KR20140027853A - Hybrid nox elimination system comprising yellow plume elimination system and selective catalytic reduction system - Google Patents

Abstract

Provided is a reduction method of nitrogen dioxide by using a reducing agent for the nitrogen dioxide among exhaust gases of stationary sources. The present invention has a feature of spraying one reducing agent which is selected from a group comprising of oxygenated hydrocarbons which include one or more hydroxyl group, ether group, aldehyde group, or ketone group and has three or more carbon numbers in one molecule; or which include two or more hydroxyl groups, ether groups, aldehyde groups, or ketone groups and has two or more carbon numbers in one molecule; carbohydrate; and a mixture thereof from one or more spraying spots to a moving path for exhaust gas containing nitrogen dioxide. The present invention has an advantage of effectively reducing nitrogen dioxide with low operating costs by reducing an amount of by-products which are generated or increasing a removal rate of nitrogen dioxide base on an injection amount of a reducing agent in a wide range of temperature.

Description

Hybrid NOx elimination system comprising yellow plume elimination system and selective catalytic reduction system

The present invention relates to a method for removing nitrogen dioxide in a flue gas of a fixed emission source, and more particularly, to a method for removing nitrogen dioxide from a flue gas of a fixed emission source by increasing the nitrogen dioxide removal rate or reducing the amount of produced by- To a method and apparatus for converting nitrogen dioxide into nitrogen monoxide, nitrogen, etc., in an exhaust gas of a fixed source that can effectively reduce nitrogen dioxide at a low operating cost.

In general, nitrogen oxides (NOx) contained in exhaust gases refer to nitrogen monoxide, nitrogen dioxide, nitrous oxide, and the like, and are one of the representative substances causing environmental pollution such as other carbon oxides and sulfur oxides. Recently, environmental standards have become stricter, and many of the power plants using natural gas as a fuel, which is known as clean fuel, are being built, pollution caused by sulfur oxides is reduced in severity, while NOx generated by oxidation of nitrogen in the air at high temperature is still a problem have. As the operating conditions are changed, nitrogen oxides in the exhaust gas are discharged to a level that satisfies the emission allowance standards. However, if the concentration of nitrogen dioxide (NO2) in the exhaust gas exceeds about 12 ppm, visible smoke may appear. Particularly, NO2, which occurs mainly at low load operation, causes serious yellow smoke problem in urban areas. Visible soot is mainly caused by the concentration of nitrogen dioxide, which is mainly reddish brown. The diameter of the stack, the flow rate and temperature of the exhaust gas, and the residence time of the gas in the stack indirectly influence the visibility. For example, in the case of a combined-cycle power plant, visible smoke generated from low-power sources causes serious psychological and visible pollution of nearby residents. In addition, it requires maneuvering and stopping measures during the daytime in the dispatch operation plan. However, When the start and stop of the turbine is performed during the daytime, the visible smoke is observed by the nearby residents and becomes a psychological pollution. Therefore, there is a problem in that economic loss is caused compared to the case where the engine is started and stopped normally.

As a technique for reducing nitrogen oxides containing nitrogen dioxide, combustion control and exhaust gas treatment techniques have been developed. Among them, the nitrogen oxide reduction technique by the exhaust gas treatment is roughly divided into a case of using a catalyst and a case of treating without using a catalyst.

A method of reducing visible smoke using a reducing catalyst is disclosed in Korean Patent Publication No. 1999-0069935. When the above catalyst is used, nitrogen dioxide can be effectively removed, but there is a problem such as a cost burden and a pressure loss due to the installation of the catalyst.

In particular, the amount of the catalyst required for the selective catalytic reduction reaction is determined by the space velocity determined by the manufacturer or the engineering company. In the case of the commercial NH3-SCR method, about 3,000 to 7,000 h -1 is usually applied. Although the flow rate of the exhaust gas of the stationary source varies depending on the amount of power generation, the amount of catalyst of 70 to 200 m 3 is required in consideration of 500,000 to 1,000,000 Nm 3 / h in general.

Further, in the case of a stationary source using gas as fuel at the above-mentioned space velocity, when the catalytic reactor is installed in the existing system, the flow of gas is disturbed by the differential pressure and the combustion reaction at the front end may be affected. There is a problem in that a large amount of investment cost is required to remove a small amount of nitrogen dioxide since the expansion is necessary. In the case of existing facilities, there is a problem that the installation area increases due to the installation of the catalyst, there was.

On the other hand, selective non-catalytic reduction (SNCR) is a technique of direct reduction of NOx into nitrogen and water vapor by direct injection of ammonia in a high temperature region or direct injection of urea aqueous solution. The NOx reduction rate is 930 to 980 The NOx reduction rate of 60 ~ 80% was obtained by converting NOx into N2 and H2O in the narrow temperature range of.

This method has lower reduction efficiency than Selective Catalytic Reduction (SCR) using a catalyst but has a shorter installation cost and installation period and requires no additional facility. Therefore, it is required to reduce NOx effective. However, since the optimum temperature range for this method is narrow, the reduction efficiency is lowered when ammonia or urea aqueous solution is injected at an equivalent ratio, and if excess amount is injected, NOx may be generated by side reaction rather than ammonia slip the ammonium compound can be formed with a slip.

Particularly, in a power plant where troubles such as external complaints due to nitrogen dioxide are widespread, the exhaust gas temperature of the pipe through which the exhaust gas flows when starting and stopping is 200 to 700 ° C, which is 900-1,200 Lt; 0 > C, and it is difficult to apply it without going through a separate heating step or the like.

Therefore, there is an increasing demand for a technique capable of removing NO2 from exhaust gas at a moderate temperature range of about 200 to 700 DEG C in a fixed emission source such as a power plant.

Visible smoke removal technology using ethanol is disclosed in Republic of Korea Patent Publication No. 2004-0092497, but there is room for improvement because the width of the application temperature range is not very wide.

On the other hand, the Yellow Plume Elimination System (YPES) is mainly caused by the NO2 component among the NOx (NO, NO2) generated in a large amount due to incomplete combustion and temperature conditions during initial combustion, and yellow NO2 combustion air is supplied through the stack. It is emitted as a large amount of harmful substances, with visual discomfort. In particular, in the initial combustion, the NOx component ratio is composed of NO2 (about 90%) and NO (about 10%).

Existing sulfur reduction method set the temperature band with high reactivity after initial G / T flame ON and sprayed reducing agent in the section temperature to maximize sulfur reduction effect, but the temperature change and condition according to G / T manufacturer and model There was a problem that can not be obtained a complete sulfur reduction effect.

Therefore, the first technical problem to be achieved by the present invention is to reduce nitrogen dioxide at a low operating cost by increasing the nitrogen dioxide removal rate or reducing the amount of by-products generated in a wide temperature range (particularly 200 ~ 700 ℃) compared to the reducing agent injection amount It is to provide a method for removing nitrogen dioxide in the exhaust gas of a fixed discharge source.

In addition, the second technical problem to be achieved by the present invention is to provide an apparatus that can be applied to the method of removing nitrogen dioxide in the exhaust gas of the fixed discharge source.

The present invention is a hybrid NOx reduction device for removing nitrogen compounds to remove nitrogen compounds generated in the combustion process of a fixed source using a reducing agent; The nitrogen compound removal device comprises (A) a gas turbine, (B) a nitrogen dioxide removal device, and (c) an optional catalytic reduction device; A front end of the nitrogen dioxide removal device is connected to the gas turbine, and a front end of the selective catalytic reduction device is connected to a rear end of the nitrogen dioxide removal device; The nitrogen dioxide removal device is operated under the condition that the loading value of the gas turbine is below a certain value, and the selective catalytic reduction device is operated under the condition that the loading value of the gas turbine exceeds the specific value. To provide a hybrid NOx reduction device for.

As described above, according to the present invention, it is possible to effectively remove nitrogen dioxide in the exhaust gas of a fixed emission source at a low operating cost by increasing the removal rate of nitrogen dioxide relative to the reducing agent injection amount or by reducing the amount of generated byproducts in a wide temperature range.

According to various embodiments of the present invention, not only the problem of not being able to obtain a complete sulfur reduction effect due to various temperature changes and conditions depending on the G / T manufacturer and the model described above has been solved, and the various effects described below are further expressed. You can.

In addition, according to various embodiments of the present invention, it is possible to maximize the reduction of nitrogen dioxide and nitrogen monoxide in the exhaust gas, in particular, to maximize the reduction rate of nitrogen dioxide in the initial operation corresponding to within 30 minutes after the start of operation as well as 30 minutes after the start of operation Maximization of the nitrogen monoxide reduction rate under normal operation conditions can also be achieved.

In addition, the amount of reducing agent required to remove the same amount of nitrogen dioxide can be greatly reduced.

In addition, substantially uniform nitrogen dioxide removal efficiency can be achieved even in an irregular combustion exhaust gas discharge environment for 15-30 minutes after the start of operation.

In addition, not only irregular combustion flue gas emission environment for 15-30 minutes after the start of operation, but also extremely irregular for a period of 0-15 minutes after the start of operation (that is, for a time of 15 minutes after the start of operation). Even in a combustion exhaust gas exhaust environment, a substantially uniform nitrogen dioxide removal efficiency can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a configuration diagram showing an example of an exhaust gas treatment apparatus according to the present invention. Fig.
2 is a configuration diagram showing another example of an exhaust gas treating apparatus according to the present invention.
Fig. 3 is a configuration diagram showing still another example of the flue gas treating apparatus according to the present invention.
4 is a configuration diagram showing still another example of the exhaust gas treating apparatus according to the present invention.
5 is a configuration diagram showing still another example of the exhaust gas treating apparatus according to the present invention.
Fig. 6 is a configuration diagram showing still another example of the flue gas treating apparatus according to the present invention. Fig.
7 is a graph showing the conversion of nitrogen dioxide using a reducing agent according to the present invention.
8 is a graph showing the conversion of nitrogen dioxide according to the molar ratio of reducing agent / nitrogen dioxide according to the present invention.
9 is a graph showing the conversion of nitrogen dioxide according to the molar ratio of the reducing agent / nitrogen dioxide according to the present invention.
10 is a graph showing the conversion of nitrogen dioxide according to the first stage and the multi-stage injection of the reducing agent according to the present invention.
11 is a graph showing the results of measurement of NO2 removal activity with time in Comparative Examples 2, 12, and 13. Fig.
12 is a graph showing the results of measurement of NO2 removal activity over time in Comparative Examples 2, 14, and 15. FIG.
13 is a graph showing the results of measurement of NO2 removal activity according to the amount of starch injected in Example 16 and Example 17. Fig.
14 is a view showing a sulfur reduction equipment (YPES).

Hereinafter, the present invention will be described in more detail.

According to an aspect of the present invention, as a hybrid NOx reduction device for nitrogen compound removal to remove the nitrogen compound generated in the combustion process of the fixed source using a reducing agent; The nitrogen compound removal device comprises (A) a gas turbine, (B) a nitrogen dioxide removal device, and (c) an optional catalytic reduction device; A front end of the nitrogen dioxide removal device is connected to the gas turbine, and a front end of the selective catalytic reduction device is connected to a rear end of the nitrogen dioxide removal device; The nitrogen dioxide removal device is operated under the condition that the loading value of the gas turbine is below a certain value, and the selective catalytic reduction device is operated under the condition that the loading value of the gas turbine exceeds the specific value. Hybrid NOx abatement device is provided.

Here, the fact that the front end of the nitrogen dioxide removal unit is connected to the gas turbine does not mean that the front end of the nitrogen dioxide removal unit is directly connected to the gas turbine directly without any means of spatial intervention therebetween, and the selective catalytic reduction device therebetween. The concept includes a case in which a pipe or other equipment is included except for a case in which a selective catalytic reduction device is not spatially interposed therebetween and a gas turbine is connected to the front end of the nitrogen dioxide removal device. .

Likewise, the front end of the selective catalytic reduction device is connected to the rear end of the nitrogen dioxide removal device only when the front end of the selective catalytic reduction device is directly connected to the rear end of the nitrogen dioxide removal device without any spatial intervention in between. Not including, but including, in the intervening case, pipes or other equipment other than gas turbines, that is, gas turbines are not spatially interposed therebetween, and the front end of the selective catalytic reduction unit is connected to the front end of the nitrogen dioxide removal unit. It includes all cases.

In addition, the loading value of the gas turbine refers to generation load (power generation) according to the operating state of the gas turbine, and means the ratio of the current operating capacity to the design capacity of the gas turbine. For example, a gas turbine designed with a capacity of 100 MW is operated, and a loading value of 40 MW can be regarded as 40%. In addition, the design capacity and operating capacity can be determined based on the amount of power, or the flow rate can be determined based on the amount of electricity, and the data analyzed by an analyzer installed in the stack can be used to determine whether the capacity is based on the amount of power. Even the flow reference capacity can be easily identified.

The process of preheating while starting the gas turbine and keeping the power output low is called the low-loading-value state, and when the temperature of the steam generator (HRSG) reaches a certain section along with the turbine preheating The load is gradually raised to a full-loading-value state in normal operation.

As such, the loading value of the gas turbine may be considered to be a clear concept that can be clearly understood by those skilled in the art based on common sense in the present application as long as it is based on the contents disclosed by the present invention.

According to one embodiment of the invention, the specific value of the gas turbine loading value may be selected in the range of 20-80%, preferably in the range of 40-60%. That is, when the gas turbine loading value rises around a specific value within the 20-80% or 40-60% range, the nitrogen dioxide removal device is operated below the specific value, and when the specific value is exceeded, the selective catalytic reduction device is turned on. I'm driving.

Here, as a factor for determining the selective operation of the nitrogen dioxide removal device or the selective catalytic reduction device, the temperature of the exhaust gas in the pipe may be used, or the composition of the nitrogen compound in the discharged exhaust gas may be used. It was confirmed that only reduction of nitrogen dioxide and nitrogen monoxide in the flue-gas can be achieved only when using the turbine loading value.

In particular, by setting the value between 40-60% of the gas turbine loading value, the nitrogen dioxide removal device is operated below that value, and when the specific value is exceeded, the selective catalytic reduction device is operated to operate the corresponding operation within 30 minutes after the start of operation. It was confirmed that the maximization of the reduction rate of nitrogen dioxide at the initial stage and the maximization of the reduction rate of nitrogen monoxide under the normal operating conditions at the same time 30 minutes after the start of operation were achieved.

According to another embodiment of the present invention, the nitrogen dioxide removal device is (a) a pipe for providing a movement path of the exhaust gas, (b) at least one or more connected to the pipe to supply a reducing agent to the exhaust gas passing through the pipe Reducing agent injecting means, (c) a reducing agent storage tank connected to the reducing agent injecting means for storing the reducing agent, (d) a dispersion auxiliary fluid connected to the reducing agent injecting means for supplying a dispersion auxiliary fluid to the reducing agent injecting means Supply means, and (e) a plurality of conveying pipes connecting the plurality of points of the pipe and the dispersion auxiliary fluid supply means; A part of the flue gas flowing along the pipe is transported through the plurality of transport pipes, and the transport flue gases conveyed through the plurality of transport pipes are mixed to form a transport mixed flue gas; The returned mixed exhaust gas may be supplied to the dispersion auxiliary fluid supply means and supplied to the reducing agent injecting means so that the exhaust gas may be used as a dispersion auxiliary fluid.

Here, the external fluid, steam or water may be used as the dispersion auxiliary fluid to be discharged from the fluid supply means 10, or the transfer pipe 24 formed on one side of the pipe 2 may be connected to the fluid supply means 10 The flue gas flowing along the piping 2 after the installation is transferred to the fluid supply means 10 and then supplied to the dispersion means 4 to be used as a dispersion auxiliary fluid.

It is more preferable that the exhaust gas is taken out from one point of the piping and transported, but it is more preferable that the mixed gas is taken out from a plurality of points of the piping and mixed with each other.

Unexpectedly, it has been found that the amount of reducing agent required to remove the same amount of nitrogen dioxide is greatly reduced by providing a condition through which the reducing agent can be vaporized at a constant temperature.

According to another embodiment of the present invention, at least two or more of the plurality of conveying pipes may include a conveying pipe opening and closing means for adjusting the amount of the conveying exhaust gas flowing through the conveying pipe.

Further, according to another embodiment of the present invention, the two or more conveying so that the fluctuation range of the temperature of the dispersion auxiliary fluid supplied from the dispersion auxiliary fluid supply means to the reducing agent injection means is maintained within the range 0.001-100 ℃ The conveyance amount of each of the conveying flue gas conveyed from the tube may be adjusted through the conveying tube opening and closing adjusting means.

(I) a temperature fluctuation width of the transport mixed flue gas supplied to the dispersion auxiliary fluid supply means, or (ii) a temperature fluctuation range of the transport mixed flue gas supplied to the reducing agent injection means The conveyance amount of each of the conveying exhaust gases conveyed by the two or more conveyance pipes is controlled so that the temperature fluctuation width of the dispersion assisting fluid is maintained within a range of 0.001-100 캜, preferably 0.001-50 캜, more preferably 0.001-30 캜. .

Particularly, it has been confirmed that substantially uniform NO 2 removal efficiency is achieved even when the temperature width is maintained within the range of 0.001-50 ° C, especially in an irregular combustion exhaust gas exhaust environment for 15-30 minutes after the start of operation.

According to another embodiment of the present invention, the dispersion auxiliary fluid supply means includes a dispersion auxiliary fluid temperature sensor capable of measuring the temperature of the dispersion auxiliary fluid at the front end or the rear end of the dispersion auxiliary fluid supply means; The two or more conveyance pipes each include a conveyance flue gas temperature sensor capable of measuring the temperature of the conveyed flue gas conveyed; The conveyance pipe opening and closing control means may adjust the amount of each transporting flue gas based on the temperature of the dispersion auxiliary fluid transmitted from the dispersion auxiliary fluid temperature sensor and the transporting flue gas temperature sensor and the temperature data of each transporting flue gas.

According to another embodiment of the present invention, the plurality of points of the pipe has a temperature difference of 5-100 ℃ temperature between the pipes of the points, or the plurality of points of the pipes 50 cm to 50 m distance from each other Can be as far apart.

That is, the plurality of points of the pipe may be a point where the temperature difference in the pipe is 5 to 100 ° C, preferably 10 to 50 ° C to each other, or 50 cm to 50 m distance from each other, preferably 1-30 It may be a point away by m distance.

Particularly, when the temperature difference in the piping at a plurality of points of the piping is 10-50 ° C, or a plurality of points of the piping are separated by a distance of 1-30 m, irregular combustion exhaust gas Substantially uniform NO 2 removal efficiencies, even in the exhaust environment, as well as in extremely severe irregular combustion exhaust gas environments during 0-15 minutes after commencement of operation (i.e., from immediately after commencement of operation to 15 minutes after commencement of operation) Respectively.

Hereinafter, other aspects and various other embodiments of the present invention will be described.

A method for removing nitrogen dioxide in a flue gas of a stationary source according to the present invention is a method for removing nitrogen dioxide in an exhaust gas containing nitrogen dioxide generated in a combustion process of a stationary source, An ether group, an aldehyde group, and a ketone group and having 3 or more carbon atoms, or oxygenated hydrocarbons containing two or more hydroxyl groups, ether groups, aldehyde groups, and ketone groups in one molecule and having 2 or more carbon atoms, Carbohydrates and mixtures thereof can be injected at one or more injection points to increase the removal rate of nitrogen dioxide relative to the amount of injection over a wide temperature range or to reduce the amount of byproducts generated, Monoxide of nitrogen dioxide in flue gas Cows, characterized in that the removal was converted to nitrogen and the like.

According to the present invention, the nitrogen dioxide can be converted into nitrogen monoxide, nitrogen or the like using the reducing agent having a reducing ability. Reducing agents having a reducing ability are various, but in the case of the present invention, any one reducing agent selected from the group consisting of oxygen-containing hydrocarbons having functional groups including oxygen such as hydroxyl group, ether group, aldehyde group and ketone group, carbohydrates and mixtures thereof The point is characterized.

The method of removing nitrogen dioxide from the exhaust gas of the fixed source to which the reducing agent of the present invention is applied is mainly concerned with a temperature range of 200 to 700 ° C and a case where the total nitrogen oxide concentration is low but the nitrogen dioxide emission amount is large .

The mechanism of thermochemical reactions is complex and unpredictable, but the use of nitrogen-containing reducing agents may increase the production of nitrogen oxides in addition to nitrogen in the molecular state. In the case of the reducing agent containing nitrogen, the final product of the reaction is reduced to nitrogen in the high temperature range (900 to 1100 ° C), but in the middle temperature range (200 to 700 ° C), which is the main application temperature range of the present invention, It may be said that it is likely to react with oxygen to increase the amount of nitrogen oxides generated. At high temperatures, a reducing agent containing nitrogen such as ammonia by radical reaction may provide a nitrogen atom in the reaction of reducing nitrogen oxides to nitrogen, so that nitrogen oxides in the exhaust gas can be replaced with stable nitrogen molecules, but in the middle temperature range Radicals can not be generated, and the amount of nitrogen molecules to be produced is small, and the amount of unstable nitrogen oxides is likely to increase. This can be attributed to the fact that in order to be more thermodynamically more stable, it is necessary to go beyond the high energy barrier, but not enough energy to reach the energy barrier in the middle temperature region. Therefore, in the present invention, such unfavorable oxygenated hydrocarbons or carbohydrates are used as a reducing agent for removing nitrogen dioxide.

In order to remove nitrogen dioxide from the exhaust gas of a stationary source, it is preferable to use an oxygen-containing hydrocarbon having a large number of reducing functional groups such as a hydroxyl group, an ether group, an aldehyde group and a ketone group, Carbohydrates can be used.

Ethanol has only one hydroxyl group, but the reducing agent used in the present invention has a plurality of groups capable of reducing a hydroxyl group, an ether group, an aldehyde group, a ketone group, and the like, so that the equivalent amount of the reducing agent consumed in the removal of nitrogen dioxide is reduced . In addition, even if the number of reducing functional groups of the reducing agent used in the present invention is not plural, when the reducing agent having a larger number of carbons than ethanol is used, the molecular weight of the reducing agent is increased, and the reaction product is reacted with nitrogen dioxide under milder conditions. It is conceivable that the amount of production decreases and that the reducing capacity of the reducing agent is used to reduce the nitrogen dioxide. As a result, compared to ethanol, the reducing agents of the present invention are increased in the ratio of conversion to carbon dioxide, the amount of by-products is reduced, and the conversion amount of nitrogen dioxide is increased by the amount converted to carbon dioxide. It is considered that the conversion rate of nitrogen monoxide relative to the equivalent amount is increased.

The material usable as a reducing agent includes at least one of a hydroxyl (OH) group, an ether group, an aldehyde group, and a ketone group in one molecule and has 3 or more carbon atoms or two or more hydroxyl groups, ether groups, aldehyde groups, Is not particularly limited as long as it is a reducing agent for at least one of hydrocarbons having two or more carbon atoms and carbohydrates and is not limited to iso-butyl alcohol, iso-propyl alcohol, glycerin, allyl alcohol N-butyl alcohol, n-propyl alcohol, ethylene glycol, methoxy propanol, n-butyl alcohol, n-butyl alcohol, N-octyl alcohol, iso-octanol, 2-ethyl hexanol, acetylacetonate, maleic acid (fumaric acid) ), Glyoxal, glyoxalic acid, But are not limited to, methoxypropanol, cyclohexanol, cyclohexanone, 1,3-propanediol, 1,2-propanediol, propanal, 1,4-butanediol, iso-butylaldehyde, n-butylaldehyde, pentanediols, 1,5-hexanediol (1 5-hexanediols, glutalaldehyde, dioxane, trioxane, furan, tetrahydrofurane, tartaric acid, citric acid, Diethyl acetaldehyde, propyl alcohol, tert-butyl ether, glycerin carbonate, glyceraldehyde, glyceric acid, tetralin, Tetralol, tetralone, benzaldehyde, terephthaldehyde, terephthalaldehyde, 1,4-cyclohexanedialcohol, xylenol and its isomers, oleic acid, stearic acid, palmitic acid, lauric acid, Linoleic acid, salicylic acid, vinylcyclohexene, and the like.

Examples of the carbohydrates include sugars such as glucose, dextrose, fructose, sucrose, maltose, lactose, trisaccharides, and sugar chains as starches, starch as starch, polysaccharides as celluloses, glycogen glycogen, pectin, agar, carrageenan and natural rubber or mixtures thereof can be used. However, the carbohydrates usable in the present invention are not limited to the above examples.

The above-mentioned oxygen-containing hydrocarbon or carbohydrate may include all of the above-mentioned compounds as a main component, whether synthetic or natural.

The above-mentioned sugar is also called sucrose, and sucrose is mainly used as a chemical name. Sugar is used for sugar, sugar, sugar, milk sugar, raw sugar, refined sugar, ground sugar, (invert sugar), brown sugar and artificially called sugar, artificial or natural things can be said to mean.

The starch is a polysaccharide produced by the condensation of di-glucose (glucose), and is a mixture of amylose and amylopectin. It may be one of the storage materials present in a plant having chlorophyll, and the starch may be called starch, starch, sweet potato starch, And the like. The term " artificial " or " natural "

The wheat flour is made by powdering the end portion of the wheat and may include proteins such as carbohydrates and gluten. The carbohydrate contained in the flour is mainly polysaccharide starch, which may account for about 70% of the total flour weight, and may include disaccharides and monosaccharides.

Ethanol may be mixed with the reducing agent and injected, or ethanol may be further injected at a separate injection point from the injection point.

Even when the reducing agent is injected together with the ethanol alone, the amount of the by-products is not significantly different, but the conversion of nitrogen dioxide to the reducing agent / nitrogen dioxide equivalent can be increased by the action of the reducing agent. Conversely, even if the reducing agent / nitrogen dioxide equivalent is lowered, it is possible to reduce the amount of by-products generated while maintaining the nitrogen dioxide conversion. That is, it is possible to increase the removal rate of nitrogen dioxide at the same equivalent ratio as compared with the case where only the conventional ethanol is supplied, so that the amount of ethanol used can be reduced and consequently the amount of byproducts generated can be reduced.

According to the present invention, it is possible to increase the degree of contact and mixing with the exhaust gas by widening the region where the exhaust gas is treated with one or more injection points of the reducing agent, and as a result, the removal efficiency of nitrogen dioxide in the exhaust gas can be increased. It is also expected that the reduction effect of by-products can be expected by allowing the reducing agent to sufficiently participate in the reaction.

In order to inject the reducing agent into the exhaust gas of the fixed emission source, the injection auxiliary fluid may be used. In order to use the reducing agent in a liquid phase such as inert gas or liquid or sugar which is not reactive with the reducing agent, the solubility of the reducing agent It is possible to use a part of the flue gas at the front of the stack or the air in consideration of the price and the availability of the flue gas.

The present invention also relates to a method for removing nitrogen dioxide in a flue gas of a fixed emission source, wherein at least one end of the pipe is connected to one or more injection means to remove nitrogen dioxide, and the reducing agent is injected into the flue gas . As described above, by spraying the reducing agent through the plurality of stages, it is possible to cause a reaction in a wider reaction region. Also, by allowing the reducing agent to sufficiently participate in the reaction, the occurrence of by-products can be reduced.

The method for removing nitrogen dioxide from the exhaust gas of the fixed emission source according to the present invention can be applied to an exhaust gas treatment apparatus or boiler interior as shown in FIG. 1, front and rear ends of an air preheater, an exhaust gas moving duct, and the like. Conventional ammonia-based SNCR (selective non-catalytic reduction) can be used only in a high-temperature range (900 to 1,100 ° C). In the case of using an exhaust gas treatment device, it is necessary to warm the treatment device to set the temperature condition, When the processing apparatus is not used, it can be applied to a limited area satisfying a high temperature condition such as a combustion chamber rear end or a secondary combustion chamber. In addition, in the case of the method of removing nitrogen dioxide using ethanol, it can be applied to a limited range in the middle temperature range, and it may be difficult to cope with various operating conditions at the time of removing nitrogen dioxide. However, in the present invention, .

An apparatus for removing nitrogen dioxide in an exhaust gas containing nitrogen dioxide generated in a combustion process of a fixed emission source according to the present invention comprises a pipe for providing a path for moving the exhaust gas, a pipe connected to the pipe for supplying the reducing agent to the exhaust gas passing through the pipe, At least one injection means connected to the injection means, and a storage tank for storing the reducing agent.

The apparatus may further include an injection pump provided between the storage tank in which the reducing agent is stored and the injection means connected to the reducing agent to supply the reducing agent stored in the storage tank to the injection means.

And a fluid supplying unit connected to the injecting unit and supplying the dispersion assisting fluid to the injecting unit.

In order to use the reducing agent in a liquid phase such as an inert gas or liquid or sugar which is not reactive with the reducing agent, the solubility of the reducing agent It is possible to use a part of the flue gas at the front of the stack or the air in consideration of the price and the availability of the flue gas.

Particularly, the reducing agent according to the present invention can be injected into the exhaust gas without being mixed with the dispersion auxiliary fluid such as air, steam, water, etc. However, when only the reducing agent is injected into the injection means without mixing the dispersion assisting fluid, The reducing agent may not be uniformly mixed throughout. Therefore, in this case, it is preferable that the exhaust gas and the reducing agent are easily mixed by providing a mixing means in the moving path of the exhaust gas in the present invention.

At this time, the mixing means allows the reducing agent provided in the flow path of the flue gas to be easily mixed with the flue gas, and any means may be used as long as it can achieve this purpose. However, A swirler or the like can be used.

Meanwhile, the injection means according to the present invention is for injecting a reducing agent alone into the exhaust gas or mixing the same with a dispersion assisting fluid such as air, steam, water, etc., and injects the reducing agent and / Any fluid may be used as long as it can supply auxiliary fluid. For example, a nozzle, a RIG (Reactant injection grid) or the like may be used.

In addition, the exhaust gas treatment apparatus according to the present invention ultimately treats contaminants as the reducing agent contacts the exhaust gas after supplying the reducing agent to the movement path of the exhaust gas containing nitrogen dioxide, And a mixing means is provided behind the portion to which the reducing agent is supplied, so that the reducing agent and the exhaust gas are mixed with each other to treat the contaminants.

In this case, the flue gas treating apparatus according to the present invention is advantageous in that it does not require a dispersion auxiliary fluid for widely spraying the reducing agent discharged from the injection means onto the flue gas.

And a fluid supply means connected to the injection means and the injection means is connected to the ejector and a path through which the reducing agent discharged from the storage tank is connected to one side of the ejector. This is for uniform spraying of the reducing agent using the venturi principle.

In addition, at least one end is provided inside the pipe with at least one end connected to at least one of the injection means, and the dispersion auxiliary fluid and the reducing agent can be injected into the exhaust gas through the end. By providing at least one stage inside the pipe, the reducing agent can be uniformly injected into the exhaust gas.

A valve disposed at one side of the pipe to adjust the flow of the fluid flowing through each pipe and at least one pipe for providing a path for moving the flue gas to measure the temperature of the flue gas flowing through the pipe, And adjusting means connected to the temperature sensor and the valve for opening and closing the valve based on the temperature data inputted from the temperature sensor. It is possible to effectively remove the nitrogen dioxide in the exhaust gas by using the reducing agent by opening a valve in a suitable temperature range (200 to 700 ° C) for reacting with the reducing agent based on the temperature data inputted from the temperature sensor.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and embodiments, but the present invention is not limited thereto.

Fig. 1 is a configuration diagram showing an example of an exhaust gas treating apparatus according to the present invention. Fig. 2 is a structural view showing another example of the exhaust gas treating apparatus according to the present invention. Fig. 3 is a view showing still another example of the exhaust gas treating apparatus according to the present invention Fig. 4 is a configuration diagram showing still another example of the flue gas treating apparatus according to the present invention, Fig. 5 is a configuration diagram showing still another example of the flue gas treating apparatus according to the present invention, Fig. And another configuration example of the flue gas treating apparatus will be described together.

Referring to FIG. 1, the apparatus for treating an exhaust gas according to the present invention is basically constructed to provide the reducing agent to the path of the exhaust gas. More specifically, the apparatus includes a pipe 2 for providing a path of the exhaust gas, At least one injection means 4 connected to the pipeline 2 for supplying the reducing agent to the flue gas passing through the pipeline 2 and connected to the injection means 4, And a storage tank 6 for storing the reducing agent. The apparatus for treating flue gas according to the present invention may be configured in various forms in order to achieve the object of providing a reducing agent or the like in the path of the flue gas. If necessary, air, steam, or water may be added to the reducing agent, A fluid for dispersion auxiliary made of the fluid of the present invention may be provided together so that the reducing agent can be easily mixed with the exhaust gas. The dispersion assisting fluid may be supplied to the path of the exhaust gas together with the reducing agent through the fluid supplying means 10 connected to one side of the injecting means 4. The apparatus for treating flue gas according to the present invention may further comprise an injection pump 8 disposed between the storage tank 6 for storing the reducing agent and the injection means 4 to supply the reducing agent stored in the storage tank 6 to the injection means The pipe 2 according to the present invention can be easily connected to a fixed emission source so that the exhaust gas containing nitrogen dioxide generated in the combustion process of the fixed emission source using the gas as fuel can be introduced. And a stack 12 on which the exhaust gas containing nitrogen dioxide is passed through the pipe 2 and can be discharged to the outside can be connected to the other side opposite to the exhaust pipe. The injecting means 4 according to the present invention injects the reducing agent individually into the exhaust gas containing nitrogen dioxide which is installed in the pipe 2 or mixes with a dispersion assisting fluid such as air, (RIG) 26 shown in FIG. 2 or the like can be used as long as it can supply the reducing agent and / or the dispersion auxiliary fluid to the movement path through which the exhaust gas flows. However, have. In particular, the injection means 4 according to the present invention may be provided in any form as long as it can supply the reducing agent and / or the dispersion auxiliary fluid to the movement path through which the exhaust gas flows. The reducing agent can be easily injected into the exhaust gas containing nitrogen dioxide flowing along the pipe 2 or can be injected into the pipe 2 through the RIG Can be used to supply the reducing agent to the exhaust gas. Here, the term " first stage " means that a plurality of holes are formed in one tube 14 and then the injection means 4 is fastened to the plurality of holes. In the first stage, Quot;

Referring to FIG. 3, the apparatus for treating an exhaust gas according to the present invention is characterized in that it is provided at the rear of the injection means 4 for providing the reducing agent to the exhaust gas for easy mixing of the exhaust gas introduced into the pipe 2 and the reducing agent provided in the exhaust gas And connecting the mixing means 28 to each other. The flue gas treating apparatus including the mixing means (28) can be further connected with a fluid supply means as required.

4, the apparatus for treating an exhaust gas according to the present invention includes an ejector 22 using a venturi principle in a movement path of a dispersion assisting fluid discharged from a fluid supply means 10 and flowing into a injection means 4 And connecting the movement path of the reducing agent to one side.

5, external air, steam or water may be used as the dispersion-assisting fluid discharged from the fluid supply means 10, or the transfer tube 24 constituted at one side of the pipe 2 may be connected to the fluid supply means 10 , The flue gas flowing along the pipe 2 is transferred to the fluid supply means 10 and then supplied to the injection means 4 so that it can be used as a dispersion assisting fluid.

Referring to FIG. 6, the apparatus for treating flue gas according to the present invention includes a valve 18 at one side of the tube 14 so as to adjust the flow of the fluid flowing through the tube 14 if necessary, At least one temperature sensor 20 for measuring the temperature of the flue gas flowing through the pipe 2 is provided in the pipe 2 and connected to the temperature sensor 20 and the valve 18, (16) for opening and closing the valve (18) based on the temperature data input from the control unit (20). At this time, the temperature sensor 20 may be installed anywhere in the pipe 2 as long as the temperature of the exhaust gas flowing through the pipe 2 can be easily measured.

The exhaust gas treatment apparatus according to the present invention may further comprise a step of treating the outer peripheral surface of the tube 14 to which the injection means 4 and the injection means 4 are connected, The reducing agent can be prevented from being burned.

In order to more effectively protect the reducing agent flowing in the interior of the injection means 4 and the pipe 14 from the high temperature, it is also possible to use the above-mentioned heat insulating material and also the inside of the pipe 14 and / (Not shown) capable of moving the dispersion assisting fluid can be moved to the moving path through which the dispersion assisting fluid can move to prevent the reductant from being burned from the high temperature exhaust gas have.

The injection means 4 described above is for spraying the dispersion auxiliary fluid and the reducing agent and is provided at one side thereof with a fluid supply pipe 4 which is supplied with the flue gas flowing from the outside or along the pipe 2, And a storage tank 6 in which the reducing agent is stored are successively connected to one another and the reducing agent is supplied to the injection means 4 ). ≪ / RTI > At this time, the injection pump 8 can easily transfer the reducing agent stored in the storage tank 6 to the injection means 4.

Meanwhile, the fluid supply means 10 is configured to transfer a gas or a liquid, for example, compressed air, steam, water or the like together with the reducing agent to the injection means 4 to inject the reducing agent, whereby an exhaust gas containing nitrogen dioxide and a reducing agent So that they can be easily mixed with each other.

The flue gas treating apparatus configured to supply the dispersion assisting fluid together with the reducing agent to the flue gas in the manner described above may further include a path of the reducing agent discharged from the storage tank 6 and a path of the dispersing auxiliary fluid discharged from the fluid supplying means 10 The ejector 22 using the venturi principle is installed at one side of the path of the pipe 14 connected to the injection means 4 from the fluid supply means 10, The flow path of the reducing agent may be connected to one side of the flow path 22 so that the two flows can be merged.

The operation of the flue gas treating apparatus according to the present invention having the above-described configuration will be described below.

The operation of the flue gas treating apparatus shown in Figs. 1 and 6 will be described with reference to the basic configuration of the flue gas treating apparatus according to the present invention.

First, when the exhaust gas containing nitrogen dioxide is generated in the combustion process of the fixed emission source using the gas as the fuel, the exhaust gas is transferred to the pipe 2 equipped with the injection means 4.

Then, the reducing agent filled in the storage tank 6 is transferred to the injection means 4 by using the injection pump 8. At this time, the reducing agent can be moved to the injection means 4 together with the dispersion assisting fluid by using the fluid supplying means 10.

Here, the dispersion auxiliary fluid may be used by compressing external air at a high pressure, or by circulating a portion of steam, water, or exhaust gas that moves along the pipe 2, which has recovered heat generated in the combustion process.

The dispersion auxiliary fluid and the reducing agent transferred to the injection means 4 provided in the pipe 2 are supplied to the exhaust gas containing nitrogen dioxide flowing through the pipe 2 to convert the nitrogen dioxide The exhaust gas is passed through a stack 12 connected to the end of the pipe 2 and discharged to the outside.

Here, the dispersion-assisting fluid provided from the fluid supply means 10 is transferred to the injection means 4 together with the reducing agent to inject the reducing agent so that the exhaust gas containing nitrogen dioxide and the reducing agent are easily mixed with each other.

The exhaust gas treatment apparatus according to the present invention can be constructed without using the fluid supply means 10. In this case, the reducing agent discharged to the exhaust gas through the injection means 4 is passed through the mixing means 28, So that the reducing agent can be easily mixed with each other, and this mixing means 28 can be installed and used together with the fluid supply means 10. [

On the other hand, the flue gas treating apparatus according to the present invention treats the exhaust gas more efficiently by using the adjusting means 16 for opening and closing the valve 18 on the basis of the temperature data inputted from the temperature sensor 20 at one side thereof can do.

The apparatus is constructed such that at least one pipe 14 having a plurality of injection means 4 is provided inside the pipe 2 and the pipe 14 is connected to the injection pump 10 and the fluid supply means 8), and at least one temperature sensor (20) is provided in the pipe (2).

A valve 18 is provided at one side of each of the tubes 14 and the valve 18 and the temperature sensor 20 are connected to the adjusting means 16.

When the exhaust gas containing nitrogen dioxide is generated in the combustion process of the fixed emission source using the gas as the fuel, the exhaust gas is transferred to the pipe 2 provided with the pipe 14 provided with the plurality of injection means 4.

At this time, the temperature of the exhaust gas flowing into the pipe 2 is measured by a temperature sensor 20 provided inside the pipe 2, and the data is transmitted to the control means 16.

Next, the adjusting means 16 is provided with an injecting means 4 located in a temperature range suitable for reaction based on the temperature data inputted from the temperature sensor 20, for example, a temperature range of 200 to 700 캜 The valve 18 of the installed pipe 14 is opened and the valve 18 of the remaining pipe 14 is shut off.

The reducing agent filled in the storage tank 6 is then transferred to the pipe 14 through the valve 18 using an infusion pump 8 and at the same time, And conveys air to the tube 14 in which the valve 18 is opened.

The air and the reducing agent transferred to the pipe 14 in which the valve 18 provided in the pipe 2 is opened then passes through the injection means 4 provided in the pipe 14 and flows into the pipe 2, The nitrogen dioxide is reduced to nitrogen monoxide or reacted with nitrogen to remove the exhaust gas. Then, the exhaust gas is passed through a stack 12 connected to the end of the pipe 2, .

The compressed air compressed by the fluid supply means 10 is transferred to the injection means 4 together with the reducing agent to spray the reducing agent so that the exhaust gas containing nitrogen dioxide and the reducing agent are easily mixed with each other.

Hereinafter, various embodiments of the present invention will be described in detail with reference to examples, but the scope of the present invention can not be construed to be limited or limited thereto.

Example 1

As shown in FIG. 1, a pipe having a cylindrical pipe (height 15 cm, width 15 cm, length 100 cm) was made of SUS 304, and a plurality of injection means (TN050-SRW, total injection means, ] Were installed at intervals of 20 cm. Then, the storage tank was filled with isobutyl alcohol [Duksan Chemical Industry Co., Ltd.] as a reducing agent, and the storage tank was connected to an infusion pump [M930, Youngin apparatus, Korea], and the infusion pump [M930, Korea, Korea] was connected to a tube provided with the injection means [TN050-SRW, total nozzle, Korea]. Then, a fluid supply means (HP2.5, air bank compressor, Korea) for supplying air from the outside was connected to a tube provided with an injection means [TN050-SRW, total nozzle, Korea]. Then, an inflow gas having a composition similar to that of the flue gas generated in the combustion process using LPG and LNG gas as a fuel was injected into the pipe. Here, the composition of the inflow gas is shown in Table 1.

gas NO NO2 CO O2 H2O N2 Furtherance 3 ppm 22 ppm 370 ppm 16% 6% balance

On the other hand, when the inflow gas passes through the piping and is filled in the outside air and the storage tank using the fluid supply means (HP2.5, Air Bank Compressor, Korea) and the infusion pump [M930, Isobutyl alcohol was transferred to injection means [TN050-SRW, total nozzle, Korea] and sprayed inside the pipe. The temperature inside the pipe was maintained at 250 to 650 ° C using an electric furnace [Kibo, Korea], and the temperature was measured using a K-type thermocouple. The molar ratio of isobutyl alcohol / nitrogen dioxide was 3 And the injection means used the first stage of the injection tube at the front end of the flue gas inlet side. The contact time of isobutyl alcohol (Duksan Chemical Co., Ltd., Korea) injected from the injection means (TN050-SRW, total injection means, Korea) and the exhaust gas passing through the pipe was set to 0.731 seconds.

The exhaust gas before and after the reaction was analyzed using a portable NOx analyzer [MK II, Eurotron, Italy], and the conversion rate of nitrogen dioxide was calculated by the following equation (1).

[Equation 1]

NO2 conversion ratio (%) = (NO2 concentration before the reaction - NO2 concentration after the reaction) / NO2 concentration before the reaction ㅧ 100

The results are shown in Fig.

Example 2

Was carried out in the same manner as in Example 1 except that isopropyl alcohol [Duksan Chemical Co., Ltd., Korea] was used instead of isobutyl alcohol as a reducing agent, and the molar ratio of isopropyl alcohol / nitrogen dioxide was 3. The results are shown in Fig.

Example 3

Instead of isobutyl alcohol, was used as a reducing agent, and the molar ratio of glycerin / nitrogen dioxide was adjusted to 3 by using glycerin (Doosan, Korea) as a reducing agent. The results are shown in Fig.

Example 4

The procedure of Example 1 was repeated, except that sugar instead of isobutyl alcohol (Samyang, Korea) was used as a reducing agent and the molar ratio of sugar / nitrogen dioxide was 3. The results are shown in Fig.

Example 5

The procedure of Example 1 was repeated except that the molar ratio of isobutyl alcohol / nitrogen dioxide was 1. The results are shown in Fig.

Example 6

The procedure of Example 1 was repeated except that the molar ratio of isobutyl alcohol / nitrogen dioxide was 2. The results are shown in Fig.

Example 7

The procedure of Example 1 was repeated except that sugar instead of isobutyl alcohol was used as a reducing agent and the removal activity of nitrogen dioxide was measured at a molar ratio of 1 of sugar / nitrogen dioxide. The results are shown in Fig.

Example 8

The same procedure as in Example 1 was carried out except that sugar instead of isobutyl alcohol was used as a reducing agent and the removal activity of nitrogen dioxide was measured at a molar ratio of 2 of sugar / nitrogen dioxide. The results are shown in Fig.

In the conventional method for removing NO2 from a stationary source using ethanol, the NO2 conversion was 30% at a molar ratio of ethanol / NO2 and a temperature range of 400 to 600 DEG C, and a NO2 conversion of 45% at a molar ratio of 2 and a temperature range of 350 to 550 & Of NO2 conversion. From the results shown in FIGS. 7 to 9, it can be seen that isobutyl alcohol exhibits a NO2 conversion of 45% or more and a conversion rate of 80% or more at a maximum in the temperature range of 300 to 600 ° C under the condition of the reducing agent / NO2 3 molar ratio. In the case of isopropyl alcohol, the similar tendency is shown except that the maximum conversion ratio is 70% or more. 8 showing the result of changing the molar ratio of isobutyl alcohol, the NO2 conversion rate increases with an increase in the molar ratio, and the conversion ratio is higher and the applicable temperature range is larger than that of the conventional ethanol / NO2 2 molar ratio at a molar ratio of 2 .

7, it can be seen that when the glycerin and the sugar are injected, the temperature range showing the maximum NO2 conversion shifts to the low temperature range and the maximum conversion rate also increases. The main component of sugar is sucrose, which is very large in molecular weight and is hydrolyzed in an aqueous solution to become glucose having an aldehyde group. Therefore, it is thought that sugar has a reducing ability and a high conversion of NO2.

9, it can be seen that as the molar ratio of sugar to nitrogen dioxide increases, the NO2 conversion increases, but the increase is not large. This is because even when the molar ratio of the sugar to the nitrogen dioxide is 1, the effect of the increase of the molar ratio is not significant because the conversion of NO2 is large.

When combining the above, ethanol has only one hydroxyl group, but when the reducing agent used in the present invention has a plurality of reducing functional groups such as a hydroxyl group, an ether group, an aldehyde group and a ketone group, the removal ratio of nitrogen dioxide is high in the same ratio as ethanol, In the case of using a reducing agent having a larger number of carbon atoms and a larger molecular weight, it reacts with nitrogen dioxide under a mild condition, so that the reducing ability of the reducing agent can be all used for reducing nitrogen dioxide, so that it can be judged that the conversion rate of nitrogen dioxide increases. As a result, as the conversion of nitrogen dioxide increases, the reducing agent is converted to carbon dioxide and the amount of by-products such as formaldehyde and acetaldehyde is reduced.

Comparative Example 1

The procedure of Example 1 was repeated except that ethanol was used as a reducing agent instead of isobutyl alcohol and the internal temperature of the pipe was maintained at 350 to 400 ° C. At this time, the molar ratio of ethanol / nitrogen dioxide and by-products were measured in the state that the removal activity of nitrogen dioxide was 60%. The measurement method used was EPA Method TO-11. The results are shown in Table 2.

Example 9

The same procedure as in Example 1 was carried out except that sugar instead of isobutyl alcohol was used as a reducing agent and the internal temperature of the pipe was maintained at 350 to 400 ° C. At this time, the molar ratio of sugar / nitrogen dioxide and byproducts were measured under the condition of 60% removal activity of nitrogen dioxide. The measurement method used was EPA Method TO-11. The results are shown in Table 2.

Temperature() Reducing agent / NO2
Mole ratio Formaldehyde (ppm) Acetaldehyde (ppm) Comparative Example 1 350 3 moles 0.30 0.31 400 2 moles 0.18 0.21 Example 9 350 0.25 mol 0.08 0.01 400 0.5 mole 0.14 0.03

As shown in Table 2, it can be seen that the reducing agent / NO2 molar ratio and the amount of produced by-products are small in the case of Example 9 as compared with Comparative Example 1 in the state of showing the same NO2 removal rate of 60%. That is, when the sugar was injected as the reducing agent, the reducing agent / NO2 molar ratio and the amount of by-products were reduced while showing the same removal rate of nitrogen dioxide as in the case of injecting ethanol.

Since the reaction takes place under a more relaxed condition since the molecular weight is larger than that of ethanol and has many reducing groups, the reducing ability of the reducing agent can be all used for reducing nitrogen dioxide, so that the molar ratio of the reducing agent required for removing nitrogen dioxide is less than that of ethanol, It can be judged that the occurrence of byproducts such as water is low. Also, the applicable temperature range is considered to be wide.

Example 10

The procedure of Example 1 was repeated except that sugar was used instead of isobutyl alcohol as a reducing agent and the molar ratio of sugar / nitrogen dioxide was 0.5. The results are shown in Fig.

Example 11

Except that sugar was used instead of isobutyl alcohol as a reducing agent, the molar ratio of sugar / nitrogen dioxide was 0.5, and all the four tubes provided at intervals of 20 cm were used in the inside of the pipe. The results are shown in Fig.

10, the difference between the NO2 reduction rate and the application temperature can be known in the case of single stage injection and multi-stage injection. In the case of multi-stage injection, the reduction ratio is larger under the same sugar / nitrogen dioxide molar ratio than the first stage injection in the entire temperature range. Thus, it is judged that the same amount of the reducing agent is injected into a wide area by multi-stage injection to increase the reaction with nitrogen dioxide.

Comparative Example 2

Ethanol was used instead of isobutyl alcohol as a reducing agent, the molar ratio of ethanol / nitrogen dioxide injection was 1, and the internal temperature of the pipe was maintained at 420 ° C. EPA Method TO-11 was used for the by-product measurement.

The composition of the inflow gas is shown in Table 3.

gas NO NO2 CO O2 H2O N2 Furtherance 14 ppm 18 ppm 600ppm 18.5% 6% balance

The measurement results of the by-products are shown in Table 4, and the results of the removal activity measurement are shown in Fig.

Example 12

Ethanol and wheat flour [CJ, Korea] were used instead of isobutyl alcohol as a reducing agent, ethanol / nitrogen dioxide injection molar ratio was 1, and wheat flour was 2.5g / min. The reducing agent in powder form was injected separately from ethanol, and a certain amount of the reducing agent was injected by compressed air. The internal temperature of the pipe was kept at 420 캜. EPA Method TO-11 was used for the by-product measurement. The measurement results of the by-products are shown in Table 4, and the results of the removal activity measurement are shown in Fig.

Example 13

Ethanol and starch [Yeonpurun, Korea] was used as a reducing agent, and ethanol / nitrogen dioxide injection molar ratio was 1 and starch was added 2.5 g per minute in the same manner as in Example 1 except that ethanol and starch instead of isobutyl alcohol were used. The reducing agent in powder form was injected separately from ethanol, and a certain amount of the reducing agent was injected by compressed air. The internal temperature of the pipe was kept at 420 캜. EPA Method TO-11 was used for the by-product measurement. The measurement results of the by-products are shown in Table 4, and the results of the removal activity measurement are shown in Fig.

Example 14

Ethanol and wheat flour [CJ, Korea] were used as a reducing agent instead of isobutyl alcohol. Ethanol / nitrogen dioxide injection molar ratio was 1, and wheat flour was injected 5.0 g / min. The reducing agent in powder form was injected separately from ethanol, and a certain amount of the reducing agent was injected by compressed air. The internal temperature of the pipe was kept at 420 캜. EPA Method TO-11 was used for the by-product measurement. The measurement results of by-products are shown in Table 4, and the results of the removal activity measurement are shown in Fig.

Example 15

Ethanol and starch (Yeongpulun, Korea) were used as a reducing agent in place of isobutyl alcohol, and a molar ratio of ethanol / nitrogen dioxide injection of 1 and starch of 5.0 g / min was injected in the same manner as in Example 1. The reducing agent in powder form was injected separately from ethanol, and a certain amount of the reducing agent was injected by compressed air. The internal temperature of the pipe was kept at 420 캜. EPA Method TO-11 was used for the by-product measurement. The measurement results of by-products are shown in Table 4, and the results of the removal activity measurement are shown in Fig.

Temperature (℃) Formaldehyde (ppm) Acetaldehyde (ppm) Comparative Example 2 420 0.20 0.23 Example 12 420 0.22 0.25 Example 13 420 0.21 0.25 Example 14 420 0.25 0.27 Example 15 420 0.23 0.26

As shown in Table 4, when the starch or wheat flour is sprayed with ethanol, the amount of byproducts generated is comparable to that of ethanol-only spray. However, FIGS. 11 and 12 show a conversion rate of about 30% 50% in Example 12, 70% in Example 13, 50% or more in Example 14, and 70% or more in Example 15. [ That is, when starch or wheat flour is sprayed with ethanol, the generation amount of by-products is maintained at a level similar to that of ethanol-only spraying, and the conversion rate of nitrogen dioxide is greatly increased. It is judged that nitrogen dioxide is converted into nitrogen monoxide or the like by the reducing ability of amylose which is a main component of starch and glucose which is a monomer of amylopectin and that the conversion rate is further increased when starch is mixed as compared with the case of mixing wheat flour, The conversion rate of starch was lower than that of starch.

Example 16

It was carried out in the same manner as in Comparative Example 2, ethanol and wheat flour [Snow White, Korea] was carried out as a reducing agent, ethanol / nitrogen dioxide injection molar ratio of 1, flour was injected into 1.25, 2.5, 5.0, 7.5g per minute.

Example 17

Ethanol / nitrogen dioxide injection molar ratio was changed to 1, and starch was changed to 1.25, 2.5, 5.0, and 7.5 g per minute, respectively, in the same manner as in Comparative Example 2 except that ethanol and starch [ Respectively.

The measurement results of removal activity according to Examples 16 and 17 are shown in Fig.

13, when the amount of starch injected per minute exceeded 5 g, there was no significant change in the elimination activity, but rather, the occurrence of dust was observed to increase. When the injection amount per minute was in the range of 0 g to 2.5 g, But it was observed that the range of removal activity was not so large in the range of 2.5g to 5g.

Description of the Related Art
2: piping 4: injection means
6: Storage tank 8: Infusion pump
10: fluid supply means 12: stack (stack)
14: tube 16: regulating means
18: valve 20: temperature sensor
22: Ejector 24: Return pipe
26: RIG (Reactant injection grid) 28: mixing means

Claims (1)

A hybrid NOx abatement apparatus for removing nitrogen compounds that removes nitrogen compounds generated in a combustion process of a fixed source using a reducing agent;
The nitrogen compound removal device comprises (A) a gas turbine, (B) a nitrogen dioxide removal device, and (c) an optional catalytic reduction device; A front end of the nitrogen dioxide removal device is connected to the gas turbine, and a front end of the selective catalytic reduction device is connected to a rear end of the nitrogen dioxide removal device;
The nitrogen dioxide removal device is operated when the loading value of the gas turbine is below a specific value, and the selective catalytic reduction device is operated when the loading value of the gas turbine exceeds a specific value. Hybrid NOx Reduction Device

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