KR102262615B1 - Apparatus for removing carbon particulate material through addition of nitrogen oxide - Google Patents

Abstract

The present invention discloses a system for removing carbon particulate matter through addition of nitrogen oxides. According to the present invention, an atmospheric low-temperature plasma reactor for supplying ozone generated through an oxidation reaction of oxygen or air; and _{a combustion reactor filled with a perovskite catalyst having an ABO 3} or A ₂ BO ₄ structure, and burning carbon particulate matter using ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor. system is provided.

Description

System for removing carbon particulate material through addition of nitrogen oxide

The present invention relates to a system for removing carbon particulate matter through addition of nitrogen oxides.

Nowadays, environmental health problems related to fine dust are getting serious. Efforts to reduce fine dust emissions from various sources of fine dust are being actively carried out.

Fine dust contains various chemical components including hydrate particles derived from nitrogen oxides and sulfur oxides, but a significant part of fine dust consists of carbon particulate matter. Carbon particulate matter is emitted from fixed sources such as thermal power plants, steel mills and chemical plants that use fossil fuels as energy sources, and mobile sources such as internal combustion engine vehicles.

Carbon particulate matter is generated by incomplete combustion reactions that accompany the process of burning various types of fossil fuels to obtain thermal energy necessary for the operation of the process. Efforts such as introducing an oxygen combustion reaction are generally attempted.

However, even if such process improvement is made, there are many cases where the generation and discharge of some carbon particulate matter is unavoidable, and a post-treatment method of removing carbon particulate matter by installing a catalytic combustion reactor in the exhaust gas pipeline is often introduced. .

For low-temperature combustion of carbon particulate matter, a method of introducing ozone as an oxidizing agent may be considered as follows.

[Scheme 1]

O ₃ (g) + C(s) → CO ₂ (g) + 0.5 O ₂ (g)

The above reaction is theoretically known to burn carbon particulate matter from room temperature, and the combustion rate increases as the temperature increases, and then the combustion rate decreases when ozone starts to be thermally decomposed by the increased temperature. When ozone reaches 300~350℃ where ozone is completely decomposed, the combustion reaction is terminated.

Therefore, since the combustion reaction of carbon particulate matter by ozone is limited by temperature, it is necessary to devise a method for improving the combustion reaction rate under a given reaction temperature condition.

Korean Patent Registration 10-1863940

In order to solve the problems of the prior art, the present invention intends to propose a carbon particulate matter removal system through the addition of nitrogen monoxide that can improve the combustion reaction rate of carbon particulate matter by ozone even at low temperature conditions.

In order to achieve the above object, according to an embodiment of the present invention, there is provided a system for removing carbon particulate matter through the addition of nitrogen oxide, comprising: an atmospheric low temperature plasma reactor supplying ozone generated through an oxidation reaction of oxygen or air; and _{a combustion reactor filled with a perovskite catalyst having an ABO 3} or A ₂ BO ₄ structure, and burning carbon particulate matter using ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor. system is provided.

It is disposed in front of the combustion reactor, nitrogen monoxide and ozone are supplied in a stoichiometric ratio of 1:1 may further include a mixer for converting nitrogen monoxide to nitrogen dioxide and discharging.

The nitrogen oxide supplied to the combustion reactor may have a concentration range of 0.1 to 0.2 compared to the ozone.

The low-temperature combustion of the carbon particulate material may be performed within a range of 100 to 300°C.

The atmospheric pressure low-temperature plasma reactor may be a dielectric barrier discharge (DBD) reactor.

According to another aspect of the present invention, there is provided a system for removing carbon particulate matter through the addition of nitrogen oxides, comprising: a mixer in which nitrogen monoxide and ozone are supplied in a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge; and _{a combustion reactor filled with a perovskite catalyst having an ABO 3} or A ₂ BO ₄ structure, and combusting carbon particulate matter using ozone and nitrogen dioxide converted in the mixer is provided. .

According to the present invention, it is possible to promote the combustion reaction of carbon particulate matter under ozone supply and low-temperature conditions through the addition of nitrogen oxide.

1 is a view showing a carbon particulate matter removal system through the addition of nitrogen oxide according to an embodiment of the present invention.
Figure 2 shows the results of the ozone thermal decomposition experiment, reactive gas: O ₂ 10%, O ₃ 2500 ppm, N ₂ balance. 300 cc/min; The change in ozone concentration at a temperature rise rate of 3°C/min is shown.
3 is a diagram showing the configuration of a DBD plasma reactor for ozone generation to be used for PM low-temperature combustion according to the present embodiment.
4 shows the change in the carbon particulate matter catalytic combustion reaction performance according to the change in the concentration _{of O 3 .}
5 shows the change in the carbon particulate matter catalyst combustion reaction performance according to the _{NO 2 concentration change.}

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

1 is a view showing a carbon particulate matter removal system through the addition of nitrogen oxide according to an embodiment of the present invention.

As shown in FIG. 1 , the apparatus for removing carbon particulate matter according to the present embodiment may include a mixer and a combustion reactor (filter).

The exhaust gas containing carbon particulate matter, nitrogen monoxide and ozone are introduced into the mixer according to this embodiment, and nitrogen dioxide and ozone are discharged.

In the mixer according to this embodiment, nitrogen monoxide and ozone are supplied in a stoichiometric ratio of 1:1, and the nitrogen monoxide is converted into nitrogen dioxide and discharged.

For an ozone generating system that consumes less power, according to the present embodiment, a dielectric barrier discharge (DBD) reactor, which is one of low-temperature plasma methods, is used.

The nitrogen dioxide and ozone discharged from the mixer enter the catalyst-coated combustion reactor. The filter according to this embodiment collects carbon particulate matter and discharges carbon dioxide through a catalytic reaction with nitrogen dioxide and ozone.

In this embodiment, nitrogen monoxide is supplied and converted into nitrogen dioxide through a reaction with ozone (reaction 2), then supplied to a particulate matter combustion reactor corresponding to a filter, and ABO ₃ (A = La, B = Mn) Alternatively, the combustion reaction rate of the carbon particulate matter is improved by attempting to burn the carbon particulate matter by ozone in a state in which the perovskite catalyst having the _{A 2} BO _{4 structure is applied (Reaction 3).}

[Scheme 2]

O ₃ (g) + NO (g) → NO ₂ (g) + O ₂ (g)

[Scheme 3]

NO ₂ (g) + O ₃ (g) + C(s) → CO ₂ (g) + O ₂ (g) + NO

The perovskite catalyst according to this embodiment may have an ABO ₃ or A ₂ BO ₄ structure.

Here, A site is selected as one or a mixture of two or more metals from La, Pr, Ce, Sr, Ba, Li, K, and Mg, and the A site has one of the metals as a main component, and the main component is It may be partially substituted with one of the remaining metals.

In addition, the B site may be selected as one of Mn, Fe, Co, Zr, Cr, Ti, Cu and V or a mixture of two or more metals.

B site has one of the metals as a main component, and the main component may be partially substituted with one of the other metals.

Hereinafter, examples of the perovskite catalyst having the _{ABO 3 structure will be described in detail.}

[Example 1] ABO ₃ Synthesis of Structured Perovskite Catalyst (A = La, B = Mn)

Metal acetate aqueous solutions of A site and B site metals constituting the catalyst were prepared at a certain concentration, and the aqueous solutions were mixed according to the stoichiometric ratio for each element of the catalyst to be synthesized, followed by stirring at room temperature for 30 minutes. Citric Acid may be added in the same amount as the metal ion in the aqueous solution preparation step. The stirred solution was evaporated to dryness at 50°C to obtain a particle-form precipitate, dried at 120°C under air conditions for 24 hours, primary calcined at 400°C, and secondary calcined at 950°C to obtain ABO ₃ catalyst. prepared.

[Example 2] Search for ozone concentration maintenance section

_{O 3} concentration change was observed while increasing the temperature from room temperature to 3° C./min at the ozone (O ₃ ) concentration of 2,500 ppm and the reaction gas flow rate of 300 cc/min.

Figure 2 shows the results of the ozone thermal decomposition experiment, reactive gas: O ₂ 10%, O ₃ 2500 ppm, N ₂ balance. 300 cc/min; The change in ozone concentration at a temperature rise rate of 3°C/min is shown.

Confirmed that the temperature began to occur O ₃ conversion (O ₃ Conversion) from 100 ℃ the temperature is increased ozone conversion rate while continued to rise O ₃ conversion rate is all thermally decomposed 100%, that O ₃ reaches 300 ℃ according to could

Therefore, the O ₃ concentration is maintained and the temperature at which the carbon particulate matter combustion reaction by _{O 3 can be expected is 300° C. or less.}

[Example 3] ABO of carbon particulate matter according to change in ozone concentration ₃ catalytic combustion reaction

A particle mixture of 10 mg of carbon particulate matter and 20 mg of ABO ₃ (A=La, B=Mn; hereinafter LaMnO ₃ ) as a catalyst material was charged in the center of a cylindrical quartz reactor (particulate matter combustion reactor). NO was supplied to the front end of the reactor to a concentration of 250 ppm, and 250 ppm O ₃ was supplied to convert all NO to 250 ppm of NO _{2 .} Alternatively, 250 ppm of NO ₂ may be directly supplied without going through this step. In this state, O ₃ was additionally supplied, and the combustion reaction of carbon particulate matter was carried out at each concentration while _{the O 3 concentration in the reaction gas was changed stepwise to 500, 1250, 1500, and 2500 ppm.} The reactive gas contained 10% oxygen (O ₂ ) in addition to NO and O ₃ , and the total flow rate was 300 cc/min.

3 is a diagram showing the configuration of a DBD plasma reactor for ozone generation to be used for PM low-temperature combustion according to the present embodiment.

The electrode of the plasma reactor used SUS Mesh and Cu Rod, and Quartz Tube was used as the dielectric. The Power Supplier used for power supply has a frequency range of 50 Hz to 1 Khz, a primary voltage range of 0 to 15 Kv, and a maximum power of 300 W. The voltage supplied to the plasma reactor using an oscilloscope (Tektronix TDS 220) and The current was observed.

4 shows the change in the carbon particulate matter catalytic combustion reaction performance according to the change in the concentration _{of O 3 .}

In FIG. 4, fixed bed: carbon particulate matter (Printex-U) 10 mg + LaMnO ₃ 20 mg: reactive gas: NO ₂ 250 ppm, O ₂ 10%, O ₃ 500, 1250, 1500 or 2500 ppm, N ₂ balance. 300 cc/min; The temperature rise rate is 3°C/min.

Referring to FIG. 4 , it can be confirmed that the combustion reaction of carbon particulate matter by _{O 3} proceeds as the generation of _{carbon monoxide (CO) and carbon dioxide (CO 2} ) is sensed in a temperature region below 300° C. in which the concentration of _{O 3 is maintained.} . As the O ₃ concentration was increased to 500, 1250, 1500, and 2500 ppm, it was confirmed that the carbon particulate matter combustion reaction proceeded at a faster rate in the temperature range below 300 °C, resulting in _{higher concentrations of CO and CO 2 produced.}

[Example 4] ABO of carbon particulate matter by ozone following addition of nitrogen monoxide ₃ Improvement of catalytic combustion reaction rate

In the same manner as in Example 3 _{, the O 3} concentration was fixed at 2500 ppm in a packed bed in _{which 10 mg of carbon particulate matter and 20 mg of LaMnO 3 catalyst were mixed, and the NO 2} concentration was changed to 0, 250, 500, 1250, 2500 ppm. A reaction experiment was performed. (Same as in Example 3, the O ₂ concentration was 10%, and the flow rate of the reaction gas was 300 cc/min.) Here, the NO _{2 concentrations set respectively are directly supplying NO 2} gas capable of implementing the corresponding concentration, or NO gas and It can be implemented by reacting _{O 3} or more in a stoichiometric ratio of 1:1.

5 shows the change in the carbon particulate matter catalyst combustion reaction performance according to the _{NO 2 concentration change.}

In FIG. 5, fixed bed: carbon particulate matter (Printex-U) 10 mg + LaMnO3 20 mg: reactive gas: NO2 0, 250, 500, 1250, or 2500 ppm, O2 10%, O3 2500 ppm, N2 balance. 300 cc/min; The temperature rise rate is 3°C/min.

Referring to FIG. 5 , when NO ₂ is not included (0 ppm) compared to when the NO ₂ concentration is 250 and 500 ppm, it can be seen that the concentrations _{of CO and CO 2 are increased.} If the NO ₂ concentration is 1250 and 2500 ppm is NO ₂ 0 ppm contrast rather performance (CO, CO ₂ concentration level) of the combustion reaction, were reduced, which while NO ₂ is adsorbed excess to the catalyst and the catalyst is adsorbed O ₃ This is because it interferes with the production of active oxygen.

_{Therefore, it was found that the ABO 3} catalytic combustion reaction rate of carbon particulate matter caused by ozone _{can be improved when nitrogen dioxide (NO 2} ) at a concentration corresponding to 500 ppm, which is 10% of the ozone concentration of 2500 ppm, is supplied. can

That is, when the concentration of nitrogen oxide has a range of 0.1 to 0.2 compared to the ozone concentration, it can be confirmed that the combustion reaction rate is improved.

Or NO ₂ instead of supplying the nitrogen monoxide (NO) in the same concentration and stoichiometric ratio 1: 1 can be reacted with an ozone concentration of more than expected, the same effect also by NO ₂ supply.

The above-described embodiments of the present invention have been disclosed for purposes of illustration, and various modifications, changes, and additions will be possible within the spirit and scope of the present invention by those skilled in the art having ordinary knowledge of the present invention, and such modifications, changes and additions should be regarded as belonging to the following claims.

Claims (6)

A system for removing carbon particulate matter through nitrogen oxide addition,
an atmospheric low-temperature plasma reactor supplying ozone generated through an oxidation reaction of oxygen or air; and
ABO ₃ or A ₂ BO ₄ A perovskite catalyst having a structure is filled, including a combustion reactor for burning carbon particulate matter using ozone and nitrogen oxide supplied to the atmospheric low-temperature plasma reactor,
The nitrogen oxide supplied to the combustion reactor is a carbon particulate matter removal system having a concentration range of 0.1 to 0.2 compared to the ozone. According to claim 1,
The carbon particulate matter removal system further comprising a mixer disposed at the front end of the combustion reactor, wherein nitrogen monoxide and ozone are supplied in a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge. delete According to claim 1,
The low-temperature combustion of the carbon particulate matter is made within the range of 100 to 300 ℃ carbon particulate matter removal system. According to claim 1,
The atmospheric low-temperature plasma reactor is a carbon particulate matter removal system that is a dielectric barrier discharge (DBD) reactor. As a system for removing carbon particulate matter through addition of nitrogen oxide,
a mixer in which nitrogen monoxide and ozone are supplied in a stoichiometric ratio of 1:1 to convert nitrogen monoxide into nitrogen dioxide and discharge; and
ABO ₃ or A ₂ BO ₄ A perovskite catalyst having a structure is filled, including a combustion reactor that burns carbon particulate matter using ozone and nitrogen dioxide converted in the mixer,
The nitrogen dioxide supplied to the combustion reactor is a carbon particulate matter removal system having a concentration range of 0.1 to 0.2 compared to the ozone.

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