JP2006241976A - Device for treating drainage containing soot and dust - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for treating drainage containing soot and dust, for efficiently separating, burning and removing solid matter such as particulates contained in the drainage. <P>SOLUTION: The device for treating drainage containing soot and dust, comprises: a wet type exhaust gas treating device 13 for performing wet processing of exhaust gas 11 from an exhaust gas source 10 to be cleaned gas 12; and a catalytic combustion device 16 for performing catalytic combustion of the solid matter 15 contained in the drainage 14 from the wet type exhaust gas treating device 13. The catalytic combustion efficiently removes the soot and dust such as particulates and solid matter contained in the drainage 14 from the wet type exhaust gas treating device 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention decomposes solid matter such as suspended particulates (SPM) contained in wastewater after wet processing exhaust gas from, for example, an internal combustion engine such as a diesel engine for marine use, land use, and stationary use. The present invention relates to an apparatus for treating dust-containing wastewater to be removed.

  Conventionally, desulfurization equipment for treating soot, SOx, etc. contained in exhaust gas from marine, on-shore, and stationary diesel is installed, and wet exhaust gas treatment devices such as seawater scrubbers and wet electrostatic precipitators are installed ( Patent Document 1). In addition, the present applicant has previously proposed a method for combusting dust in exhaust gas (Patent Document 2).

JP 2004-66009 A JP 2001-173426 A

  However, in the waste water from this wet exhaust gas treatment device, for example, dust and solids of suspended fine particles (SPM, hereinafter referred to as “fine particles”) are present and cannot be discarded as they are. However, there is a problem that treatment of the filtrate is required separately. For example, when the filtrate is burned by a heater, heating at a high temperature of 600 ° C. or higher is usually required, resulting in an increase in processing cost.

  In particular, in the case of treatment using activated carbon fibers in the desulfurization of exhaust gas in ships, etc., in order to release dilute sulfuric acid as wastewater to the outside of the ship, efficient removal of solids in dilute sulfuric acid is desired. ing.

  In view of the above problems, an object of the present invention is to provide a dust-containing wastewater treatment apparatus that can efficiently separate and burn off solid matters such as suspended fine particles (SPM) contained in wastewater.

  A first invention of the present invention for solving the above-described problems includes a wet exhaust gas treatment device for treating exhaust gas in a wet manner, and a catalytic combustion device for catalytic combustion of solid matter contained in waste water from the wet exhaust gas treatment device. It is in the processing apparatus of the wastewater containing a dust characterized by comprising.

  According to a second aspect, in the first aspect, the catalytic combustion device collects a solid matter contained in the waste water, and a catalyst attachment portion attaches a catalyst solution to the surface of the collected solid matter. And a dust-containing wastewater treatment apparatus characterized in that the collected solid matter is combusted and decomposed.

  According to a third aspect of the present invention, there is provided a dust-containing wastewater treatment apparatus according to the second aspect of the present invention, wherein a solid-liquid separation device is provided between the wet exhaust gas treatment device and the catalytic combustion device.

  4th invention is 2nd invention. WHEREIN: The collection part which consists of at least 2 units which collects the said solid substance, The draining part which drains the solid substance collected by the collection part, and solid after the said draining A catalyst adhering part for adhering a catalyst solution to the material, and collecting the solid matter in the waste water alternately in the collecting part, and collecting the solid matter by supplying waste water to one of the collecting parts. In addition, drainage drainage gas is supplied and drained, and then the solid matter in the wastewater is collected in the other collection part while the solid matter is burned by heat. In the processing unit.

  According to a fifth invention, in any one of the first to fourth inventions, the wet exhaust gas treatment device is one of a desulfurization device having a catalyst layer formed of an activated carbon fiber layer, a seawater scrubber, and a wet electric dust collector. It exists in the processing apparatus of the dust containing waste water characterized by being.

  A sixth invention is the dust-containing wastewater treatment apparatus according to any one of the first to fifth inventions, wherein the exhaust gas is any one of diesel exhaust gas, boiler exhaust gas, and gasifier exhaust gas.

  ADVANTAGE OF THE INVENTION According to this invention, soot and solids, such as floating particulates etc. which exist in the waste_water | drain from a wet exhaust gas processing apparatus can be catalytically removed by combustion efficiently.

  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.

  The processing apparatus of the dust containing waste_water | drain based on the Example by this invention is demonstrated with reference to drawings. FIG. 1 is a conceptual diagram illustrating a dust-containing wastewater treatment apparatus according to the present embodiment. As shown in FIG. 1, a dust-containing wastewater treatment apparatus according to the present embodiment includes a wet exhaust gas treatment apparatus 13 that treats exhaust gas 11 from an exhaust gas source 10 in a wet process to produce purified gas 12, and a wet exhaust gas treatment apparatus 13. And a catalytic combustion device 16 for catalytically burning the solid matter 15 contained in the waste water 14 from the waste water.

For example, as shown in FIG. 2, the catalytic combustion device 16 includes a filter 21 that is a collection unit that collects the solid matter 15 contained in the waste water 14, and a dust slurry 20 that contains the collected solid matter 15. A catalyst adhering portion 23 for adhering the catalyst solution 22 to the surface is provided, and the collected solid matter is combusted and decomposed by a heating portion 24 such as a heater. The catalyst adhering portion 23 includes a storage portion 23a for storing the catalyst solution 22 and a pipe 23c provided with a pump 23b for supplying the catalyst solution 22.
Further, a draining gas 25 for draining drainage is supplied to the catalytic combustion device 16 so as to remove the moisture in the dust slurry 20 as much as possible.

  Here, the catalyst of the catalyst solution 22 in the present invention includes at least one of alkali metals such as potassium carbonate and sodium carbonate, and alkaline earth metals. Seawater can also be used as an alkali catalyst. Moreover, you may make it contain at least 1 sort (s) of the said alkali metal or alkaline-earth metal in seawater.

  In the present invention, the catalyst and dust can be brought into uniform contact by spraying, impregnating and supporting the alkali catalyst solution so as to cover the surface of the solid matter in the dust slurry collected by the filter. As a result, the combustion field can be made uniform and catalytic combustion can be performed in the range of 300 to 400 ° C.

  Since the material of the filter 21 repeats combustion and spraying of an aqueous solution, it is necessary to use a material having excellent thermal shock resistance. Examples of the thermal shock resistant filter include a metal filter and a ceramic filter. Also, a laminated metal mesh type filter formed by laminating a metal filter on a support layer that retains filter strength, and a laminated metal nonwoven fabric type filter formed by laminating a metal nonwoven fabric on a support layer that retains filter strength can do.

Further, the filter may carry a metal catalyst such as platinum as required. Here, in addition to platinum, for example, rhodium, palladium, vanadium, chromium, manganese, iron, nickel, etc., and as an oxide catalyst, for example, titanium oxide, alumina, silica, zeolite, perovskite type structure, spinel type structure However, the present invention is not limited to these.
Thereby, the catalytic combustion of the solid substance of the part which contacts a catalyst can be accelerated | stimulated.
Moreover, while carrying platinum etc. of the said filter and supplying a catalyst solution, the catalytic action of the catalyst which contacts the said solid substance on the filter surface side, and the catalytic action of the alkaline catalyst adhering to the solid substance are used in combination. Due to the effect, the combustion efficiency can be further improved.

In addition, as shown in FIG. 3, a solid-liquid separation device 30 may be provided between the wet exhaust gas treatment device 13 and the catalytic combustion device 16.
The solid-liquid separation device 30 removes water in the waste water 14 and separates it into a solid content 31 and water (dust removal) 32, and supplies the solid content 31 to the catalytic combustion device 16 described above. The catalyst may be combusted.

In FIG. 3, a part of the exhaust gas 11 is used as the combustion heat source of the catalytic combustion device 16.
By using the solid-liquid separator 30, the waste water is not processed as it is compared to the apparatus of FIG. 2, so that the gas amount can be reduced by about 1/10 and the apparatus can be made compact. it can.

  FIG. 4 shows two catalytic combustion portions provided for efficient catalytic combustion. As shown in FIG. 4, the catalytic combustion device 16 includes a first collection unit 41-1 having a first filter 21-1, and a second collection unit 41-2 having a second filter 21-2. In addition, the first collecting unit 41-1 and the second collecting unit 41-2 are drained from the solids collected by the collecting unit with a draining gas 25, and solid after the draining. And a catalyst attachment part (not shown) for attaching the catalyst solution to the product. V1 to V4 are valves for supplying the draining gas 25.

And the solid substance 15 in waste_water | drain is alternately collected by the said collection part, and the catalyst solution 22 is supplied to one 1st collection part 41-1. While the drainage gas 25 is supplied to drain the dust slurry 20, and then the exhaust gas 11 is supplied and the solid matter is burned by the heat, the other second collection unit 41-2 is in the drainage 14. The solid matter 15 is collected.
This makes it possible to continuously treat the waste water.

  In the present invention, the wet exhaust gas treatment device is not particularly limited, and examples thereof include a desulfurization device having a catalyst layer formed of an activated carbon fiber layer, a seawater scrubber, and a wet electric dust collector. it can.

  Moreover, as exhaust gas, it can be set as any of diesel exhaust gas, boiler exhaust gas, and gasifier exhaust gas, for example, It does not specifically limit.

  Next, a wet exhaust gas treatment device having an activated carbon fiber layer is applied as a treatment device for exhaust gas from marine diesel engines to remove SOx and PM in the exhaust gas and to efficiently treat the waste water. To do.

A method of desulfurizing sulfur oxide in exhaust gas will be described with reference to FIG.
As shown in FIG. 5, the purification tower 104 in which the exhaust gas 11 containing sulfur oxides from the marine diesel engine 200 circulates has a catalyst layer 107 formed of an activated carbon fiber layer that performs desulfurization. SOx is washed away with water to store dilute sulfuric acid. And the catalytic combustion apparatus 16 which processes the stored dilute sulfuric acid 106 is provided.

In the present embodiment, the catalytic combustion apparatus 16 including the first collection unit 41-1 and the second collection unit 41-2 shown in FIG. 4 is provided.
In this apparatus, for example, the exhaust gas 11 discharged from a boiler or the like is removed by the dust collector 201, and then sent by the pushing fan 121. The exhaust gas 11 cools the exhaust gas temperature and passes through a humidifying cooling device 116 that gives humidity. Is introduced into the purification tower 104 from the introduction part 104a. The introduced exhaust gas 11 is desulfurized in a catalyst tank 107 formed of an activated carbon fiber layer. 105 is supplied to the catalyst tank 107 from water supply means 111 including a water tank 111a and a supply pump 111b. While supplying the water 105 from the supply means 111 from the upper part, the gas 101 is passed through the catalyst tank 107 from the lower part to remove SOx from the gas 11. The purified gas 109 that has passed through the catalyst tank 107 is discharged from the discharge section 104b at the top of the purification tower 104, and is released to the atmosphere through the chimney.

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.
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 way, sulfur dioxide (SO ₂ ) of the gas 11 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 ). By generating and removing it, desulfurization in the exhaust gas is performed.
A schematic diagram of this desulfurization is shown in FIG.

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 catalytic action are not limited.

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.
(Production Example 2)
Polyacrylonitrile-based activated carbon fiber (“FX-600”, manufactured by Toho Rayon Co., Ltd.) is used, and this is fired for 1 hour in a temperature range of 900 to 1200 ° C. in a nitrogen atmosphere.

FIG. 8 is a perspective view of an activated carbon fiber layer disposed in the purification tower 104 according to the present embodiment. As shown in FIG. 8, 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.

  Then, as shown in FIG. 6, water is supplied in a spray form from the watering nozzle 122 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 11 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. .

  In addition, as shown in FIGS. 9-1 to 9-2 and FIG. 10, when the activated carbon fiber layer is continuously used in two or more stages, the first stage activated carbon fiber layer 125-1 and the second stage are used. You may make it arrange | position so that the opening with the activated carbon fiber layer 125-2 may overlap. FIG. 9A shows the first stage activated carbon fiber layer 125-1 and the second stage activated carbon fiber layer 125-2 that are slightly shifted from each other. FIG. 9-2 shows the first stage activated carbon fiber layer 125-2. The activated carbon fiber layer 125-1 and the second-stage activated carbon fiber layer 125-2 are arranged so as to be orthogonal to each other. Moreover, it is not orthogonal, and arbitrary angle shifts are also possible. FIG. 10 is installed so that the openings of the second-stage activated carbon fiber layer 125-2 are arranged between the openings of the first-stage activated carbon fiber layer 125-1. Thereby, SOx in the exhaust gas when passing through the passage of the activated carbon fiber layer can be efficiently removed.

  In addition, as the combustion gas used in the catalytic combustion device 16 in FIG. 5, the exhaust gas on the upstream side of the humidification cooling device 116 is branched and introduced for use in the combustion treatment. It should be upstream of the economizer. As a result, solid matter is removed, so that clogging can be prevented.

In addition to the humidification cooling upstream, the combustion exhaust gas return path may be upstream of the supercharger, between the purification tower 104 and the mist eliminator 203, upstream of the chimney 202, or the like.
By using the exhaust gas 11 as a heat source for combustion of the catalytic combustion device 16, it is possible to reduce the device running cost without installing a separate heating device such as a heater.
Gas can be vented without a blower by selecting a route for introducing the exhaust gas 11.

  Further, the dilute sulfuric acid from which dust or the like has been purified can be reused for the humidified cooling water 115 and the added water of the humidified cooling device 116 again.

  As described above, the dust-containing wastewater treatment apparatus according to the present invention is suitable for use in efficiently catalytically removing dust such as suspended particulates and solids present in the wastewater from the wet exhaust gas treatment apparatus. ing.

It is the schematic of the processing apparatus of the dust containing waste water which concerns on a present Example. It is the schematic of the catalytic combustion apparatus which concerns on a present Example. It is the schematic of the other catalytic combustion apparatus which concerns on a present Example. It is the schematic of the other catalytic combustion apparatus which concerns on a present Example. It is a schematic diagram of the exhaust gas treatment system according to the present embodiment. It is a schematic diagram of the purification tower which concerns on a present Example. It is a schematic diagram which shows a desulfurization reaction. It is a perspective view of an activated carbon fiber layer. It is a schematic diagram of arrangement | positioning of an activated carbon fiber layer. It is a schematic diagram of arrangement | positioning of an activated carbon fiber layer. It is a schematic diagram of arrangement | positioning of an activated carbon fiber layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exhaust gas source 11 Exhaust gas 12 Purified gas 13 Wet exhaust gas processing apparatus 14 Waste water 15 Solid substance 16 Catalytic combustion apparatus 21 Filter 22 Catalyst solution 23 Catalyst adhesion part 24 Heating part 25 Drain gas

Claims (6)

A wet exhaust gas treatment device for treating exhaust gas in a wet manner;
An apparatus for treating dust-containing wastewater, comprising: a catalytic combustion device for catalytically burning solid matter contained in wastewater from the wet exhaust gas treatment device. In claim 1,
The catalytic combustion apparatus includes a collection unit that collects solid matter contained in the waste water, and a catalyst attachment unit that attaches a catalyst solution to the surface of the collected solid matter. An apparatus for treating wastewater containing dust, which is decomposed by combustion.   The apparatus for treating dust-containing wastewater according to claim 2, wherein a solid-liquid separation device is provided between the wet exhaust gas treatment device and the catalytic combustion device. In claim 2,
A collecting unit comprising at least two groups for collecting the solid material, a draining unit for draining the solid material collected by the collecting unit, and a catalyst adhering unit for adhering a catalyst solution to the solid material after draining. The collection unit alternately collects solids in the wastewater, supplies the wastewater to one of the collection units to collect the solids, and supplies the drainage gas of the wastewater to drain the solids. Then, while the solid matter is burned by heat thereafter, the solid matter in the wastewater is collected by the other collection unit, and the dust-containing wastewater treatment apparatus. In any one of Claims 1 thru | or 4,
The apparatus for treating wastewater containing dust, wherein the wet exhaust gas treatment apparatus is any one of a desulfurization apparatus having a catalyst layer formed of an activated carbon fiber layer, a seawater scrubber, and a wet electric dust collector. In any one of Claims 1 thru | or 5,
The dust-containing wastewater treatment apparatus, wherein the exhaust gas is any of diesel exhaust gas, boiler exhaust gas, and gasifier exhaust gas.

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