KR20240053852A - Exhaust gas purifying device and method for removing VOCs and NOx - Google Patents

Abstract

The present invention relates to an exhaust gas purification device capable of removing VOCs and NOx and a method using the same, which increases the temperature of exhaust gas containing volatile organic compounds (VOCs) and nitrogen oxides (NOx) to a temperature of 150 to 400 ° C. heating unit; and a catalyst module including a NOx reduction catalyst that reduces NOx to nitrogen by using volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent. Regarding a VOCs and NOx removal device and a VOCs and NOx removal method using the same. will be.

Description

Exhaust gas purifying device capable of removing VOCs and NOx and exhaust gas purifying method using the same {Exhaust gas purifying device and method for removing VOCs and NOx}

The present invention relates to an exhaust gas purification device capable of removing VOCs and NOx and a method using the same. More specifically, an exhaust gas purification device capable of simultaneously removing VOCs and NOx according to the facility size and hazardous substance emission pattern of the workplace. It is about the development of the system.

Numerous thermal power plants using coal or oil as fuel are in operation around the world, and numerous industrial boilers are in operation. As regulations on environmental pollution have been strengthened, the spread of combined cycle power generation facilities with high energy use efficiency among power generation systems has rapidly increased. Looking at the structure of combined cycle power generation facilities, a gas turbine is first operated, and the high-heat exhaust generated from it is discharged. The heat recovery steam generator (HRSG) is heated with gas to generate high-temperature steam to operate the steam turbine. Combined cycle power generation facilities are often installed around urban areas to supply heat and are subject to stricter environmental regulations than other power generation facilities, so they mainly use clean fuels such as natural gas. Some areas where natural gas supply is difficult use low-sulfur oil as fuel. Combined cycle power plants mainly generate nitrogen oxides (NOx) during operation, so nitrogen oxides in exhaust gas are removed through an HC-DeNOx catalyst.

The denitrification facility using the HC-DeNOx catalyst is a facility that sprays a reducing agent such as ammonia or urea into the exhaust gas and converts nitrogen oxides (NOx) into pollution-free water and nitrogen on the catalyst as follows.

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

However, as environmental regulations have recently been strengthened, it is required to remove carbon monoxide (CO) and volatile organic compounds (VOCs) generated during gas turbine operation in addition to NOx, so these pollutants are removed by installing an oxidation catalyst in front of the HC-DeNOx catalyst. there is. A seawater desalination power generation system using exhaust gas is proposed in Korea Patent Publication No. 10-2013-0131641, but it is difficult to discharge the used exhaust gas directly into the atmosphere because it contains various pollutants, and must be forcibly discharged through a chimney. There is a downside to this.

Moreover, in the case of small businesses, there are generally many processes for drying organic solvents through boilers or small combustion furnaces, which simultaneously emit volatile organic compounds (VOCs) and NOx, which are hazardous substances with a high possibility of deteriorating the atmospheric environment as precursors to fine dust. In most cases, this is generally removed using activated carbon adsorption carbon, but if appropriate replacement or regeneration measures are not taken according to the usage cycle of activated carbon, it is difficult to remove the above-mentioned harmful substances.

Therefore, there is a need to develop a modular reduction technology that can be variably applied and can simultaneously remove VOCs and NOx according to the facility size and hazardous substance emission pattern of the workplace.

Accordingly, one aspect of the present invention is to provide an exhaust gas purification device that can be variably applied according to the VOCs and NOx generated at each business site.

Another aspect of the present invention is to provide an exhaust gas purification method that can simultaneously remove VOCs and NOx according to the facility size and hazardous substance emission pattern of the workplace using the device of the present invention.

According to one aspect of the present invention, an exhaust gas heating unit that raises the temperature of exhaust gas containing volatile organic compounds (VOCs) and nitrogen oxides (NOx) to a temperature of 150 to 400 ° C.; And an exhaust gas purification device that simultaneously reduces VOCs and NOx is provided, including a catalyst module including a NOx reduction catalyst that reduces NOx to nitrogen by using volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent.

According to another aspect of the present invention, the steps of introducing exhaust gas containing VOCs and NOx into the device of the present invention and increasing the temperature of the exhaust gas to a temperature of 150 to 400 ° C. through an exhaust gas heat exchanger; and introducing volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent at the front of the catalyst module including the NOx reduction catalyst.

According to the present invention, VOCs and NOx emitted from small businesses can be converted into nitrogen, carbon dioxide, and moisture more efficiently than commonly used activated carbon adsorption towers and urea NOx reduction catalysts. In particular, the catalyst module can be variably applied. This makes it possible to build an exhaust treatment system tailored to the exhaust gases at the installation location.

1 schematically shows an exemplary VOCs and NOx removal exhaust gas purification system of the present invention including a NOx reduction catalyst module.
Figure 2 schematically shows an exemplary VOCs and NOx removal exhaust gas purification system of the present invention comprising two (a) and three (b) NOx reduction catalyst modules.
Figure 3 shows the temperature change (a), NOx conversion rate (%) (b), and toluene conversion rate (%) (c) over time in Experimental Example 1.
Figure 4 shows the temperature change (a) and NOx conversion rate (%) (b) over time in Experimental Example 2.
Figure 5 shows the results of evaluating NOx reduction catalyst performance after oxidizing the catalyst in Experimental Example 2.
Figure 6 shows the NOx conversion rate (%) and ethylbenzene conversion rate (%) according to temperature in Experimental Example 3. (White circle: ethylbenzene conversion rate, black circle: NOx conversion rate)
Figure 7 shows NOx conversion rate (%) and ethylbenzene conversion rate (%) according to temperature and silver content in Experimental Example 3.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

The purpose of the present invention is to provide a VOCs and NOx reduction system that can be variably applied to volatile organic compounds (VOCs) and nitrogen oxides (NOx) generated in small businesses.

To implement this, a NOx reduction catalyst was applied to use volatile organic compounds (VOCs) instead of ammonia as a reducing agent to oxidize VOCs to carbon dioxide and simultaneously reduce NOx to nitrogen. Since the general NOx reduction system uses ammonia as a reducing agent, a device capable of spraying urea must be installed in the system. However, the present invention configures the system with a NOx reduction catalyst, so the devices required to build the system can be reduced compared to the existing system. there is.

In more detail, the VOCs and NOx removal device of the present invention includes an exhaust gas heating unit that raises the temperature of exhaust gas containing volatile organic compounds (VOCs) and nitrogen oxides (NOx) to a temperature of 150 to 400 ° C.; and a catalyst module including a NOx reduction catalyst that reduces NOx to nitrogen by using volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent.

In the case of small-scale businesses, there is a lot of drying of organic solvents through boilers or small combustion furnaces, so volatile organic compounds (VOCs) and NOx are emitted at the same time. Among VOCs, organic compounds with aromatic rings are particularly high. . The volatile organic compounds (VOCs) may include benzene, formaldehyde, acetaldehyde, toluene, ethynebenzene, xylene, styrene, etc., for example, toluene and/or ethylbenzene among organic compounds with an aromatic ring. It can be included.

For example, when using toluene as a reducing agent, the exhaust gas temperature increase temperature may be 260°C to 300°C, for example, 260 to 280°C, and when using ethylbenzene as a reducing agent, it may be 190 to 400°C, for example, 200 to 350°C. , or it may be 200 or more and less than 250 ℃.

The device of the present invention may include 1 to 5, for example, 2 or 3 catalyst modules, as shown in FIGS. 1 and 2.

An exemplary system of the present invention is configured as shown in FIG. 1. In more detail, the drying furnace and exhaust air conditioning equipment (1) refers to a work facility where VOCs and NOx are emitted at the workplace, and the VOCs and NOx generated and discharged therein are concentrated in the dust collection pipe (2) and the exhaust air conditioning fan ( 3) It can be transferred through. The transferred exhaust gas passes through the exhaust gas heating unit, that is, the exhaust gas heat exchanger (5), is heated to a temperature of 150 to 400°C, and passes through the catalyst module (7) including the NOx reduction catalyst (6). In the present invention, the NOx reduction catalyst is also called HC-DeNOx catalyst, and serves to reduce NOx to nitrogen using VOCs and CO as reducing agents. The catalyst module is a device that includes a catalyst module (7) including an exhaust gas heat exchanger (5) and a NOx reduction catalyst (6), and can be added depending on the amount of hazardous substances discharged. Figure 1 shows one NOx reduction catalyst module. It was applied.

The energy recovery heat exchanger 4 can recover the heat contained in the exhaust gas that has passed through the NOx reduction catalyst module 7 and reduce the energy load of the exhaust gas heat exchanger 5, which raises the temperature of the newly introduced exhaust gas. The adsorbent module for concentrating VOCs (8) plays a role in adsorbing/desorbing remaining VOCs and assists the reaction in the VOCs and CO oxidation catalyst module (9) that converts VOCs and CO into CO ₂ and moisture through oxidation. Some of the heat generated as VOCs and CO are oxidized is recovered through the exhaust gas heat exchanger (5), and then transferred to the workplace chimney (11) through the exhaust air conditioning fan (10) to remove nitrogen, carbon dioxide, and moisture generated by the conversion of VOCs and NOx. It can be released into the atmosphere.

Among these, the energy recovery heat exchanger (4) and exhaust gas heat exchanger (5) are sized and installed according to the operating temperature of the catalyst module (7) containing the NOx reduction catalyst (6) and the VOCs and CO oxidation catalyst module (9). The shape can be adjusted.

If the concentration of NOx emitted from the workplace is relatively high and it is not possible to reduce all NOx even by using the simultaneously emitted volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent, volatile organic compounds (VOCs) such as exhaust gas after boiler combustion ) and exhaust gas with a high concentration of carbon monoxide (CO) can be additionally injected in front of the passive SCR catalyst module to improve NOx reduction performance.

Carbon monoxide can be introduced at a concentration of 800 to 10,000 ppm, for example, 800 to 5,000 ppm. It is used as a reducing agent for NOx, and the remaining CO reacts with O ₂ and is converted to CO ₂ , resulting in a CO concentration in the product. is emitted at a level of less than 1.5 ppm, for example, 0.1 to 0.3 ppm.

As described above, the volatile organic compound that can be used as a reducing agent of the present invention includes, for example, toluene, ethylbenzene, and organic compounds containing an aromatic ring, as well as at least one component selected from the group consisting of all hydrocarbons. may be, for example, toluene, ethylbenzene, or a mixture thereof may be used.

Furthermore, the device of the present invention may further include an oxidation catalyst module that oxidizes volatile organic compounds and carbon monoxide and converts them into CO ₂ and moisture, thereby performing a step of regenerating the activity of the catalyst. For example, the VOCs and NOx reduction system of the present invention can additionally configure a VOCs oxidation catalyst module to reduce the VOCs at the downstream stage if the VOCs emissions exceed the VOCs expected to be consumed by the NOx reducer based on the NOx in the workplace exhaust gas. In the oxidation step for regeneration, a step of recovering the activity of the catalyst can be performed by heat treatment at 300 to 1000°C, for example, 400 to 700°C, under an oxygen atmosphere, for example, under an oxygen atmosphere of 10% by volume or more. .

Meanwhile, the active materials of the catalyst applied to the catalyst module including passive SCR and/or the VOCs and CO oxidation catalyst module are transition metals and noble metals, typically silver (Ag), platinum (Pt), gold (Au), and palladium. It may contain at least one noble metal component selected from the group consisting of (Pd), rhodium (Rh), iridium (Ir), and ruthenium (Ru). For example, the NOx reduction catalyst may include silver (Ag), platinum, etc. It may contain (Pt) or a mixture thereof, and may additionally contain metals such as cobalt (Co) and copper (Cu), and may be changed and applied depending on the composition and temperature of the exhaust gas at the business site.

The noble metal component may be included in the support in an amount of 0.5 to 5% by weight based on the total weight of the catalyst, for example, 1 to 3% by weight, or 2 to 4% by weight. If the noble metal component, which is the active material of the catalyst, is less than 0.5% by weight, the catalytic activity may be insufficient, and when the active material and precious metal component in the catalyst increases, the performance increase effect is minimal, which is undesirable in terms of process economy, and it is not supported on a support due to self-agglomeration. As this happens, the distribution tends to worsen.

The catalyst support may be at least one selected from the group consisting of TiO ₂ , Al ₂ O ₃ , SiO ₂ , and zeolite, but is not limited thereto.

Furthermore, the device of the present invention may additionally include an adsorbent module for concentrating volatile organic compounds that adsorbs and desorbs residual volatile organic compounds, and the adsorbent module for concentrating VOCs is an adsorbent module for concentrating VOCs that is discharged from the rear end of the catalyst module containing the NOx reduction catalyst. At least one selected from the group consisting of zeolite and lanthanide elements can be used according to the content of VOCs, but the adsorbent type and amount can be adjusted without being limited thereto.

Meanwhile, according to another aspect of the present invention, a removal method for simultaneously removing VOCs and NOx using the device of the present invention is provided.

More specifically, the VOCs and NOx removal method of the present invention involves inputting exhaust gas containing VOCs and NOx into the VOCs and NOx removal device of the present invention described above, and heating the exhaust gas to a temperature of 150 to 400 ° C. through an exhaust gas heat exchanger. Raising the temperature; And it includes the step of using volatile organic compounds (VOCs) and carbon monoxide (CO) as reducing agents.

At this time, the exhaust gas to which the present invention can be applied may contain 1500 to 2500 ppm of volatile organic compounds, 10 to 100 ppm of NOx, and 10 ppm or less of SO ₂ .

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are merely examples to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

Example 1

An exemplary system of the present invention is configured as shown in FIG. 1. In more detail, the drying furnace and exhaust air conditioning equipment (1) refers to a work facility where VOCs and NOx are emitted at the workplace, and the VOCs and NOx generated and discharged therein are concentrated in the dust collection pipe (2) and the exhaust air conditioning fan ( 3) It can be transferred through. The transferred exhaust gas is heated to a temperature of 150 to 400° C. while passing through the exhaust gas heat exchanger (5) and passes through the catalyst module (7) including the NOx reduction catalyst (6). In the present invention, the NOx reduction catalyst is also called HC-DeNOx catalyst, and serves to reduce NOx to nitrogen using VOCs and CO as reducing agents. The NOx reduction catalyst module is a device that includes a catalyst module (7) including an exhaust gas heat exchanger (5) and a NOx reduction catalyst (6), and can be added depending on the amount of hazardous substances discharged. Figure 1 shows one NOx reduction catalyst. The module is applied. The energy recovery heat exchanger 4 recovers the heat of the exhaust gas that has passed through the catalyst module 7 containing the NOx reduction catalyst and reduces the energy load of the exhaust gas heat exchanger 5, which raises the temperature of the newly introduced exhaust gas. The adsorbent module for concentrating VOCs (8) plays a role in adsorbing/desorbing remaining VOCs and assists in the reaction of converting VOCs and CO into CO ₂ and moisture through oxidation of VOCs and CO in the VOCs and CO oxidation catalyst module (9). Some of the heat generated as VOCs and CO are oxidized is recovered through the exhaust gas heat exchanger (5), and then transferred to the workplace chimney (11) through the exhaust air conditioning fan (10) to remove nitrogen, carbon dioxide, and moisture generated by the conversion of VOCs and NOx. exhausts into the atmosphere.

Among these, the energy recovery heat exchanger (4) and the exhaust gas heat exchanger (5) are sized according to the operating temperature of the catalyst module (7) including the NOx reduction catalyst (6) and the VOCs and CO oxidation catalyst module (9). and shape can be adjusted.

The active materials of the catalyst applied to the catalyst module (7) containing the NOx reduction catalyst (6) and the VOCs and CO oxidation catalyst module (9) are composed of Pt, Pd, Rh, Ag, Co, Cu, etc., and are composed of business exhaust gas composition. This can be changed and applied depending on the temperature.

The adsorbent module for VOCs concentration (8) can adjust the type and amount of adsorbents such as zeolite and activated carbon according to the content of VOCs discharged from the rear end of the catalyst module (7) including the NOx reduction catalyst (6).

Example 2

An exemplary system of the present invention was constructed as shown in FIG. 2(a) in the same manner as Example 1, except that two catalyst modules containing a NOx reduction catalyst were applied.

Example 3

An exemplary system of the present invention was constructed as shown in FIG. 2(b) in the same manner as Example 1, except that three catalyst modules containing a NOx reduction catalyst were applied.

2. Performance test results

Based on the results of analyzing the emission status of small businesses, the performance of the system of the present invention was confirmed for exhaust gas containing 1500 to 2500 ppm of VOCs, 50 ppm of NOx, and 10 ppm of SO2 or less.

(1) Performance evaluation of NOx reduction catalyst using platinum

When a catalyst of 1 wt% Pt/Al ₂ O ₃ was applied, performance was evaluated according to the type of reducing agent. At this time, the catalyst used in this experiment was 1 g, and the Pt content in the catalyst was 1 wt%. Meanwhile, the unit of gas composition used in this experiment was Vol.%.

1) NOx reduction catalyst performance evaluation using toluene as a reducing agent [1%Pt/Al ₂ O ₃ ] - Experimental Example 1

Using 300ppm toluene as a reducing agent, under the condition of a space velocity of 47,000h ^-1 , if the temperature of the exhaust gas containing 400ppm NO, 10% O ₂ , and 5% CO ₂ is raised from 200°C, toluene is reduced from about 240°C. It was confirmed that oxidation begins and the conversion of NOx begins at about 260°C.

As a result, it was confirmed that the NOx conversion rate was at the level of 53.7% and the toluene conversion rate was 100% above 280°C, and the results are shown in Figures 3(a) to 3(c).

Meanwhile, the NOx reduction catalyst performance was evaluated according to CO incorporation under the same conditions as above. At this time, CO was mixed with the exhaust gas and added to the front of the NOx reduction catalyst. As a result, it was confirmed that the CO ₂ concentration generated changes depending on the CO concentration, as shown in Table 1 below. This is the result of CO and O ₂ reacting and being converted into CO ₂ , and as a result, the CO concentration in the product was not high and was measured at the level of 1 ppm.

Input CO concentration Exhaust _O2 (vol%) Emission _CO2 (vol%) Emission CO (ppm) NOx conversion rate (%) Toluene conversion rate (%) 4,000 ppm 9.8 5.5 0.9 49.0 100.0 2,000 ppm 9.8 5.4 1.3 50.6 100.0 800 ppm 9.9 5.3 1.2 47.2 100.0 0 ppm 9.9 5.3 1.2 48.7 100.0

* Common reaction conditions: 300ppm toluene, 400ppm NO, 10% O ₂ , 5% CO ₂ , CO input at a space velocity of 47,000h ^-1

Referring to Table 1 above, the 2CO + O ₂ → CO ₂ reaction can be confirmed as the O ₂ concentration decreases and the CO ₂ concentration increases as the concentration increases.

2) NOx reduction catalyst performance evaluation using ethylbenzene as a reducing agent [1%Pt/Al ₂ O ₃ ] - Experimental Example 2

The temperature was raised from 200°C under the same conditions as in Experimental Example 1, except that 300ppm ethylbenzene was used as a reducing agent.

When the reaction temperature was set to 200°C and the gas released after the reaction was analyzed, it was found that the NOx conversion rate increased at the beginning of the reaction. The conversion rate was about 70%, but N ₂ O was measured to be about 10%, so N ₂ The actual NOx conversion rate was about 60%. The results are shown in Figures 4(a) and 4(b).

On the other hand, when the reaction was carried out by raising the temperature to 250℃, the activity appeared for about 20 minutes and then the activity gradually decreased. To check whether the temperature caused the inactivation, the temperature was lowered from 250℃ to 200℃, but the activity was not observed. It was confirmed that it would not recover.

Accordingly, the catalyst was heat treated at 500°C in a 10% O ₂ atmosphere and then an experiment was performed at 200°C under the same conditions. As a result, as can be seen in Figure 5, activity appears depending on the injection of the reactant, and the NOx conversion rate is about 70%, but N ₂ O is measured to be about 10%, so it can be confirmed that the actual NOx conversion rate converted to N ₂ is about 60%. there was. However, the maintenance of activity lasted for about 30 minutes, after which the activity decreased again.

(2) Evaluation of NOx reduction catalyst performance using silver

When 1 g of 2 wt% Ag/Al ₂ O ₃ catalyst was applied, the performance was evaluated according to the type of reducing agent.

1) Evaluation of NOx reduction catalyst performance using ethylbenzene as a reducing agent [2wt.% Ag/Al ₂ O ₃ ] - Experimental Example 3

Using 300ppm ethylbenzene as a reducing agent, performance evaluation was conducted on exhaust gas containing 400ppm NO, 10% O ₂ , and 5% CO ₂ under the conditions of a space velocity of 142,000 h ^-1 .

As a result of performing experiments at different temperatures while injecting ethylbenzene, high activity was observed at 300°C, as can be seen in the graph marked with a black circle in Figure 6(a) (white circle: Ethylbenzene conversion rate, black circle: NOx conversion rate). , At this time, the NOx conversion rate was 48.7%. Meanwhile, it can be seen that the NOx conversion rate decreased rapidly at high temperatures, but the converted NO was converted to NO ₂ and was not reflected in the NOx conversion rate.

The conversion rate of ethylbenzene was confirmed using FT-IR, and 100% conversion was confirmed at temperatures higher than 350°C.

Furthermore, the performance of NOx reduction catalysts according to Ag content was compared under the same conditions, and as can be seen in Figure 6(b), the NOx conversion rate for the 1wt.% Ag/Al ₂ O ₃ catalyst was lowered from 400°C. It began to appear, and at 450°C, a 22.0% NOx conversion rate was confirmed. Compared to the 2wt.% AgAl ₂ O ₃ catalyst, the Ag content is low, so the activity is not high, and the amount converted to NO ₂ is also not high, so the conversion rate even when looking at just NO I was able to confirm that it was not high.

(3) Comparative evaluation of catalyst activity containing non-precious metal components

In order to confirm the possibility of using Cu-containing zeolites other than Pt catalysts as catalysts capable of denitrification using VOC as a reducing agent, Cu/Al ₂ O ₃ and Cu-containing catalysts were evaluated.

1) Cu/Al ₂ O ₃ Denitrification experiment - Experimental example 4

Cu/Al ₂ O ₃ was prepared by impregnation, and the experiment was performed under the same conditions as Experiment 1 except for the catalyst composition.

As a result, the conversion rate of NO to NO ₂ was high at 250°C, and the conversion rate of NO alone was 60.1%, but the NOx conversion rate was 38.5% and the toluene conversion rate was 70.2%, while at 300°C, almost no NOx conversion occurred.

2) Cu/Al ₂ O ₃ and Pt/Al ₂ O ₃ Mixed catalyst denitrification experiment - Experimental example 5

To examine whether there is an additive effect in the Pt or Ag catalyst when Cu is contained, Pt/Al ₂ O ₃ and Cu/Al ₂ O ₃ were first mixed at a mass ratio of 1:1, and the mixture was used as in Experimental Example 1 except for the catalyst composition. Activity evaluation was performed under the same conditions.

As a result, the NOx conversion rate at 300°C was 55.0% and the toluene conversion rate was 58.2%. Comparing this result with the result using only Pt/Al ₂ O ₃ , the NOx conversion rate is similar, but the toluene conversion rate is not 100%, which indicates that the proportion of reducing agent used by Cu has been reduced.

3) Cu-Ag/Al ₂ O ₃ Catalytic denitrification experiment - Experimental example 6

In order to examine the effect of Cu by using a catalyst impregnated with both Cu and Ag, a catalyst containing Cu and Ag at a mass ratio of 1:1 was prepared, and under the same conditions as in Experimental Example 1 except for this catalyst composition. Activity evaluation was performed.

As a result, the NOx conversion rate at 300°C was 56.5% and the toluene conversion rate was 99.6%. Through these results, it was confirmed that Ag/Al ₂ O ₃ allows denitrification and oxidation reactions to occur simultaneously even in the presence of Cu.

1: Drying furnace and exhaust air conditioning equipment for VOCs/NOx emission processes such as painting facilities
2: Dust collection tube for capturing hazardous substances including VOCs and NOx
3, 10: Exhaust air conditioning fan
4: Heat exchanger for energy recovery
5: Exhaust gas heat exchanger (exhaust gas heating unit)
6: Catalyst module containing NOx reduction catalyst
7: Catalyst module containing NOx reduction catalyst
8: Adsorbent module for VOCs concentration
9: VOCs and CO oxidation catalyst module
10: Exhaust air conditioning fan
11: Business chimney

Claims (7)

An exhaust gas heating unit that raises the temperature of exhaust gas containing volatile organic compounds (VOCs) and nitrogen oxides (NOx) to a temperature of 150 to 400 ° C.; and
A catalyst module including a NOx reduction catalyst that reduces NOx to nitrogen by using volatile organic compounds (VOCs) and carbon monoxide (CO) as a reducing agent;
Including, an exhaust gas purification device.
The exhaust gas purification device according to claim 1, wherein the volatile organic compound is at least one component selected from the group consisting of toluene, ethylbenzene, benzene, formaldehyde, acetaldehyde, xylene, and styrene.
The method of claim 1, wherein the NOx reduction catalyst is selected from the group consisting of silver (Ag), platinum (Pt), gold (Au), palladium (Pd), rhodium (Rh), iridium (Ir), and ruthenium (Ru). An exhaust gas purification device comprising at least one precious metal component.
The exhaust gas purification device according to claim 1, further comprising an adsorbent module for concentrating volatile organic compounds that adsorbs and desorbs residual volatile organic compounds, wherein the adsorbent is at least one selected from the group consisting of zeolite and lanthanide elements. .
The exhaust gas purification device of claim 1, further comprising an oxidation catalyst module that oxidizes volatile organic compounds and carbon monoxide and converts them into CO ₂ and moisture.
The exhaust gas purification device according to claim 5, wherein the active material of the catalyst applied to the VOCs and CO oxidation catalyst module is at least one selected from the group consisting of Pt, Pd, Rh, Ag, Co, and Cu.
Injecting exhaust gas containing VOCs and NOx into the device of any one of claims 1 to 6, and increasing the temperature of the exhaust gas to a temperature of 150 to 400 ° C. through an exhaust gas heat exchanger; and
A step in which volatile organic compounds (VOCs) and carbon monoxide (CO) are introduced as a reducing agent in front of the NOx reduction catalyst module.
Including, a method of purifying exhaust gas.