KR101239638B1 - Preferential oxidation reactor and preferential oxidation system having the same - Google Patents

Abstract

PURPOSE: A selective oxidation reactor and a selective oxidation system including the same are provided to flow a product into a next selective oxidation reactor without additional cooling as the product passed through a catalyst is cooled by cooling water to control the temperature to the temperature similar to reactants before being ejected from the selective oxidation reactor, and to reduce the volume and weight of the selective oxidation system as the water of the reactants is removed and the temperature of the reactants is controlled without a further water collecting apparatus and heat changer. CONSTITUTION: A selective oxidation reactor comprises an outer container(110), an upper plate(130), a tube(140), a guide member(120), and a connecting member. The outer container has a hollow part(113) filled with cooling water. Reactants are flowed in and out of upper and lower parts of the outer container. The upper plate is installed on the inner periphery of the outer container so as to cover the hollow part, and arranged with a space from the upper end of the outer container toward the inner side. The upper plate has a through-hole. The tube is inserted into the through-hole, and has a protrusion part(141) projected from the upper plate. A catalyst(142) causing selective oxidation of said reactants is filled within the tube. The guide member is installed within the outer container with a distance from the inner periphery of the outer container, the upper plate, and one end of the tube so that steam contained in the reactants are condensed by being contacted to the upper plate before the reactants are flowed into the protrusion part. The connecting member connects at least one among the inner periphery of the outer container, the upper plate, and the tube to the guide member in order to fix the position of the guide member. [Reference numerals] (AA) Reactant; (BB) Resultant

Description

Selective Oxidation Reactor and Selective Oxidation Reaction System Having Same {PREFERENTIAL OXIDATION REACTOR AND PREFERENTIAL OXIDATION SYSTEM HAVING THE SAME}

The present invention relates to a selective oxidation reactor for oxidizing and converting carbon monoxide contained in a reformed gas for a fuel cell into carbon dioxide, and a selective oxidation reaction system having the same.

A fuel cell is an energy conversion device that directly converts chemical energy into electrical energy through a chemical reaction between a fuel and an oxidant by using a reverse reaction of an electrolysis reaction of water.

Most fuel cells use hydrogen as a fuel, but at present, since there is no supply system for hydrogen fuel, hydrogen is produced by reforming hydrocarbon-based fuels and then used in a transitional stage. have. However, the reformed gas that decomposes hydrocarbons contains carbon monoxide, which poisons the platinum catalyst in the fuel cell stack, making normal operation impossible, and thus requires further removal of carbon monoxide.

Carbon monoxide is removed using Water Gas Shift (WGS) and Selective Oxidation (PROX). The selective oxidation reactor is a device for reacting carbon monoxide with oxygen to make carbon dioxide. It is necessary to properly control the reaction temperature to induce only the desired oxidation reaction without removing an unintended reaction.

In the conventional selective oxidation reactor, when the temperature of the reactants is lowered to 100 ° C. or lower in order to control the reaction temperature, water contained in the reactants condenses, and the catalyst disposed inside the reactor has a problem of deterioration in performance. In addition, in the case of constructing a selective oxidation reaction system by connecting the selective oxidation reactors in two or more stages, additional heat exchangers are placed between the two reactors to control the reaction temperature, thereby increasing the volume and weight of the entire system. There was a limited problem.

One object of the present invention is to provide a selective oxidation reactor that can prevent the catalyst from getting wet to maintain the performance of the reactor.

Another object of the present invention is to provide a selective oxidation reaction system capable of maintaining the reaction temperature necessary for the oxidation reaction without additional heat exchanger between the selective oxidation reactors connected to each other.

In order to achieve the above object of the present invention, the selective oxidation reactor according to an embodiment of the present invention, the outer container and the outer portion is formed to have a hollow portion filled with the cooling water and the reactants are introduced and discharged to the top and bottom, Installed on the inner circumferential surface of the outer container so as to cover the hollow portion and disposed to be spaced inwardly from the upper end and having a through hole and a protrusion inserted into the through hole and protruding from the top plate, and selectively selecting the reactant therein. The inner circumference of the outer container is installed in the tube filled with the catalyst causing the oxidation reaction, and the inside of the outer container to contact the top plate before the reactant enters the protrusion to condense the water vapor contained in the reactant, And a guide member spaced apart from one end of the upper plate and the tube. .

According to an example related to the present invention, the guide member is formed to be inclined to guide the reactant introduced from the upper portion of the guide member to be introduced into the gap between the guide member and the outer container.

According to another example related to the present invention, the tubes are arranged in a plurality of spaced apart from each other so that continuous condensation of the water vapor occurs to form a space in which the reactants can contact the top plate between the tubes. .

According to another embodiment related to the present invention, the inner circumferential surface of the outer container to fix the position of the guide member further comprises a connection member connecting at least one of the upper plate, the tube and the guide member.

According to another example related to the present invention, the water vapor further comprises a drain pipe connected to the top plate to discharge the water formed by condensation to the outside of the outer container.

According to another example related to the present invention, the catalyst is disposed at the inlet and the outlet of the tube to prevent the catalyst from escaping to the outside of the tube, and the turbulent flow in the reactant flowing into the protrusion and the gas passing through the catalyst ( It further includes a stopper having a permeable gap irregularly formed to generate a flow.

In addition, the present invention discloses a selective oxidation reaction system in order to realize the above object. The selective oxidation reaction system according to an embodiment of the present invention comprises a plurality of the selective oxidation reactors connected in series and configured to cause a selective oxidation reaction to the incoming reactants to convert carbon monoxide contained in the reactants into carbon dioxide. , The gas passing through any one of the selective oxidation reactors is passed by the cooling water through a stopper disposed at the outlet of the tube before exiting the outer container to allow entry into the next selective oxidation reactor without additional cooling. It cools to the temperature of 80-110 degreeC.

According to the present invention having the configuration described above, by contacting the top plate before the reactant is introduced into the tube, water vapor is condensed and removed from the reactant, thereby preventing the catalyst inside the tube from getting wet.

In addition, the present invention can be introduced into the next selective oxidation reactor directly without additional cooling since the product passing through the catalyst is cooled by the cooling water before being discharged from the selective oxidation reactor and adjusted to a temperature similar to the temperature of the reactants.

In addition, the present invention can reduce the volume and weight of the selective oxidation reaction system because the water of the reactants can be removed and the temperature of the reactants can be controlled without additional water recovery and heat exchanger. This makes it possible to use a selective oxidation reaction system in an installation space or in an environment with limited installation weight.

1 is a perspective view of a selective oxidation reactor according to an embodiment of the present invention.
FIG. 2 is an exploded view of the selective oxidation reactor shown in FIG. 1. FIG.
3 is a cross-sectional view taken along the line III-III of FIG.
4 is a conceptual diagram of a selective oxidation reactor according to another embodiment of the present invention.
5A and 5B are conceptual views comparing a selective oxidation reaction system according to an embodiment of the present invention with the conventional one.

Hereinafter, the selective oxidation reactor according to the present invention will be described in more detail with reference to the accompanying drawings. In the present specification, the same or similar reference numerals are given to different embodiments in the same or similar configurations. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

1 is a perspective view of a selective oxidation reactor 100 according to an embodiment of the present invention.

The selective oxidation reactor 100 is made so that the reformed gas, which is a reactant at the top, is introduced and discharged to the bottom. In the selective oxidation reactor 100, a selective oxidation reaction (CO + 0.5O ₂ ↔CO ₂ ) occurs in which carbon monoxide included in the reactant is combined with oxygen to form carbon dioxide.

The outer container 110 forms the body of the selective oxidation reactor 100. Cooling water inlet 111 is formed below the outer circumferential surface of the outer container 110, the cooling water inlet 112 is formed on the outer circumferential surface of the outer container 110 to discharge the cooling water. One side of the outer container 110 is provided with a drain pipe 114 so that water condensed in the selective oxidation reactor 100 can be discharged out of the outer container 110.

Since the selective oxidation reaction is exothermic, the temperature inside the reactor gradually increases while the reactants pass through the selective oxidation reactor 100. Therefore, the cooling water is not stagnant in the selective oxidation reactor 100, but is continuously introduced through the cooling water inlet 111 and continuously discharged through the cooling water outlet 112.

The guide member 120 is disposed inside the outer container 110 to cover an open portion of the outer container 110. The guide member 120 is formed to have a size smaller than the cross-sectional area of the outer container 110 so that the guide member 120 does not seal the outer container 110 and a gap is formed between the outer container 110. The reactant may be introduced into the selective oxidation reactor 100 through the gap.

Hereinafter, the specific structure of the selective oxidation reactor 100 will be described with reference to FIG. 2.

2 is an exploded perspective view of the selective oxidation reactor 100 shown in FIG.

The outer container 110 includes a hollow portion 113 with an upper and lower portion opened. Inside the outer container 110, the guide member 120, the upper plate 130, the tube 140, the lower plate 150 is disposed in combination.

The guide member 120 is disposed at the top of the components disposed inside the outer container 110 and the reactants are first contacted. The guide member 120 is disposed on the upper portion of the tube 140 so that the reactant does not directly enter the tube 140 so as to bypass the guide member 120.

The connection member 121 is disposed between the guide member 120 and the upper plate 130 to fix the position of the guide member 120. However, the present invention is not limited thereto, and the connection member 121 may be disposed between the guide member 120 and the tube 140 or may be disposed between the guide member 120 and the outer container 110. The connection member 121 not only fixes the position of the guide member 120 but also separates the guide member 120 from the inner circumferential surface of the outer container 110, the tube 140, and the upper plate 130, respectively. The connecting member 121 is preferably formed in a cross-linked form so as to pass the reactants as shown.

The upper plate 130 is disposed below the guide member 120. Water vapor contained in the reactant is cooled and condensed by the cooling water flowing under the upper plate 130 while contacting the upper plate 130. Therefore, the top plate 130 should be disposed at a height similar to the height of the drain pipe 114 so that water is easily discharged out of the outer container 110. The size of the upper plate 130 is preferably formed in the same size as the cross-sectional area of the outer container 110 to cover the hollow portion 113 of the outer container 110 so that the coolant inside the outer container 110 does not flow out. Do. The upper plate 130 has a through hole 131 to which the tube 140 is inserted and coupled.

The tube 140 is inserted into the through hole 131 of the upper plate 130 and coupled to the upper plate 130. The reactant is discharged downward through the tube 140, and carbon monoxide reacts with oxygen and is converted into carbon dioxide while passing through the tube 140. The inside of the tube 140 is filled with a catalyst for the selective oxidation of the reactants.

The lower plate 150 is disposed below the tube 140, and has a through hole 151 to allow the tube 140 to be coupled thereto. As shown in the drawing, when the tube 140 is formed in a cylindrical shape, the through holes 131 and 151 formed in the upper plate 130 and the lower plate 150 correspond to each other. However, in the case where the formation of the tube 140 is variously modified into a spiral shape to control the selective oxidation reaction in a limited space, the through holes 131 and 151 may not correspond to each other. The lower plate 150 is formed to have the same size as the cross-sectional area of the outer container 110 to cover the lower portion of the hollow portion 113 like the upper plate 130 so that the coolant inside the outer container 110 does not flow out. desirable.

In the selective oxidation reactor 100, the upper plate 130 and the lower plate 150 are coupled to the upper and lower portions of the outer container 110, respectively, and the tube 140 has a through hole formed in the upper plate 130 and the lower plate 150. By being coupled to the 131, 151, the cooling water filled in the hollow portion 113 is made so as not to leak to the upper and lower portions of the outer container (110). In addition, the inside and the outside of the tube 140 are spatially separated. Accordingly, the reactants passing through the inside of the tube 140 and the cooling water flowing outside the tube 140 do not mix with each other as they exchange heat with the tube 140 interposed therebetween.

Since the selective oxidation reaction is exothermic, the temperature of the reactant gradually increases as it passes through the tube 140. Accordingly, since the lower temperature of the tube 140 is higher than the upper temperature, the cooling water inlet 111 is preferably disposed below the outer container 110. In addition, the coolant outlet 112 is preferably disposed above the outer container 110 so that the coolant can cool the entire inside of the outer container 110.

Hereinafter, a process of passing the reactant through the selective oxidation reactor 100 will be described in detail with reference to FIG. 3.

3 is a cross-sectional view taken along the line III-III of FIG. 1.

The guide member 120 blocks a part of the hollow part 113 so that the reactant does not directly enter the tube 140. The reactants are introduced at the top of the selective oxidation reactor 100 and are in contact with additionally supplied air so that the selective oxidation reaction can take place. Carbon monoxide in the reactants is converted to carbon dioxide by binding to oxygen in the air. Reactant after the guide member 120 meets the flow path is changed in the transverse direction, through the gap formed between the inner circumferential surface of the outer container 110 and the guide member 120 is introduced into the outer container 110, the top plate 130 ).

The reactant introduced into the selective oxidation reactor 100 contains a large amount of water vapor. Therefore, when the reactant is introduced into the tube 140 together with water vapor, water vapor condenses in water in a section of 100 ° C. or less, so that the catalyst 142 existing inside the tube 140 may get wet. When the catalyst 142 is wet, the active area causing the reaction is reduced, so that the performance of the selective oxidation reactor 100 is reduced.

This problem can be solved by additionally passing the water recovery device before the reactant enters the reactor.However, if a separate water recovery device is installed, the volume and weight of the fuel cell system increase, making it difficult to use in an environment where space and installation weight are limited. there is a problem. Accordingly, the selective oxidation reactor 100 is formed to contact the top plate 130 before the reactant is introduced into the tube 140, the water contained in the reactant is condensed by the cooling water flowing under the top plate 130 It is made to separate from the reactants. The selective oxidation reactor 100 may prevent the catalyst 142 from getting wet during the selective oxidation reaction because water is separated from the reactants.

The tube 140 is coupled to the top plate 130 such that at least a portion thereof protrudes from the top plate 130. Since the reactants are moved by diffusion, the initially introduced reactants are subsequently moved toward the center of the upper plate 130 by being pushed by the introduced reactants. At this time, if the tube 140 does not protrude from the top plate 130, the reactant moved to the center will fall into the tube 140 as it is without having a sufficient cooling time.

In the selective oxidation reactor 100 of the present invention, the tube 140 includes a protrusion 141 protruding from the upper plate 130, so that the reactant moved to the center is not directly dropped into the tube 140, but is additionally introduced by the reactant. There is sufficient cooling time until it is pushed up to the inlet of the tube 140. Accordingly, the water vapor contained in the reactant may be sufficiently condensed and separated from the reactant.

The plurality of tubes 140 are disposed spaced apart from each other. As the reactants move by diffusion, some of the reactants may enter the adjacent tube 140, while some of the reactants may move between the tubes 140 without entering the adjacent tube 140. The plurality of tubes 140 disposed to be spaced apart from each other forms a space 143 through which reactants that do not flow into the tube 140 may contact the upper plate 130 again, thereby allowing continuous condensation to occur. .

The inside of the tube 140 is filled with a catalyst 142 for the selective oxidation reaction and the carbon monoxide contained in the reactant passes through the catalyst 142 and combines with oxygen to become carbon dioxide. In order for the selective oxidation reaction to occur continuously, the reaction temperature must be controlled. Therefore, the cooling water for controlling the reaction temperature flows around the tube 140.

Plugs 160a and 160b are disposed at the inlet and the outlet of the tube 140. The stoppers 160a and 160b have permeable pores of a smaller size than the catalyst 142 so as to prevent the catalyst 142 in the form of pellets filled inside the tube 140 from escaping. Permeable voids are formed irregularly, such that turbulence occurs in the reactants as they pass through a complex path.

The stopper 160a disposed at the inlet of the tube 140 maximizes mixing of the reactants by generating turbulence in the reactants so that a stable reaction occurs in the entire region of the selective oxidation reactor 100. Since the reactants include several different gases, it is necessary to mix before passing through the tube 140 for a stable reaction.

As the reactant passes through the tube 140, a selective oxidation reaction (CO + 0.5O ₂ ↔CO ₂ ) is performed together with the catalyst in the form of pellets 142 in the tube 140. When the temperature rises above 220 ° C., selective oxidation does not occur properly, and unintentional reactions occur. Thus, the coolant flowing around the tube 140 exchanges heat with the inside of the tube 140, thereby allowing the inside of the tube 140 to be 220 ° C. Keep within the following temperature range.

The stopper 160b disposed at the outlet of the tube 140 generates turbulence again in the gas passing through the catalyst 142 to increase the frequency of heat exchange with the cooling water and maximize the cooling effect. The stopper 160b disposed at the outlet of the tube 140 is disposed above the lower plate 150 so as to cool the product, unlike the stopper 160a disposed at the inlet. Since the coolant flows through the upper portion of the lower plate 150, the product may be cooled by the coolant flowing around the tube 140. At this time, the product is cooled to a temperature before contacting the top plate 130 so that the product can directly enter the next selective oxidation reactor 100 without further cooling.

Since the temperature of the product is discharged after cooling to the temperature of the reactant when discharged from the tube 140, it can be introduced directly to the other selective oxidation reactor 100 connected to the selective oxidation reactor 100 without additional cooling.

By the above configuration, if the temperature of the reactant flowing into the selective oxidation reactor 100 is set to 80 ~ 110 ℃, the temperature is gradually increased by the selective oxidation reaction which is exothermic while the reactant passes through the catalyst 142 To 150-220 ° C., and the product passed through the catalyst 142 is cooled again while passing through the stopper 160b disposed at the outlet of the tube 140, and has a temperature of 80-110 ° C. from the tube 140. May be discharged. As a result, in the selective oxidation reactor 100 of the present invention, the temperature of the incoming reactant and the discharged product are both within the temperature range of 80 to 110 ° C.

4 is a cross-sectional view of a selective oxidation reactor 200 according to another embodiment of the present invention.

The selective oxidation reactor 200 is generally similar to the selective oxidation reactor 100 shown in FIG. 3, but has a different shape of the guide member 220.

The guide member 220 is formed to be inclined to guide a reactant flowing from the top to a gap formed between the guide member 220 and the outer container 210. Since the reactants move downwards, the guide member 220 may guide the reactants to flow into the gap formed between the inner circumferential surface of the outer container 210 and the guide member 220 even if the reactant contacts any of the guide members 220. Can be. Accordingly, the reactant moving by diffusion may be prevented from being moved back to the upper portion of the guide member 220 by being pushed by the additionally introduced reactant.

5A and 5B are conceptual views comparing the selective oxidation reaction system 300 according to an embodiment of the present invention with the conventional one.

To remove large amounts of carbon monoxide from the reactants, the amount of catalyst present in the selective oxidation reactor must also be increased. The amount of air supplied to the selective oxidation reactor must also be increased in proportion to the amount of carbon monoxide. According to this need, the selective oxidation reactor is configured to implement a selective oxidation reaction system by connecting a plurality in series rather than using one. In this case, air is also supplied separately from the inlet of each selective oxidation reactor.

The selective oxidation reaction in which carbon monoxide combines with oxygen to form carbon dioxide is an exothermic reaction, so the temperature of the product is higher than the temperature of the reactant. Therefore, although it depends on the type of catalyst, generally, the selective oxidation reactor is designed such that the temperature of the gas passing through the selective oxidation reactor is 80-110 ° C. before the selective oxidation reaction occurs and 150-220 ° C. after the selective oxidation reaction occurs. Only sustained selective oxidation can occur.

If the reaction temperature is not properly controlled, unintended reactions occur, such as oxygen reacting with hydrogen contained in the reformed gas to produce water, or hydrogen and carbon reacting to produce methane. These unintended reactions quickly consume hydrogen, which is the fuel of the fuel cell, and cause a series of exothermic reactions, making the normal fuel cell impossible to use.

5A is a conceptual diagram illustrating a selective oxidation reaction system configured by connecting a conventional selective oxidation reactor in series and showing a graph of temperature change according to a gas position. The temperature rises to 150-220 ° C. by exothermic reaction while the reactants having a temperature of 80-110 ° C. pass through the first selective oxidation reactor. Therefore, in order for the gas passing through the first selective oxidation reactor to flow into the second selective oxidation reactor so that a normal selective oxidation reaction occurs, the gas must first be cooled to 80 to 110 ° C. through a heat exchanger. However, when a separate heat exchanger is included in the selective oxidation reaction system, the volume and weight of the entire system are increased, thereby making it impossible to use the selective oxidation reaction system in a confined space or in an environment where mounting weight is limited.

Conventional selective oxidation reactor can control the reaction temperature to maintain the temperature of the inlet and outlet of the reactor at 80 ~ 110 ℃, 150 ~ 220 ℃, respectively, but the temperature of the product formed up to 150 ~ 220 ℃ again 80 It could not be lowered to ˜110 ° C. If the temperature of the outlet is set to 80 ~ 110 ℃ only with the cooling water, the inlet is also correspondingly lowered to a temperature lower than 80 ~ 110 ℃ because it can not induce a normal selective oxidation reaction.

Figure 5b is a graph showing the temperature change according to the position of the gas and one embodiment of the selective oxidation reaction system 300 according to the present invention. The selective oxidation system 300 is configured by connecting the first selective oxidation reactor 310 and the second selective oxidation reactor 320 in series. The first selective oxidation reactor 310 and the second selective oxidation reactor 320 may be, for example, any one of the selective oxidation reactors 100 and 200 illustrated in FIG. 3 or 4. The selective oxidation reaction system 300 according to the present invention may be configured by connecting two or more selective oxidation reactors.

The reactant at the inlet of the first selective oxidation reactor 310 has a temperature of 80 ~ 110 ℃ for the selective oxidation reaction. The reactant rises to 150-220 ° C. by exothermic reaction while passing through the first selective oxidation reactor 310. Referring to FIG. 3 or 4, the gas passing through the catalysts 142 and 242 passes through the stoppers 160b and 260b before being discharged to the outside of the tubes 140 and 240, and the inlet temperature is 80 at the inlet temperature. Cool down to ˜110 ° C. Therefore, since the temperature of the gas discharged from the first selective oxidation reactor 310 has the same temperature range as that of the inlet of the first selective oxidation reactor 310, the gas may flow directly into the second selective oxidation reactor 320 without further cooling. Can be. This reaction is the same in the second selective oxidation reactor 320.

Accordingly, even if a heat exchanger for additional cooling is not installed between the first selective oxidation reactor 310 and the second selective oxidation reactor 320, the two selective oxidation reactors 310 and 320 may cause normal selective oxidation reactions. The selective oxidation reaction system 300 and the fuel cell can be used even in an environment where space and mounting weight are limited.

The selective oxidation reactor and the selective oxidation reaction system described above are not limited to the configuration and method of the above-described embodiments, but the embodiments may be selectively combined with each or all of the embodiments so that various modifications may be made. It may be configured.

Claims (7)

External container having a hollow portion is filled with the cooling water, the reactant is formed to enter and exit the top and bottom;
An upper plate installed on an inner circumferential surface of the outer container so as to cover the hollow part, and disposed to be spaced inwardly from the upper end and having a through hole;
A tube inserted into the through hole, the protrusion having a protrusion protruding from the upper plate, and filled with a catalyst causing a selective oxidation reaction of the reactant therein;
Installed inside the outer container, the inner circumferential surface of the outer container, so as to be spaced apart from one end of the upper plate and the tube so that the reactant is in contact with the top plate before the reactant flows into the protrusion to condense the water vapor contained in the reactant A guide member disposed; And
Selective oxidation reactor characterized in that it comprises a connecting member for connecting the guide member and the inner circumferential surface of the outer container, the upper plate, the tube to fix the position of the guide member. The method of claim 1,
The guide member is formed to be inclined to guide the reactant flowing from the upper portion of the guide member to be introduced into the gap between the guide member and the outer container. The method of claim 1,
Wherein the tubes are arranged so that a plurality of them are spaced apart from each other so that continuous condensation of the water vapor occurs to form a space in which the reactants can contact the top plate between the tubes. delete The method of claim 1,
Selective oxidation reactor further comprises a drain pipe connected to the top plate to discharge the water formed by condensing the water vapor to the outside of the outer container. The method of claim 1,
Respectively disposed at the inlet and the outlet of the tube to prevent the catalyst from escaping to the outside of the tube, and irregularly formed to generate turbulence in the reactant flowing into the protrusion and the gas passing through the catalyst. The selective oxidation reactor further comprises a stopper having permeable pores. A selective oxidation reaction is carried out to the incoming reactant to change carbon monoxide contained in the reactant into carbon dioxide, and the selective of any one of claims 1 to 3 and 5 to 6 so as to be connected in series. Including a plurality of oxidation reactors,
The gas passing through any one of the selective oxidation reactors is passed through a stopper disposed at the outlet of the tube prior to exiting the external container so that it can enter the next selective oxidation reactor without further cooling of the reactant by the cooling water. Selective oxidation system, characterized in that cooled to a temperature of 80 ~ 110 ℃.

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