KR101471719B1 - Apparatus and Method for Denitrifying and Desulfurizing Exhaust Gas - Google Patents

Abstract

The present invention relates to a process for the production of nitrogen oxides and sulfur oxides contained in an exhaust gas, comprising a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides, a reaction part performing a pretreatment step of forming nitrogen dioxide from nitrogen monoxide contained in the exhaust gas, A plasma generation unit coupled to the reaction unit to generate a plasma for performing the plasma treatment, a denitrification process for the nitrogen dioxide formed through the pretreatment process, and a desulfurization process for the sulfur dioxide remaining in the exhaust gas through the primary treatment process And a control unit connected to the reaction unit and performing the primary treatment process from the exhaust gas supplied from the reaction unit to the reaction unit so as to perform a secondary treatment process including the step of supplying sodium bicarbonate to the exhaust gas discharged from the reaction unit, The formed ammonium salt and sodium formed through the secondary treatment process To the about the same time the flue gas desulfurization denitration apparatus including a bag filter for collection and off-gas denitrifying desulfurization process,
According to the present invention, not only the denitration process and the desulfurization process can be performed in parallel using the sodium bicarbonate contained in the exhaust gas, but also the pretreatment process of increasing the specific gravity of the nitrogen dioxide among the nitrogen oxides is carried out and then reacted with the sodium bicarbonate, It is possible to improve the efficiency of the denitrification process.

Description

TECHNICAL FIELD [0001] The present invention relates to a flue gas desulfurization apparatus and a flue gas desulfurization apparatus,

The present invention relates to a flue gas desulfurization desulfurization apparatus and a flue gas desulfurization desulfurization method for removing harmful substances such as sulfur oxides and nitrogen oxides from flue gas discharged from a workplace such as a steel mill or a power plant.

Generally, in a workplace such as a steel mill or a power plant, an exhaust gas containing harmful substances is generated. For example, the exhaust gas contains harmful substances such as sulfur oxides (SOx) and nitrogen oxides (NOx). These harmful substances cause environmental problems such as smog, acid rain, global warming and ozone layer destruction. In recent years, in order to solve environmental problems caused by harmful substances contained in flue gas, the standards for discharging toxic substances to business sites have been strictly enhanced, and technologies for removing harmful substances from flue gas discharged from the business sites have been actively developed.

To remove sulfur oxides and nitrogen oxides contained in the flue-gases, prior art flue-gas treatment systems include desulfurization and denitrification plants.

The desulfurization facility performs a desulfurization process to remove sulfur oxides from the exhaust gas. The desulfurization process includes a wet process and a dry process. The wet process removes sulfur oxides by using water or an alkali solution, which has a high removal efficiency of 90%, but it requires a large amount of water and generates secondary pollutants. The dry process is a process of removing sulfur oxides by using calcium hydroxide or Na-based absorbent, which is advantageous in that the generation of secondary pollutants is less in comparison with the wet process, but there is a disadvantage that the removal efficiency and the absorbent are expensive.

The denitration facility performs a denitration process for removing nitrogen oxides from the exhaust gas. The denitrification facility includes Selective Catalytic Reduction (SCR) or Selective Non-Catalytic Reduction (SNCR). SCR removes nitrogen oxides from the exhaust gas by injecting nitrogen oxide and ammonia, which is a reducing agent, into the V ₂ O ₅ / TiO ₂ catalyst to convert the nitrogen oxides to nitrogen and water. However, SCR generates wastewater, which is a secondary pollutant, and uses an expensive catalyst, which raises the operating cost. On the other hand, SNCR removes nitrogen oxides by injecting ammonia directly into the hot exhaust gas. Since SNCR does not use a catalyst, the operating cost for the catalyst is low, but the reaction temperature must be kept high and the removal efficiency of nitrogen oxide is less than 60%.

In the conventional flue gas treating system, the desulfurization facility and the denitration facility are separately provided to remove sulfur oxides and nitrogen oxides from the flue gas. Since the desulfurization facility and the denitrification facility are installed separately from each other, the exhaust gas treatment system according to the related art requires a considerably large installation area, and thus there is a large restriction on the site area and a large burden on the investment cost.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a flue gas desulfurization apparatus and flue gas desulfurization desulfurization method capable of simultaneously removing sulfur oxides and nitrogen oxides from flue gas.

In order to solve the above problems, the present invention includes the following configuration.

The method for desulfurizing exhaust gas according to the present invention comprises the steps of: plasma-reacting an exhaust gas to perform a primary treatment process of forming an ammonium salt from nitrogen oxides and sulfur oxides contained in the exhaust gas; Performing a secondary treatment process including a denitration process for nitrogen oxides and a desulfurization process for sulfur oxides by supplying sodium bicarbonate to the exhaust gas that has undergone the primary treatment process; And simultaneously collecting the ammonium salt formed through the primary treatment process from the exhaust gas passed through the secondary treatment process and the sodium salt formed through the secondary treatment process. The step of subjecting the exhaust gas to a plasma reaction includes performing a pretreatment process of oxidizing the nitrogen monoxide contained in the exhaust gas to nitrogen dioxide in order to increase the efficiency of the denitration process using sodium bicarbonate performed in the secondary treatment process. The step of performing the secondary treatment includes a denitration process for the nitrogen dioxide formed through the pretreatment process and a desulfurization process for the sulfur dioxide remaining in the exhaust gas passed through the primary treatment process.

The method for desulfurizing exhaust gas according to the present invention includes a desulfurizing step of performing a plasma reaction on an incoming exhaust gas to form an ammonium salt from the sulfur oxide contained in the exhaust gas, and a pretreatment step of oxidizing the nitrogen oxide contained in the exhaust gas into nitrogen dioxide ; Performing a denitrification process of supplying sodium bicarbonate to the exhaust gas that has undergone the pretreatment process to form a sodium salt from the generated nitrogen dioxide; And simultaneously collecting the ammonium salt formed through the desulfurization process and the sodium salt formed through the denitrification process.

The exhaust gas denitrification apparatus according to the present invention comprises a reaction unit for performing a primary treatment process for forming an ammonium salt from nitrogen oxides and sulfur oxides contained in an exhaust gas and a pretreatment process for forming nitrogen dioxide from nitrogen monoxide contained in the exhaust gas; A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit; Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a denitration process for the nitrogen dioxide formed through the pretreatment process and a secondary treatment process including a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process are performed ; And a bag filter connected to the reaction unit and collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process at the same time.

According to the present invention, the following effects can be achieved.

The present invention can perform the denitrification process and the desulfurization process in parallel using the sodium bicarbonate contained in the flue gas as well as the pretreatment process for increasing the specific gravity of the nitrogen dioxide among the nitrogen oxides and then react with the sodium bicarbonate, The efficiency of the denitrification process can be improved.

The present invention is implemented so as to simultaneously perform the denitration process and the desulfurization process on the flue gas, thereby reducing the size of the installation area, thereby alleviating the restriction on the site area, and thus constituting a facility for removing harmful substances from the flue gas The investment cost can be reduced.

1 is a schematic diagram of a flue gas desulfurization apparatus according to the present invention;
2 is a schematic configuration diagram of an exhaust gas denitrification apparatus according to a modified embodiment of the present invention
3 is a schematic flow chart of a flue gas denitrification process according to the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a flue gas desulfurization apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a flue gas desulfurization apparatus according to the present invention, and FIG. 2 is a schematic configuration diagram of a flue gas desulfurization apparatus according to a modified embodiment of the present invention.

Referring to FIG. 1, the exhaust gas denitrification apparatus 1 according to the present invention is for removing contaminants from exhaust gas discharged from an exhaust gas generator 10. The exhaust gas generator 10 may be a steel mill, a power plant, or the like. For example, the exhaust gas generating source 10 may be a sintering facility for performing a sintering process for processing iron ore into a massive form which is easy to be charged into a blast furnace or the like in a steelworks. The exhaust gas discharged from the exhaust gas generator 10 contains contaminants such as sulfur oxides (SOx) and nitrogen oxides (NOx). The exhaust gas denitrification apparatus 1 according to the present invention removes contaminants from the exhaust gas supplied from the exhaust gas generator 10 and then discharges the exhaust gas from the contaminants to the atmosphere through the stack 20.

To this end, the flue gas desulfurization apparatus 1 according to the present invention comprises a reaction part 2 for performing a primary treatment process and a pretreatment process on an exhaust gas discharged from the flue gas generator 10, (2) for supplying sodium bicarbonate (NaHCO ₃ ) to the exhaust gas discharged from the reaction part (2) so as to perform a secondary treatment process, a plasma generator (3) coupled to the reaction part And a bag filter 6 for simultaneously collecting ammonium salts, sodium salts, and the like from the exhaust gas supplied from the reaction portion 2.

Through the primary treatment process, the exhaust gas denitrification apparatus 1 according to the present invention forms an ammonium salt from the sulfur oxides contained in the exhaust gas. Accordingly, the flue gas desulfurization apparatus 1 according to the present invention performs the desulfurization process on the sulfur oxides contained in the flue gas through the primary treatment process. Through the primary treatment process, the exhaust gas denitrification apparatus 1 according to the present invention may form an ammonium salt from nitrogen oxides and sulfur oxides contained in the exhaust gas.

Through the pretreatment process, the exhaust gas desulfurization apparatus 1 according to the present invention oxidizes nitrogen monoxide (NO) contained in the exhaust gas to form nitrogen dioxide (NO ₂ ). Accordingly, the exhaust gas denitrification apparatus 1 according to the present invention increases the specific gravity of nitrogen dioxide contained in the exhaust gas before the secondary treatment process is performed, thereby improving the efficiency of the denitration process using sodium bicarbonate in the secondary treatment process .

Through the secondary treatment process, the exhaust gas denitrification apparatus 1 according to the present invention forms a sodium salt from the nitrogen dioxide formed through the pretreatment process. Accordingly, the exhaust gas denitrification apparatus 1 according to the present invention performs a denitration process on the nitrogen dioxide contained in the exhaust gas through the secondary treatment process. Through the secondary treatment process, the exhaust gas denitrification apparatus 1 according to the present invention is capable of performing a denitrification process for the nitrogen dioxide formed through the pretreatment process and a denitrification process for the sulfur dioxide (SO ₂ ) remaining in the exhaust gas passing through the primary treatment process And a desulfurization step may be performed in parallel. In this case, the exhaust gas denitrification apparatus 1 according to the present invention forms a sodium salt from each of the nitrogen dioxide and sulfur dioxide contained in the exhaust gas.

The bag filter 5 simultaneously collects the ammonium salt formed through the primary treatment process and the sodium salt formed through the secondary treatment process to finally remove contaminants from the exhaust gas.

Therefore, the flue gas denitrification apparatus 1 according to the present invention can achieve the following operational effects.

First, even when the pre-treatment process is not performed, the secondary treatment process exhibits a predetermined efficiency for the denitrification process and the desulfurization process using sodium bicarbonate. However, when the pretreatment process is not performed, the efficiency of the denitrification process in the secondary treatment process is relatively low.

In order to solve this problem, the exhaust gas denitrification apparatus (1) according to the present invention performs the pretreatment process before performing the secondary treatment process to increase the specific gravity of the nitrogen dioxide contained in the exhaust gas, The efficiency of the denitration process using sodium bicarbonate can be maximized. Accordingly, the flue gas desulfurization apparatus 1 according to the present invention can perform the desulfurization process with high efficiency using sodium bicarbonate, and at the same time, the pretreatment process is performed before performing the secondary treatment process In this secondary treatment step, the treatment efficiency with respect to the contaminants contained in the exhaust gas can be improved by performing the denitration process in parallel with high efficiency using sodium bicarbonate.

Secondly, conventionally, the desulfurization process and the denitrification process for the exhaust gas are performed individually in the desulfurization facility and the denitrification facility, respectively. Accordingly, in the related art, a considerably large installation area is required, so that there is a large restriction on the site area and a large burden on the investment cost. The exhaust gas denitrification apparatus 1 according to the present invention simultaneously performs a denitration process and a desulfurization process on the flue gas through the secondary treatment process, and simultaneously removes contaminants from the flue gas through the bag filter 5. Therefore, the exhaust gas denitrifying apparatus 1 according to the present invention can alleviate the restriction on the site area by reducing the size of the installation area as compared with the conventional technology. Accordingly, the flue gas denitrification apparatus 1 according to the present invention can reduce the investment cost for constructing the facility for removing harmful substances from the flue gas, as compared with the prior art.

Hereinafter, the reaction unit 2, the plasma generating unit 3, the dope supply unit 4, and the bag filter 5 will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the reaction part 2 is installed between the exhaust gas generating source 10 and the bag filter 5. The exhaust gas discharged from the exhaust gas generator 10 is supplied to the reaction part 2 and then supplied to the bag filter 5 via the reaction part 2. The plasma generating part 3 is coupled to the reaction part 2. The plasma generator 3 generates a plasma by discharging the exhaust gas located inside the reaction part 2. [ Accordingly, the reaction part (2) performs a primary treatment process of forming an ammonium salt from each of the nitrogen oxide and the sulfur oxide contained in the exhaust gas by plasma reaction of the exhaust gas.

In addition, the reaction part 2 performs a pretreatment process of forming nitrogen dioxide by oxidizing nitrogen monoxide contained in the exhaust gas by plasma reaction of the exhaust gas. Accordingly, the flue gas desulfurization apparatus 1 according to the present invention can increase the efficiency of the denitrification process for the flue gas by using the sodium bicarbonate supplied from the sulfuric acid supply unit 4 by performing the pretreatment process. Specifically, it is as follows.

First, a part of the nitrogen monoxide contained in the exhaust gas is removed by being formed into an ammonium salt through the primary treatment step, but the removal efficiency is not high. For example, the primary treatment process may exhibit a removal efficiency of about 40% with respect to nitrogen monoxide depending on process conditions. Even if the primary treatment process is performed in this way, since the nitrogen monoxide remaining in the exhaust gas does not react with the sodium bicarbonate supplied from the secondary feed unit 4, nitrogen monoxide remains in the exhaust gas after the secondary treatment process. Therefore, if the pre-treatment is not performed, there is a problem that the efficiency of the denitrification process is low in the secondary treatment process. Therefore, if the pre-treatment is not performed, there is a problem that a separate denitrification facility capable of performing the denitrification process for nitrogen monoxide from the exhaust gas having passed through the secondary treatment process is required.

In order to solve this problem, the exhaust gas denitrification apparatus 1 according to the present invention performs the pretreatment process in the reaction unit 2. The nitric oxide contained in the exhaust gas is oxidized and formed of nitrogen dioxide which is reactive with sodium bicarbonate supplied from the heavies supply unit 4 as the pretreatment process is performed in the reaction unit 2. Therefore, the exhaust gas denitrification apparatus 1 according to the present invention performs the pre-treatment process before performing the secondary treatment process to increase the specific gravity of the nitrogen dioxide contained in the exhaust gas, so that sodium bicarbonate The efficiency of the denitrification process can be increased.

For example, in the exhaust gas denitrification apparatus 1 according to the present invention, the pretreatment process is performed so that the nitrogen oxide contained in the exhaust gas in the reactor 2 accounts for 60 to 100 mol% By performing the denitrification process for nitrogen dioxide using sodium bicarbonate through the process, the efficiency for the denitrification process can be increased to 70% or more.

Accordingly, the flue gas desulfurization apparatus 1 according to the present invention can perform the desulfurization process with high efficiency using sodium bicarbonate, and at the same time, the pretreatment process is performed before performing the secondary treatment process In this secondary treatment step, the treatment efficiency with respect to the contaminants contained in the exhaust gas can be improved by performing the denitration process in parallel with high efficiency using sodium bicarbonate. That is, in the flue gas desulfurization apparatus 1 according to the present invention, after the sulfuric acid and nitrogen oxides are primarily removed through the primary treatment step, the sulfuric acid and nitrogen oxides remaining in the flue gas subjected to the pretreatment step are treated with sodium bicarbonate The removal efficiency of harmful substances can be improved. The flue gas is mainly removed through the primary treatment process, and the nitrogen oxide is mainly removed through the secondary treatment process.

Although not shown, the reaction part 2 may include a discharge electrode or the like so that the exhaust gas can be discharged by using the electric power supplied from the plasma generating part 3. The reaction part 2 may include a perforated plate provided on the inlet side and the outlet side so that the flue gas can be uniformly introduced and discharged. The reaction part 2 may be a low-temperature plasma reactor.

The reaction part (2) may be connected to the reaction part duct (30). One end of the reaction part duct 30 is connected to the exhaust gas generating source 10 and the other end is connected to the reaction part 2. The exhaust gas is discharged from the exhaust gas generator 10 and then supplied to the reaction part 2 through the reaction part duct 30. A first fan (100) for moving the exhaust gas may be coupled to the reaction part duct (30). The first fan 100 may discharge the exhaust gas from the exhaust gas generating source 10 and move the exhaust gas discharged from the exhaust gas generating source 10 from the reaction unit 2 to the bag filter 5. [

Referring to FIG. 1, the plasma generating unit 3 is coupled to the reaction unit 2. The plasma generator 3 can generate plasma in the reaction part 2 by supplying electric power to the exhaust gas located inside the reaction part 2. The plasma generator 3 can control the energy density of the power supplied to the reactor 2 according to the process conditions. The plasma generator 3 controls the energy density to 4.6 to 5.3 Wh / Nm < ³ > so that the nitrogen oxide occupies 60 to 100 mol% in the nitrogen oxides remaining in the exhaust gas after the pretreatment, . Accordingly, the exhaust gas denitrification apparatus 1 according to the present invention increases the specific gravity of nitrogen dioxide among the nitrogen oxides remaining in the exhaust gas subjected to the pretreatment process, and thereby, by using the sodium bicarbonate supplied from the heavies supply unit 4, The efficiency of the denitrification process for removing the included nitrogen oxides can be improved.

The plasma generating part 3 may be supplied to the reaction part 1 by controlling the energy density so that nitrogen oxide occupies 90 to 100 mol% among the nitrogen oxides remaining in the exhaust gas after the pretreatment. In this case, the exhaust gas denitrification apparatus (1) according to the present invention further increases the specific gravity of nitrogen dioxide among the nitrogen oxides remaining in the exhaust gas subjected to the pretreatment process, so that the efficiency of the denitration process using sodium bicarbonate Can be maximized.

The plasma generator 3 may include a power supply 31 (shown in FIG. 2) and a pulse generator 32 (shown in FIG. 2). 2) is applied to the pulse generator 32 (shown in FIG. 2), and the high voltage generated in the pulse generator 32 (shown in FIG. 2) A pulse is applied to the reaction part (2), so that plasma can be generated in the reaction part (2). The high voltage pulse may be supplied to the reaction part 2 through a copper pipe. The power supply 31 (shown in Fig. 2) applies 130 to 160 kV of electricity to the pulse generator 32 (shown in Fig. 2).

Referring to FIG. 1, the heald supply unit 4 supplies sodium bicarbonate to the exhaust gas discharged from the reaction unit 2. As sodium bicarbonate is supplied to the exhaust gas discharged from the reaction part 2, the flue gas desulfurization apparatus 1 according to the present invention performs a secondary treatment process on the flue gas. In the secondary treatment step, a desulfurization step and a denitration step are performed in parallel according to the following reaction formulas 1 and 2.

[Reaction Scheme 1]

[Reaction Scheme 2]

Scheme 1 shows the desulfurization process. Sulfur dioxide (SO ₂ ) remaining in the exhaust gas after the primary treatment is reacted with sodium bicarbonate supplied from the heavies supply unit 4 according to the above reaction formula 1 to form sodium sulfate (NaSO ₄ ) do.

Scheme 2 shows the denitrification process. The NO ₂ gas contained in the exhaust gas through the pretreatment process reacts with sodium bicarbonate supplied from the heavies supply unit 4 according to the reaction formula 2 to form sodium nitrate (NaNO ₃ ), thereby performing the denitrification process. Since the nitrogen oxide remaining in the exhaust gas occupies 60 mol% or more of the nitrogen oxides remaining in the exhaust gas through the pretreatment process, the exhaust gas denitrification apparatus (1) according to the present invention can reduce the efficiency of the denitration process using sodium bicarbonate Can be improved.

As a result, the nitrogen oxides and the sulfur oxides included in the exhaust gas react with each other according to the reaction formulas 1 and 2 to form the sodium salt. Thus, the desulfurization process and the denitration process are performed at the same time.

The intermediate feeder 4 can supply sodium bicarbonate in an amount corresponding to the amount of sulfur oxides and nitrogen oxides contained in the exhaust gas to the exhaust gas. When the heavy duty feeder 4 supplies an excessive amount of sodium bicarbonate to the amount of sulfur oxides and nitrogen oxides contained in the exhaust gas, the sulfur oxides and the nitrogen oxides are not reacted with each other in the secondary treatment step and are slipped Sodium bicarbonate is generated. If the heavies supply section 4 supplies sodium bicarbonate in an amount insufficient relative to the amount of sulfur oxides and nitrogen oxides contained in the exhaust gas, the sulfuric acid and nitrogen oxides which are not formed of the sodium salt remain in the secondary treatment step .

In order to prevent this, the aqueous sodium hydrogen supplying portion 4 is NOx and sodium bicarbonate 1: 1 stoichiometric ratio (NOx: NaHCO ₃ = 1: 1) to the reaction, and the sulfur oxides and sodium bicarbonate 1: Chemistry of 2 stoichiometric ratio _{(SOx: NaHCO 3 = 1:} 2) to react with may adjust the supply amount of sodium bicarbonate to be supplied to the exhaust gas. The supply of the sodium bicarbonate to the exhaust gas may be adjusted so that the nitrogen dioxide and sodium bicarbonate react at a stoichiometric ratio of 1: 1 and the sulfur dioxide and sodium bicarbonate react at a stoichiometric ratio of 1: 2. The sodium bicarbonate supply unit 4 can supply sodium bicarbonate to the flue gas by adjusting the normalized stoichiometric ratio (NSR) to 1.6 to 2.5. When the heptasupply supply unit 4 supplies sodium bicarbonate to the exhaust gas with an NSR of less than 1.6, the sulfuric acid and nitrogen oxides which are not formed of the sodium salt remain in the secondary treatment process. When the sodium bicarbonate supply unit 4 supplies sodium bicarbonate to the exhaust gas with an NSR of more than 2.5, sodium bicarbonate which does not react with sulfur oxides and nitrogen oxides in the secondary treatment step is generated.

The heavies supply unit 4 supplies sodium bicarbonate to the exhaust gas flowing from the reaction unit 2 to the bag filter 5. [ In this case, the dewar feeder 4 may be connected to the bag filter duct 40. One end of the bag filter duct 40 is connected to the reaction part 2 and the other end is connected to the bag filter 5. The exhaust gas is discharged from the reaction part 2 and then supplied to the bag filter 5 through the bag filter duct 40. The sodium bicarbonate supply unit 4 supplies sodium bicarbonate to the bag filter duct 40 so that a secondary treatment process is performed on the exhaust gas discharged from the reaction unit 2. [

Although not shown, the dewatering unit 4 may include a dewatering unit for storing sodium bicarbonate and a dewatering unit for supplying sodium bicarbonate stored in the dewatering unit to the flue gas. The intermediate feeder means can regulate the amount of sodium bicarbonate supplied to the exhaust gas. To this end, the dunnage supply means may include a damper, a flow rate control valve, and the like.

Referring to FIG. 1, the bag filter 5 is connected to the reaction part 2. The bag filter 5 may be connected to the reaction unit 2 through the bag filter duct 40. The bag filter (5) collects liquid or solid matter due to fine processing, thereby blocking the passage of liquid or solid matter. Accordingly, the bag filter 5 simultaneously collects the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit 2, and the sodium salt formed through the secondary treatment process. For example, the bag filter 5 is _{NH 4 NO 3, NH 4 HSO} 3, NH 4 HSO 4, (NH 4) 2 SO 3, (NH 4) formed from the SO ₂ formed from NO over the first treatment step ₂ SO ₄ , and Na ₂ SO ₄ formed from NaNO ₃ , SO ₂ formed from NO ₂ through the secondary treatment process. Therefore, the bag filter 5 can finally remove harmful substances from the exhaust gas supplied from the reaction part 2. [ The surface of the bag filter 5 may be coated with a material having excellent filtering ability such as Teflon. Accordingly, the flue gas denitrification apparatus 1 according to the present invention can improve the removal efficiency of the bag filter 5 to remove harmful substances from the flue gas.

The bag filter (5) may further collect dust or the like from the exhaust gas supplied from the reaction part (2). The bag filter 5 may further collect unreacted sodium bicarbonate. Although not shown, the exhaust gas denitrification apparatus 1 according to the present invention may include a recovery apparatus for recovering unreacted sodium bicarbonate collected in the bag filter 5. [ The recovery device may store unreacted sodium bicarbonate recovered from the bag filter 5 or may supply the unreacted sodium bicarbonate to the neutralization tank 4 for reuse.

The bag filter (5) is connected to the stack (20) via a discharge tube (50). The exhaust gas through which the harmful substances have finally been removed through the bag filter 5 is discharged to the atmosphere through the stack 20 after moving along the discharge pipe 50. A second fan (200) for moving the exhaust gas may be coupled to the discharge pipe (50). The second fan 200 may discharge the flue gas from the bag filter 5 and move the flue gas discharged from the bag filter 5 to the atmosphere through the stack 20.

1 and 2, the exhaust gas denitrification apparatus 1 according to the present invention further includes an ammonia supply unit 6 for supplying ammonia (NH ₃ ).

The ammonia supply unit 6 supplies ammonia to the exhaust gas supplied to the reaction unit 2. The ammonia supplied from the ammonia supply unit 6 is mixed with the exhaust gas so that the reaction unit 2 is used to form an ammonium salt from each of the nitrogen oxides and sulfur oxides contained in the exhaust gas through the primary treatment process. After passing through the reaction part 2, nitrogen oxide remains in the exhaust gas. The ammonia supply part 6 is provided with a quantity of ammonia such that nitrogen oxide occupies 60 mol% or more among the nitrogen oxides remaining in the exhaust gas after the pre- To the exhaust gas. Preferably, the ammonia supply unit 6 may supply ammonia to the flue gas by adjusting the amount of ammonia so that nitrogen oxide occupies 90 mol% or more among the nitrogen oxides remaining in the flue gas after the pretreatment. The ammonia supply unit 6 can regulate the amount of ammonia to an NSR of 0.3 to 0.8 and supply it to the exhaust gas. The thus treated flue gas is removed from the flue gas by being collected by the bag filter 5 after the denitrification process for nitrogen dioxide is carried out by the sodium bicarbonate supplied from the dunnage supply unit 4. [

The ammonia supply unit 6 can supply the exhaust gas with ammonia in an amount corresponding to the amount of sulfur oxides and nitrogen oxides contained in the exhaust gas. When the ammonia supply unit 6 regulates the amount of ammonia to be equal to or higher than NSR 0.8 and supplies the exhaust gas to the exhaust gas, ammonia that slips without reacting with sulfur oxide and nitrogen oxide in the primary treatment step is generated. When the ammonia supply unit 6 regulates the amount of ammonia to less than NSR 0.3 and supplies the exhaust gas to the exhaust gas, the sulfuric acid and nitrogen oxides which are not formed of ammonium salts remain in the primary treatment step.

The ammonia supply unit 6 can supply ammonia to the exhaust gas supplied to the reaction unit 2 by supplying ammonia to the reaction unit 2. The ammonia supply unit 6 may supply ammonia to the exhaust gas supplied to the reaction unit 2 by supplying ammonia to the reaction part duct 30. In this case, the ammonia supply part 6 may be connected to the reaction part duct 30.

Although not shown, the ammonia supply portion 6 may include an ammonia storage portion in which ammonia is stored, and ammonia supply means for supplying ammonia stored in the ammonia storage portion to the exhaust gas. The ammonia supply means can regulate the supply amount of ammonia to be supplied to the exhaust gas. For this purpose, the ammonia supplying means may include a damper, a flow rate control valve, and the like.

Referring to FIGS. 1 and 2, the exhaust gas denitrification apparatus 1 according to the present invention further includes a hydrocarbon supply unit 7 for supplying a hydrocarbon.

The hydrocarbon feeder 7 feeds hydrocarbon to the exhaust gas supplied to the reactor 2. For example, the hydrocarbon may be propylene (C ₃ H _6). Hydrocarbons supplied to the flue gas form RO ₂ peroxides (R = H, CH ₃ , HCO ₃ , C ₂ H ₃ , C ₂ H _5, etc.) by reacting with oxygen atoms, . The RO ₂ peroxides can be by oxidizing the nitrogen monoxide to nitrogen dioxide more effectively, improving the efficiency of the pre-processing step. In addition, RO ₂ peroxide can oxidize sulfur dioxide more effectively with sulfur trioxide, thereby improving the efficiency of the primary treatment process. Accordingly, the hydrocarbon supply unit 7 can improve the efficiency of the primary treatment process per energy density of the electric power supplied to the reaction unit 2 by the plasma generation unit 3, so that the plasma generation unit 3 Can be reduced. Therefore, the exhaust gas denitrification apparatus 1 according to the present invention can reduce the operating cost.

The hydrocarbon feeder 7 can regulate the amount of hydrocarbon to an amount corresponding to the energy density of the electric power supplied to the reactor 2 by the plasma generator 3 and supply the hydrocarbon to the exhaust gas. The hydrocarbon feeder 7 can supply the exhaust gas with an amount of hydrocarbons corresponding to an NSR of 0.6 to 1.0. When the amount of hydrocarbons supplied to the exhaust gas is controlled by adjusting the amount of hydrocarbons to more than NSR 1.0, the hydrocarbon feeder 7 generates hydrocarbons that are slipped due to an excessive amount of hydrocarbon supplied. When the amount of hydrocarbons to be supplied to the exhaust gas is less than the energy density, the amount of energy consumed by the plasma generating unit 3 is reduced. .

The hydrocarbon supply unit 7 can supply hydrocarbon to the reaction unit 2 by supplying hydrocarbon to the reaction unit 2. The hydrocarbon feeder 7 may feed hydrocarbon to the reactant duct 30 by supplying hydrocarbon to the reactant duct 2. In this case, the hydrocarbon supply part 7 may be connected to the reaction part duct 30. The hydrocarbon feeder 7 may be connected to the reactant duct 30 at a position spaced apart from the ammonia feeder 6. The hydrocarbon feeder 7 may be connected to the reactant duct 30 between the exhaust gas generator 10 and the ammonia feeder 6.

Although not shown, the hydrocarbon feeder 7 may include a hydrocarbon storage for storing hydrocarbons, and a hydrocarbon feed for feeding the hydrocarbon stored in the hydrocarbon storage to the flue gas. The hydrocarbon supply means can regulate the supply amount of the hydrocarbon supplied to the flue gas. For this purpose, the hydrocarbon supply means may include a damper, a flow rate control valve, and the like.

1 and 2, the exhaust gas denitrification apparatus 1 according to the present invention further includes an activated carbon supply section 8 for supplying activated carbon.

The activated carbon supply unit 8 supplies activated carbon to the exhaust gas supplied to the bag filter 5. [ The activated carbon supplied to the flue gas adsorbs dioxins contained in the flue gas. The bag filter (5) can collect dioxin-adsorbed activated carbon to remove dioxin from the exhaust gas. The activated carbon supply unit 8 can supply activated carbon to the exhaust gas supplied to the bag filter 5 by supplying activated carbon to the exhaust gas moving from the reaction unit 2 to the bag filter 5. [ In this case, the activated carbon supply unit 8 may be connected to the bag filter duct 40. The activated carbon supply unit 8 may supply activated carbon to the bag filter duct 40 so that the dioxins contained in the exhaust gas are adsorbed on the activated carbon. The activated carbon supply unit 8 may be connected to the bag filter duct 40 at a position spaced apart from the heavy duty supply unit 4.

The activated carbon supply unit 8 may be connected to the bag filter duct 40 so as to be positioned between the heavy duty supply unit 4 and the bag filter 5 so that activated carbon is supplied after sodium bicarbonate is supplied to the exhaust gas. When activated carbon is supplied to the exhaust gas before sodium bicarbonate, the activated carbon reacts with harmful substances other than dioxins contained in the exhaust gas, so that the amount of activated carbon supplied by the activated carbon supplying unit 8 increases. The deodorization desulfurization apparatus (1) according to the present invention can prevent the activated carbon from reacting with harmful substances other than dioxin by supplying sodium bicarbonate to the exhaust gas and then supplying the activated carbon later. Therefore, the dehydrogenation desulfurization apparatus 1 according to the present invention can reduce consumption of activated carbon.

Although not shown, the activated carbon supply unit 8 may include an activated carbon storage unit for storing activated carbon, and an activated carbon supply unit for supplying activated carbon stored in the activated carbon storage unit to the exhaust gas. The activated carbon supply means can regulate the amount of activated carbon supplied to the exhaust gas. To this end, the activated carbon supply means may include a damper, a flow rate control valve, and the like.

2, the exhaust gas denitrification apparatus 1 according to the present invention includes a measuring unit 9 for measuring the content of at least one of nitrogen oxides, sulfur oxides and ammonia from exhaust gas discharged from the bag filter 5 .

The measuring unit 9 is installed between the bag filter 5 and the stack 20. The measuring unit 9 may be installed in the discharge pipe 50. The measuring unit 9 may measure the content of at least one of nitrogen oxides, sulfur oxides, and ammonia from the exhaust gas flowing from the bag filter 5 to the stack 20 through the discharge pipe 50. The measuring unit 9 may include at least one of a sulfur oxide analyzer, a nitrogen oxide analyzer, and an ammonia analyzer.

The measuring unit 9 measures the content of at least one of nitrogen oxides, sulfur oxides and ammonia from the exhaust gas discharged from the bag filter 5 and obtains measured values from the ammonia supply unit 6 ). The ammonia supply unit 6 may adjust the supply amount of ammonia supplied to the exhaust gas according to the measurement value provided from the measurement unit 9. [ For example, when the measured value of ammonia measured by the measuring unit 9 exceeds a predetermined reference value, the ammonia supply unit 6 can reduce the supply amount of ammonia supplied to the exhaust gas. Accordingly, the ammonia supply unit 6 can reduce the amount of ammonia contained in the exhaust gas discharged from the bag filter 5 by reducing ammonia that is not used in the primary treatment and slip. For example, when the measurement value of the nitrogen oxide or sulfur oxide measured by the measuring unit 9 exceeds a preset reference value, the ammonia supply unit 6 can increase the supply amount of ammonia supplied to the exhaust gas. Accordingly, the ammonia supplying unit 6 increases the amount of the ammonium salt formed from the nitrogen oxide and the sulfur oxide in the primary treatment step, thereby increasing the amount of nitrogen oxides or sulfur oxides contained in the exhaust gas discharged from the bag filter 5 The amount can be reduced.

The measurement unit 9 measures the content of at least one of nitrogen oxides and sulfur oxides from the exhaust gas discharged from the bag filter 5 and obtains measurement values, . According to the measured value provided from the measuring unit 9, the heavy duty supply unit 4 can adjust the supply amount of sodium bicarbonate to be supplied to the exhaust gas. For example, when the measured value of nitrogen oxides or sulfur oxides measured by the measuring unit 9 exceeds a preset reference value, the heavies supply unit 4 can increase the supply amount of sodium bicarbonate to be supplied to the exhaust gas. Accordingly, by increasing the amount of the sodium salt formed from the nitrogen oxides and the sulfur oxides in the secondary treatment step, the heavy duty supply unit 4 can increase the amount of nitrogen oxides or sulfur oxides contained in the exhaust gas discharged from the bag filter 5 Can be reduced. The measurement unit 9 may further measure the amount of dust, the temperature, the moisture content, and the like from the exhaust gas discharged from the bag filter 5.

According to an embodiment of the present invention, the plasma generating part 3 adjusts the energy density to 5.4 and supplies it to the reaction part 2. The hydrocarbon supplying part 7 adjusts the NSR of 0.6 to supply hydrocarbons, When the ammonia supply unit 6 was adjusted to NSR 0.6 to supply ammonia, the nitric oxide contained in the exhaust gas through the pretreatment process was oxidized by 89% to form nitrogen dioxide. Thereafter, the sodium bicarbonate removal rate of the exhaust gas reached 72% and the removal rate of sulfur dioxide was found to reach 99% by adjusting sodium bicarbonate to NSR 2.5.

Hereinafter, preferred embodiments of the flue gas desulfurization method according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic flow chart of a flue gas desulfurization method according to the present invention.

1 to 3, the exhaust gas desulfurization method of the present invention is for removing contaminants from the exhaust gas discharged from the exhaust gas generator 10. The flue gas denitrification method according to the present invention can be carried out using the flue gas denitrification apparatus 1 according to the present invention described above. The flue gas denitrification method according to the present invention includes the following constitution.

First, the exhaust gas denitrification apparatus 1 performs a plasma reaction on the exhaust gas discharged from the exhaust gas generator 10 (S10). In this step S10, the plasma supplying part 4 discharges the exhaust gas located in the reaction part 2 and plasma-reacts the exhaust gas.

The step (S10) of plasma-reacting the exhaust gas includes a step (S11) of performing the primary treatment step and a step (S12) of performing the pre-treatment step.

The step (S11) of performing the primary treatment process may include discharging the exhaust gas to induce sulfur oxides and nitrogen oxides contained in the exhaust gas into a plasma state, and finally reacting with ammonia to form an ammonium salt. This step (S11) may be performed in the reaction part (3). The primary treatment may be carried out according to the following Reaction Schemes 3 and 4.

[Reaction Scheme 3]

[Reaction Scheme 4]

In the above reaction schemes 3 and 4, [O] means various kinds of oxides. For example, [O] can be hydroxyl group (OH), oxygen atom (O), ozone (O ₃ ), etc. formed as the exhaust gas is discharged and is induced to a plasma state. The nitrogen oxides and sulfur oxides contained in the exhaust gas are reacted with the [O] oxides to be oxidized and then reacted with water molecules (H ₂ O) contained in the exhaust gas or the air existing in the reactor 3, ₃ ) and sulfuric acid (H ₂ SO ₄ ). The thus formed nitric acid and sulfuric acid react with ammonia (NH ₃ ) to form ammonium nitrate (NH ₄ NO ₃ ) and ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), respectively. The ammonia may be contained in the exhaust gas or may be supplied from the ammonia supply unit 6.

As a result, the nitrogen oxide and the sulfur oxide contained in the exhaust gas react with each other according to the reaction scheme 3 and the reaction scheme 4 to form the ammonium salt, thereby performing the primary treatment process.

Step (S12) for performing the pre-processing step is formed by oxidizing the nitrogen monoxide (NO) contained in exhaust gas to increase the efficiency of NOx removal processes using aqueous sodium bicarbonate nitrogen dioxide (NO ₂₎ is performed in the second treatment step . Accordingly, the flue gas denitrification method of the present invention can achieve the following operational effects.

First, even when the pretreatment step is not performed, the secondary treatment step exhibits a predetermined efficiency with respect to the denitrification step and the desulfurization step using sodium bicarbonate. However, part of the nitrogen monoxide contained in the exhaust gas is removed by being formed as an ammonium salt through the primary treatment step, but the removal efficiency is not high, so that even if the primary treatment process is performed, the nitrogen monoxide remains in the exhaust gas. Since this nitrogen monoxide does not react with sodium bicarbonate supplied from the above-mentioned heavies supplying section 4, nitrogen monoxide still remains in the exhaust gas after the secondary treatment process. Therefore, if the pre-treatment is not performed, there is a problem that the efficiency of the denitrification process is low in the secondary treatment process.

In order to solve this problem, the pretreatment process is performed to increase the specific gravity of the nitrogen oxide contained in the exhaust gas (S12) before performing the secondary treatment process in the exhaust gas desulfurization method of the present invention. Accordingly, the exhaust gas denitrification method of the present invention can oxidize the nitrogen monoxide contained in the exhaust gas through the pretreatment process to form nitrogen dioxide which reacts with sodium bicarbonate, so that the efficiency of the denitration process using sodium bicarbonate in the secondary treatment process . Therefore, the desulfurization method of exhaust gas of the present invention can perform the desulfurization process with high efficiency by using sodium bicarbonate, and at the same time, the pretreatment process is performed before the secondary treatment process, The treatment efficiency with respect to the contaminants contained in the exhaust gas can be improved by performing the denitration process in parallel with high efficiency using sodium bicarbonate in the treatment process.

For example, the pretreatment process of the exhaust gas denitrification method according to the present invention may be performed such that the nitrogen oxide contained in the exhaust gas in the reactor 2 occupies 60 mol% or more of the nitrogen oxide contained in the exhaust gas. Accordingly, the exhaust gas denitrification method of the present invention can increase the efficiency of the denitrification process to 70% or more by performing a denitration process for nitrogen dioxide using sodium bicarbonate through the secondary treatment process. Preferably, the exhaust gas denitrification method according to the present invention is characterized in that the pretreatment step is carried out in the reaction part (2) so that the nitrogen oxide occupies 90% by mole or more of the nitrogen oxides contained in the exhaust gas, The efficiency of the denitration process using sodium can be maximized.

In the step S12 of performing the pretreatment process, nitrogen monoxide contained in the exhaust gas is discharged into the plasma state by discharging the exhaust gas, so that nitrogen monoxide can be formed from nitrogen dioxide according to the following reaction formula. This step (S12) may be performed in the reaction part (3).

[Reaction Scheme 5] e + O ₂ ? O + O + e

[Reaction Scheme 6] e + O ₂ ? O + O ( ¹ D) + e

[Chemical Formula 7] O ( ¹ D) + H ₂ O → O + H ₂ O

???????? O ( ¹ D) + O ₂ ? O + O ₂ ?????

O ( ¹ D) + N ₂ O + N ₂

[Reaction Scheme 10] e + H ₂ O? OH + e

(11) O ( ¹ D) + H ₂ O → OH + OH

OH + OH - > H ₂ O + O

[Reaction Scheme 13] O + O ₂ ? O ₃

[Reaction Scheme 14] NO + (O, O3 ) → NO 2

Specifically, the exhaust gas and the air existing in the reactor 3 are discharged to the plasma state by the plasma generation unit 3 in the reaction unit 2, Or part of the oxygen molecule (O ₂ ) contained in the air reacts according to scheme 5 to form oxygen atom (O). Then, a part of the oxygen molecules (O ₂ ) contained in the exhaust gas or the air reacts according to the reaction formula (6) to form the oxygen atom (O) and the oxygen atom in the excited state (O ( ¹ D)).

Some of the oxygen atoms (O) formed according to Reaction Schemes 5 and 6 form nitrogen dioxide (NO ₂ ) by reacting with nitrogen monoxide (NO) contained in the exhaust gas according to Scheme 14. A part of the oxygen atoms O formed according to the reaction formulas 5 and 6 reacts with the oxygen molecules O ₂ contained in the exhaust gas or air according to the reaction formula 13 to form ozone O ₃ , (NO ₂ ) contained in the exhaust gas by reacting with nitrogen monoxide (NO) contained in the exhaust gas.

The oxygen atoms (O ( ¹ D)) in the excited state formed according to Scheme 6 can be converted into water molecules (H ₂ O), oxygen molecules (O ₂ ), nitrogen molecules (N ₂ ) to form oxygen atoms (O). A portion of the oxygen atom (O) formed according to Scheme 7 through Scheme 9 forms a nitrogen dioxide (NO ₂ ) by reacting with nitrogen monoxide (NO) according to Scheme 14 above. A part of the oxygen atoms O formed according to the reaction formulas 7 to 9 forms an ozone O ₃ by reacting with oxygen molecules O ₂ contained in the exhaust gas or air according to the reaction formula 13, (NO ₂ ) contained in the exhaust gas by reacting with nitrogen monoxide (NO) contained in the exhaust gas.

Meanwhile, as the exhaust gas and the air existing in the reactor 3 are discharged by the plasma generating unit 3 and are induced into a plasma state, water molecules (H ₂ O) (OH), and reacts according to the reaction scheme (12) to form an oxygen atom (O). Some of the oxygen atoms (O) formed according to scheme 10 and scheme 12 react with nitrogen monoxide (NO) according to scheme 14 to form nitrogen dioxide (NO ₂ ). A portion of the oxygen atom (O) formed according to Scheme 10 and Scheme 12 reacts with the oxygen molecule (O ₂ ) contained in the exhaust gas according to Scheme 13 to form ozone (O ₃ ) the forms nitrogen dioxide (NO ₂₎ by reaction with nitrogen monoxide (NO). The hydroxyl group (OH) used in Scheme 12 may be formed by reacting an excited oxygen atom (O ( ¹ D)) formed according to Scheme 6 with a water molecule (H ₂ O) according to Scheme 11.

As a result, the nitric oxide contained in the exhaust gas is oxidized by reacting with the oxygen atom (O) or the ozone (O ₃ ) according to the reaction formula 14 and is thus formed of nitrogen dioxide, whereby the pretreatment process is performed (S12).

The step of performing the pre-treatment step (S12) and the step of performing the primary treatment step (S11) may be performed simultaneously in the reactor (3). The step of performing the pre-treatment step (S12) and the step of performing the primary treatment step (S11) may be performed first in the reactor (3), and the remaining one may be performed later. In the case where the step S11 of performing the primary treatment step is performed first, the step of performing the pre-treatment step (S12) may include oxidizing the nitrogen monoxide remaining in the exhaust gas by nitrogen dioxide after the primary treatment step Lt; / RTI >

The step S10 of reacting the exhaust gas with the plasma may be performed by adjusting the energy density for generating the plasma to 4.6 to 5.3 Wh / Nm ³ in the reaction part 2. This process can be performed by the plasma generating section 3. [ Accordingly, the pretreatment process may be performed so that the nitrogen oxide contained in the exhaust gas occupies 60 mol% or more of the nitrogen oxide contained in the exhaust gas.

Next, the flue gas desulfurization apparatus 1 performs the secondary treatment by supplying sodium bicarbonate (S20). This step S20 may be performed by supplying the sodium bicarbonate to the exhaust gas discharged from the reaction part 2 and supplied to the bag filter 5. [ A denitration process for the nitrogen dioxide formed through the pretreatment process and a desulfurization process for the sulfur dioxide remaining in the exhaust gas after the primary treatment process are performed in parallel by the step S20 of performing the secondary treatment process. The step (S20) of performing the secondary treatment may be performed by treating the denitrification process according to the above-described reaction formula (2). In addition, the step S20 of performing the secondary treatment may be performed by treating the desulfurization step according to the above-described reaction formula 1.

Step (S20) for performing the secondary processing step is a nitrogen oxide and sodium bicarbonate 1: 2: the reaction is referred to as, and sulfur oxides and sodium bicarbonate 1 stoichiometric ratio of _{1 (1 NOx:: NaHCO 3} = 1) the stoichiometric ratio _{(SOx: NaHCO 3 = 1:} 2) to react with may include the step of controlling the supply amount of sodium bicarbonate to be supplied to the exhaust gas. This process can be performed by adjusting the supply amount of sodium bicarbonate by the dunnilup supply unit 4. [ In the step S20 of performing the secondary treatment, the amount of sodium bicarbonate can be adjusted to NSR 1.6-2.5 and supplied to the exhaust gas. In the step S20 of performing the secondary treatment process, the sulfuric acid supply unit 4 reacts with nitrogen dioxide and sodium bicarbonate at a stoichiometric ratio of 1: 1, and the sulfur dioxide and sodium bicarbonate react at a stoichiometric ratio of 1: The amount of sodium bicarbonate to be supplied to the reaction vessel may be controlled.

Next, the flue gas desulfurization apparatus 1 simultaneously collects the ammonium salt and the sodium salt from the flue gas (S30). This step (S30) can be performed by the bag filter (5) simultaneously collecting the ammonium salt and the sodium salt from the exhaust gas that has undergone the secondary treatment process. By the step of collecting the ammonium salt and the sodium salt (S30), the nitrogen oxide and the sulfur oxide can finally be removed from the exhaust gas. The step (S30) of collecting the ammonium salt and the sodium salt may be carried out by further collecting the sodium unreacted sodium carbonate in the bag filter (5). The exhaust gas passing through the step of collecting the ammonium salt and the sodium salt (S30) is discharged to the atmosphere through the stack (20).

1 to 3, the exhaust gas denitrification method according to the present invention further includes a step (S40) of supplying ammonia.

The ammonia supplying step S40 may be performed by supplying the ammonia to the exhaust gas discharged from the exhaust gas generating source 10 and supplied to the reaction part 2 by the ammonia supplying part 6. [ By the step of supplying ammonia (S40), the exhaust gas is located inside the reaction part 2 in a state mixed with ammonia. The step (S40) of supplying ammonia can be performed by adjusting the amount of ammonia to 0.3 to 0.8 and supplying the exhaust gas to the exhaust gas. Accordingly, the exhaust gas denitrification method of the present invention can make the nitrogen oxide occupy 60% by mole or more of the nitrogen oxides remaining in the exhaust gas after the pretreatment.

1 to 3, the exhaust gas denitrification method of the present invention further includes a step (S50) of supplying hydrocarbon.

The step (S50) of supplying the hydrocarbon may be performed by supplying the hydrocarbon to the exhaust gas supplied to the reaction part (2) by the hydrocarbon supplying part (7). By the step of supplying the hydrocarbon (S50), the exhaust gas is located inside the reaction part 2 in a mixed state with the hydrocarbon. The step of supplying hydrocarbon (S50) may be performed after the ammonia supplying step (S40) is performed and before the step (S10) of plasma-reacting the exhaust gas is performed. The step (S50) of supplying the hydrocarbon may be carried out by adjusting the amount of propylene to NSR 0.6 to 1.0 and supplying it to the exhaust gas.

In this case, the step (S10) of plasma-reacting the exhaust gas may be performed by discharging the exhaust gas in which the ammonia and the hydrocarbon are mixed. By discharging the flue gas mixed with ammonia and hydrocarbon, the flue gas denitrification method of the present invention can more efficiently oxidize nitrogen monoxide with nitrogen dioxide, thereby improving the efficiency of the pretreatment process. The exhaust gas denitrification method according to the present invention improves the efficiency of the primary treatment process per energy density of the power supplied to the reactor 2 by the plasma generator 3, 3) can be reduced.

1 to 3, the exhaust gas denitrification method of the present invention further includes a step (S60) of supplying activated carbon.

The step S60 of supplying the activated carbon may be performed by supplying activated carbon to the exhaust gas supplied to the bag filter 5 by the activated carbon supplier 8. By the step of supplying the activated carbon (S60), the exhaust gas is supplied to the bag filter (5) with dioxin adsorbed on the activated carbon. The bag filter (5) can collect dioxin-adsorbed activated carbon to remove dioxin from the exhaust gas. The step of supplying the activated carbon (S60) may be performed after the step (S20) of performing the secondary treatment step and the step (S30) of simultaneously collecting the ammonium salt and the sodium salt are performed.

1 to 3, the method for desulfurizing exhaust gas of an exhaust gas according to the present invention may further include a step (S70) of measuring the content of at least one of nitrogen oxides, sulfur oxides and ammonia from an exhaust gas.

The step of measuring the content (S70) may be performed by measuring the content of at least one of nitrogen oxides, sulfur oxides and ammonia from the exhaust gas discharged from the bag filter (5) by the measuring part (9). The measuring unit 9 may provide a measured value for at least one of nitrogen oxides, sulfur oxides, and ammonia to at least one of the ammonia supply unit 6 and the helium supply unit 4.

In this case, the step of supplying ammonia (S40) may include a step of adjusting the supply amount of ammonia according to the measured value. This process can be performed by regulating the supply amount of ammonia by the ammonia supply unit 6. [ The measured value is a measurement value of at least one of nitrogen oxide, sulfur oxide and ammonia obtained in the step of measuring the content (S70).

The step S20 of performing the secondary treatment may include a step of adjusting the supply amount of sodium bicarbonate according to the measured value. This process can be performed by adjusting the supply amount of sodium bicarbonate by the dunnilup supply unit 4. [ The measurement value is a measurement value for at least one of nitrogen oxides and sulfur oxides obtained in the step of measuring the content (S70).

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be clear to those who have knowledge.

1: Flue gas denitrification apparatus 2: Reactor 3: Plasma generator
4: Heavy duty feeder 5: Bag filter 6: Ammonia feeder 7: Hydrocarbon feeder
8: activated carbon supply part 9: measuring part 10: generator 20: stack
30: Reactor duct 31: Power supply unit 32: Pulse generator
40: bag filter duct 50: exhaust pipe 100: first fan 200: second fan

Claims (17)

delete delete Subjecting the exhaust gas to a plasma reaction so as to perform a primary treatment process of forming ammonium salts from the nitrogen oxides and sulfur oxides contained in the exhaust gas;
Performing a secondary treatment process including a denitration process for nitrogen oxides and a desulfurization process for sulfur oxides by supplying sodium bicarbonate to the exhaust gas that has undergone the primary treatment process; And
Collecting the ammonium salt formed through the primary treatment process from the exhaust gas that has undergone the secondary treatment process and the sodium salt formed through the secondary treatment process at the same time,
The step of subjecting the exhaust gas to plasma reaction includes a step of performing a pretreatment step of oxidizing nitrogen monoxide contained in the exhaust gas to nitrogen dioxide in order to increase the efficiency of the denitration process using sodium bicarbonate performed in the secondary treatment step,
The step of performing the secondary treatment includes a step of performing a denitration process for the nitrogen dioxide formed through the pretreatment process and a desulfurization process for the sulfur dioxide remaining in the exhaust gas passing through the primary treatment process, And then supplying the flue gas to the desulfurization unit. delete delete Adjusting ammonia to a normalized stoichiometric ratio (NSR) of 0.3 to 0.8 and supplying the ammonia to an exhaust gas;
Subjecting the exhaust gas to a plasma reaction so as to perform a primary treatment process of forming ammonium salts from the nitrogen oxides and sulfur oxides contained in the exhaust gas;
Performing a secondary treatment process including a denitration process for nitrogen oxides and a desulfurization process for sulfur oxides by supplying sodium bicarbonate to the exhaust gas that has undergone the primary treatment process; And
Collecting the ammonium salt formed through the primary treatment process from the exhaust gas that has undergone the secondary treatment process and the sodium salt formed through the secondary treatment process at the same time,
The step of subjecting the exhaust gas to a plasma reaction includes a step of performing a pretreatment process of oxidizing nitrogen monoxide contained in the exhaust gas to nitrogen dioxide in order to increase the efficiency of a denitration process using sodium bicarbonate performed in the secondary treatment step, Adjusting the energy density for generating the plasma to 4.6 to 5.3 Wh / Nm ³ in the reaction part in which the pretreatment step and the primary treatment step are performed such that nitrogen dioxide occupies 60 to 100 mol% among the included nitrogen oxides / RTI >
Wherein the step of performing the secondary treatment includes a denitrification process for the nitrogen dioxide formed through the pretreatment process and a desulfurization process for the sulfur dioxide remaining in the exhaust gas passed through the primary treatment process, . Supplying propylene to the flue gas by regulating the propylene to an NSR of 0.6 to 1.0 and regulating the ammonia to an NSR of 0.3 to 0.8;
Subjecting the exhaust gas to a plasma reaction so as to perform a primary treatment process of forming ammonium salts from the nitrogen oxides and sulfur oxides contained in the exhaust gas;
Performing a secondary treatment process including a denitration process for nitrogen oxides and a desulfurization process for sulfur oxides by supplying sodium bicarbonate to the exhaust gas that has undergone the primary treatment process; And
Collecting the ammonium salt formed through the primary treatment process from the exhaust gas that has undergone the secondary treatment process and the sodium salt formed through the secondary treatment process at the same time,
The step of subjecting the exhaust gas to a plasma reaction includes a step of performing a pretreatment process of oxidizing nitrogen monoxide contained in the exhaust gas to nitrogen dioxide in order to increase the efficiency of a denitration process using sodium bicarbonate performed in the secondary treatment process, And discharging the mixed flue gas,
Wherein the step of performing the secondary treatment includes a denitrification process for the nitrogen dioxide formed through the pretreatment process and a desulfurization process for the sulfur dioxide remaining in the exhaust gas passed through the primary treatment process, . delete delete delete delete A reaction part in which a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides contained in the exhaust gas and a pretreatment step of forming nitrogen dioxide from the nitrogen monoxide contained in the exhaust gas are performed;
A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit;
Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a denitration process for the nitrogen dioxide formed through the pretreatment process and a secondary treatment process including a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process are performed ; And
And a bag filter connected to the reaction unit and simultaneously collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process,
The sodium bicarbonate is adjusted to an NSR of 1.6 to 2.5 so that the denitrification process for the nitrogen dioxide formed through the pretreatment process and the desulfurization process for the sulfur dioxide remaining in the exhaust gas passing through the primary treatment process are performed in parallel A flue gas desulfurization device characterized by. A reaction part in which a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides contained in the exhaust gas and a pretreatment step of forming nitrogen dioxide from the nitrogen monoxide contained in the exhaust gas are performed;
A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit;
Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a denitration process for the nitrogen dioxide formed through the pretreatment process and a secondary treatment process including a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process are performed ;
A bag filter connected to the reaction unit and collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process at the same time; And
And an ammonia supply unit for supplying ammonia to the exhaust gas supplied to the reaction unit,
The ammonia supplying unit may supply ammonia to the ammonia supplying unit such that the nitrogen oxide contained in the exhaust gas discharged from the reactor through the pretreatment process occupies 60 to 100% by mole in order to increase the efficiency of the denitration process performed in the secondary treatment process NSR is adjusted to 0.3 ~ 0.8 and supplied to the flue gas,
In order to increase the efficiency of the denitrification process performed in the secondary treatment process, the plasma generating unit may perform the pre-treatment so that the nitrogen oxide contained in the exhaust gas discharged from the reaction unit occupies 60 to 100 mol% Wherein an energy density for generating a plasma in the inside of the unit is adjusted to 4.6 to 5.3 Wh / Nm ³ . A reaction part in which a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides contained in the exhaust gas and a pretreatment step of forming nitrogen dioxide from the nitrogen monoxide contained in the exhaust gas are performed;
A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit;
Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a denitration process for the nitrogen dioxide formed through the pretreatment process and a secondary treatment process including a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process are performed ;
A bag filter connected to the reaction unit and collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process at the same time; And
Further comprising a hydrocarbon supply part for supplying propylene to the exhaust gas supplied to the reaction part,
Wherein the hydrocarbon feeder regulates propylene to an NSR of 0.6 to 1.0 and feeds the exhaust gas to the exhaust gas. A reaction part in which a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides contained in the exhaust gas and a pretreatment step of forming nitrogen dioxide from the nitrogen monoxide contained in the exhaust gas are performed;
A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit;
Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a denitration process for the nitrogen dioxide formed through the pretreatment process and a secondary treatment process including a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process are performed ;
A bag filter connected to the reaction unit and collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process at the same time;
A reaction part duct connecting the exhaust gas generating source and the reaction part;
A hydrocarbon supply unit for supplying hydrocarbon to the exhaust gas supplied to the reaction unit; And an ammonia supply unit for supplying ammonia to the exhaust gas supplied to the reaction unit,
Wherein the reaction buoyant is connected to the ammonia supply unit and the hydrocarbon supply unit, respectively, so that ammonia and hydrocarbon are supplied to the exhaust gas supplied to the reaction unit. delete A reaction part in which a primary treatment step of forming ammonium salts from nitrogen oxides and sulfur oxides contained in the exhaust gas and a pretreatment step of forming nitrogen dioxide from the nitrogen monoxide contained in the exhaust gas are performed;
A plasma generator coupled to the reaction unit to generate a plasma for performing the pre-treatment process and the primary treatment process in the reaction unit;
Sodium bicarbonate is supplied to the exhaust gas discharged from the reaction unit so that a secondary treatment process including a denitration process for nitrogen dioxide formed through the pretreatment process and a desulfurization process for sulfur dioxide remaining in the exhaust gas through the primary treatment process is performed ;
A bag filter connected to the reaction unit and collecting the ammonium salt formed through the primary treatment process from the exhaust gas supplied from the reaction unit and the sodium salt formed through the secondary treatment process at the same time;
An ammonia supply unit for supplying ammonia to the exhaust gas supplied to the reaction unit; And
And a measuring section for measuring the content of at least one of nitrogen oxides, sulfur oxides and ammonia from the exhaust gas discharged from the bag filter,
The ammonia supply unit adjusts the supply amount of ammonia according to the measurement value provided from the measurement unit,
Wherein the heavies supply unit adjusts the supply amount of sodium bicarbonate according to a measurement value provided from the measurement unit.

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