JP2005028216A - Gas cleaning apparatus and flue gas desulfurization system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas cleaning apparatus capable of efficiently cleaning sulfur oxides and soot dust in a gas. <P>SOLUTION: The gas cleaning apparatus comprises a catalyst layer 107 provided in a cleaning tower 104 circulated with exhaust gas containing the sulfur oxides or produced gas 101 and formed with an active carbon fiber layer; and a water feeding means 111 provided in the cleaning tower 104 and feeding water for producing sulfuric acid to the catalyst layer 107. A first filter layer 151 for removing the soot dust in the gas 101 is provided at a gas upstream side of the catalyst layer 107 in the cleaning tower 104. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas purification device for removing sulfur oxide (SOx) and dust in exhaust gas discharged from a boiler, a gas turbine, an engine, a gasification furnace, an incinerator or the like that burns fuel such as coal or heavy oil. And to a flue gas desulfurization system.
[0002]
[Prior art]
Conventionally, as a method for removing sulfur oxides in exhaust gas, a lime-gypsum method has been employed in which limestone or slaked lime slurry is used as an absorbent and the sulfur content in the exhaust gas is recovered as gypsum. As another method, an adsorption method using dry activated carbon is known.
[0003]
In the conventional lime-gypsum method, the exhaust gas is humidified and cooled and SOx is absorbed simultaneously by spraying limestone or slaked lime slurry into the exhaust gas. For this reason, it is necessary to circulate a large amount of slurry, and power for circulating the slurry and a large amount of water are required.
[0004]
On the other hand, in the case of the dry method, a large amount of heat is required to desorb the sulfur adsorbed on the activated carbon by heating. Moreover, in this method, disposal of the produced dilute sulfuric acid, wear of the adsorbent, and the like become problems. Therefore, desulfurization that does not require a sulfur oxide absorbent or large equipment, can obtain high concentration sulfuric acid during desulfurization, and produces gypsum with low power using the same equipment as the lime gypsum method. The appearance of equipment is desired.
[0005]
For this reason, as a device for removing SOx in the exhaust gas, SOx in the exhaust gas is adsorbed on a porous carbon material such as activated carbon fiber, and the sulfur component is generated by oxygen contained in the exhaust gas by utilizing the catalytic action of the porous carbon material. It has been proposed to oxidize and remove it from the porous carbon material as sulfuric acid by absorbing it (Patent Document 1).
[0006]
In a conventional flue gas treatment apparatus using activated carbon fibers according to Patent Document 1, an activated carbon fiber tank for adsorbing SOx in exhaust gas is disposed in an adsorption tower and activated by supplying exhaust gas from below. SO on the surface of carbon fiber₂SO₃  Oxidized to form SO₃  Reacts with the supplied water to produce sulfuric acid (H₂  SO₄  ) Is generated.
[0007]
Here, the amount of exhaust gas from a boiler that burns fuel such as coal and heavy oil is enormous, and in the case of processing a large amount of this exhaust gas, it is necessary to improve the desulfurization efficiency. For this reason, it is essential to simply increase the size of the adsorption tower, but it is desired that the desulfurization reaction of the activated carbon fiber is efficient and the apparatus configuration of the desulfurization system is compact.
[0008]
In order to efficiently perform the catalytic action, the reaction is optimized and SO₂Oxidized SO₃It is necessary to remove the water efficiently using water and to uniformly add water with the minimum amount of water to avoid the increase in the size of ancillary equipment for supplying the water. It becomes.
[0009]
Furthermore, in recent years, it has been proposed to perform coal gasification fuel cell combined power generation as fuel for a fuel cell as well as simply diverting gas from a gasification furnace to a boiler (Patent Document 2).
[0010]
[Patent Document 1]
JP 11-347350 A
[Patent Document 2]
JP 2000-48444 A
[0011]
In such a fuel cell according to Patent Document 2, if a very small amount of S component is present in the gas, the electrode catalyst of the fuel cell is poisoned and causes deterioration. Therefore, the S component is removed to a very low concentration. It is hoped that.
Similarly, in the synthesis method of liquid fuels such as methanol and dimethyl ether using gasification gas, coal and biomass are gasified in a gasification furnace and then reformed into liquid fuel such as methanol and dimethyl ether using a catalyst. However, since the S component in the gas also causes poisoning to the catalyst of the reforming means, it is desired to remove it to a low concentration.
[0012]
Further, not only the S component but also dust (tar component, hydrocarbon) and the like present in the gas are required to be reduced to a very small amount when the gas is effectively used.
[0013]
In view of the above problems, an object of the present invention is to provide a gas purification device and a flue gas desulfurization system that can efficiently purify sulfur oxides and dust in a gas.
[0014]
[Means for Solving the Problems]
A first invention that solves the above-described problem is provided in a purification tower in which an exhaust gas or a product gas containing a sulfur oxide flows, and is provided in a catalyst layer formed of an activated carbon fiber layer, and in the purification tower. In the gas purification apparatus comprising water supply means for supplying sulfuric acid-producing water to the catalyst layer, the gas purification device is provided in the purification tower, and removes dust in the gas upstream of the catalyst layer. 1 is a gas purification device comprising a filter layer.
[0015]
According to a second aspect of the present invention, there is provided the gas purification apparatus according to the first aspect, further comprising a sulfuric acid circulation means for circulating the sulfuric acid produced in the catalyst layer in the purification tower.
[0016]
According to a third aspect of the present invention, there is provided the gas purification apparatus according to the first or second aspect, further comprising a heating means for heating the first filter layer.
[0017]
A fourth invention is the gas purification apparatus according to any one of the first to third inventions, wherein a second filter layer is provided on the exhaust gas downstream side of the catalyst layer.
[0018]
A fifth invention is the gas purification apparatus according to any one of the first to fourth inventions, wherein the first filter layer and the second filter layer are formed of activated carbon fibers.
[0019]
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a moisture increasing means for supplying moisture to the gas is provided, and a moisture amount (moisture / humidified gas) when contacting the catalyst layer is saturated. The gas purification apparatus is characterized in that the amount of water vapor is +0.5 to 10% by volume.
[0020]
A seventh invention is the gas purification apparatus according to any one of the first to sixth inventions, wherein the humidification temperature is 60 ° C. or higher.
[0021]
An eighth invention is the gas purification apparatus according to any one of the first to seventh inventions, wherein the mist particle size in the gas for increasing the humidity is 10 to 150 μm.
[0022]
A ninth invention is the gas purification apparatus according to any one of the first to eighth inventions, wherein the flow rate of the humidified gas into the purification tower is 0.5 to 10 m / s. It is in.
[0023]
A tenth aspect of the invention is the gas purification apparatus according to any one of the first to ninth aspects, wherein the particle size of the added water supplied from the water supply means or the circulating diluted sulfuric acid is 100 to 1000 μm. is there.
[0024]
In an eleventh aspect of the invention, in any one of the first to tenth aspects of the invention, the supply amount of the added water supplied from the water supply means or the circulating dilute sulfuric acid is 5 to 50 ml / m³The gas purification apparatus is characterized by being a gas.
[0025]
A twelfth aspect of the present invention is the gas purification apparatus according to any one of the first to eleventh aspects, wherein the catalyst layer is laminated in a plurality of stages by a support device.
[0026]
In a thirteenth aspect of the present invention based on any one of the first to twelfth aspects of the present invention, a gas inlet is provided at the lower part of the tower, and a water supply device for generating sulfuric acid is provided above the catalyst layer provided in the tower. The gas purification apparatus is characterized by the above.
[0027]
A fourteenth aspect of the invention is obtained by using any one of the first to thirteenth gas purification apparatuses, a gypsum reaction tank for reacting the dilute sulfuric acid and the lime slurry from the gas purification apparatus to obtain a gypsum slurry, and the gypsum reaction tank. And a dehydrator for separating the water from the obtained gypsum to obtain gypsum.
[0028]
A fifteenth aspect of the present invention is a flue gas desulfurization system comprising any one of the first to thirteenth gas purification devices and a concentration tank for concentrating dilute sulfuric acid obtained by the gas purification device. .
[0029]
A sixteenth aspect of the invention is characterized by comprising any one of the first to thirteenth gas purification devices and reforming means for reforming the purified gas obtained by the gas purification device into a liquid fuel. Located in smoke desulfurization system.
[0030]
According to a seventeenth aspect of the present invention, there is provided a flue gas desulfurization system comprising any one of the first to thirteenth gas purification apparatuses and a fuel cell using the purified gas obtained by the gas purification apparatus as a fuel. It is in.
[0031]
An eighteenth invention is the gas according to any one of the fourteenth to seventeenth inventions, wherein the gas is a gas discharged from a boiler, a gas turbine, an engine, a gasification furnace, and various incinerators, and removes dust in the gas. A flue gas desulfurization system comprising dust removal means.
[0032]
A nineteenth aspect of the invention is an exhaust gas desulfurization system according to the eighteenth aspect of the invention, wherein the gas is a product gas from a coal gasification furnace and is used as a fuel cell gas for a coal gasification fuel cell combined power generation. .
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Although the form of this invention is demonstrated below, this invention is not limited to these embodiment.
[0034]
[First Embodiment]
Here, a method for desulfurizing sulfur oxide in exhaust gas will be described with reference to FIG.
As shown in FIG. 1, a catalyst layer 107 formed of an activated carbon fiber layer is provided in a purification tower 104 through which an exhaust gas containing sulfur oxide or a product gas 101 flows, and is provided in the purification tower 104. In the gas purification apparatus comprising the water supply means 111 for supplying the catalyst layer 107 with water for generating sulfuric acid, the dust is contained in the gas 101 provided in the purification tower 104 and on the gas upstream side of the catalyst layer 107. The first filter layer 151 for removing the film is provided.
By providing the first filter layer 151, the dust in the gas 101 is removed in the upstream flow introduced into the catalyst layer 107.
[0035]
The first filter layer 151 that collects or adheres the dust is sprinkled by the water supply means 111 by a circulation pump 152 that circulates dilute sulfuric acid 106 generated by oxidation of the catalyst layer 107 accumulated in the lower part of the purification tower 104. By supplying dilute sulfuric acid through circulation from the nozzle 122, it is concentrated to the dilute sulfuric acid concentration by the catalyst, and soot and dust adhering to the first filter layer 151 is decomposed and removed.
In order to circulate the dilute sulfuric acid 106, a switching valve 153 is installed in the passage of the water supply means 111 so as to switch as necessary.
[0036]
Although the material of the first filter layer 151 is not particularly limited, it is desirable that the first filter layer 151 be an activated carbon fiber having an action described later. That is, by using activated carbon fiber, it is possible to promote deoxidation of sulfur oxide in the gas as well as dust removal in the gas 101, and desulfurize.
[0037]
That is, according to the present apparatus, for example, the exhaust gas 101 discharged from a boiler or the like is sent from the pushing fan 121 and purified from the introduction portion of the lower side wall through the humidification cooling device 116 that cools the exhaust gas temperature and applies humidity. It is introduced into the tower 104. First, in the introduced gas 101, dust in the gas is removed in the first filter layer 151. Next, on the downstream side of the first filter layer 151, a catalyst tank 107 formed of an activated carbon fiber layer is provided, and in the catalyst tank 107, water 105 for sulfuric acid generation is supplied with a water tank 111a and a supply pump 111b. It is supplied from the water supply means 111 consisting of The water 105 from the supply means 111 is supplied from the upper part, and the gas 101 is passed through the catalyst tank 107 from the lower part, so that SOx is removed from the gas 101 by reaction. The purified gas 109 that has passed through the catalyst tank 107 is discharged from the discharge section at the upper part of the purification tower 104, and is released to the atmosphere through a chimney.
[0038]
The catalyst tank 107 includes a catalyst composed of a plurality of activated carbon fiber layers, and a desulfurization reaction occurs on the surface of each activated carbon fiber layer by, for example, the following reaction.
(1) SO2 in the exhaust gas to the activated carbon fiber layer of the catalyst₂Adsorption.
(2) Adsorbed sulfur dioxide SO₂And oxygen in exhaust gas O₂SO3 by reaction with (which can be supplied separately)₃Oxidation to.
(3) Oxidized sulfur trioxide SO₃Water H₂Sulfuric acid H by dissolution in O₂SO₄Generation.
(4) Produced sulfuric acid H₂SO₄Detachment from the activated carbon fiber layer.
[0039]
The reaction formula at this time is as follows.
SO₂+ 1 / 2O₂+ H₂O → H₂SO₄
[0040]
In this way, sulfur dioxide (SO 2) of the gas 101 in the activated carbon fiber layer of the catalyst tank 107.₂) Is adsorbed and oxidized to form water (H₂O) and sulfuric acid (H₂SO₄) Is generated and removed to perform desulfurization in the exhaust gas.
A schematic diagram of this desulfurization is shown in FIG.
[0041]
Here, an example of the activated carbon fiber used in the catalyst tank 107 of the present invention and an example of its production are shown below.
Examples of the activated carbon fiber used in the present invention include pitch-based activated carbon fiber, polyacrylonitrile-based activated carbon fiber, phenol-based activated carbon fiber, and cellulose-based activated carbon fiber, but the present invention is limited to these. However, the activated carbon fibers exhibiting the above catalytic action are not limited in any way.
[0042]
Specific production examples are shown below.
(Production Example 1)
A phenol-based activated carbon fiber (“Kractive 20”, manufactured by Kuraray Chemical Co., Ltd.) is used, and this is fired in a nitrogen atmosphere at a temperature range of 900 to 1200 ° C. for 1 hour.
[0043]
(Production Example 2)
Polyacrylonitrile-based activated carbon fiber (“FX-600”, manufactured by Toho Rayon Co., Ltd.) is used, and this is fired in a nitrogen atmosphere at a temperature range of 900 to 1200 ° C. for 1 hour.
[0044]
FIG. 3 is a perspective view of the activated carbon fiber layer disposed in the purification tower 104 according to the present embodiment.
[0045]
As shown in FIG. 3, the activated carbon fiber layer 125 forming one unit of the catalyst tank 107 is formed by alternately laminating flat plate-like activated carbon fiber sheets 126 and corrugated plate-like corrugated activated carbon fiber sheets 127. The linear space formed between them becomes the passage 128, and the passage 128 extends vertically.
The flat activated carbon fiber sheet 126 and the corrugated activated carbon fiber sheet 127 are plate-like, and the corrugated active carbon fiber sheet 127 is further formed into a corrugated shape using, for example, a corrugator.
In addition to the corrugated plate shape, the exhaust gas may be formed into a shape that passes in parallel to the activated carbon fiber sheet, such as a honeycomb shape.
[0046]
As shown in FIG. 1, water is supplied from the watering nozzle 122 in the form of a spray and the gas 101 is sent from below, and the water 105 circulated through the activated carbon fiber layer 125 has a particle size of about several millimeters. Fall to the bottom.
And since the gas 101 distribute | circulates the channel | path 128 formed by laminating | stacking alternately the flat activated carbon fiber sheet 126 and the corrugated activated carbon fiber sheet 127, the increase in pressure loss is suppressed. .
[0047]
In order to dispose the catalyst layer 107 in the purification tower, first, an activated carbon fiber layer 125 laminated in a frame (not shown) is filled and a catalyst tank (for example, 0.5 to 4 m in height) is filled. The catalyst tank is installed in the purification tower 104 by, for example, lifting means. At this time, the catalyst layer 107 may be provided in a plurality of stages.
[0048]
In addition, when the first filter layer 151 is activated carbon fiber, the diameter of the passage 128 may be reduced. In addition, a filter may be disposed so as to be orthogonal to the gas, or a certain angle may be provided.
[0049]
Here, the amount of water (moisture / humidified exhaust gas) when the gas 101 in the purification tower 104 according to the present embodiment comes into contact with the catalyst tank is the amount of saturated water vapor +0.5 to 10, preferably saturated water vapor. The amount is preferably set to 1.0 to 1.5% by volume. The saturated water vapor amount is, for example, 12.2% by volume (50 ° C.) at 50 ° C.
The saturated water vapor amount at 40 ° C. is 7.3% by volume, and the saturated water vapor amount at 60 ° C. is 19.7% by volume. This is because desulfurization of sulfuric acid in the desulfurization action as described above is not performed well below the saturation amount. For this reason, as shown in FIG. 1, a saturated water vapor amount exceeding a certain level is obtained by using a humidified cooling device 116 that supplies a humidified cooling water 115 to the gas 101 before being supplied to the purification tower 104. .
[0050]
Further, the cooling temperature of the humidified cooling may be appropriately determined depending on the relationship between the temperature of the exhaust gas and the amount of water, but in the case of normal desulfurization, for example, it is preferably 40 to 60 ° C. This is because when the temperature exceeds 60 ° C., the evaporation amount of water increases, the amount of water supply increases, and the processing cost increases. On the other hand, when the temperature is lower than 40 ° C., the temperature cannot be lowered below that in the case of humidified cooling for general exhaust gas.
[0051]
On the other hand, when positively decomposing and removing soot using the first filter layer 151, the temperature is preferably 60 ° C. or higher. This is because the decomposition of the dust attached to the first filter layer 151 is promoted.
In addition, what is necessary is just to use well-known measuring means, such as a filter paper method and a laser method, for the measurement of soot dust.
[0052]
That is, when the gas 101 is supplied into the purification tower 104 in a state in which the moisture is saturated by the humidification cooling of the humidification cooling device 116 and is brought into contact with the catalyst tank 107, the exhaust gas moisture amount is set to the saturated steam amount +0. 5 to 10 (preferably saturated water vapor amount +1.0 to 1.5% by volume), so that SO on the catalyst surface₂Produced by oxidation of₃Detachment proceeds rapidly. As a result, since sulfuric acid does not remain on the surface of the activated carbon fiber, the active sites are effectively used and the desulfurization efficiency is improved.
[0053]
Here, in FIG. 1, the gas 101 is supplied from the lower side of the tower. In this case, since the mist that is water may remain in the lower part of the tower, the moisture content of the exhaust gas is the saturated steam quantity +0.5 to It is necessary to slightly increase the amount of water from the watering nozzle 122 so as to be 10 (preferably saturated water vapor amount +1.0 to 1.5% by volume).
On the other hand, unlike the apparatus configuration of FIG. 1, when the exhaust gas 101 is lowered from the upper side of the tower, the mist is also supplied to the catalyst tank 107, so that the amount of water spray is reduced as compared with the case shown in FIG. May be possible.
[0054]
In any case, it is important that the exhaust gas is equal to or higher than saturated steam, and in particular, by making the saturated steam amount +1.0 to 1.5% by volume, an extremely efficient hydration activity as a catalyst. It can be applied to the surface of the carbon fiber.
That is, with only the saturated water vapor amount, SO₂  Oxidized SO₃  Is insufficient to desorb as sulfuric acid due to moisture, and if the amount of saturated steam + 1.5% by volume is exceeded, the amount of moisture becomes excessive, dilute sulfuric acid is further diluted, and the amount of water used is Increases and becomes unfavorable. Furthermore, when the amount of water is large, as a result of covering the active points on the surface of the activated carbon fiber, the function as a catalyst cannot function, and as a result, the desulfurization efficiency is lowered.
[0055]
The relationship between saturated steam and steam mist is not clear, but SO₂Oxidized SO₃When water is discharged as sulfuric acid, if the water is insufficient, it cannot be discharged as sulfuric acid and the next SO₂Is insufficiently oxidized. On the other hand, if the water is excessive, the sulfuric acid is diluted. Furthermore, when moisture becomes excessive, for example, when a water film or a water wall is formed on the surface of the activated carbon fiber, the activated point of the activated carbon fiber is covered.₂Thus, the catalyst cannot be desulfurized and the desulfurization efficiency is lowered.
Therefore, when the amount of water (moisture / humidified exhaust gas) when the exhaust gas comes into contact with the catalyst tank as in the present invention is set to the saturated water vapor amount +1.0 to 1.5% by volume, the water droplets are intermittently shaped like a ball. As a result, the water is supplied to the activated carbon fiber surface without excess or deficiency, and the desulfurization of sulfuric acid is efficiently performed. As a result, the desulfurization of the exhaust gas is effectively performed.
[0056]
The particle size of the cooling water supplied from the watering nozzle 122 as the water supply means is preferably 300 to 1000 μm. This is because if the above range is exceeded, effective moisture cannot be supplied on the surface of the activated carbon fiber, and the desorption action of sulfuric acid does not proceed well, which is not preferable. In particular, when the exhaust gas is supplied from the lower side, the mist-like water from the watering nozzle 122 rises and it becomes impossible to supply a good moisture. On the other hand, if the water particle size is too large, it becomes a water wall state, and although it is possible to desorb sulfuric acid, the active sites do not surface and the desulfurization reaction does not proceed, which is not preferable.
[0057]
For this purpose, the supply amount of water 105 supplied from the water supply means 111 is preferably 5 to 50 ml / m when the flow rate of the gas 101 into the purification tower is 0.5 to 5 m / s.³  It is good to use exhaust gas.
[0058]
Moreover, it is preferable that the mist particle size in the exhaust gas humidified and cooled by the humidification cooling device 116 is 50 to 150 μm. If it is less than 50 μm, moisture evaporation in the exhaust gas proceeds immediately before introduction into the purification tower 104, and if it exceeds 150 μm, moisture will adhere to the pipe, It is because it is not preferable.
[0059]
Here, a mist catcher (not shown) for replenishing the mist may be provided. By providing this mist catcher, it is possible to suppress the introduction of moisture into the purification tower, and the sulfuric acid produced by the desulfurization in the catalyst tank 107 is not diluted.
[0060]
The flow rate of the gas 101 subjected to the humidification cooling into the purification tower is 0.5 to 5 m / s, preferably 1 to 3 m / s. This is because the pressure loss increases when the flow velocity is faster than 5 m / s, while the installation area is increased when the flow velocity is less than 0.5 m / s, both are not preferable.
[0061]
In addition to adjusting the temperature of the gas passing through the first filter layer 151 by the humidification cooling device 116 to increase the temperature, a heating means 154 such as a heater is provided as shown in FIG. That's fine. By heating with the heating means 154, the dust attached to the first filter layer 151 may be decomposed. It is possible to efficiently decompose soot dust by the synergistic effect of sulfuric acid produced by desulfurization and heating.
[0062]
In addition, although heating is so preferable that it is high temperature, it is preferable from a durable point that it is below the heat-resistant temperature of the binder which comprises activated carbon fiber.
As an example, since the melting temperature of the binder is about 110 ° C., when activated carbon fiber is used for the first filter layer 151, it is desirable to heat at 110 ° C. or less.
[0063]
[Second Embodiment]
Next, the system which processes exhaust gas using the gas purification apparatus mentioned above is demonstrated with reference to FIG.
As shown in FIG. 5, a boiler 200 that generates steam for driving a steam turbine, a dust remover 201 that removes the dust in the exhaust gas 101 from the boiler 200, and the dust exhaust gas supplied to the purification tower 104. A push-in fan 121, a humidifying / cooling device 116 for cooling and increasing the humidity of the exhaust gas 101 before supplying to the tower, a first filter 151 and a catalyst layer 107 are arranged inside, and an inlet at the bottom wall of the tower is provided. The exhaust gas 101 is supplied from 104a and water is supplied from above the catalyst layer 107 by the watering nozzle 122, so that SOx in the exhaust gas is diluted with dilute sulfuric acid (H₂SO₄), A chimney 202 for exhausting the desulfurized purified gas from the exhaust port 104b at the top of the tower to the outside, and dilute sulfuric acid (H) from the purification tower 104 via the pump 108.₂SO₄) 106 is stored and a lime slurry 211 is supplied to precipitate gypsum, a gypsum reaction tank 212 for precipitating gypsum, a thickener 213 for precipitating gypsum, and water is removed from the gypsum slurry 214 as drainage (filtrate) 217. And a dehydrator 216 for obtaining gypsum 215. Note that a mist eliminator 203 may be interposed in the line for discharging the purified purified gas 109 discharged from the purification tower 104, if necessary, so that moisture in the gas is separated.
[0064]
Here, in the boiler 200, for example, fuel f such as coal and heavy oil is burned in a furnace in order to generate steam for driving a steam turbine (not shown) of the thermal power generation facility. The exhaust gas of the boiler 200 contains sulfur oxide (SOx). The exhaust gas is denitrated by a denitration device (not shown), cooled by a gas gas heater, and then dedusted by a dust collector 201.
[0065]
In this exhaust gas purification system, the lime slurry 211 is supplied to the dilute sulfuric acid 106 obtained in the purification tower 104 to obtain the gypsum slurry 214, and then dehydrated and used as the gypsum 215. The diluted sulfuric acid 106 may be used as it is as sulfuric acid.
[0066]
[Third Embodiment]
Next, a system for treating exhaust gas using the above-described gas purification device means will be described with reference to FIG. In the third embodiment, the second filter layer 161 is disposed between the watering nozzle 122 and the catalyst layer 107 of the purification tower 104 in the purification device of the second embodiment. The second filter 161 is made of the above-mentioned activated carbon fiber, and the passage is bent so as to positively collide with the passage wall surface when gas passes.
By disposing the second filter layer 161, SO that is a sulfur oxide not captured by the catalyst layer 107 is obtained.₃Are actively caught and removed.
As shown in FIG. 2, the SO in the gas₂Is activated by the catalytic action of activated carbon fiber.₃Is oxidized to SO₃Is suspended in the form of a mist in the gas and has a large mass inertia, and may not be caught by contact with activated carbon fiber. Therefore, the floating mist-like SO that has passed through the catalyst layer 107₃In the second filter layer 161, so that the floating mist SO₃Is dilute sulfuric acid.
As a result, the sulfur oxide component (so-called S component) in the purified gas 109 is almost completely removed.
The second filter is a mist-like SO₃In addition to the passage being bent, the activated carbon fiber sheet is provided with a plurality of pores, and the plurality of pores are formed so that the pores overlap each other. You may make it laminate | stack the sheet-like activated carbon fiber which has.
[0067]
Such purified gas 109 does not poison the fuel electrode catalyst of the fuel cell, and may poison the reforming catalyst in gas reforming to liquid fuel such as methanol and dimethyl ether. Absent.
Note that the second filter layer 161 may be provided either before or after the first filter layer 151.
[0068]
[Fourth Embodiment]
FIG. 7 is a schematic diagram of a coal gasifier fuel cell combined power generation system.
As shown in FIG. 7, a coal gasifier fuel cell combined power generation system includes a coal gasifier, a fuel cell that uses the produced gas obtained in the gasifier as fuel, and exhaust gas from the fuel cell. It is a system that uses a turbine and a steam turbine for efficient power generation.
[0069]
Here, the fuel supply system 1 to the combustor 52 will be described. First, the coal 2 is partially oxidized in the coal gasification furnace 3 to generate coal gasification gas as fuel. Note that oxygen for oxidation in the coal gasification furnace 3 flows into the air separation device 7 through the pipe 15 and flows into the air separation device 7 through the compressed air flowing out from the air compressor 51 of the gas turbine system. , Sent through the pipe 16. The discharged coal gasification gas flows into the dedusting device 4 through the pipe 11 to be purified, and then flows into the purification tower 104, which is a gas purification device, through the pipe 12, and is desulfurized. 13 is introduced into a fuel cell 6 (in this embodiment, a solid oxide fuel cell (hereinafter referred to as “SOFC”)) 6. On the other hand, compressed air is also introduced into the SOFC 6 from the air compressor 51 through the pipes 15 and 17. The coal gasification gas and the compressed air introduced into the SOFC 6 are introduced into the combustor 52 through the pipes 14 and 18 after operating the SOFC 6. At this time, since the temperatures of the coal gasification gas and the compressed air flowing out from the SOFC 6 are increased, the combustion temperature in the combustor 52 is increased as described above, and the efficiency of the turbine is increased as the exhaust gas temperature is increased. ing.
[0070]
The gas turbine system 50 includes an air compressor 51 that takes in and compresses air 54, a combustor 52 that receives and burns compressed air flowing out from the air compressor 51 and fuel from the fuel supply system 1, and the combustor 52. It comprises a gas turbine 53 that performs work with the combustion gas from and a generator 55 that is coupled to the gas turbine 53 and the air compressor 51 in a single axis.
[0071]
The exhaust gas from the gas turbine 53 is recovered by an exhaust gas recovery boiler (not shown), and steam is generated using the heat of the exhaust gas. The generated steam is supplied to the steam turbine 61 of the steam turbine system 60 and is discharged from the chimney 63 after performing work. Note that a generator 62 is coupled to the steam turbine on one axis.
[0072]
As described above, the combined power plant in which the gas turbine system 50 and the steam turbine system 60 are combined is 10% more efficient than the power plant having only the gas turbine.
[0073]
On the other hand, when the fuel for combustion is supplied to the combustor 52 via the fuel cell 6 or the like, the exhaust gas temperature after power generation in the fuel cell is kept high, thereby increasing the temperature of the exhaust gas from the combustor 52, It has been found that the efficiency of the turbine is improved. And in the combined power plant, the efficiency when the fuel cell is used is improved by 15% in the whole plant.
At this time, by using the gas purification apparatus according to the present invention as a purification means for purifying the generated gas from the coal gasification furnace 3, sulfur oxide and soot as a generated gas component are extremely reduced. There is no poisoning, a decrease in power generation efficiency can be prevented, and power generation can be performed stably over a long period of time.
[0074]
[Fifth Embodiment]
FIG. 8 is a schematic view of a fuel synthesis system having a biomass gasification furnace.
As shown in FIG. 8, a fuel synthesis system having a biomass gasification furnace includes a gasification furnace 61 that gasifies an organic fuel 60 such as biomass, and soot and dust in the product gas obtained in the gasification furnace 61. A dust removing device 63 that removes sulfur, a purification tower 104 that is a gas purification device that removes sulfur oxides in the gas after dust removal, and a fuel reforming means that synthesizes liquid fuel such as methanol from the purified gas using a catalyst. And a certain liquid fuel synthesizing device 64.
According to this system, even in a method for synthesizing liquid fuel such as methanol and dimethyl ether using gasification gas, biomass or the like is gasified in the gasification furnace 61 and then purified by the purification tower 104 to cause a catalyst poisoning substance. Since the S component in a certain gas is removed, the synthesis efficiency is improved.
[0075]
【The invention's effect】
As described above, according to the present invention, the catalyst layer formed by the activated carbon fiber layer is provided in the purification tower through which the exhaust gas or product gas containing sulfur oxide flows, and is provided in the purification tower. In the gas purification apparatus comprising water supply means for supplying sulfuric acid-producing water to the catalyst layer, the gas purification device is provided in the purification tower, and removes dust in the gas upstream of the catalyst layer. Since one filter layer is provided, the dust in the gas can be efficiently removed. Further, by providing a second filter layer in the purification tower, a mist-like SO₃Can be efficiently removed. As a result, even if the purified gas is used for reforming, the reforming catalyst is not poisoned. Even when the purified gas is used for fuel cell combined power generation, the fuel cell catalyst is not poisoned, and high power generation efficiency can be stably maintained over a long period of time.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a purification tower according to the present embodiment.
FIG. 2 is a schematic diagram showing a desulfurization reaction.
FIG. 3 is a perspective view of an activated carbon fiber layer according to the present embodiment.
FIG. 4 is a schematic diagram of a purification tower according to another embodiment of the present embodiment.
FIG. 5 is a schematic view of an exhaust gas treatment system according to the present embodiment.
FIG. 6 is a schematic diagram of an exhaust gas treatment system of another embodiment according to the present embodiment.
FIG. 7 is a configuration diagram of a coal gasification fuel cell combined power generation system.
FIG. 8 is a schematic view of a fuel synthesis system having a biomass gasification furnace.
[Explanation of symbols]
101 Exhaust gas or product gas (gas)
104 Purification tower
107 catalyst layer
111 Water supply means
151 First filter layer
152 Circulation pump
153 Switching valve
161 Second filter layer

Claims (19)

Provided in a purification tower through which exhaust gas containing sulfur oxides or product gas flows, and a catalyst layer formed of an activated carbon fiber layer, provided in the purification tower, and water for sulfuric acid generation is provided in the catalyst layer. In a gas purification device comprising water supply means for supplying,
A gas purification apparatus provided in the purification tower, wherein a first filter layer for removing dust in the gas is provided on the gas upstream side of the catalyst layer. In claim 1,
A gas purification apparatus comprising a sulfuric acid circulation means for circulating sulfuric acid produced in the catalyst layer in a purification tower. In claim 1 or 2,
A gas purification apparatus comprising a heating means for heating the first filter layer. In any one of Claims 1 thru | or 3,
A gas purification apparatus comprising a second filter layer on the exhaust gas downstream side of the catalyst layer. In any one of Claims 1 thru | or 4,
The gas purification apparatus, wherein the first filter layer and the second filter layer are formed of activated carbon fibers. In any one of Claims 1 thru | or 5,
Gas purification characterized in that a moisture increasing means for supplying moisture to the gas is provided, and the amount of moisture (moisture / humidified gas) in contact with the catalyst layer is saturated water vapor amount +0.5 to 10% by volume apparatus. In any one of Claims 1 thru | or 6,
The gas purification apparatus, wherein the humidification temperature is 60 ° C or higher. In any one of Claims 1 thru | or 7,
A gas purification apparatus, wherein the mist particle size in the gas for increasing the humidity is 10 to 150 μm. In any one of Claims 1 to 8,
A gas purification apparatus, wherein the flow rate of the humidified gas into the purification tower is 0.5 to 10 m / s. In any one of Claims 1 thru | or 9,
A gas purifier having a particle size of 100 to 1000 μm of added water supplied from the water supply means or circulating dilute sulfuric acid. In any one of Claims 1 thru | or 10,
The gas purification apparatus, wherein the supply amount of the added water supplied from the water supply means or the circulating diluted sulfuric acid is 5 to 50 ml / m ³ gas. In any one of Claims 1 thru | or 11,
A gas purification apparatus, wherein the catalyst layer is laminated in a plurality of stages by a support device. In any one of claims 1 to 12,
A gas purification apparatus having a gas inlet at the bottom of the tower and a water supply device for sulfuric acid generation above a catalyst layer provided in the tower. A gas purification device according to any one of claims 1 to 13,
A gypsum reaction tank for reacting dilute sulfuric acid and lime slurry from the gas purification device to obtain a gypsum slurry;
A flue gas desulfurization system comprising: a dehydrator for separating water from gypsum obtained by the gypsum reaction tank to obtain gypsum. A gas purification device according to any one of claims 1 to 13,
A flue gas desulfurization system comprising a concentration tank for concentrating dilute sulfuric acid obtained by the gas purification device. A gas purification device according to any one of claims 1 to 13,
A flue gas desulfurization system comprising: reforming means for reforming the purified gas obtained by the gas purification device into a liquid fuel. A gas purification device according to any one of claims 1 to 13,
A flue gas desulfurization system comprising: a fuel cell that uses the purified gas obtained by the gas purification device as fuel. In any one of Claims 14 thru | or 17,
A flue gas desulfurization system comprising dust removal means for removing the dust in the gas, wherein the gas is a gas discharged from a boiler, a gas turbine, an engine, a gasification furnace, and various incinerators. In claim 18,
A flue gas desulfurization system, wherein the gas is a generated gas from a coal gasification furnace and is used as a fuel cell gas for a combined coal gasification fuel cell power generation.

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