RU2843010C1 - Method of producing nitric acid and apparatus for realizing said method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry and in production of fertiliser. Method of producing nitric acid involves: a) air compression stage with production of compressed air flow; b) a step of producing first and second streams of ammonia gas; c) a step of producing an ammonia-air mixture, comprising mixing a first ammonia stream with a stream of compressed air obtained at step a); d) a step of converting the ammonia-air mixture obtained at step c) into nitrous gases; e) a step of cooling the nitrous gases obtained in step d); f) a step for absorbing nitrous gases obtained in step e), to obtain nitric acid and separating the stream of tail gases; g) a step of heating the tail gases obtained in step f) by cooling the nitrous gases obtained in step d); h) a step of heating the tail gases obtained in step g) in a turbine combustion chamber by heat of exhaust gases obtained from burning natural gas in the turbine combustion chamber; i) a step for mixing the tail gases obtained in step h) with a second ammonia gas stream obtained in step b); j) a step for catalytically cleaning the tail gases obtained in step i) in a selective cleaning reactor with separation of the stream of cleaned tail gases; k) a step of recovering energy of the scrubbed tail gases obtained in step j). An apparatus for producing nitric acid is also disclosed.

EFFECT: group of inventions increases efficiency of cleaning tail gases from production of nitric acid due to simultaneous reduction of emissions of NO and N₂O into the atmosphere, improves environmental friendliness of production of nitric acid.

14 cl, 2 dwg, 1 tbl, 2 ex

Description

Field of technology

The proposed invention relates to a method and installation for producing nitric acid and can be used in the chemical industry and in the production of fertilizers.

Prior art

To obtain nitric acid from ammonia, the following steps are traditionally used:

⋅ air preparation and compression;

⋅ preparation of gaseous ammonia;

⋅ preparation of ammonia-air mixture;

⋅ conversion of ammonia into nitrous gases;

⋅ cooling of nitrous gas with heat recovery;

⋅ absorption of nitrogen oxides;

⋅ catalytic purification of exhaust (tail) gases from residual nitrogen oxides;

⋅ energy recovery of purified exhaust gas;

⋅ storage and distribution of production acid.

From D1 (A.P. Ilyin et al., Production of nitric acid. Textbook. Ivan. state chemical-technological university, Ivanovo, 2011, Fig. 2.1) a method for obtaining nitric acid is known, including:

a) a stage of air compression to obtain a flow of compressed air, part of which is used to cool the elements of the gas turbine;

b) a stage of preparing an ammonia-air mixture, including mixing ammonia with a flow of compressed air obtained in stage a);

c) a stage of converting the ammonia-air mixture obtained in stage b) into nitrous gases;

d) a stage of cooling the nitrous gases obtained in stage c);

e) a stage of absorption of nitrous gases obtained in stage d) to produce nitric acid and release a tail gas stream;

f) a stage of heating the tail gases obtained in stage e) in a first stage tail gas heater by cooling the nitrous gases;

g) a stage of heating the tail gases obtained in stage f) in the combustion chamber of the reactor;

h) a stage of catalytic purification (using a palladium-containing catalyst) of the tail gases obtained in stage g) from nitrogen oxides with the release of a stream of purified tail gases;

i) the stage of mixing the purified tail gases with the flue gases of the turbine combustion chamber;

j) the stage of converting the internal energy of purified tail gases into mechanical energy.

In the proposed method, the stage of catalytic cleaning of tail gases precedes the stage of heating the tail gases in the combustion chamber of the turbine. In the combustion chamber, nitrogen oxides are formed, which are then released into the atmosphere, which reduces the environmental friendliness of the technology. In addition, in the proposed method for catalytic cleaning of tail gases, a catalyst containing rare, hard-to-extract palladium is used. Also in this method, the elements of the gas turbine are cooled by a flow of compressed air, which reduces the amount of compressed air that can be supplied to the technology in order to increase the production of nitric acid.

The closest analogue of the present invention is the method for producing nitric acid known from D2 (A.P. Ilyin et al., Production of nitric acid. Study guide. Ivan. state chemical-technological university, Ivanovo, 2011, Fig. 2.15), which includes:

a) a stage of air compression to obtain a flow of compressed air, part of which is used to cool the elements of the gas turbine;

b) a stage for obtaining first and second streams of gaseous ammonia;

c) a stage of obtaining an ammonia-air mixture, including mixing the first flow of ammonia with the flow of compressed air obtained in stage a);

d) a stage of converting the ammonia-air mixture obtained in stage c) into nitrous gases;

e) a stage of cooling the nitrous gases obtained in stage d);

f) a stage of absorption of nitrous gases obtained in stage e), with the production of nitric acid and the separation of a tail gas stream;

g) a stage of heating the tail gases obtained in stage f) by cooling the nitrous gases obtained in stage d);

h) a stage of catalytic purification of the tail gases obtained in stage g) in a selective purification reactor with the separation of a stream of purified tail gases, into which a second stream of gaseous ammonia obtained in stage b) is also fed);

i) a step of heating the purified tail gases obtained in step h) in the combustion chamber of the turbine using the heat of the flue gases obtained from the combustion of natural gas in the combustion chamber of the turbine;

j) a stage of energy recovery from the purified tail gases obtained in stage i).

In this method, the stage of catalytic cleaning of tail gases precedes the stage of heating the tail gases in the combustion chamber of the turbine. In the combustion chamber, nitrogen oxides are formed, which are then released into the atmosphere, which reduces the environmental friendliness of the technology. In addition, the vanadium catalyst used in the method generates additional nitrous oxide, rather than facilitating its removal, which further reduces the environmental friendliness of the technology. Also in this method, the elements of the gas turbine are cooled by a flow of compressed air, which reduces the amount of compressed air that can be supplied to the technology in order to increase the production of nitric acid.

Disclosure of the essence of the invention

The objective and technical result of the present invention is to improve the environmental performance of nitric acid production by simultaneously reducing NO _x and N ₂ O emissions into the atmosphere. Additionally, increasing the energy efficiency of the technology while improving the environmental performance of production, increasing the efficiency of reducing NO _x at the system outlet to ≥ 98.5%, increasing the efficiency of reducing N ₂ O at the system outlet to ≥ 97%, increasing the service life of the catalyst, with estimated indicators from the start of operation: ≥ 5 years after the first exposure to gas.

To solve the problem and achieve a technical result, a method for obtaining nitric acid is proposed, including:

a) the stage of air compression to obtain a flow of compressed air;

b) a stage for obtaining first and second streams of gaseous ammonia;

c) a stage of obtaining an ammonia-air mixture, including mixing the first flow of ammonia with the flow of compressed air obtained in stage a);

d) a stage of converting the ammonia-air mixture obtained in stage c) into nitrous gases;

e) a stage of cooling the nitrous gases obtained in stage d);

f) a stage of absorption of nitrous gases obtained in stage e), with the production of nitric acid and the separation of a tail gas stream;

g) a stage of heating the tail gases obtained in stage f) by cooling the nitrous gases obtained in stage d);

h) a stage of heating the tail gases obtained in stage g) in the combustion chamber of the turbine using the heat of the flue gases obtained from the combustion of natural gas in the combustion chamber of the turbine;

i) a step of mixing the tail gases obtained in step h) with the second stream of gaseous ammonia obtained in step b);

j) a stage of catalytic purification of the tail gases obtained in stage i) in a selective purification reactor with the separation of a stream of purified tail gases;

k) a stage of energy recovery from the purified tail gases obtained in stage j).

Nitrogen oxides formed in the combustion chamber enter the selective purification reactor, where they are reduced to nitrogen. Thus, in the proposed method, the content of nitrogen oxides in the purified tail gas, which negatively affects the increase in gas emissions, is reduced. Conditions are provided for the removal (thermal decomposition) of nitrous oxide to nitrogen.

In this application, nitrogen oxides (NO _x ) refer to the oxides NO and NO ₂ .

In this application, tail (exhaust) gases are understood to mean gases from the production of nitric acid, leaving the absorption column, containing more than 0.05% nitrogen oxides.

In this application, purified tail (exhaust) gases are understood to mean tail (exhaust) gases after their catalytic purification from nitrogen oxides.

Preferably, a portion of the purified tail gas stream obtained in step j) is diverted as a side stream of purified tail gases for cooling in a purified tail gas cooling unit and then directed to cooling elements of a gas turbine.

In standard technologies for producing nitric acid, gas turbine elements are cooled by a flow of compressed air. The present invention proposes to cool turbine elements by a flow of purified tail gas, due to which the released air can be used in the technology, which further increases the energy efficiency of the proposed method.

Preferably, in the cooling unit for purified tail gases, two-stage cooling of the purified tail gases occurs: in the first stage - with water or by generating steam, in the second stage - with water.

In the case of using one stage, an increased temperature difference between the refrigerant and heat carriers may be observed, which will lead to additional complexity of the design and to an additional decrease in the reliability of the heat exchanger.

Preferably, a zeolite catalyst, preferably a honeycomb zeolite catalyst, is used in the selective purification reactor.

The use of a zeolite catalyst with a honeycomb structure provides a lower pressure drop, and also leads to a reduction in the use of active components of the catalyst due to the ceramic carrier, ensuring the convenience of loading and operating the catalyst, in particular, due to the absence of dust.

Preferably, Fe-ZSM-5, Fe-BEA, Fe-ZSM-12, Fe/HZSM-5, Fe-Ferrierite, Cu-ZSM-5, Cu-BEA, Cu-ZSM-12, Cu/HZSM-5, Cu-Ferrierite are used as the zeolite catalyst.

By modifying iron or copper to the beta position, the catalyst gains increased efficiency in the nitrous oxide removal process without generating nitrous oxide ( _N2O ), which further improves the environmental friendliness of the process.

Preferably, step k) of recovering energy from purified tail gases comprises converting the internal energy of the gases into mechanical energy of rotation of the turbine.

Energy recovery from purified tail gases further increases the energy efficiency of the technology.

Preferably, stage j) of catalytic purification of tail gases is carried out at a temperature of 450-700°C, preferably 550-600°C.

The specified temperature range allows for the most suitable conditions for the removal of nitrous oxide (i.e. for the thermal decomposition of nitrous oxide to nitrogen).

Also, to solve the problem and achieve the technical result, a nitric acid production unit is proposed, including

a compressed air receiving unit connected to a compressed air flow discharge line;

a gaseous ammonia production unit connected to a first ammonia flow discharge line and a second ammonia flow discharge line;

an ammonia-air mixture obtaining unit connected to a compressed air flow supply line, a first ammonia flow supply line and an ammonia-air mixture flow discharge line;

an ammonia-air mixture conversion unit connected to the ammonia-air mixture flow supply line and the L1 nitrous gas flow discharge line;

a nitrous gas cooling and tail gas heating unit connected to a nitrous gas supply line L1, a cooled nitrous gas discharge line, a tail gas supply line L2 and a tail gas discharge line L3, configured to heat the tail gases by cooling the nitrous gases;

a nitrous gas absorption unit connected to a cooled nitrous gas supply line, a nitric acid discharge line and a tail gas discharge line L2;

a tail gas heating unit comprising a natural gas combustion chamber and connected to a tail gas supply line L3, and also configured to heat the tail gases with flue gases generated in the combustion chamber and connected to a tail gas discharge line L4;

a tail gas purification unit comprising a selective purification reactor configured to purify tail gases using gaseous ammonia as a reducing agent, connected to a tail gas supply line L4 and a purified tail gas discharge line, wherein line L4 is connected to a second ammonia flow supply line;

a purified tail gas energy recovery unit connected to the purified tail gas feed line.

Preferably, the line for removing the flow of purified tail gases is designed to remove a side flow of purified tail gases.

Preferably, the installation comprises a purified tail gas cooling unit connected to a supply line for a side stream of purified tail gases.

Preferably, the tail gas cooling unit includes a tail gas cooling unit with water or by generating steam and a tail gas cooling unit with water.

Preferably, the selective purification reactor comprises a zeolite catalyst, preferably a honeycomb zeolite catalyst.

Preferably, the zeolite catalyst is a Fe zeolite or a Cu zeolite, preferably Fe-ZSM-5, Fe-BEA, Fe-ZSM-12, Fe/HZSM-5, Fe-Ferrierite, Cu-ZSM-5, Cu-BEA, Cu-ZSM-12, Cu/HZSM-5, Cu-Ferrierite.

Preferably, the purified tail gas energy recovery unit includes a unit for converting the internal energy of the gases into mechanical energy of turbine rotation.

It is further noted that all the advantages of the present invention indicated in relation to the method for producing nitric acid are equally applicable to the claimed installation and are not repeated here in order to avoid unnecessary duplication.

Brief description of the drawings

The drawings are presented for a better understanding of the invention, however, it will be obvious to a person skilled in the art that the disclosed invention is not limited to the embodiment shown therein.

Fig. 1 shows a diagram of the production of nitric acid according to the prototype.

Fig. 2 shows a diagram of the production of nitric acid according to the present invention.

The best embodiment of the invention

The described examples of implementation are given solely for illustrative purposes. It will be obvious to a specialist that other embodiments are possible without changing the essence of the invention.

In this application, a line is understood to mean a means for delivering a flow from one place to another, which, in particular, includes the pipes and connecting elements necessary for this, as well as, if necessary, control means and devices.

In this application, a block is understood to be a device or a set of devices that ensure the implementation of the function specified for a given block.

It is further noted that, unless otherwise indicated, all positions (blocks, devices, lines) of the process flow diagrams, designated identically in Fig. 1, 2, imply complete functional identity.

Example 1 (prototype)

Fig. 1 shows a diagram of the production of nitric acid according to the prototype. A flow of liquid ammonia is fed into the gaseous ammonia preparation unit 1 via line 100 from the plant network (not shown). In unit 1 , a flow of gaseous ammonia is prepared, which is fed via line 103 to the ammonia-air mixture preparation unit 3 .

The atmospheric air flow is taken by the axial compressor OK along line 200 through the air intake pipe (not shown) into the air preparation unit 2 (air filter), where the air is cleaned. The air entering the axial compressor is heated by feeding hot air into it from the supercharger CN .

From the air preparation unit 2 , the purified air flow is fed through line 201 to the axial compressor OK , where it is compressed and heated. Then the air flow is fed through line 202 to the intermediate air cooler VP , where it is cooled by circulating water (not shown) and then through line 203 to the centrifugal supercharger CN , where it is compressed and heated. The axial compressor OK and the centrifugal supercharger CN of the GTT-3M gas turbine unit are driven by the gas turbine GT , which is structurally combined in one casing with the compressor.

From the blower, the air flow is fed through line 303 to block 3 for preparing the ammonia-air mixture.

Air is also directed through line 208 to the purge column 8 as additional air for the oxidation of nitrogen oxide into dioxide and the purge of nitrogen oxides from the product acid.

In addition, the air flow through line 204 is directed into the combustion chamber of the UKST turbine.

In addition, part of the air flow is directed to the gas turbine of the GTT-3M unit to cool the elements of the flow part of the housing (not shown).

Next, in block 3 for preparing the ammonia-air mixture, where a flow of air is supplied through line 303 and ammonia through line 103 , an ammonia-air mixture is formed, which is then purified from impurities and supplied to contact apparatus 4 through line 304 .

In the contact apparatus, ammonia is oxidized to nitrogen oxide (II) and, partially, to nitrogen oxide (IV). The hot nitrous gases formed during the oxidation of ammonia enter the waste heat boiler (not shown). In the waste heat boiler, due to the cooling of the nitrous gases, the feed water evaporates, producing superheated steam (not shown).

The flow of nitrous gases obtained in the contact apparatus 4 is directed via line 400 to the oxidizer O with a built-in tail gas heater UGS2 , where the oxidation of nitrogen oxides (II) into nitrogen oxides (IV) occurs. Then, part of the flow of nitrous gases is directed to UGS2 and cooled by heating the tail gases in UGS2 . The second part of the flow of nitrous gases from O is bypassed past UGS2 , then both flows are combined and fed via line 500 (L1) to the first stage tail gas heater UGS . In the tail gas heater, nitrous gases are cooled, heating the tail gases.

From the UGS, the flow of nitrous gases is fed through line 600 into the intertube space of the refrigerator-condensers 5 , 6 , where the flow is cooled by circulating water (not shown) coming from the absorption unit 7 .

From the refrigerator-condensers, nitrous gases are fed through line 607 to absorption block 7 , where nitric acid is formed.

The nitric acid stream after the absorption unit 7 is fed to the purge column 8 , where nitrogen oxides are purged from it with hot additional air. The purged (bleached) nitric acid from the purge column is discharged into one of the storage facilities of the warehouse via line 800. The purged gases from the purge column, in order to ensure complete oxidation of nitrogen oxide (II) (NO) into nitrogen oxide (IV) (NO ₂ ), are fed into the nitrous gas pipeline before the absorption column via line 807 .

The tail (exhaust) gas flow leaving the absorption column enters the UGS via line 706 (L2), where it is heated by nitrous gases. The tail gas flow is then sent via line 605 to the UGS2 tail gas heater, built into the oxidizer, where the tail gas flow is heated by the heat of the nitrous gases.

The heated tail gas flow is sent via line 606 to the selective purification reactor RSO , where ammonia is also supplied via line 101. In the selective purification reactor, the process of reducing nitrogen oxides mainly to molecular nitrogen occurs at temperatures of 200-350°C.

In the RSO, a stream of purified tail gas is formed, which is fed through line 900 into the universal combustion chamber of the UKST turbine. Then the purified tail gas enters the gas turbine GT through line 901. In the gas turbine, the internal energy of the gases is converted into mechanical energy (turbine rotation energy).

Then the purified tail gases are fed to the gas turbine waste heat boiler GKU via line 902 , then to the economizer E via line 904 , where they are cooled and then released into the atmosphere via line 905. In the waste heat boiler, superheated steam with a pressure of no more than 1.5 MPa is generated due to the cooling of purified gases, which is discharged into the plant network via line 903 (not shown). Heated deaerated chemically purified water (not shown) is used as feed water for the waste heat boilers. The feed water passes through the economizer E , where it is heated by purified tail gases to a temperature and fed to the waste heat boiler GKU . In the waste heat boiler, due to the heat of the purified tail gases, the feed water evaporates, forming steam.

Example 2

Fig. 2 shows a modernized scheme for obtaining nitric acid according to the present invention. The stages of implementing the example, which coincide with the prototype, are not repeated in order to avoid duplication.

The heated tail gas flow is directed through line 608 (L3) to the universal combustion chamber of the UKST turbine, where it is heated to 610÷620°C by mixing it with flue gases obtained from burning natural gas supplied through line 909 in a flow of air supplied through line 204. The tail gas flow leaving the combustion chamber is diverted through line 609 (L4), mixed with a flow of ammonia supplied through line 101 and supplied to the RSO.

The purification process is carried out with ammonia at a temperature of 450÷700°C on a zeolite catalyst of a honeycomb structure in a vertical reactor according to the following reactions:

4NO + O ₂ + 4NH ₃ → 4N ₂ + 6H ₂ O

NO + NO ₂ + 2NH ₃ → 2N ₂ + 3H2O

6NO ₂ + 8NH ₃ → 7N ₂ + 12H ₂ O

The presence of NO _x will promote the decomposition of N ₂ O:

_2N2O → _2N2 + _O2

The flow of purified tail gases leaving the RSO is diverted via line 901 to the gas turbine GT. In the gas turbine, the internal energy of the gases is converted into mechanical energy (turbine rotation energy).

Part of the purified tail gas flow is diverted via line 906 to purified tail gas cooling unit 9. In purified tail gas cooling unit 9, two-stage cooling of the purified tail gas occurs: at the first stage - by generating steam, at the second stage - by water.

At the first stage, cooling of purified tail gases can also be carried out by additional heating of the feedwater of the GKU boiler or by means of circulating water.

At the second stage of cooling the purified tail gases, recycled water from the water circulation cycle of the enterprise, as well as chemically purified or partially desalinated water for feeding the waste heat boiler from the chemical water treatment shop, can be used.

The cooled purified tail gas flow is removed via line 907 and sent further to cool the turbine elements (not shown). Compressed air is not supplied to cool the turbine elements and is completely consumed in the technology to increase the production of nitric acid.

All the above lines are equipped with means for measuring volume flow, temperature and pressure. Lines 606, 608, 905 are additionally equipped with automated gas analyzers with the ability to measure nitrogen oxide content.

The table below shows the results of the experiment (volume flow rate is reduced to standard conditions: 20°C, 1 atm):

Indicator Meaning (Fig. 1) Meaning (Fig. 2) Ammonia in line 103 - temperature 100°С 100°С - pressure 0.7 MPa 0.7 MPa - volumetric flow rate 5953 ^m3 /h 6780 ^m3 /h Ammonia in line 101 - temperature 100°С 100°С - pressure 0.7 MPa 0.7 MPa - volumetric flow rate 120 ^m3 /h 80 ^m3 /h Air in line 303 - temperature 150°С 150°С - pressure 0.7 MPa 0.7 MPa - volumetric flow rate 51263 ^m3 /h 58400 ^m3 /h Ammonia-air mixture in line 304 - temperature 145°C 145°C - pressure 0.7 MPa 0.7 MPa - volumetric flow rate 57216 ^m3 /h 65180 ^m3 /h Nitrous gases in line 400 - temperature 285°C 285°C - pressure 0.7 MPa 0.7 MPa - volumetric flow rate 56910 ^m3 /h 65570 ^m3 /h Nitrous gases in line 500 - temperature 272°C 272°C - pressure 0.689 MPa 0.689 MPa - volumetric flow rate 56408 ^m3 /h 64320 ^m3 /h Nitrous gases in line 607 - temperature 45°C 45°C - pressure 0.678 MPa 0.678 MPa - volumetric flow rate 51100 ^m3 /h 53950 ^m3 /h Tail gases in line 706 - temperature 35°C 35°C - pressure 0.62 MPa 0.62 MPa - volumetric flow rate 51508 ^m3 /h 58220 ^m3 /h Tail gases in line 605 - temperature 153°C 153°C - pressure 0.618 MPa 0.618 MPa - volumetric flow rate 51508 ^m3 /h 58220 ^m3 /h Tail gases in line 606 - temperature 250°С - - pressure 0.616 MPa - - volumetric flow rate 51508 ^m3 /h - Tail gases in line 608 - temperature - 280°С - pressure - 0.616 MPa - volumetric flow rate - 58220 ^m3 /h Tail gases in line 609 - temperature - 600°С - pressure - 0.61 MPa - volumetric flow rate - 72720 ^m3 /h Cleaned tail gases in line 900 - temperature 265°C - - pressure 0.61 MPa - - volumetric flow rate 51810 ^m3 /h - Cleaned tail gases in line 901 - temperature 650°С 620°С - pressure 0.61 MPa 0.61 MPa - volumetric flow rate 66010 ^m3 /h 72800 ^m3 /h Cleaned tail gases in line 902 - temperature 353°C 350°С - pressure 0.104 MPa 0.104 MPa - volumetric flow rate 74210 ^m3 /h 78200 ^m3 /h Cleaned tail gases in line 906 - temperature - 620°С - pressure - 0.61 MPa - volumetric flow rate - 5400 ^m3 /h Cleaned tail gases in line 907 - temperature - 150°С - pressure - 0.6 MPa - volumetric flow rate - 5400 ^m3 /h Cleaned tail gases in line 904 - temperature 265°C 265°C - pressure 0.099 MPa 0.099 MPa - volumetric flow rate 74210 ^m3 /h 78200 ^m3 /h The catalyst used AVK-10M Fe-BEA Nitric acid monohydrate performance 15.5 t/h 16.5 t/h NOx content in gases supplied via line 606 1200 ppm - NOx content in gases supplied via line 608 - 1200 ppm NOx content in gases discharged via line 905 50 ppm 10 ppm NOx reduction efficiency 96% 99% _N2O content in gases supplied via line 606 1200 ppm - _N2O content in gases supplied via line 608 - 1200 ppm _N2O content in gases discharged via line 905 1320 ppm 10 ppm _N2O Reduction Efficiency Generation of additional _N2O up to 10% 99% Service life of the catalyst from the beginning of operation ≥ 5 years ≥ 5 years

Thus, the proposed group of inventions allows to ensure:

- improving the environmental performance of nitric acid production by simultaneously reducing NO _x and N ₂ O emissions into the atmosphere;

- increasing the energy efficiency of technology while improving the environmental performance of production;

- efficiency of NO _x reduction at the system outlet ≥ 98.5%;

- efficiency of _N2O reduction at the system outlet ≥ 97%;

- increase in the service life of the catalyst with calculated indicators from the start of operation: ≥ 5 years after the first exposure to gas.

Claims (34)

1. A method for producing nitric acid, comprising a) the stage of air compression to obtain a flow of compressed air; b) a stage for obtaining first and second streams of gaseous ammonia; c) a stage of obtaining an ammonia-air mixture, including mixing the first flow of ammonia with the flow of compressed air obtained in stage a); d) a stage of converting the ammonia-air mixture obtained in stage c) into nitrous gases; e) a stage of cooling the nitrous gases obtained in stage d); f) a stage of absorption of nitrous gases obtained in stage e), with the production of nitric acid and the separation of a tail gas stream; g) a stage of heating the tail gases obtained in stage f) by cooling the nitrous gases obtained in stage d); h) a stage of heating the tail gases obtained in stage g) in the combustion chamber of the turbine using the heat of the flue gases obtained from the combustion of natural gas in the combustion chamber of the turbine; i) a step of mixing the tail gases obtained in step h) with the second stream of gaseous ammonia obtained in step b); j) a stage of catalytic purification of the tail gases obtained in stage i) in a selective purification reactor with the separation of a stream of purified tail gases; k) a stage of energy recovery from the purified tail gases obtained in stage j). 2. The method according to paragraph 1, characterized in that part of the flow of purified tail gases obtained in stage j) is diverted as a side flow of purified tail gases for cooling in a purified tail gas cooling unit and then sent to cool elements of the gas turbine. 3. The method according to paragraph 2, characterized in that in the cooling unit for purified tail gases, two-stage cooling of the purified tail gases is carried out: in the first stage with water or by generating steam, and in the second stage with water. 4. The method according to claim 1, characterized in that a zeolite catalyst, preferably a zeolite catalyst with a honeycomb structure, is used in the selective purification reactor. 5. The method according to claim 4, characterized in that the zeolite catalyst used is a Fe zeolite or a Cu zeolite, preferably Fe-ZSM-5, Fe-BEA, Fe-ZSM-12, Fe/HZSM-5, Fe-Ferrierite, Cu-ZSM-5, Cu-BEA, Cu-ZSM-12, Cu/HZSM-5, Cu-Ferrierite. 6. The method according to claim 1, characterized in that stage k) of recovering the energy of purified tail gases includes converting the internal energy of the gases into mechanical energy of rotation of the turbine. 7. The method according to claim 1, characterized in that stage j) of catalytic purification of tail gases is carried out at a temperature of 450-700°C, preferably 550-600°C. 8. A nitric acid production plant, including a compressed air receiving unit connected to a compressed air flow discharge line; a gaseous ammonia production unit connected to a first ammonia flow discharge line and a second ammonia flow discharge line; an ammonia-air mixture obtaining unit connected to a compressed air flow supply line, a first ammonia flow supply line and an ammonia-air mixture flow discharge line; an ammonia-air mixture conversion unit connected to the ammonia-air mixture flow supply line and the L1 nitrous gas flow discharge line; a nitrous gas cooling and tail gas heating unit connected to a nitrous gas supply line L1, a cooled nitrous gas discharge line, a tail gas supply line L2 and a tail gas discharge line L3, configured to heat the tail gases by cooling the nitrous gases; a nitrous gas absorption unit connected to a cooled nitrous gas supply line, a nitric acid discharge line and a tail gas discharge line L2; a tail gas heating unit comprising a natural gas combustion chamber and connected to a tail gas supply line L3, and also configured to heat the tail gases with flue gases generated in the combustion chamber and connected to a tail gas discharge line L4; a tail gas purification unit comprising a selective purification reactor configured to purify tail gases using gaseous ammonia as a reducing agent, connected to a tail gas supply line L4 and a purified tail gas discharge line, wherein line L4 is connected to a second ammonia flow supply line; a purified tail gas energy recovery unit connected to the purified tail gas feed line. 9. The installation according to item 8, characterized in that the line for removing the flow of purified tail gases is designed with the possibility of removing a side flow of purified tail gases. 10. The installation according to item 9, characterized in that it contains a cooling unit for purified tail gases, connected to a supply line for a side stream of purified tail gases. 11. The installation according to item 10, characterized in that the cooling unit for purified tail gases includes a cooling unit for tail gases with water or by generating steam and a cooling unit for tail gases with water. 12. The installation according to item 8, characterized in that the selective purification reactor contains a zeolite catalyst, preferably a zeolite catalyst with a honeycomb structure. 13. The installation according to claim 12, characterized in that the zeolite catalyst is a Fe-zeolite or a Cu-zeolite, preferably Fe-ZSM-5, Fe-BEA, Fe-ZSM-12, Fe/HZSM-5, Fe-Ferrierite, Cu-ZSM-5, Cu-BEA, Cu-ZSM-12, Cu/HZSM-5, Cu-Ferrierite. 14. The installation according to item 8, characterized in that the unit for recovering the energy of purified tail gases includes a unit for converting the internal energy of gases into mechanical energy of turbine rotation.