JP4690698B2 - Smoke removal equipment - Google Patents

Description

The present invention relates to a flue gas treatment apparatus that can be performed continuously over the exhaust gas treatment in a long period of time.

  Conventionally, carbon materials such as activated carbon have been used for the removal of impurities, odorous substances, coloring substances, harmful substances, etc. present in the gas phase or liquid phase, and separation of gases and liquids.

  Examples of such carbon materials include adsorbents such as activated carbon and activated carbon fibers, and such adsorbents are used to treat exhaust gas from boilers and the like.

A flue gas treatment system that performs such exhaust gas treatment will be described with reference to FIG. As shown in FIG. 11, 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 exhaust gas that has been dust-removed is supplied into the purification tower 104. An intrusion fan 121, a humidification cooling device 116 for cooling and increasing the humidity of the exhaust gas 101 before being supplied to the tower, and a catalyst tank 107 are disposed inside, and the exhaust gas 101 is supplied from the inlet 104a on the lower side wall of the tower. At the same time, water is supplied from above the catalyst tank 107 with a water spray nozzle 122 to desulfurize SOx in the exhaust gas up to dilute sulfuric acid (H ₂ SO ₄ ), and desulfurized from the exhaust section 104b at the top of the tower and a chimney 202 for the purge gas 109 discharged outside the purification column 104 from the via pump 108 dilute sulfuric acid (H ₂ SO ₄₎ 106 lime slurry 21 with storing A gypsum reaction tank 212 for precipitating gypsum, a settling tank (thickener) 213 for precipitating gypsum, and a dehydrator 216 for removing gypsum slurry 214 as drainage (filtrate) 217 to obtain gypsum 215. Prepare. 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.

  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), and the exhaust gas 101 is denitrated by a denitration device (not shown), cooled by a gas gas heater, and then dedusted by a dust remover 201.

  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 to be used as the gypsum 215. The dilute sulfuric acid 106 may be used as sulfuric acid as it is.

  Here, the details of the purification tower 104 will be described with reference to FIG. As shown in FIG. 12, for example, exhaust gas 101 discharged from a boiler or the like is sent by a pushing fan 121, and cools the exhaust gas temperature by the humidified cooling water 115 and passes through a humidifying cooling device 116 that applies humidity to the lower side wall. Are introduced into the purification tower 104 from the introduction part. Inside the purification tower 104, a catalyst tank 107 formed of an activated carbon fiber layer is provided. In the catalyst tank 107, water 105 for generating sulfuric acid is supplied from a water supply means 111 including a water tank 111a and a supply pump 111b. Supplied. Water 105 from the water supply means 111 is supplied from the upper part through the watering nozzle 122, and the exhaust gas 101 is passed through the catalyst tank 107 from the lower part, whereby SOx is reacted and removed from the exhaust gas 101. 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. In FIG. 12, reference numeral 124 denotes a rectifying plate provided with a dispersion hole 123 for rectifying the exhaust gas.

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 activated carbon fiber sheets 127. The straight space 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.
On the surface of the activated carbon fiber layer of the catalyst tank 107, for example, a desulfurization reaction occurs by the following reaction.
That is,
(1) Adsorption of sulfur dioxide SO _{2 in} the exhaust gas onto the activated carbon fiber layer of the catalyst.
(2) Oxidation to sulfur trioxide SO ₃ by reaction between adsorbed sulfur dioxide SO ₂ and oxygen O ₂ in the exhaust gas (which can be supplied separately).
(3) Production of sulfuric acid H ₂ SO ₄ by dissolving oxidized sulfur trioxide SO ₃ in water H ₂ O.
(4) Release of the produced sulfuric acid H ₂ SO _{4 from} the activated carbon fiber layer.

The reaction formula at this time is as follows.
SO ₂ + 1 / 2O ₂ + H ₂ O → H ₂ SO ₄

In this manner, sulfur dioxide (SO ₂ ) in the purified exhaust gas 103 is adsorbed and oxidized in the activated carbon fiber layer of the catalyst tank 107 and reacted with water (H ₂ O) to produce sulfuric acid (H ₂ SO _4). ) Is generated and removed to perform desulfurization in the exhaust gas (Patent Document 1).

  By the way, when exhaust gas treatment is performed over a long period of time, heavy metals such as mercury and selenium in the exhaust gas are adsorbed to the activated carbon fibers constituting the catalyst tank 107, so that the heavy metals and the like are removed. It will be necessary.

  Conventionally, as a method for regenerating an adsorbent such as activated carbon, heat treatment at a high temperature in an inert gas has been proposed (Patent Document 2).

JP 2003-164730 A JP 2000-167395 A

  However, the proposal as in Patent Document 2 has a problem that a large facility is required for the heat treatment.

  In addition, since a flue gas processing apparatus such as a boiler is large-scale, reuse of a used adsorbent is important for low cost in continuous operation, and a simple processing method is desired.

  Accordingly, an electrolysis treatment apparatus 300 as shown in FIG. 13 can be proposed with a pair of activated carbon fibers constituting the catalyst tank, and wiring for applying a voltage from the power source 301 to the activated carbon fiber layer 125 respectively. Although it is necessary to wire 302, there is a problem that the labor of production becomes enormous. That is, as an example of the current catalyst tank, when the height is 5 m × 5 m and the height is 5 to 10 m, for example, 250 activated carbon fiber layers / m are required. This is because wiring is required. In addition, it is necessary to interpose an insulating material between the activated carbon fiber layer 125 and the activated carbon fiber layer 125 or hold the activated carbon fiber layer 125 so as not to contact at regular intervals, which complicates the configuration. .

Further, as shown in FIG. 14, even when the counter electrode is a single mesh electrode 303, there is no change in the number of wirings for the activated carbon fiber, so that there is a problem in that wiring work is similarly required.
In addition, there is a problem that the electric field is not applied uniformly, and unevenness occurs in the removal of mercury and the regeneration of activated carbon fibers.

In view of the above problems, the reproduction processing such as mercury becomes simple, and to provide a flue gas treatment apparatus that can be carried out flue gas treatment continuously.

The first invention of the present invention for solving the above-mentioned problems includes a first activated carbon fiber sheet body and a second activated carbon fiber sheet body, and these first activated carbon fiber sheet body and second activated carbon. Gas permeable and insulating first spacers provided on the inner side between the carbon fiber sheet bodies, and provided on both outer sides of the first activated carbon fiber sheet body and the second activated carbon fiber sheet body, Roll-shaped adsorption formed by permeable and insulating second and third spacers , in which the first activated carbon fiber sheet body, the second activated carbon fiber sheet body, and the spacer are integrally rolled. A member, a power source for applying a voltage to the first activated carbon fiber sheet body and the second activated carbon fiber sheet body, a case having an opening for loading the roll-shaped adsorption member, and the case disposed Purification tower and the roll In the adsorption member to the flue gas treatment apparatus characterized by comprising; and a supplying water supply device and water.

According to a second aspect of the present invention, there is provided a flue gas treatment apparatus according to the first aspect , wherein the first activated carbon fiber sheet body and the second activated carbon fiber sheet body are wound around a core body. .

According to a third aspect of the present invention, in the first or second aspect of the present invention, there is provided a flue gas treatment apparatus in which a conductive member is added to the activated carbon fiber .

  According to the present invention, the adsorbing member provided in the purification tower through which the exhaust gas circulates is composed of a pair of sheet bodies arranged with a predetermined interval, and the pair of sheet bodies is wound or folded. Therefore, the wiring in the regeneration process does not become complicated, and labor required for wiring of the electric electrode is greatly saved. As a result, the carbon material can be regenerated by simple regeneration, and the configuration can be simplified, so that the manufacturing cost can be reduced.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

An adsorption member according to Example 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a flue gas treatment apparatus including an adsorption member according to the first embodiment.
As shown in FIG. 1, the flue gas treatment apparatus 10 according to the present embodiment includes a pair of first sheet body 11-1 and second sheet body 11-2 arranged with a predetermined interval. Are formed in a purification tower 14 provided with a plurality (9 in this embodiment) of adsorbing members 13 wound in a roll, and a pair of first sheet body 11-1 and second sheet body 11-2. A power supply 15 for applying a voltage and a water supply device 17 for supplying water 16 to the adsorption member 13 are provided.

  In the purification tower 14, an exhaust gas introduction part 14a for introducing the exhaust gas 101 is provided at the lower part of the tower, and an exhaust part 14b for exhausting the purified gas 109 is provided at the top of the tower. Further, dilute sulfuric acid 106 generated by removing sulfur components in the exhaust gas is stored on the bottom side of the purification tower 14. In the figure, reference numeral 18 denotes wiring, and 19-1 and 19-2 denote terminals. FIG. 1 is a schematic view in which the purification tower 14 is partially cut away, and wiring is omitted. Further, a spacer provided between sheet bodies to be described later is omitted.

  Here, the said 1st and 2nd sheet | seat body consists of the carbon material which has a catalytic action in desulfurization as mentioned above, and can mention what made the flat activated carbon fiber into the sheet form. 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. It is not limited, and there is no limitation as long as it is an activated carbon fiber that exhibits the above catalytic action.

  In this embodiment, nine roll-shaped adsorption members 13 are arranged in the purification tower 14, but the present invention is not limited to this. Moreover, it is good also as a roll body with a large diameter by enlarging the roll number of rolls.

FIG. 2 shows the state of purification of exhaust gas from the adsorbing member 13 in the form of a roll, and FIG. 3 shows the state of desorption of heavy metals such as mercury.
First, as shown in FIG. 2, in the normal exhaust gas treatment, when purifying the exhaust gas 101, the switch 20 of the power source 15 is turned off and the water 16 is supplied in a shower form. SO ₂ is adsorbed on the surface of the carbon fiber and oxidized to SO _3, and sulfuric acid is generated by the supplied shower water to perform desulfurization.

On the other hand, as shown in FIG. 3, in the regeneration process, the ventilation of the exhaust gas 101 is stopped, the switch 20 of the power supply 15 is turned on, a large amount of water 16 is supplied, and the inside of the adsorption member 13 is in a water wall state. As an electrolysis. The state of this electrolysis is shown in FIG. As shown in FIG. 4, by applying a voltage from the power source 15 to the first sheet body 11-1 and the second sheet body 11-2, the first sheet body 11-1 serving as the anode is adsorbed by an oxidation-reduction reaction. The released mercury is eluted in an ionic state (Hg ₂ ²⁺ ). Moreover, mercury ions are eluted similarly from the 2nd sheet | seat body 11-2 of a counter electrode by replacing an anode and a cathode. Here, the water wall shape in the present invention means that water is filled between activated carbon fiber sheet bodies by supplying a large amount of water, as if the water is stored.

  In addition to supplying a large amount of water, electrolysis may be performed with the purification tower 14 filled with water and the adsorbing member immersed.

The electrolytic treatment solution subjected to the elution treatment is separately collected, and then an alkali agent such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) is added to increase the number of moles of Na or K over Hg. Thereafter, an oxidizing agent such as hydrogen peroxide (H ₂ O ₂ ) or ozone (O ₃ ) is added to the electrolytic treatment solution, and precipitated and recovered as mercury oxide (HgO).
Na ₂ SO ₄ may be added to the electrolytic treatment solution.

Alternatively, H ₂ S may be added instead of the oxidant to precipitate as HgS and recovered.

The distance d of the pair of sheet bodies is about 3 to 6 mm, but since it is in a roll shape, the long one is made compact, and many like the conventional 250 pieces / m. The trouble of wiring the conductors one by one is reduced, and the wiring is eliminated.
In addition, since the energization distance becomes long, it is necessary to sufficiently reduce the electric resistance. For example, a conductive member is attached to the surface or added to the inside.
Here, examples of the conductive member include noble metals such as gold and platinum, metals such as tungsten (W) and titanium (Ti), or conductive carbon.

  Further, as shown in FIG. 5, in addition to alternately energizing the power supply, the power is independently applied to the sheet bodies 11-1 and 11-2, and the sheet bodies are simply heated to elute mercury as ions. You may do it.

  An example of manufacturing such a roll-shaped adsorption member 13 is shown in FIG. As shown in FIG. 6, spacers 20-1, 20-2, and 20-3 are disposed between and on both sides of the pair of first sheet body 11-1 and second sheet body 11-2. And these are united and rolled and the roll-shaped adsorption | suction member 13 is comprised. In this embodiment, the sheet body is 1 mm and the spacer is 3 to 6 mm, but the present invention is not limited to this.

The spacers 20-1 to 20-3 preferably have good gas flowability so as to promote SO ₂ adsorption on the activated carbon fiber. For example, a gas vent 21 as shown in FIG. It is preferable to have a mesh shape or a sea surface shape.
In addition, the spacers are provided with insulating properties such as polypropylene (PP).

  In addition, as shown in FIG. 8, a plurality (9 in this embodiment) of the adsorbing members 13 in a roll shape as described above may be loaded in a case 42 having an opening 41.

  Further, the case 42 may be stacked in a plurality of stages (three stages in this embodiment) in the packed tower 14 to increase the processing capacity at a time.

  Moreover, you may make it manufacture an adsorption | suction member by winding a pair of sheet | seat body arrange | positioned with a predetermined space | interval on the circular or rectangular core.

  In this way, electrode wiring for regeneration processing can be performed with a simple configuration, and the manufacturing cost can be reduced.

FIG. 9 shows an embodiment other than the roll of a sheet body arranged with a predetermined interval.
As shown in FIG. 9, in this embodiment, the first sheet body 11-1 and the second sheet body 11-2 arranged with a predetermined interval are wound in a rectangular shape.
In order to obtain such a rectangular shape, a support portion 51 is provided at each corner to form a rectangular suction member 52.
In this embodiment, the rectangular suction member 52 is loaded in the case 53, and the power source 15 is connected to the sheet member.

  As described above, the suction member 52 wound in a rectangular shape with a predetermined interval can be used for electrode wiring for regeneration processing with a simple configuration, and the manufacturing cost can be reduced.

FIG. 10 shows an embodiment other than a sheet formed with a predetermined interval in a roll shape.
As shown in FIG. 10, the present embodiment is a case where sheet bodies 11-1 and 11-2 arranged with a predetermined interval are housed in a case 53 in a ninety-fold shape.
In order to obtain such a ninety-nine fold shape, each corner is provided with a support portion 51 to form a rectangular suction member 54.
In this embodiment, the rectangular suction member 54 is loaded in the case 53, and the power source 15 is connected to the sheet member.

  As described above, the adsorbing member 54 wound in a 99-fold shape with a predetermined interval can be used for electrode wiring for regeneration processing with a simple configuration, and the manufacturing cost can be reduced.

  As described above, the adsorbing member according to the present invention rolls the sheet body arranged with a predetermined interval, so that the conventional wiring is eliminated and the exhaust gas treatment is continuously performed. It is suitable for use.

1 is a schematic diagram of a flue gas treatment apparatus according to Embodiment 1. FIG. It is the schematic of the use condition of the adsorption member concerning Example 1. FIG. It is the schematic of the reproduction | regeneration state of the adsorption | suction member concerning Example 1. FIG. It is the schematic which shows the elution state of mercury from the adsorption | suction member concerning Example 1. FIG. It is the schematic which shows the elution state of mercury from the other adsorption member concerning Example 1. FIG. 1 is a schematic configuration diagram of a suction member according to Example 1. FIG. 3 is a schematic diagram of a main part of a spacer according to Example 1. FIG. It is the schematic of the case where the adsorption member concerning Example 1 is loaded. It is a schematic diagram of the adsorption member made into the rectangular shape concerning Example 2. FIG. It is a schematic diagram of the adsorbing member made into a 99-fold shape according to Example 3. It is a schematic diagram of a flue gas treatment system. It is the schematic of a purification tower. It is the schematic which shows the reproduction | regeneration state of activated carbon fiber. It is the schematic which shows the other reproduction | regeneration state of activated carbon fiber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Smoke exhaust processing apparatus 11-1 1st sheet | seat body 11-2 2nd sheet | seat body 13 Adsorption member 14 Purification tower 15 Power supply 16 Water 17 Water supply apparatus

Claims (3)

The first activated carbon fiber sheet body and the second activated carbon fiber sheet body, and the gas-permeable and insulating material provided between the first activated carbon fiber sheet body and the second activated carbon fiber sheet body . The first spacer is provided on both outer sides of the first activated carbon fiber sheet body and the second activated carbon fiber sheet body, and is composed of gas permeable and insulating second and third spacers. A roll-shaped adsorption member formed by rolling the first activated carbon fiber sheet body and the second activated carbon fiber sheet body together with the spacer;
A power source for applying a voltage to the first activated carbon fiber sheet body and the second activated carbon fiber sheet body;
A case having an opening for loading the roll-shaped adsorption member;
A purification tower in which the case is disposed;
A smoke exhausting apparatus comprising a water supply device for supplying water to the roll-shaped adsorption member. In claim 1,
The first activated carbon fiber sheet body and the second activated carbon fiber sheet body are wound around a core body. In claim 1 or 2,
An exhaust smoke treatment apparatus, wherein a conductive member is added to the activated carbon fiber.

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