KR101199267B1 - Hybrid NOx elimination system comprising selective non-catalytic reduction system for eliminating yellow plume and selective catalytic reduction system for eliminating nitrogen monoxide - Google Patents

Abstract

PURPOSE: A hybrid nitrogen oxides reducing apparatus is provided to maximize the reducing rat of nitrogen dioxides and nitrogen monoxides. CONSTITUTION: A hybrid NO_x reducing apparatus includes a gas turbine, a selective non-catalytic nitrogen dioxide removing unit, and a selective catalyst reducing unit. The front end part of the selective catalyst reducing unit is connected to the rear end part of the selective non-catalytic nitrogen dioxide removing unit. If the loading value of the gas turbine is lower than or equal to a pre-determined value, the selective non-catalytic nitrogen dioxide removing unit operates. The pre-determined value is in a range between 40 and 60%. The selective non-catalytic nitrogen dioxide removing unit includes an exhaust gas moving pipe(2), at least one reducing agent injection unit, a reducing agent storing tank, a dispersion auxiliary fluid supplying unit, and a plurality of transferring pipes. The reducing agent injection unit supplies a reducing agent to exhaust gas through the pipe. The dispersion auxiliary fluid supplying unit supplies dispersion auxiliary fluid to the reducing agent injection unit. The transferring pipes connect a plurality of points of the pipe and the dispersion auxiliary fluid supplying unit. A part of exhaust gas through the pipe is mixed with returning exhaust gas through returning pipes to form returned mixed exhaust gas. The returned mixed exhaust gas is injected to the dispersion auxiliary fluid supplying unit to be supplied to the reducing agent injection unit as dispersion auxiliary fluid.

Description

Hybrid NOx elimination system comprising selective non-catalytic reduction system for eliminating yellow plume and selective catalytic reduction system for eliminating nitrogen monoxide }

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 oxide (NOx) contained in the exhaust gas refers to nitrogen monoxide, nitrogen dioxide and nitrous oxide, and is one of the representative substances causing environmental pollution, such as other carbon oxides and sulfur oxides. Recently, due to the stricter environmental standards, many power plants using natural gas, known as clean fuel, have been constructed. Pollution by sulfur oxides has reduced severity, while NOx, which is caused by the oxidation of nitrogen in the air at high temperatures, remains 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 standard, but when the concentration of nitrogen dioxide (NO 2) in the exhaust gas exceeds about 12 ppm, visible smoke may occur. In particular, NO2, which occurs mainly in low load operation, causes serious yellow plume problems in urban areas. Visible soot appears mainly as the concentration of nitrogen dioxide, which is reddish brown, is indirectly affected by the diameter of the stack, the flow rate and temperature of the exhaust gas, and the residence time of the gas inside the stack. For example, in a combined cycle power plant, visible smoke from low power not only causes severe psychological and visible pollution of neighboring residents, but also requires low-power operation during start-up and shutdown measures during power supply operation plans. When the turbine starts and stops during the daytime, visible smoke is observed to neighboring residents, which causes psychological pollution. Therefore, start and stop must be avoided during the daytime, and there is a problem that economic losses occur when the turbine starts and stops normally.

As a technique for reducing nitrogen oxides including nitrogen dioxide, combustion control and exhaust gas treatment technologies 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 Laid-Open Publication No. 1999-0069935. When the catalyst is used, nitrogen dioxide can be effectively removed, but there are problems such as cost burden and pressure loss due to the catalyst installation.

In particular, in the case of selective catalytic reduction reaction, the amount of catalyst required is determined by the space velocity determined by the manufacturer or engineering company. In the case of commercialized NH3-SCR method, about 3,000 to 7,000 h-1 is commonly applied. The flow rate of the exhaust gas of the stationary source varies depending on the amount of power generation, but in general, considering that it is 500,000 to 1,000,000 Nm 3 / h, a large amount of catalyst is required since it requires 70 to 200 m 3 of catalyst.

In addition, in the case of the stationary generator using gas as fuel at the above space velocity, if the catalytic reactor is installed in the existing system, the flow of gas may be disturbed by the differential pressure and the combustion reaction of the shear may be affected. There is a problem that a large investment cost is required to remove a small amount of nitrogen dioxide visible soot due to the expansion, and in the case of existing facilities, the installation area increases with the installation of a catalyst, making it difficult to secure the site according to the expansion of the facility. there was.

On the other hand, Selective Non-Catalytic Reduction (SNCR) is a technique to reduce NOx by converting NOx into nitrogen and water vapor by directly spraying ammonia in high temperature region or by directly spraying urea aqueous solution. The NOx reduction rate of 60 ~ 80% was obtained by converting NOx to N2 and H2O in the narrow temperature range.

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 in the equivalent ratio, and when excessively injected, side reactions may cause NOx formation and ammonia slip. There may be a problem that an ammonium compound may be formed by 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, the demand for a technology that can remove the NO 2 in the flue gas in the medium temperature range of about 200 to 700 ℃ in a fixed discharge 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, by increasing the removal rate of nitrogen dioxide or reducing the amount of by-products generated relative to the reducing agent injection amount in a wide temperature range, it is possible to effectively remove nitrogen dioxide in the exhaust gas of the fixed emission source at a low operating cost.

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 the 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 diagram showing the conversion rate of nitrogen dioxide using a reducing agent according to the present invention.
8 is a diagram showing the conversion rate of nitrogen dioxide according to the molar ratio of reducing agent / nitrogen dioxide according to the present invention.
9 is a diagram showing the conversion rate of nitrogen dioxide according to the molar ratio of reducing agent / nitrogen dioxide according to the present invention.
10 is a diagram showing the conversion of nitrogen dioxide according to the first and the multi-stage injection of the reducing agent according to the present invention.
11 is a graph showing the results of measuring NO 2 removal activity over time in Comparative Example 2, Example 12, and Example 13. FIG.
12 is a graph showing the results of measuring NO 2 removal activity over time in Comparative Example 2, Example 14, and Example 15. FIG.
FIG. 13 is a graph showing the results of measuring NO 2 removal activity according to the amount of starch injected in Examples 16 and 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 exhaust gas flowing along the pipe is conveyed through the plurality of conveying tubes, and the conveying exhaust gases conveyed through the plurality of conveying tubes are mixed with each other to form a conveying mixed exhaust 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 dispersion auxiliary fluid discharged from the fluid supply means 10 uses external air, steam, or water, or connects a return pipe 24 configured at one side of the pipe 2 to the fluid supply means 10. After installation, the exhaust gas flowing along the pipe 2 is conveyed to the fluid supply means 10 and then supplied to the dispersing means 4 to be used as a dispersion auxiliary fluid.

The exhaust gas may be taken out and conveyed at one point of the pipe, but it is more preferable to convey the mixed gas obtained by drawing it out at a plurality of points in the pipe and mixing them with each other.

Specifically, it was found that the amount of reducing agent required to remove the same amount of nitrogen dioxide was greatly reduced by providing a condition under which the reducing agent could evaporate 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.

That is, further comprising a conveying pipe opening and closing control means and using the opening and closing control means, (i) the temperature fluctuation range of the conveying mixed flue gas supplied to the dispersion auxiliary fluid supply means or (ii) is supplied to the reducing agent injection means The conveyance amount of each conveyance flue gas conveyed by the said 2 or more conveyance pipes so that the temperature fluctuation range of the dispersion | distribution auxiliary fluid may be maintained in 0.001-100 degreeC, preferably 0.001-50 degreeC, More preferably, 0.001-30 degreeC. It is desirable to adjust

In particular, when the temperature range is maintained in the 0.001-50 ℃ range, it was confirmed that substantially uniform nitrogen dioxide removal efficiency is achieved, especially in the irregular combustion exhaust gas discharge 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 or rear end of the dispersion auxiliary fluid supply means; The two or more conveying tubes each include a conveying flue gas temperature sensor capable of measuring the temperature of conveyed conveying flue gas; The conveying pipe opening and closing adjusting means may adjust the amount of each conveying exhaust gas based on the temperature of the dispersing auxiliary fluid transmitted from the dispersing auxiliary fluid temperature sensor and the conveying exhaust gas temperature sensor and the temperature data of each conveying exhaust 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.

In particular, when the temperature difference in the pipes of the plurality of points of the pipe is 10-50 ℃ or the plurality of points of the pipe is separated by 1-30 m distance, irregular combustion flue gas for 15-30 minutes after the start of operation In addition to the exhaust environment, substantially uniform nitrogen dioxide removal efficiencies are achieved, even in the presence of extremely irregular combustion flue gas emissions from 0-15 minutes after the start of operation (i.e., from immediately after the start of operation to 15 minutes after the start of operation). It was confirmed that it was achieved.

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 vary, but in the present invention, any one reducing agent selected from the group consisting of oxygen-containing hydrocarbons, carbohydrates, and mixtures thereof having functional groups containing oxygen such as hydroxyl groups, ether groups, aldehyde groups, ketone groups, etc. There is a characteristic in point.

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 a reducing agent containing nitrogen, the final product of the reaction is nitrogen oxides reduced to nitrogen in the high temperature range (900 to 1100 ° C.), but the reducing agent is rather in the mid temperature range (200 to 700 ° C.), which is the main application temperature range of the present invention. It can be said that there is a possibility of increasing the amount of nitrogen oxides by reacting with oxygen. At high temperatures, a reducing agent containing nitrogen, such as ammonia, provides a nitrogen atom to replace nitrogen oxide in the flue gas with a stable nitrogen molecule in the reaction of reducing nitrogen oxide to nitrogen by a radical reaction. It is considered that there is a small amount of nitrogen molecules that cannot generate radicals, and that the production of more unstable nitrogen oxides may 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 ability such as hydroxyl group, ether group, aldehyde group, ketone group, etc., thus, it is considered that the equivalent amount of reducing agent consumed to remove 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 with ethanol, the reducing agent of the present invention has a higher ratio of conversion to carbon dioxide, so that the amount of by-products is reduced, and the amount of conversion of nitrogen dioxide is also increased by the amount of conversion to carbon dioxide. Nitrogen monoxide conversion to Equivalent is expected to increase.

Substances which can be used as the reducing agent include at least one hydroxyl group (OH) group, ether group, aldehyde group and ketone group in one molecule and at least 3 carbon atoms, or include at least two hydroxyl group, ether group, aldehyde group and ketone group in one molecule. And is not particularly limited as long as it is one or more reducing agents of hydrocarbons and carbohydrates having 2 or more carbon atoms, and isobutyl alcohol, isopropyl alcohol, glycerin, allyl alcohol ), Tert-butanol, n-propyl alcohol, ethylene glycol, methoxy propanol, n-butyl alcohol, en- N-octyl alcohol, isooctanol, 2-ethyl hexanol, acetylacetonate, maleic acid (fumaric acid) ), Glyoxal, glyoxalic acid, Methoxypropanol, cyclohexanol, cyclohexanone, 1,3-propanediol, 1,2-propanediol, 1,2-propanediol, propane (propanal), 1,4-butanediol, 1,4-butanediol, isobutylaldehyde, isobutylaldehyde, n-butylaldehyde, pentanediols, 1,5-hexanediol (1 5-hexanediols, glutaraldehyde, dioxane, trioxane, furan, tetrahydrofurane, tartaric acid, citric acid , Diethyl acetaldehyde, propagyl alcohol, tert-butylether, glycerincarbonate, glyceraldehyde, glyceric acid, tetral Tetralol, Tetralone, Benzaldehyde, Terephthaldehyde , 1,4-cyclohexanedialcohol, xylenol and its isomers, oleic acid, stearic acid, palmitic acid, li Examples thereof include linoleic acid, salicylic acid, and vinylcyclohexene.

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 sugar is also known as sucrose, but sucrose is mainly used as a chemical name, while sugar is sugar cane, sugar free, wheat sugar, wheat flour, raw sugar, refined sugar, arable white sugar, white sugar, heavy white sugar, samon sugar, powdered sugar, sugar cube, invert sugar (invert sugar), brown sugar, such as artificial or natural ones commonly known as sugar can mean a whole.

The starch is a polysaccharide formed by condensation of di-glucose (glucose), which is a mixture of amylose and amylopectin, and may be one of the storage substances present in a plant having chlorophyll. It can be referred to collectively as artificial or natural ones containing.

The wheat flour may be made from the endosperm of 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 sprayed by mixing ethanol with the reducing agent, or may be further sprayed at an injection point separate from the injection point.

Compared with the case of spraying only ethanol, the amount of by-products generated when the reducing agent is injected together does not have a large difference, but the conversion rate of the nitrogen dioxide relative to the reducing agent / nitrogen dioxide equivalent may be increased by the action of the reducing agent. On the contrary, even if the reducing agent / nitrogen dioxide equivalent is lowered, the by-product generation amount can be reduced while maintaining the nitrogen dioxide conversion rate. That is, compared with the case of supplying only ethanol, the removal rate of nitrogen dioxide can be increased at the same equivalent ratio, so that it is possible to reduce the amount of ethanol and as a result, the amount of by-products can be reduced.

According to the present invention, it is possible to increase the degree of contact and mixing with the exhaust gas by increasing the region for treating the exhaust gas with at least one injection point of the reducing agent, and as a result, the efficiency of removing nitrogen dioxide in the exhaust gas can be improved. In addition, the reduction of by-products can be expected by allowing the reducing agent to fully 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. The injection auxiliary fluid is to allow the reducing agent to be widely injected into the exhaust gas. In order to use a reducing agent that needs to be injected into a liquid phase such as an inert gas or a liquid or sugar that is not reactive with the reducing agent, the solubility of the reducing agent is reduced. A non-hazardous fluid capable of dispersing such as a high solvent may be used. However, in consideration of cost and availability, some of the exhaust gas at the front end of the stack or air may be used.

The present invention also provides a pipe with one or more injection means connected to remove nitrogen dioxide in the exhaust gas of the fixed discharge source as a single stage, and at least one or more stages are installed inside the pipe, through which the reducing agent is injected into the exhaust gas. Can be. As described above, the reaction may occur in a wider reaction region by spraying a reducing agent through a plurality of stages. In addition, by allowing the reducing agent to fully participate in the reaction, the generation of by-products can also 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. The conventional SNCR (selective non-catalytic reduction method) using ammonia can be used only in the high temperature range (900 ~ 1,100 ℃). When using the flue gas treatment system, it is necessary to heat the treatment device to adjust the temperature conditions. When the treatment device was not used, it could only be applied to a limited place that satisfies high temperature conditions such as the rear end of the combustion chamber or the secondary combustion chamber. In addition, the method of removing nitrogen dioxide using ethanol may be applicable to a limited range in the middle temperature range, so it may be difficult to cope with various operating conditions when removing nitrogen dioxide, but according to the present invention, the range of operating conditions that can be applied is broadened. Can be.

The apparatus for removing nitrogen dioxide in the exhaust gas containing nitrogen dioxide generated in the combustion process of the fixed emission source according to the present invention is a pipe for providing a movement path of the exhaust gas, is installed in connection with the pipe to supply the reducing agent to the exhaust gas passing through the pipe. At least one injection means, it may include a storage tank connected to the injection means for storing the reducing agent.

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

In addition, it may further include a fluid supply means connected to the injection means for supplying a dispersion auxiliary fluid to the injection means.

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.

On the other hand, the injection means according to the present invention is to inject the reducing agent alone to the exhaust gas, or to mix and inject with a dispersion auxiliary fluid such as air, steam, water, etc., the reducing agent and / or dispersion in the flow path through which the exhaust gas flows As long as the auxiliary fluid can be supplied, any one can be used. For example, a nozzle, a reactive injection grid (RIG), or the like can be used.

In addition, the exhaust gas treating apparatus according to the present invention ultimately supplies a reducing agent to the moving path of the exhaust gas containing nitrogen dioxide, and then processes the contaminants as the reducing agent contacts each other with the exhaust gas. After supplying, a contaminant may be treated by mixing the reducing agent and the exhaust gas with a mixing means behind the portion to which the reducing agent is supplied.

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.

In addition, the injection means and the fluid supply means connected to the injection means may be installed connected to the ejector, the movement path of the reducing agent discharged from the storage tank to one side of the ejector may be installed. This is to spray the reducing agent evenly 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 installing one or more stages inside the piping, the reducing agent can be evenly injected into the flue gas.

In addition, at least one valve provided on one side of the pipe to control the flow of the fluid flowing through each pipe, the pipe providing a movement path of the exhaust gas is provided to measure the temperature of the exhaust gas flowing through the pipe It may include a temperature sensor and the control means connected to the temperature sensor and the valve to open and close the valve based on the temperature data input from the temperature sensor. The nitrogen dioxide in the exhaust gas can be effectively removed by using the reducing agent by opening a valve having a temperature range (200 to 700 ° C.) suitable for the reducing agent to react based on the temperature data input from the temperature sensor.

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

1 is a configuration diagram showing an example of the exhaust gas treatment apparatus according to the present invention, Figure 2 is a configuration diagram showing another example of the exhaust gas treatment apparatus according to the present invention, Figure 3 is another example of the exhaust gas treatment apparatus according to the present invention 4 is a configuration diagram showing another example of the exhaust gas treatment apparatus according to the present invention, FIG. 5 is a configuration diagram showing another example of the exhaust gas treatment apparatus according to the present invention, and FIG. It demonstrates together as a block diagram which shows still another example of the waste gas processing apparatus.

Referring to Figure 1, the exhaust gas treatment apparatus according to the present invention is basically configured to provide the reducing agent to the movement path of the exhaust gas, more specifically the pipe (2) for providing a movement path of the exhaust gas, the piping (2) is connected to the at least one injection means 4 and the injection means 4 for supplying the reducing agent to the exhaust gas passing through the pipe (2) and is provided to the injection means (4) It may include 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 auxiliary fluid may be supplied to the movement path of the exhaust gas together with the reducing agent through the fluid supply means 10 connected to one side of the injection 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 injection means 4 according to the present invention is installed inside the pipe 2 to inject the reducing agent alone into the exhaust gas containing nitrogen dioxide, or by mixing with a dispersion auxiliary fluid such as air, steam, water, etc. In order to supply the reducing agent and / or dispersion auxiliary fluid to the flow path through which the exhaust gas flows, any one may be used, but a nozzle or a reactive injection grid (RIG) 26 of FIG. 2 may be used. 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. It may be installed in one or multiple stages on one side of the pipe (2), to facilitate the injection of a reducing agent to the exhaust gas containing nitrogen dioxide flowing along the pipe (2), or RIG as injection means (4) It 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 exhaust gas treatment apparatus including the mixing means 28 may further be connected to the fluid supply means if necessary.

Referring to FIG. 4, the apparatus for treating exhaust gas according to the present invention includes an ejector 22 using a venturi principle in a movement path of a distributing auxiliary fluid discharged from the fluid supply means 10 and introduced into the injection means 4. It may include connecting the installation path of the reducing agent to one side.

Referring to FIG. 5, the dispersion auxiliary fluid discharged from the fluid supply means 10 uses external air, steam, or water, or the conveying pipe 24 configured at one side of the pipe 2 may provide a fluid supply means 10. After being installed in connection with), the exhaust gas flowing along the pipe (2) is conveyed to the fluid supply means (10) and then supplied to the injection means (4) to be used as a dispersion auxiliary fluid.

Referring to FIG. 6, the exhaust gas treating apparatus according to the present invention includes a valve 18 at one side of the tube 14 so as to adjust a flow of a fluid flowing through the inside of the tube 14 as necessary. At least one temperature sensor 20 for measuring the temperature of the exhaust gas flowing through the pipe (2) is provided in the pipe (2) and is connected to the temperature sensor 20 and the valve 18 is installed to the temperature sensor ( Adjusting means 16 to open and close the valve 18 on the basis of the temperature data input from 20 may be further provided. In this case, the temperature sensor 20 may be installed anywhere in the pipe 2 as long as the temperature sensor 20 can easily measure the temperature of the exhaust gas flowing through the pipe 2.

The exhaust gas treating apparatus according to the present invention treats the outer circumferential surface of the injection means 4 and the pipe 14 on which the injection means 4 is connected to the exhaust gas discharged at a temperature of 200 to 700 ° C. as a heat insulating material if necessary. This can prevent the reducing agent from burning.

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 be easily transported to the injection means 4, the reducing agent stored in the storage tank (6).

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.

As described above, the exhaust gas treatment apparatus configured to supply the dispersion auxiliary fluid with the reducing agent to the exhaust gas may include the movement path of the reducing agent discharged from the storage tank 6 and the dispersion auxiliary fluid discharged from the fluid supply means 10 as necessary. The movement paths may be configured to be merged with each other, and after the ejector 22 using venturi principle is installed on one side of a path of the pipe 14 connected to the injection means 4 from the fluid supply means 10, the ejector One side of (22) may be connected to the movement path of the reducing agent so that the two flows are merged.

Looking at the operation of the exhaust gas treatment apparatus according to the present invention having the configuration as described above are as follows.

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 using the injection pump 8. In this case, the reducing agent may be moved to the injection means 4 together with the dispersion auxiliary fluid using the fluid supply means 10.

Here, the dispersion auxiliary fluid may be used by compressing the outside air at a high pressure, or by circulating some of the exhaust gas moving along the steam, water, or the pipe 2 which recovers 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 auxiliary 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 exhaust gas treatment apparatus according to the present invention more efficiently by using the adjusting means 16 to open and close the valve 18 on the one side based on the temperature data input from the temperature sensor 20. can do.

First, the configuration of the apparatus is provided with at least one or more pipes (14) having a plurality of injection means (4) installed inside the pipe (2) and then the pipe (14) injection pump 10 and the fluid supply means ( 8) is connected to, and is configured to be provided with at least one or more temperature sensors 20 inside the pipe (2).

Here, one side of each pipe 14 is provided with a valve 18, the valve 18 and the temperature sensor 20 is connected to the adjusting means 16.

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

At this time, by measuring the temperature of the exhaust gas flowing into the pipe (2) with a temperature sensor 20 provided in the pipe (2) and transmits the data to the adjusting 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.

Then, the reducing agent filled in the storage tank (6) is transferred to the pipe (14) in which the valve (18) is opened by using the injection pump (8), and at the same time, the fluid supply means (10) Air is sent to a tube 14 in which the valve 18 is open.

Then, the air and the reducing agent delivered to the tube 14 with the valve 18 provided inside the pipe 2 open through the injection means 4 installed in the pipe 14 to the pipe 2. It is injected into the exhaust gas containing nitrogen dioxide flowing through to reduce the nitrogen dioxide to nitrogen monoxide or react with nitrogen to remove the exhaust gas passed through a stack (12) connected to the end of the pipe (2) to the outside Will be discharged.

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 more detail based on examples, but the scope of the present invention can be reduced or limited and thus cannot be interpreted.

Example 1

As shown in Figure 1, after making a pipe made of a cylindrical tube [height 15cm, width 15cm, length 100cm] with SUS 304 a plurality of injection means [TN050-SRW, total injection means, South Korea] ] Were installed four at 20cm intervals. Then, fill the isobutyl alcohol [Duksan Pharmaceutical Co., Ltd., Korea] with a reducing agent in the storage tank and connect the storage tank to an injection pump [M930, Yeonglin Equipment, Korea], and install the injection pump [M930, Younglin]. Device, South Korea] was connected to the pipe provided with the injection means [TN050-SRW, total nozzle, South 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 inlet 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, while the inlet gas passes through the pipe and is filled in the outside air and the storage tank by using the fluid supply means [HP2.5, Airbank Compressor, Korea] and the injection pump [M930, Yeonglin, Korea] Isobutyl alcohol was transferred to the injection means [TN050-SRW, Total Nozzle, South Korea] and injected into the pipe. At this time, the temperature inside the pipe was maintained to a temperature of 250 to 650 ℃ using an electric furnace [Kibo, Korea], the temperature was measured using a K-type thermocouple, the molar ratio of isobutyl alcohol / nitrogen dioxide is 3 Injecting means was used in the first stage of the injection pipe of the front end of the exhaust gas inlet. The contact time between the isobutyl alcohol [Duksan Pharmaceutical Co., Ltd., Korea] and the exhaust gas which is injected from the injection means [TN050-SRW, total injection means, Korea] is 0.731 seconds.

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

[Equation 1]

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

The results are shown in Fig.

Example 2

It was carried out in the same manner as in Example 1, but instead of isobutyl alcohol, isopropyl alcohol [Duksan Pharmaceutical Co., Ltd., Korea] was used 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

It carried out in the same manner as in Example 1, using sugar [Samyang, South Korea] as a reducing agent instead of isobutyl alcohol, the molar ratio of sugar / nitrogen dioxide to 3. The results are shown in Fig.

Example 5

The same procedure as in Example 1 was carried out, 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

In the same manner as in Example 1, sugar was used as a reducing agent instead of isobutyl alcohol, and the removal activity of nitrogen dioxide was measured at a molar ratio of sugar / nitrogen dioxide 1. The results are shown in FIG.

Example 8

In the same manner as in Example 1, sugar was used as a reducing agent instead of isobutyl alcohol, and the removal activity of nitrogen dioxide was measured at a molar ratio of sugar / nitrogen dioxide 2. The results are shown in FIG.

In the conventional method of removing nitrogen dioxide from the fixed source using ethanol, the ethanol / NO2 1 mole ratio and the conversion rate of NO2 was 30% in the temperature range of 400 ~ 600 ℃, 2 molar ratio and 45% in the temperature range of 350 ~ 550 ℃ NO2 conversion was shown. From the results of FIGS. 7 to 9, isobutyl alcohol exhibits a conversion rate of 45% or more and a maximum conversion rate of 80% or more in a temperature range of 300 to 600 ° C. under a reducing agent / NO 2 molar ratio. In addition, it can be seen that the isopropyl alcohol shows a similar trend except that the maximum conversion rate is 70% or more. Referring to FIG. 8 showing the result of changing the molar ratio of isobutyl alcohol, as the molar ratio increases, the NO 2 conversion increases, and in the case of the 2 molar ratio, the conversion ratio is larger than that of the conventional ethanol / NO 2 2 molar ratio, and the applicable temperature range is wide. It can be seen.

Referring to Figure 7, it can be seen that when the glycerin and sugar is injected, the temperature range representing the maximum NO 2 conversion is shifted to the low temperature range, and the maximum conversion is also increased. Since sugar has a very high molecular weight as sucrose and is hydrolyzed in aqueous solution to form glucose having an aldehyde group, the sugar has a reducing ability and a high NO 2 conversion.

9, it can be seen that as the molar ratio of sugar to nitrogen dioxide increases, the NO 2 conversion increases, but the increase is not large. This is because even when the molar ratio of sugar to nitrogen dioxide is 1 because the NO2 conversion rate is large, the effect of increasing the molar ratio is not significant.

In sum, the ethanol has only one hydroxyl group, but the reducing agent used in the present invention has a high removal rate of nitrogen dioxide at the same equivalence ratio as ethanol when it has a plurality of reducing functional groups such as hydroxyl group, ether group, aldehyde group and ketone group, In the case of using a reducing agent having a larger number of carbons than ethanol and having a high molecular weight, the reactant is reacted with nitrogen dioxide under mild conditions, and thus the conversion rate of nitrogen dioxide may be increased because all of the reducing ability of the reducing agent can be used to reduce nitrogen dioxide. As a result, as the conversion rate 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

In the same manner as in Example 1, using ethanol as a reducing agent instead of isobutyl alcohol, the internal temperature of the pipe was maintained at 350 to 400 ℃. 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

In the same manner as in Example 1, using sugar as a reducing agent instead of isobutyl alcohol, the internal temperature of the pipe was maintained at 350 to 400 ℃. At this time, the molar ratio and the by-product of the sugar / nitrogen dioxide was measured in the state of 60% removal activity of nitrogen dioxide. The measurement method used was EPA Method TO-11. The results are shown in Table 2.

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

As shown in Table 2, it can be seen that in Example 9 compared to Comparative Example 1, the amount of reducing agent / NO 2 molar ratio and by-products is low in the state showing the same nitrogen dioxide removal rate of 60%. That is, when sugar was injected into the reducing agent, the removal rate of the reducing agent / NO2 molar ratio and by-products was reduced while showing the same removal rate of nitrogen dioxide as when ethanol was injected.

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. It is also believed that the applicable temperature range also appears wide.

Example 10

It was carried out in the same manner as in Example 1, wherein sugar was used as a reducing agent instead of isobutyl alcohol, and the molar ratio of sugar / nitrogen dioxide was 0.5. The results are shown in FIG.

Example 11

In the same manner as in Example 1, sugar was used as a reducing agent instead of isobutyl alcohol, and the molar ratio of sugar / nitrogen dioxide was 0.5, and the injection means used all four tubes provided at intervals of 20 cm inside the pipe. The results are shown in FIG.

Referring to Figure 10 it can be seen the difference between the NO2 reduction rate and the application temperature in the case of single stage injection and multistage injection. In the case of multi-stage injection, it can be seen that the reduction rate is higher under the same sugar / nitrogen dioxide molar ratio condition than the single stage injection in the whole 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 inlet gas is shown in Table 3.

gas NO NO2 CO O2 H2O N2 Furtherance 14 ppm 18 ppm 600 ppm 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 powder reducing agent was injected separately from ethanol, and was injected by compressed air while a predetermined amount was added. The internal temperature of the pipe was maintained at 420 ℃. 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 powder reducing agent was injected separately from ethanol, and was injected by compressed air while a predetermined amount was added. The internal temperature of the pipe was maintained at 420 ℃. 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

In the same manner as in Example 1, but instead of isobutyl alcohol ethanol and flour [CJ, South Korea] was used as a reducing agent, ethanol / nitrogen dioxide injection molar ratio of 1, flour was injected 5.0g per minute. The powder reducing agent was injected separately from ethanol, and was injected by compressed air while a predetermined amount was added. The internal temperature of the pipe was maintained at 420 ℃. EPA Method TO-11 was used for the by-product measurement. The by-product measurement results are shown in Table 4, and the removal activity measurement results are shown in FIG.

Example 15

In the same manner as in Example 1, but instead of isobutyl alcohol, ethanol and starch [Neulpur, South Korea] was used as a reducing agent, ethanol / nitrogen dioxide injection molar ratio of 1, starch was injected 5.0g per minute. The powder reducing agent was injected separately from ethanol, and was injected by compressed air while a predetermined amount was added. The internal temperature of the pipe was maintained at 420 ℃. EPA Method TO-11 was used for the by-product measurement. The by-product measurement results are shown in Table 4, and the removal activity measurement results 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

Looking at Table 4, when the starch or wheat flour is sprayed with ethanol, the amount of by-products is similar to that of ethanol-only injection, but in FIGS. 11 and 12, the conversion rate is about 30% when only ethanol is injected. Example 12 shows a conversion of 50%, Example 13 of 70%, Example 14 of 50% or more, and Example 15 of 70% or more. 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 was judged that nitrogen dioxide was converted to nitrogen monoxide by the reducing ability of amylose, the main component of starch, and glucose, the monomer of amylopectin, and the conversion rate increased more when the starch was mixed than when the flour was mixed. As there are other parts than phosphorus carbohydrates, the conversion rate is 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

The same method as in Comparative Example 2 was carried out, ethanol and starch [Geunpur, Korea] as a reducing agent, ethanol / nitrogen dioxide injection molar ratio of 1, starch was changed to 1.25, 2.5, 5.0, 7.5g per minute It was.

The removal activity measurement results of Examples 16 and 17 are shown in FIG. 13.

Referring to FIG. 13, when the amount of starch injected per minute exceeded 5 g, there was no significant change in the removal activity. Rather, a tendency to increase dust generation was observed. In the range of 0 g to 2.5 g per minute, the removal activity increased. Although the width was large, it was observed that the increase in removal activity was not very large in the range of 2.5 g to 5 g.

Description of the Related Art
2: pipe 4: injection means
6: storage tank 8: injection pump
10: fluid supply means 12: stack
14 tube 16: control means
18: valve 20: temperature sensor
22: ejector 24: carrier pipe
26: Reactant injection grid (RIG) 28: Mixing means

Claims (9)

delete delete delete delete delete delete delete delete 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) an optional non-catalytic nitrogen dioxide removal device, and (c) an optional catalytic reduction device; A front end of the selective catalyst free nitrogen dioxide removal device is connected to the gas turbine, and a front end of the selective catalyst reduction device is connected to a rear end of the selective catalyst free nitrogen dioxide removal device;
Only the selective catalytic non-nitrogen dioxide removal device is operated under the condition that the gas turbine has a loading value below a certain value, and only the selective catalytic reduction device is operated under the condition that the loading value of the gas turbine exceeds a certain value; The specific value of the gas turbine loading value is any one selected from the range of 40-60%;
The selective non-catalyst nitrogen dioxide removal device is (a) at least one reducing agent injection means for supplying a reducing agent to the exhaust gas passing through the pipe is installed, connected to the pipe (b) a pipe providing a movement path of the exhaust gas, (c) Reducing agent storage tank connected to the reducing agent injecting means for storing the reducing agent, (d) Dispersion auxiliary fluid supply means for supplying a dispersion auxiliary fluid to the reducing agent injecting means connected to the reducing agent injecting means, and (e) A plurality of conveying pipes connecting the plurality of points of the pipe and the dispersion auxiliary fluid supplying means;
A part of the exhaust gas flowing along the pipe is conveyed through the plurality of conveying tubes, and the conveying exhaust gases conveyed through the plurality of conveying tubes are mixed with each other to form a conveying mixed exhaust gas; The returned mixed exhaust gas is supplied to the dispersion auxiliary fluid supply means and supplied to the reducing agent injecting means so that the exhaust gas is used as a dispersion auxiliary fluid;
At least two or more conveying tubes of the plurality of conveying tubes include conveying tube opening and closing adjusting means for adjusting the amount of conveying exhaust gas flowing through the conveying tubes; The conveying amount of each of the conveying flue gas conveyed from the two or more conveying pipes so that the fluctuation range of the temperature of the dispersing auxiliary fluid supplied from the dispersing auxiliary fluid supplying means to the reducing agent injecting means is within a range of 0.001-100 ° C. Controlled through tube opening and closing means;
The dispersion auxiliary fluid supplying means includes a dispersion auxiliary fluid temperature sensor capable of measuring a temperature of the dispersion auxiliary fluid at the front end or the rear end of the dispersion auxiliary fluid supplying means; The two or more conveying tubes each include a conveying flue gas temperature sensor capable of measuring the temperature of conveyed conveying flue gas; The conveying pipe opening and closing adjusting means adjusts the amount of each conveying exhaust gas based on the temperature of the dispersing auxiliary fluid transmitted from the dispersing auxiliary fluid temperature sensor and the conveying exhaust gas temperature sensor and the temperature data of each conveying exhaust gas;
The plurality of points of the pipe show a temperature difference of 5-100 ° C. between the pipes of the points; And a plurality of points of the pipe are separated from each other by a distance of 50 cm to 50 m.

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