KR20160090658A - Non-degradable noxious gas treatment system using the same process - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas treating system for decomposing and processing a refractory waste gas contained in an exhaust gas generated in a semiconductor, a flat panel display (FPD), a liquid crystal display (LCD) More particularly, the present invention relates to a supply unit for supplying a noxious decomposable noxious gas; A pre-heating zone for increasing the decomposition reactivity of the noxious gas; An oxidant injector for injecting an oxidant to generate explosive gas and reaction by-product powder among the gases to be treated; An oxidizer reaction unit; And a plasma ignitor added to the reaction part; A reactor in which a full decomposition reaction takes place; A quenching section for lowering the temperature of the treated gas; A shear-scrubber for collecting by-products; A dust demister for removing dust; A decomposition part through catalyst and dielectric heating; And a rear stage dust collecting unit, and a processing method using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a process for treating a harmful gas,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment system for decomposing and processing a non-degradable waste gas contained in an exhaust gas generated in a manufacturing process of a semiconductor, a flat panel display (FPD), or a liquid crystal display An oxidizing agent is introduced into a heated refractory gas which has passed through a pre-heating zone for heating a refractory gas between the reflux portion and the oxidizer input portion, the flue gas is decomposed using a plasma ignitor, And a dust collecting unit for collecting and collecting the by-product powder using an enemy. The first reaction is a demister for removing fine particles of waste gas, a decomposition unit for mixing catalyst and dielectric heating, An exhaust gas treatment system composed of a post wet scrubber for finally removing a substance, and an exhaust gas treatment using the exhaust gas treatment system ≪ / RTI >

Recently, waste gas used in the semiconductor process, flat panel display (FPD), liquid crystal display (LCD) manufacturing process, or as a by-product after use has a great influence on the environment and global warming Are reported.

Particularly, there are NF ₃ , SF ₆ , PF ₆ and N ₂ O as the kinds of decomposable gases to be discharged, and silane, TEOS, DCS, WF ₆ , TiCl ₄ and SiF ₄ And is highly corrosive and has very explosive gases such as F ₂ , HF, Cl ₂ , HCl, ClF ₃ , NH ₃ , BCl ₃ , B ₂ H ₄ and PH ₃ , DCS, WF _6, NH _3, H _2, B ₂ H _4, CO, etc. in addition, contains oxygen (O _2), ozone (O _3), the argon inert gas (Ar), helium (he) or the like, Also, various kinds of organic noxious gases generated in various kinds of organic solvents such as acetone, methanol, trichlorethylene and the like which are mainly used in the washing process of the manufacturing process are also included and discharged. As such, various types of waste gas discharged from the above process contain highly stable compounds ranging from thousands to tens of thousands of years in the natural state. Since the global warming index is several thousands to several tens of thousand times that of carbon dioxide, As agreed in the Convention, future emissions are strictly limited.

Therefore, technologies for decomposing these gases are required to prevent air pollution caused by these waste gases and global warming. Typical processes for removing such refractory waste gas include an oxidation process such as combustion (Japanese Laid-Open Patent Publication No. 2006-17453), a chemical adsorption process (Korean Patent Publication No. 2003-0078949, and plasma 2008-259953), and the like.

In the direct oxidation process such as the above-mentioned combustion, a method of decomposing by heating to a predetermined temperature or higher and discharging it as a harmless gas, or heating and precipitating in powder form by mixing with other gases is mainly used. In the case of water- And is recovered and discharged. Among them, the plasma method is widely used for the decomposition and removal of the degradable waste gas. However, the conventional plasma removing technique for the refractory gas is a technique using a plasma torch having a very high temperature. Hundreds of LPM Consumes several tens of kilowatts of power to process the waste gas of a flat panel display (FPD). In a flat panel display (FPD) manufacturing process, the amount of exhaust gas increases to 2500 LPM depending on the case, It is consumed.

All of the above-mentioned waste gas treatment methods are required to heat and decompose the refractory gas. Until now, a plasma arc torch has been used or a direct heating method using a heater has been used. (Korean Patent Publication No. 10-0619237). However, the method of using the heater is relatively inefficient because the electrode has a short life span due to the high temperature and the plasma discharge, Although it has an advantage of being able to treat gas at low cost, it has a drawback (Korean Patent Laid-Open Publication No. 2009-0041880) that it is not easy to treat the waste gas at a high temperature because an indirect heating method using a heater is used. Particularly, a poorly decomposable gas such as PFCs in the waste gas can be decomposed at a temperature of 900 ° C or higher, and it is difficult to heat and maintain the decomposition gas directly to the decomposition temperature.

It is an object of the present invention to provide a flue gas treating system for treating refractory noxious gas and a flue gas treating method using the flue gas treating system. In order to increase the decomposition reactivity of noxious gas, An oxidant injector for injecting an oxidant to generate explosive gas and reaction by-product powder in the gas to be treated by heating the waste gas in the pre-heating zone to increase the temperature; An oxidizer reaction unit; And a plasma ignitor added to the reaction part; A reactor in which the reaction takes place; A quenching section for lowering the temperature of the treated gas; A shear dust collector for collecting reaction byproducts; A demister for removing the fine particles; A decomposition unit that mixes the catalyst and the dielectric heating; And a post wet scrubber for finally removing an acidic substance, and an exhaust gas treating method using the exhaust gas treating system.

Another problem to be solved by the present invention is to provide a method for pretreating a refractory exhaust gas without explosion by providing a continuous ignition by using a plasma igniter in order to prevent the explosion hazardous gas explosion, Which can be operated at a relatively low temperature.

In order to achieve the above object, the present invention provides a treatment system for treating a refractory noxious gas, comprising: an exhaust gas inlet through which exhaust gas flows; Oxidant input; A plasma ignitor; A reactor; A quenching section; A shear dust collector; Dust removal (demister); Catalyst and dielectric heat decomposition apparatus; And a rear stage dust collecting part for treating the noxious gas.

And a pre-heating zone between the exhaust gas inlet and the oxidant inlet.

The pre-heating zone may be maintained at a temperature of 100 ° C to 600 ° C.

A safety device for suppressing a rapid oxidation reaction may be added to the oxidant input part.

At least one oxidizing agent selected from oxygen (O ₂ ) or moisture may be added to the oxidant input portion.

The reaction unit may be a chamber structure.

The chamber may form a water film forming portion and inhibit clogging of the reaction-generated powder in the chamber.

The front end or rear end scrubber may be a wet scrubber.

At least one droplet selected from a spray nozzle, a fog jet nozzle, and a spray pyrolysis may be formed on the front end of the front end dust collecting part to aggregate the reaction by-products.

The plasma ignitor is composed of at least one plasma ignition part, and the flame is composed of at least one selected from the longitudinal and transverse directions, and may be overlapped or parallel.

The mixed form of the oxidizing agent mixture and the flue gas may be composed of one or more mixed forms selected from T type, Swirl type, or cyclic mixed.

The plasma ignition part may be replaced with any one of an electric heater, a combustible gas igniter, a combustible liquid fuel igniter, a combustible solid fuel igniter, an ignition coil, an ignition plug, and a preheating plug.

The present invention relates to a method for treating a flue gas for decomposing noxious harmful gases, comprising the steps of: supplying an exhaust gas through an exhaust gas inlet installed at one end of a pretreatment apparatus; Heating the exhaust gas through a pre-heating zone; Introducing an oxidizing agent into the heated flue gas; Reacting the oxidant and the flue gas inside the reactor; A cooling step of lowering the temperature of the reacted exhaust gas; Collecting by-products of the cooled flue-gas; Further removing the differential generated in the dust collecting part; Decomposing the waste gas by the catalyst and the dielectric heating; And using a wet scrubber to treat the acidic material. ≪ Desc / Clms Page number 2 >

And a step of additionally including a pre-heating zone between the exhaust gas inlet and the oxidizer inlet, wherein the exhaust gas passes through a pre-heating zone and is heated.

In the pre-heating zone, the temperature can be raised in the range of 100 ° C to 600 ° C.

The oxidant injector may use a safety device for suppressing a rapid oxidation reaction.

The safety device may be a plasma ignitor.

At least one oxidizing agent selected from oxygen (O ₂ ) or moisture may be added to the oxidizing agent supplying step.

The reaction part can be reacted in a chamber structure.

In the reaction chamber, a water film forming part is formed and the reaction-generated powder is prevented from clogging in the chamber.

The dust collecting part may use a wet dust collecting part.

At least one selected from the group consisting of a spray nozzle, a fog jet nozzle and a spray pyrolysis may be used in front of the dust collecting part to collect droplets of the reaction by-products.

As described in detail above, in the exhaust gas treatment system and the treatment method of the present invention, after the waste gas is heated through the preliminary heat treatment, the solid reaction by-products produced by the thermal decomposition of the mixture of the oxidizer and the waste gas and the plasma ignition unit are agglomerated into droplets A pretreatment unit A1 for performing a dust collecting process in the front end dust collecting unit, and a post-treatment unit composed of a dust removing unit, a decomposition reaction unit and a rear end dust collecting unit. There is an effect of increasing the decomposition rate and decomposition efficiency according to the application of the mixed decomposition method of the catalyst and the derivative heating of the post-treatment section (B1).

1 is a schematic view of an exhaust gas pretreatment apparatus of the present invention.
2 is a flue gas pretreatment method using the flue gas pretreatment apparatus of the present invention.

In order to increase the thermal decomposition rate and the thermal decomposition rate of the non-decomposable waste gas through the pre-heating zone immediately before the waste gas supplied to the reactor is introduced into the reactor, And the temperature of the waste gas is heated to 100 ° C to 600 ° C and supplied. Generally, the decomposing waste gas is decomposed at a temperature of 900 ° C or higher, but it is preferable to increase the reaction activity of the waste gas by adding a pretreatment section in order to increase decomposition rate and decomposition efficiency. In particular, in the case of the present invention, the operation can be performed at a relatively low temperature by applying a mixing method of catalyst and dielectric heating.

Prior to the description of the preferred embodiments of the present invention, the present invention relates to a treatment system and a treatment method for treating a refractory gas, wherein the refractory waste gas is mainly generated in semiconductor, FPD, and LCD manufacturing processes, a representative gas commonly cited as a cause of global warming NF _3, SF _6, PF _6, N ₂ O either one, or may be mixtures thereof, is generated in the step silane (silane) is discharged, TEOS, DCS, WF of _6, TiCl _4, SiF _4, etc., _{and, F 2, HF, Cl 2} , HCl, ClF 3, NH 3, BCl 3, B 2 H 4, PH 3 as the explosive is very large silane corrosion resistance having an extremely strong toxicity (silane), TEOS, DCS, WF 6, NH 3, H 2, B 2 H 4, CO , etc. in addition, oxygen (O _2), ozone (O _3), the argon inert gas (Ar), helium (he) , Or any mixture thereof, but other waste gases not mentioned above are also included in the scope of the present invention .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view showing an exhaust gas treatment system shown in accordance with a preferred embodiment of the present invention, and FIG. 2 is an embodiment for a method of treating an exhaust gas using the exhaust gas treatment system according to the present invention.

According to the present invention, a preferable structure and structure for treatment of exhaust gas are as follows.

First, the exhaust gas supply unit 10, the front end heat treatment unit 20, the oxidizer input unit 30, the plasma igniter 40, the mixing-reaction unit 50, the reactor 60, A pretreatment section A1 composed of a cooler 70, a mist jet nozzle 80 and a front stage dust collecting section 90 and a fine particle removing section 100 for removing fine particles after the pretreatment, 110, and a post-stage dust collector 120 for the final removal of an acidic substance.

The waste gas supplied through the supply unit 10 passes through the shearing heat treatment unit 20 and is heated to increase the pyrolysis reaction efficiency. At this time, the front end heat treatment unit 20 is equipped with a plurality of heaters on the inner side and the outer side, so that the waste gas directly contacts to increase the thermal efficiency, thereby improving the decomposition efficiency of the waste gas. That is, conventionally, the waste gas is directly pyrolyzed by merely radiant heat, but in the present invention, heated waste gas is injected in order to increase pyrolysis efficiency, thereby increasing the decomposition efficiency and decomposition rate. It is preferable that the waste gas heated in the shearing heat treatment section 20 is heated and maintained at a temperature of 100 ° C to 600 ° C.

The shearing heat treatment unit 20 may utilize an independent heat source and may also recover waste heat generated in the mixing-reaction unit 50 and the reactor 60 and use it for heating. In terms of efficient energy utilization, it is preferable to use a hybrid type of waste heat recovered together with an independent heat source.

The oxidizing agent is introduced into the heated waste gas through the oxidizing agent input unit 30 and mixed with the oxidizing agent and the waste gas in the mixing-reaction unit 50 which decomposes the waste gas using the flame through the plasma igniter. Also, the flame generated in the plasma igniter decomposes the preheated waste gas, and the explosive waste gas is decomposed in advance to improve the stability of the waste gas decomposition processing system. The plasma ignitor is composed of at least one plasma ignition part, which is preferable from the viewpoint of pyrolysis efficiency. It is preferable that the flame generated in the ignition part is composed of at least one selected from longitudinal and transverse directions, And is generated in the flow direction of the flue gas. The plasma ignition part may be replaced with any one of an electric heater, a combustible gas igniter, a combustible liquid fuel igniter, a combustible solid fuel igniter, an ignition coil, an ignition plug, and a preheating plug.

The oxidizing agent supply unit supplies an oxidizing agent or moisture capable of promoting oxidation. As the oxidizing agent, at least one selected from oxygen (O ₂ ) and moisture may be used, and waste gas and fuel gas may be supplied at the same time. It is to be understood that a gas having a different flammability as the fuel gas and also another gas for inducing the oxidation reaction of the fuel as the oxidizing agent can be applied respectively, and the waste gas and the oxidizing agent can be introduced sequentially or simultaneously . It is preferable that the mixture form of the oxidizing agent mixture and the flue gas is composed of at least one mixed form selected from the T type, the Swirl type, and the cyclic type mixed.

The reactor 60, in which the waste gas mixed in the mixing-reaction unit 50 is fully decomposed, can be designed to have a chamber structure in which gases can react and a water film can be formed therein. It is possible to prevent the generated solid reaction product (powder) from accumulating inside the chamber.

The high-temperature waste gas thus treated passes through the cooling section 70 and lowers the temperature. The cooling unit 70 may be provided in a water-cooled or air-cooled manner, and a cooling plate may be installed therein to form a flow path of the combustion gas.

The reacted waste gas cooled at the predetermined temperature forms at least one droplet selected from a spray nozzle, a fog jet nozzle, and a spray pyrolysis unit before being supplied to the shear dust collector The micro-solid reaction product is agglomerated by the apparatus that can be used.

The solid reaction product generated in the reactor 60 and the acidic substance as a reaction by-product are collected in the shear-stage dust collector 90. The shear dust collection unit 90 may be equipped with a filter capable of screening solid reaction byproducts, and may also be configured with a wet scrubber. The waste gas decomposition apparatus according to the present invention converts a fluorine-based gas into a by-product gas which is easily dissolved in water. For example, fluorine (F) is converted to hydrofluoric acid (HF) which is soluble in water in combination with hydrogen. Therefore, the solid reaction by-product generated in the reactor and the waste gas that is easily dissolved in water can be simultaneously removed from the shear-stage dust collector 90.

The waste gas after completion of the pretreatment reaction (A1) is further subjected to removal of fine particles remaining on the particle surface through the particle removal unit (100).

The waste gas from which the fine particles are removed is finally decomposed in the decomposition unit 110 operated by mixing the catalyst and the dielectric heating. Decomposition by the catalytic reaction and the decomposition by the dielectric heating are simultaneously performed in the decomposition part 110 so that the decomposition efficiency is high even at a relatively low temperature.

The finally decomposed waste gas in the decomposition unit 110 passes through the rear stage dust collecting unit 120 to remove acidic substances. The rear end dust collector 120 may be a wet scrubber.

The flue gas treating method using the flue gas treating system shown in FIG. 2 will be described. First, a flue gas is supplied into a pretreatment device for waste gas treatment (S1); A step (S2) of raising the temperature of the waste gas through heating in the shearing heat treatment section; Introducing an oxidizing agent to induce a reaction (S3), and inducing a reaction using a plasma igniter (S4); Performing a combustion reaction inside the reactor (S5); A step (S6) of cooling the waste gas passing through the cooler after the reaction; And a step (S7) of collecting the reaction product.

In the pre-treatment step (A1), the type of the oxidizing agent is not specifically defined in the step (S3) of injecting the oxidizing agent, and at least one selected from oxygen (O ₂ ) and moisture is used as the oxidizing agent And it is also possible to supply the waste gas and the fuel gas at the same time. It is to be understood that a gas having a different flammability as the fuel gas and another gas for inducing an oxidation reaction of the fuel as the oxidizing agent can be applied, respectively, and the waste gas and the oxidizing agent can flow into each other sequentially or simultaneously .

In the dust collecting step (S7) for collecting the reaction product, the solid reaction byproduct and the waste gas dissolved in water can be separated by dissolving in water. A droplet of at least one selected from a spray nozzle, a fog jet nozzle, and a spray pyrolysis device, which is a device capable of spraying droplets before the dust collection step S7, The fine powder can be separated by agglomeration in droplets.

The waste gas passed through the pretreatment step (A1) is subjected to a step (S8) of removing fine particles which are reaction products not captured in the trapping part (S7), and a step (S9) Is capable of thermal decomposition due to catalytic reaction and dielectric heating, and has a high decomposition rate at a relatively low temperature as compared with other decomposition methods because it uses catalyst and dielectric heating at the same time.

After the step S10 of treating the acid gas with the waste gas thus treated, the waste gas is discharged.

A1: preprocessing section B1: postprocessing section
10: Inflow section 20: Shearing heat treatment section
30: oxidizer input unit 40: plasma ignition unit
50: mixing-reacting part 60: reactor
70: cooling unit 80: mist generating unit
90: shear-wave collecting part 100:
110: decomposing part 120: rear end dust collecting part

Claims (22)

1. A treatment system for treating harmful noxious gases, comprising: an exhaust gas inlet through which exhaust gas flows; Oxidant input; A plasma ignitor; A reactor; A quenching section; A shear dust collector; Dust removal (demister); Catalyst and dielectric heat decomposition apparatus; And a rear stage dust collecting part.
The harmful gas processing system according to claim 1, further comprising a pre-heating zone between the exhaust gas inlet and the oxidant inlet.
The system according to claim 2, wherein the pre-heating zone is maintained at a temperature of 100 ° C to 600 ° C.
The harmful gas processing system according to claim 1, wherein the oxidant input unit is provided with a safety device for suppressing a rapid oxidation reaction.
According to claim 3, harmful gas treatment system characterized in that the oxygen (O ₂₎ or water at least one oxidizing agent selected from (moisture) added to the oxidizing agent added in portions.
The system according to claim 1, wherein the reaction unit has a chamber structure.
7. The harmful gas processing system according to claim 6, wherein the chamber is formed with a water film forming part to inhibit clogging of the reaction-generated powder in the chamber.
The system of claim 1, wherein the front or rear end scrubber is a wet scrubber.
The method according to claim 1, wherein at least one droplet selected from a spray nozzle, a fog jet nozzle, and a spray pyrolysis is formed at the front end of the front end dust collecting part, Gas treatment system.
The plasma igniter according to claim 1, wherein the plasma ignitor comprises at least one plasma igniter, and the flame is composed of at least one selected from the longitudinal and transverse directions, and is overlapped or parallel. Hazardous gas treatment system.
2. The harmful gas processing system according to claim 1, wherein the mixed form of the oxidizer mixer and the flue gas is composed of at least one selected from the group consisting of a T shape, a Swirl shape, and a cyclic mixing.
2. The harmful gas processing system according to claim 1, wherein the plasma ignition part is replaced with any one of an electric heater, a combustible gas igniter, a combustible liquid fuel igniter, a combustible solid fuel igniter, an ignition coil, an ignition plug, .
A method of treating an exhaust gas for decomposing harmful noxious gases, comprising the steps of: supplying an exhaust gas through an exhaust gas inlet installed at one end of a pretreatment apparatus; Heating the exhaust gas through a pre-heating zone; Introducing an oxidizing agent into the heated flue gas; Reacting the oxidant and the flue gas inside the reactor; A cooling step of lowering the temperature of the reacted exhaust gas; Collecting by-products of the cooled flue-gas; Further removing the differential generated in the dust collecting part; Decomposing the waste gas by the catalyst and the dielectric heating; And using a wet scrubber to treat the acidic material. ≪ RTI ID = 0.0 > 11. < / RTI >
14. The method of claim 13, further comprising a pre-heating zone between the flue-gas inlet and the oxidizer inlet, the flue-gas passing through a pre-heating zone, Wherein the method comprises the steps of:
15. The method according to claim 14, wherein the temperature of the preheating zone is raised in a range of 100 ° C to 600 ° C.
14. The method of treating a noxious gas according to claim 13, wherein the oxidant injecting part uses a safety device for suppressing a rapid oxidation reaction.
17. The method of claim 16, wherein the safety device uses a plasma ignitor.
In the processing method of a harmful gas, characterized in that to inject the oxygen (O ₂₎ or water (moisture) one or more selected species of the oxidizing agent to the oxidizing agent added in step of claim 13.
14. The method of claim 13, wherein the reaction unit reacts in a chamber structure.
20. The method according to claim 19, wherein the reaction chamber is formed with a water film forming part so that the reaction-generated powder is prevented from clogging in the chamber.
14. The method according to claim 13, wherein the dust collecting part uses a wet dust collecting part.
22. The method of claim 21, wherein droplets are formed on the front end of the dust collecting part using at least one of a spray nozzle, a fog jet nozzle, and a spray pyrolysis, The method comprising the steps of:

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