many acids, as it displaces them from salts. In the laboratory, so can be obtained hydrochloric acid (when heated, followed by dissolving in the water of the highlighted chloride hydrogen), etc.:

2NACL + H 2 SO 4 \u003d Na 2 SO 4 + 2HCl

abbreviated ion equation:

Cl - + H + \u003d HCl

Sulfuric acid is used in industry for cleaning petroleum products, surfaces of metals before applying coatings, cleaning (refining) of copper, in the production of fertilizers, glucose, etc.

2. Getting and collecting carbon dioxide. Proof of this gas in a vessel

Carbon dioxide in the laboratory is obtained by stuck

1. hydrochloric acid to chalk:
   Caco 3 + 2HCl \u003d CaCl 2 + H 2 O + CO 2
2. salt or sulfuric acid to soda:
   Na 2 CO 3 + 2HCl \u003d 2NACL + H 2 O + CO 2

We close the test tube where the reaction is a reaction, a plug with a gas-conductive tube. The tube is lowered into the flask (carbon dioxide is heavier than air), it is advisable to cover with a piece of cotton wool.

We prove the presence of carbon dioxide, stuck in the flask a transparent solution of lime water, we take up. Lime water is purified due to the formation of an insoluble calcium carbonate:

Ca (OH) 2 + CO 2 \u003d Caco 3 ↓ + H 2 O

Sulfuric acid molecule has a cross-shaped form:

Physical properties Sulfuric acid:

• dense oily liquid without color and smell;
• density 1.83 g / cm 3;
• melting point 10.3 ° C;
• boiling point 296.2 ° C;
• very hygroscopic, mixed with water in any respect;
• in the dissolution of concentrated sulfuric acid in water, a large amount of heat is highlighted ( IMPORTANT! Acute acid into the water! It is impossible to stick water into acid !!!)

Sulfuric acid is two types:

• diluted H 2 SO 4 (spz) is an aqueous acid solution in which the percentage of H 2 SO 4 does not exceed 70%;
• concentrated H 2 SO 4 (conc) - an aqueous acid solution in which the percentage of H 2 SO 4 exceeds 70%;

Chemical properties H 2 SO 4

Sulfuric acid completely dissociates in aqueous solutions in two steps:

H 2 SO 4 ↔ H + + HSO 4 - HSO 4 - ↔ H + + SO 4 -

Diluted sulfuric acid exhibits all characteristic properties strong acidsWhen reacting:

• with main oxides: MGO + H 2 SO 4 \u003d MgSO 4 + H 2 O
• with bases: H 2 SO 4 + 2NAOH \u003d Na 2 SO 4 + 2H 2 O
• with salts: H 2 SO 4 + BACL 2 \u003d BASO 4 ↓ + 2HCl High-quality reaction to sulfate ion: SO 4 2- + Ba 2+ \u003d Baso 4 ↓

Obtaining and use of sulfuric acid

Sulfuric acid in industry is obtained in two ways: contact and nitrosny.

Contact method Preparation H 2 SO 4:

• At the first stage, sulfur gas is obtained by burning sulfur cochedane: 4fes 2 + 11o 2 \u003d 2fe 2 O 3 + 8SO 2
• At the second stage, sulfur gas oxidize oxygen to sulfuric anhydride, the reaction is in the presence of vanadium oxide, which plays the role of the catalyst: 2SO 2 + O 2 \u003d 2SO 3
• In the third, last stage, oleum is obtained, for this sulfuric anhydride is dissolved in concentrated sulfuric acid: H 2 SO 4 + NSO 3 ↔ H 2 SO 4 · NSO 3
• In the future, oleum is transported in iron tanks, and sulfuric acid is obtained from oleum by diluting with water: H 2 SO 4 · NSO 3 + H 2 O → H 2 SO 4

Nitrosical way Preparation H 2 SO 4:

• At the first stage, the sulfuric gas purified from dust is treated with sulfuric acid, in which nitro is dissolved (nitrogen oxide): SO 2 + H 2 O + N 2 O 3 \u003d H 2 SO 4 + 2NO
• The separated nitrogen oxide is oxidized by oxygen and is again absorbed by sulfuric acid: 2NO + O 2 \u003d 2NO 2 NO 2 + NO \u003d N 2 O 3

Sulfuric acid use:

• for gaza drying;
• in the production of other acids, salts, alkalis, and so on.;
• for fertilizers, dyes, detergents;
• in organic synthesis;
• in the production of organic substances.

Salt sulfuric acid

Since sulfuric acid is a two-friendly acid, it gives two types of salts: medium salts (sulfates) and sour salts (hydrosulfate).

Sulfates are well soluble in water, the exception is Caso 4, PBSO 4, BASO 4 - the first two are poorly dissolved, and barium sulfate is practically insoluble. Sulfates, which include water, are called vitriors (copper vigorous - Cuso 4 · 5H 2 O).

A distinctive feature of sulfuric acid salts is their ratio to heating, for example, sodium sulfates, potassium, barium resistant to heating, without decomposing even at 1000 ° C, at the same time, copper sulfates, aluminum, iron decompose even with insignificant heating with oxide formation Metal and sulfuric anhydride: CusO4 \u003d Cuo + SO 3.

Bitter (MgSO 4 · 7H 2 O) and Glauberova (Na 2 SO 4 · 10H 2 O) Salt is used as a laxative. Calcium sulfate (CASO 4 · 2H 2 O) - in the manufacture of gypsum bandages.