KR102452927B1 - Nitrogen oxide emission reduction system using ammonium carbonate - Google Patents

Abstract

The present invention relates to a device for reducing nitrogen oxide emissions using ammonium carbon which actively implements the simplification of a process due to the omission of the hydrolysis process of urea water and dramatically reduces nitrogen oxides due to a selective reduction catalyst method that induces direct contact between high-temperature exhaust gas and diluted ammonium carbonate. The device for reducing nitrogen oxide emissions using ammonium carbon comprises: a storage unit (100) transporting ammonium carbonate to a storage and setting path; a reaction unit (200) reducing the concentration of industrial ammonium carbonate delivered from the storage unit (100) to generate a diluted aqueous solution and generate exhaust gas by burning fossil fuel and inducing contact between ammonium carbonate and exhaust gas to reform ammonia (NH_3) vapor and then atomizing ammonia (NH_3) with compressed air; a mixed gas generating unit (300) generating a mixed gas by mixing ammonia (NH_3) delivered from the reaction unit (200) with exhaust gas; and a selective catalytic reduction unit (400) in which the mixed gas is guided from the mixed gas generating unit (300) and absorbs ammonia (NH_3) and discharges a resultant product according to the reduction reaction of nitrogen oxides (NO_x).

Description

Nitrogen oxide emission reduction system using ammonium carbonate

The present invention relates to a nitrogen oxide emission reduction device using ammonium carbon, and more particularly, due to the characteristic that the hydrolysis process of urea water is omitted, not only the simplification of the process is actively implemented, but also the high temperature exhaust gas and diluted ammonium carbonate It relates to a nitrogen oxide emission reduction device using ammonium carbon that dramatically reduces nitrogen oxides due to a selective reduction catalytic method inducing direct contact with them.

The rapid development of industrialization using fossil fuels is leading to pollution of living places, and the combustion of fossil fuels in factories or combustion devices releases nitrogen oxides, which are harmful gases. should be reduced

On the other hand, as a method of reducing nitrogen oxide emission, there are a method of reducing nitrogen oxide emission and a method of utilizing eco-friendly energy, which is an alternative energy. Among them, eco-friendly energy is not yet popularized due to insufficient technological development, but also has a constraint that it can be generated under specific conditions. As a result, a method of reducing nitrogen oxide emissions is more realistic and has been recently proposed in various ways.

For example, the technical idea regarding the "complex type nitrogen oxide reduction system" is posted in Korean Patent Publication No. 10-204621. The technical idea is characterized by a system that reduces nitrogen oxides by using urea water, but there is a fatal limitation in that it cannot change the process because another process is required according to the use of urea water.

Registered Patent Publication No. 10-204621

The present invention was created to more actively solve the above problems, and simplifies the process as the hydrolysis process of urea water is omitted, while direct contact with diluted ammonium carbonate and high-temperature exhaust gas is induced. It is a task to be solved to provide a nitrogen oxide emission reduction device using ammonium carbon that dramatically reduces nitrogen oxides by using a selective reduction catalyst method.

The configuration of the nitrogen oxide emission reduction device using ammonium carbon proposed in the present invention in order to achieve the above-mentioned problem is as follows.

The nitrogen oxide emission reduction device using ammonium carbon includes: a storage unit 100 for transporting industrial ammonium carbonate to a storage and setting path; By lowering the concentration of industrial ammonium carbonate delivered from the storage unit 100, a dilute aqueous solution is generated and exhaust gas is generated by combustion of fossil fuels, and by inducing contact between ammonium carbonate and exhaust gas, ammonia (NH ₃ ) After reforming with steam, ammonia (NH ₃ ) Reaction unit 200 for atomizing (automizing) with compressed air; A mixed gas generating unit 300 for generating a mixed gas by mixing ammonia (NH ₃ ) and exhaust gas delivered from the reaction unit 200; The mixed gas is guided from the mixed gas generating unit 300 and the selective catalytic reduction unit 400 absorbs ammonia (NH ₃ ) and discharges the result according to the reduction reaction of nitrogen oxides (NO _x ); have.

In addition, the reaction unit 200 receives industrial ammonium carbonate from the storage unit 100, reduces the concentration to generate a diluted aqueous solution, and then a dilution unit 210 for supplying it through a set path; an exhaust gas unit 220 for generating exhaust gas by burning fossil fuel and supplying it to a set path; a contact mixing unit 230 for receiving the dilution aqueous solution and exhaust gas from the dilution unit 210 and the exhaust gas generating unit 220 and making them contact each other to reform the vapor of the diluted aqueous solution into ammonia (NH ₃ ) vapor; It includes;

In addition, the selective catalytic reduction unit 400 includes a reduction reaction unit 410 in which the mixed gas is guided to perform a reduction reaction of nitrogen oxides (NO _x ); A catalyst absorption layer 420 for absorbing ammonia (NH ₃ ); It includes a _;

In addition, the storage unit 100 includes an ammonium storage unit 110 for storing a 35% concentration of industrial ammonium carbonate; and a circulation module 120 for transferring industrial ammonium carbonate to a set path.

In addition, the reaction unit 200 includes diluting the concentration of industrial ammonium carbonate to 5%.

In addition, the injector 240 includes an aqueous solution injection unit 242 for supplying a diluted aqueous solution having a size of 30 μm to 100 μm to the contact mixing unit 230 at a pressure of 2 to 6 bar; and an air supply unit 244 that sucks air and supplies it to the contact mixing unit 230 .

In addition, the exhaust gas unit 220 is a combustion unit 222 for generating exhaust gas by burning fossil fuel; It further includes;

In addition, the mixed gas generating unit 300 includes a gas receiving unit 310 for accommodating ammonia (NH ₃ ) and exhaust gas delivered from the contact mixing unit 230; Ammonia (NH ₃ ) and a gas agitator 320 for generating a mixed gas by inducing a vortex phenomenon of the exhaust gas; further includes.

According to the present invention consisting of the above-described configuration, since it is possible to convert the reducing agent precursor to the reducing agent under a low temperature, there is an effect that can significantly reduce the overall cost required for the production of the reducing agent.

In addition, in the present invention, since the high-temperature process for reforming and hydrolysis according to the use of urea water is omitted, not only the use of electric energy is reduced, but also the operation and equipment handlers are actively excluded from the dangers caused by the handling of poisons, and in particular, ammonium carbonate is used It has the advantage that a stable chemical reaction is achieved by generating ammonia and causing a reduction reaction with nitrogen oxides.

1 to 3 are block diagrams of a nitrogen oxide emission reduction device using ammonium carbon according to the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only this embodiment completes the disclosure of the present invention, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. In addition, like reference numerals refer to like elements throughout the specification.

The present invention is disclosed with respect to a nitrogen oxide emission reduction device using ammonium carbon.

Above all, the present invention not only actively implements the simplification of the process due to the characteristic that the hydrolysis process of urea water is omitted, but also nitrogen oxides due to the selective reduction catalyst method that induces direct contact between the high temperature exhaust gas and diluted ammonium carbonate Note that it is related to a nitrogen oxide emission reduction device using ammonium carbon that dramatically reduces the

Conventionally, ammonia is reformed by spraying urea water under high temperature conditions or converted into vapor phase ammonia by spraying liquid ammonia. The process is completely excluded, and since ammonia is generated in the process, there is no need to spray with separate ammonia.

That is, the present invention is mainly characterized in that the conversion from ammonium carbonate to ammonia is possible immediately and proceeds stably and rapidly even at a relatively low temperature, thereby causing a smooth reduction reaction with nitrogen oxides. Prior to describing the present invention, if it is obvious in the art or its configuration, operation, etc. are obvious, the description may be omitted, and each operation may be performed by separate sequence programming. In addition, each process may be controlled by an administrator.

Hereinafter, with reference to the accompanying drawings, it will be collectively described for the configuration of the present invention, its action and effect.

1 to 3, the present invention is a storage unit 100 for transporting industrial ammonium carbonate (ammonium carbonate) to the storage and setting path; By lowering the concentration of industrial ammonium carbonate delivered from the storage unit 100, a dilute aqueous solution is generated and exhaust gas is generated by combustion of fossil fuels, and by inducing contact between ammonium carbonate and exhaust gas, ammonia (NH ₃ ) After reforming with steam, ammonia (NH ₃ ) Reaction unit 200 for atomizing (automizing) with compressed air; A mixed gas generating unit 300 for generating a mixed gas by mixing ammonia (NH ₃ ) and exhaust gas delivered from the reaction unit 200; _It is _composed of;

As is well known, the present invention is designed to use ammonia as a reducing agent for selective catalytic reduction by decomposing industrial ammonium carbonate, which simplifies the process and greatly reduces the risk of exposure of workers to toxic substances compared to conventional urea water. .

To this end, the storage unit 100 stores industrial ammonium carbonate as a reducing agent precursor. Specifically, the storage unit 100 includes an ammonium storage unit 110 for storing 35% concentration of industrial ammonium carbonate; and a circulation module 120 for transferring industrial ammonium carbonate to a set path.

In principle, the ammonium storage unit 110 should be completely blocked from the outside and the inside so that a type of hollow housing is sufficient, and to prevent leakage and to be stored for several periods of time. Furthermore, as it is stored with 35% concentration of ammonium carbonate, it can be used immediately without a separate process.

The circulation module 120 is lifted by a circulation pump capable of bidirectional operation, and by the operation of the circulation module 120 , industrial ammonium carbonate is forcibly transferred to the reaction unit 200 . In other words, the industrial ammonium carbonate stored in the storage unit 100 is forcibly forward or reversed along the supply pipe (no identification number) connected from the storage unit 100 to the reaction unit 200 by driving the circulation module 120 . can be transported Through the forward driving of the circulation module 120, industrial ammonium carbonate can be guided from the storage unit 100 to the reaction unit 200, while the industrial ammonium carbonate can be continuously circulated in the supply pipe through reverse driving, or Industrial ammonium carbonate remaining in the industrial ammonium carbonate supply pipe can be recovered to a storage tank. That is, as the flow direction of industrial ammonium carbonate can be controlled by driving the circulation module 120 in the forward or reverse direction, freezing or crystallization of ammonium carbonate remaining in the supply pipe can be prevented in advance, which is why industrial ammonium carbonate is used as a reducing agent. When adopted as a precursor, it means securing storage, storage, and stability.

The reaction unit 200 dilutes the transferred industrial 35% ammonium carbonate with dilute ammonium carbonate (NH ₄ ) ₂ CO ₃ ) to match the intended use.

In addition, the reaction unit 200 receives industrial ammonium carbonate from the storage unit 100, reduces the concentration to generate a diluted aqueous solution, and then a dilution unit 210 for supplying it through a set path; an exhaust gas unit 220 for generating exhaust gas by burning fossil fuel and supplying it to a set path; a contact mixing unit 230 for receiving the dilution aqueous solution and exhaust gas from the dilution unit 210 and the exhaust gas generating unit 220 and making them contact each other to reform the vapor of the diluted aqueous solution into ammonia (NH ₃ ) vapor; It includes;

The dilution unit 210 dilutes the concentration of industrial ammonium carbonate to 5%. This diluted ammonium carbonate not only facilitates ammonia production at a lower temperature than urea water, but also has excellent nitrogen oxide removal efficiency, thereby contributing to securing stability in the subsequent process and improving the reactivity between ammonium carbonate and ammonia. Furthermore, it may be provided with a metering supply module (not shown) for calculating the amount of nitrogen oxide contained in the exhaust gas and the amount of ammonia required therefor according to the equivalence ratio, wherein the metering supply module includes the contact mixing unit 230 and the mixed gas generation unit. It is possible to control the supply amount of ammonia to be provided to (300).

The exhaust gas unit 220 includes a combustion unit 222 for generating exhaust gas by burning fossil fuels; It further includes; an exhaust gas supply unit 224 for supplying the exhaust gas generated according to the combustion of the combustion unit 222 to the contact mixing unit 230 at a flow rate of 10m/s to 15m/s.

The injector 240 supplies a diluted aqueous solution having a size of 30 μm to 100 μm to the contact mixing unit 230 at a pressure of 2 to 6 bar. The contact mixing unit 230 is injected together with air, the exhaust gas of the exhaust gas supply unit 224 is injected, and ammonia (NH ₃ ) is generated using the exhaust gas as a heat source.

[Formula 1]

(NH ₄ ) ₂ CO ₃ ↔ 2NH ₃ + CO ₂ + H ₂ O

In other words, the contact mixing unit 230 can reform the ammonium carbonate of the dilution unit 210 into ammonia as a reducing agent through contact with the exhaust gas at a high temperature of 200°C to 400°C discharged from the exhaust gas unit 220 . is designed

In general, ammonium carbonate can be easily decomposed into ammonia and carbon dioxide even at a heating temperature of 70° C. The decomposition of the aqueous ammonium carbonate solution into ammonia vapor should proceed as quickly as possible, as well as mixing with a significant amount of air, so that it can be dealt with immediately.

Accordingly, the injector 240 includes an aqueous solution injection unit 242 for supplying a diluted aqueous solution having a size of 30 μm to 100 μm to the contact mixing unit 230 at a pressure of 2 to 6 bar; and an air supply unit 244 that sucks air and supplies it to the contact mixing unit 230 . The injector 240 sprays a diluted aqueous solution having a size of 30 μm to 100 μm and air together to the contact mixing unit 230 at a pressure of 2 bar to 6 bar to ensure good contact with the transported exhaust gas. This makes it possible to decompose into ammonia while suppressing the explosiveness of ammonia under high temperature. The ratio of supplied ammonia to air is preferably maintained at 2% to 5%.

In addition to the above, in order to accelerate the explosion stability and decomposition response speed from ammonium carbonate to ammonia, exhaust gas at a high temperature of 200 ° C to 400 ° C is contact-mixed through the exhaust gas supply unit 224 at a flow rate of 10 m/s to 15 m/s. It is preferable to supply to the unit 230 . This prevents excessive injection of exhaust gas and contributes to reducing the explosiveness of ammonia.

Accordingly, ammonia vapor in which air and vapor phase ammonia are mixed is introduced into the mixed gas generator 300 .

The mixed gas generating unit 300 flows nitrogen oxide and ammonia vapor of the exhaust gas in a turbulent flow to mix and contact them.

Specifically, the mixed gas generating unit 300 includes a gas receiving unit 310 for accommodating ammonia (NH ₃ ) and exhaust gas delivered from the contact mixing unit 230; Ammonia (NH ₃ ) and a gas agitator 320 for generating a mixed gas by inducing a vortex phenomenon of the exhaust gas; further includes.

The gas agitator 320 flows the exhaust gas generated in the exhaust gas unit 200 and the ammonia vapor of the contact mixing unit 230 in a turbulent flow state to induce a vortex phenomenon, thereby mixing and contacting to generate a mixed gas. Through this, the mixing amount of ammonia and nitrogen oxides contained in the exhaust gas can be increased, and the mixed gas is guided and transferred to the selective catalytic reduction unit 400 according to the selective catalytic reduction method.

The selective catalytic reduction unit 400 is configured to remove nitrogen oxides by causing a reduction reaction of nitrogen oxides and ammonia.

To this end, the selective catalytic reduction unit 400 includes a reduction reaction unit 410 in which the mixed gas is guided to perform a reduction reaction of nitrogen oxides (NO _x ); A catalyst absorption layer 420 for absorbing ammonia (NH ₃ ); It includes a _;

On the other hand, the reduction reaction unit 410 is induced with the help of the reducing agent ammonia and the following chemical reaction.

[Formula 2]

4NO + 4NH ₃ + O ₂ -> 4N ₂ + 6H ₂ O

2NO ₂ + 4NH ₃ + O ₂ -> 3N ₂ + 6H ₂ O

NO + NO ₂ + 2NH ₃ -> 2N ₂ + 3H ₂ O

That is, a reduction reaction of nitrogen oxides is caused with nitrogen and water, and ammonia vapor, which is a gaseous reducing agent, is absorbed in the catalyst absorption layer 420 . Thereafter, nitrogen and water as a result of the reaction of the reduction reaction unit 410 can be discharged through the discharge unit 430 .

According to the present invention consisting of the above-described configuration, since it is possible to convert the reducing agent precursor to the reducing agent under a low temperature, there is an effect that can significantly reduce the overall cost required for the production of the reducing agent.

In addition, in the present invention, since the high-temperature process for reforming and hydrolysis according to the use of urea water is omitted, not only the use of electric energy is reduced, but also the operation and equipment handlers are actively excluded from the dangers caused by the handling of poisons, and in particular, ammonium carbonate is used It has the advantage that a stable chemical reaction is achieved by generating ammonia and causing a reduction reaction with nitrogen oxides.

100: storage unit 200: reaction unit
210: dilution part 220: exhaust gas part
230: contact mixing unit 240: injector
300: mixed gas generating unit 400: selective catalytic reduction unit
410: reduction reaction unit 420: catalyst absorption layer
430: discharge part

Claims (5)

Storage unit 100 for transporting industrial ammonium carbonate (ammonium carbonate) to the storage and setting path;
By lowering the concentration of industrial ammonium carbonate delivered from the storage unit, a dilute aqueous solution is generated and exhaust gas is generated by burning fossil fuels, and by inducing contact between ammonium carbonate and exhaust gas, ammonia (NH ₃ ) ) A reaction unit 200 for reforming with steam and then atomizing ammonia (NH ₃ ) with compressed air (automizing);
A mixed gas generating unit 300 for generating a mixed gas by mixing ammonia (NH ₃ ) and exhaust gas delivered from the reaction unit;
The mixed gas is guided from the mixed gas generating unit, and the selective catalytic reduction unit 400 absorbs ammonia (NH ₃ ) and discharges the result according to the reduction reaction of nitrogen oxide (NO _x );
The reaction unit 200,
a dilution unit 210 that receives ammonium carbonate from the storage unit 100 and lowers the concentration to generate a diluted aqueous solution and then supplies it to a set path;
an exhaust gas unit 220 for generating exhaust gas by burning fossil fuel and supplying it to a set path;
a contact mixing unit 230 for receiving the dilution aqueous solution and exhaust gas from the dilution unit 210 and the exhaust gas generating unit 220 and making them contact with each other to reform the vapor of the diluted aqueous solution into ammonia (NH ₃ ) vapor;
The injector 240 controls the supply of compressed air and diluted aqueous solution to the contact mixing unit 230;
The selective catalytic reduction unit 400,
a reduction reaction unit 410 in which the mixed gas is guided to perform a reduction reaction of nitrogen oxides (NO _x );
A catalyst absorption layer 420 for absorbing ammonia (NH ₃ );
_Including a;
The storage unit 100,
Ammonium storage unit 110 for storing 35% concentration of industrial ammonium carbonate (ammonium carbonate);
It includes; a circulation module 120 for transferring industrial ammonium carbonate to a set path;
The injector 240 is
an aqueous solution injection unit 242 for supplying a diluted aqueous solution having a size of 30 μm to 100 μm to the contact mixing unit 230 at a pressure of 2 to 6 bar;
An apparatus for reducing nitrogen oxide emissions using ammonium carbonate including; an air supply unit 244 that sucks air and supplies it to the contact mixing unit 230 .
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