JP5769610B2 - Activated carbon slurrying apparatus and method - Google Patents

Description

  The present invention relates to an activated carbon slurrying apparatus and method for slurrying waste activated carbon adsorbing harmful substances such as PCB.

  Although PCB has been widely used as an insulating oil for transformers, capacitors, and the like, it is necessary to treat PCB due to its strong toxicity. For this reason, various decomposition methods for detoxifying the PCB have been proposed (see Patent Document 1, Patent Document 2, and Patent Document 3).

Here, the PCB detoxification device processes only PCB, but the PCB contaminated container from which one PCB is extracted is subjected to a cleaning process with a cleaning liquid such as an organic solvent or a surfactant to render the container harmless. (Patent Document 4).
In addition, isopropyl alcohol (hereinafter also referred to as “IPA”) is used as an alcohol cleaning agent to remove PCBs from paper elements such as fluorescent lamp ballasts, transformers, condensers, etc., and the IPA containing the removed PCB is water. It was previously proposed to decompose PCB with a thermal oxidative decomposition apparatus (Patent Document 5).

Japanese Patent Laid-Open No. 11-253895 Japanese Patent Laid-Open No. 11-253796 JP 2000-126588 A JP 2002-248455 A JP 2005-21830 A JP 2003-31234 A

  By the way, in a facility that treats harmful substances such as PCB, used activated carbon that adsorbs harmful substances provided in an exhaust line of equipment accumulates. The harmful substances accumulated in this activated carbon contain several to 30% of PCB and trichlorobenzene.

  Conventionally, as a treatment of activated carbon that has adsorbed harmful substances, there is a proposal of making activated carbon a slurry and detoxifying it with a hydrothermal oxidative decomposition apparatus (Patent Document 6).

However, the treatment residue is increased due to the ash that the activated carbon brings inside the hydrothermal oxidative decomposition apparatus, and the processing time increases in the hydrothermal oxidative decomposition treatment containing activated carbon particles, unlike the liquid treatment such as PCB-containing insulating oil. There's a problem.
Moreover, since the capacity of the processed material is increased by about 2 to 10 times due to the adsorption of PCB to the activated carbon, the capacity of the processed material becomes large, which is a problem.

  Therefore, establishment of a method with good dispersibility and fluidity without the activated carbon slurry separating and agglomerating and agglomerating is desired.

  In view of the above problems, an object of the present invention is to provide an activated carbon slurrying apparatus and method capable of efficiently slurrying activated carbon that has adsorbed harmful substances such as PCB.

The first aspect of the present invention to solve the above problems, the activated carbon has adsorbed harmful substances A charcoal slurry apparatus for processing slurring, after supplying water to granular activated carbon with adsorbed toxic substances the monitoring and comminution means for pulverizng, a first primary slurried tank to ground granular activated carbon primary slurrying granular activated carbon, the slurry state of the primary slurried granular activated carbon of the first primary slurried tank 1 a slurry monitoring means, and the second primary slurried tank to hazardous substances fine powder activated carbon by supplying water primary slurrying finely powdered activated carbon with adsorbed primary slurry of second primary slurrying tank a second slurry monitoring means for monitoring a slurry state of fine powder activated carbon, it is provided before feeding the added pressure agent, a mixed slurry product by mixing the primary slurry of granular activated carbon and primary slurrying finely powdered activated carbon and the mixing section, the primary The first additive supply means for supplying the additive to the mixed slurry according to the fine particle size of the pulverized granular activated carbon, and the additive to the mixed slurry according to the fine particle size of the primary slurry fine powder activated carbon a second additive supply means for the mixing and stirring means for mixing the slurry product obtained by adding an additive to emulsification, the secondary slurrying tank for holding the emulsified state of the mixed emulsified slurry product at the mixing and stirring means The activated carbon slurrying apparatus is characterized by comprising:

A second invention is an activated carbon slurrying method in which activated carbon that has adsorbed harmful substances is slurried, and is supplied with water to granular activated carbon that has adsorbed harmful substances and then pulverized by a pulverizing means; A first primary slurrying step in which activated carbon is a primary slurry granular activated carbon, a second primary slurrying step in which water is supplied to finely powdered activated carbon adsorbing harmful substances to form primary slurryed finely powdered activated carbon, and primary A mixing step of mixing the slurry granular activated carbon and the primary slurry fine powder activated carbon to make a mixed slurry , and supplying the additive to the mixed slurry according to the fine particle size of the primary slurry granular activated carbon, of the additive supply step of supplying an additive in accordance with the fineness of the fine powdered activated carbon, the mixture slurry product and mixing and stirring step of emulsification with the addition of additives, it is mixed in the mixing and stirring step The emulsified slurry product, in the activated carbon slurried method characterized by comprising a secondary slurry step of holding the emulsified state of the emulsion slurry product was mixed with stirring means.

  According to the present invention, each of the granular activated carbon and the finely powdered activated carbon is slurried, mixed, and emulsified with a mixing and stirring device while supplying an additive according to the slurry situation. Can be obtained.

FIG. 1 is a schematic diagram of a regeneration treatment apparatus for harmful substance-adsorbed activated carbon according to an embodiment. FIG. 2 is a schematic diagram of a configuration of a hydrothermal oxidative decomposition apparatus for treating harmful substances.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included. 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 activated carbon slurrying apparatus and method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an activated carbon slurrying apparatus according to an embodiment.
As shown in FIG. 1, an activated carbon slurrying apparatus 10 according to this embodiment is an activated carbon slurrying apparatus for slurrying activated carbon that has adsorbed harmful substances (for example, PCB), and is a granular activated carbon 11A that has adsorbed harmful substances. Pulverizing means 19 for pulverizing by the pulverizing means after supplying water 12, a first primary slurrying tank 14A in which the pulverized granular activated carbon is primary slurryed granular activated carbon 13A, and the first primary slurrying tank 14A The primary slurry granular activated carbon according to the first slurry monitoring means 15A for monitoring the slurry state of the primary slurry granular activated carbon 13A and the fine particle size (solid matter concentration, oil concentration, particle size, etc.) of the primary slurry granular activated carbon 13A Water 12 is supplied to the additive tank 22A which is the first additive supply means for supplying the additive 21 to 13A, and the finely powdered activated carbon 11B which adsorbs the harmful substances, and the primary slurry is supplied. A second primary slurrying tank 14B as a finely divided activated carbon 13B, a second slurry monitoring means 15B for monitoring the slurry state of the primary slurryed finely powdered activated carbon 13B in the second primary slurrying tank 14B, and a primary Additive tank which is a second additive supply means for supplying the additive 21 to the primary slurry fine powder activated carbon 13B according to the fine particle size (solid concentration, oil concentration, particle size, etc.) of the slurry fine powder activated carbon 13B. 22B, a mixing unit 24 which is provided before supplying the additive, mixes the primary slurry granular activated carbon 13A and the primary slurry fine powder activated carbon 13B to form a mixed slurry 23, and a mixed slurry to which the additive is added A line mixer 25 which is a mixing and stirring means for emulsifying the compound 23, and a secondary slurry tank 27 for maintaining the emulsified state of the emulsified slurry 26 mixed in the line mixer 25; It is intended to include a.
In the figure, V _{1 to} V ₄ are valves, and P _{1 to} P ₅ are pumps.

  In the present invention, two types of granular activated carbon 11A and finely powdered activated carbon 11B having different particle diameters are slurried in primary slurry tanks 14A and 14B, respectively, and then mixed, and then the state of the slurry from additive tanks 22A and 22B. Depending on the case, additives 21A and 21B are added. Thereafter, the mixed slurry 23 to which the additives 21A and 21B have been added is introduced into the line mixer 25 and emulsified here, whereby an emulsified slurry 28 in a good emulsified state is obtained. Since this emulsified slurry 28 produces a good emulsion, it is possible to prevent clogging in the supply passage and pump when supplying to the hydrothermal oxidative decomposition apparatus 120.

Here, the granular activated carbon 11A is 3 to 8 mm pellet-shaped activated carbon, and is supplied to the pulverizer 19 via the line L _1A by the supply machine 31A. The granular activated carbon pulverized by the pulverizer 19 is supplied to the first primary slurry tank 14A.
The finely powdered activated carbon 11B is finely powdered activated carbon of 1 to 100 μm, and is directly supplied to the second primary slurrying tank 14B via the line L _1B by the supply device 31B.
A predetermined amount of supply water 12 is introduced into the supply lines L _1A and L _1B via the water lines L _2A and L _2B , and the primary slurry is made in the first and second primary slurry tanks 14A and 14B. The
Here, examples of the activated carbon include coconut shell activated carbon and coal activated carbon.

  Examples of harmful substances adsorbed on activated carbon include agricultural chemicals, dioxins, cleaning organic solvents, VOCs (volatile organic compounds) and the like in addition to PCB and trichlorobenzene.

  The first and second primary slurrying tanks 14A and 14B observe the primary slurrying state by the first and second slurry monitoring means 15A and 15B, respectively. Certain fine particle sizes (solids concentration, oil concentration, particle size, etc.) are being sent.

The primary slurry granulated activated carbon 13A and the primary slurry fine powder activated carbon 13B that have been slurried in the first and second primary slurry tanks 14A and 14B are mixed in the mixing unit 24 to become a mixed slurry 23. In accordance with the fine particle size (for example, solid concentration, oil content concentration, particle size, etc.) sent to the control means (not shown) for this mixed slurry 23, the additive tank of the first additive supply means is added to the additive 21A. Add from 22A.
Similarly, the additive 21B is added from the additive tank 22B of the second additive supply means according to the fine particle size (for example, solid concentration, oil concentration, particle size, etc.) of the primary slurry fine powder activated carbon 13B.
The mixed slurry 23 to which the additives 21A and 21B are added in accordance with the fine particle sizes of the primary slurry granular activated carbon 13A and the primary slurry fine powder activated carbon 13B is sent to the mixing and stirring means 25 and emulsified. .

  The mixing and stirring means 25 is not particularly limited as long as it can emulsify the mixed slurry 23, but for example, it is preferable to use an emulsification promoting means such as a line mixer. The rotation condition of the line mixer is, for example, about 1000 to 3000 rpm, and the slurry is completely emulsified (oil-in-water (O / W type) emulsion generation).

  The emulsified slurry 26 mixed by the mixing and stirring means 25 is sent to a secondary slurry tank 27, where the emulsified state of the emulsified slurry 28 that has been converted to secondary slurry by the stirring means is maintained.

Since this emulsified slurry 28 is in a good oil-in-water type (O / W type) emulsified state, for example, blockage or clogging of lines, valves and the like when feeding to the hydrothermal oxidative decomposition apparatus 120 is prevented. Is done.
Therefore, according to the present invention, the emulsified slurry 28 of activated carbon does not agglomerate due to particle separation or agglomeration, and dispersibility and fluidity are improved, so that stable feeding to the hydrothermal oxidative decomposition apparatus 120 is possible. It becomes possible and troubles such as clogging do not occur, so the hydrothermal oxidative decomposition efficiency of activated carbon is improved.

Here, as in the present invention, two types of activated carbon having different particle diameters are converted into a primary slurry, and then these are used as a mixture. The mixed slurry 23 is converted into a primary slurry primary activated granular activated carbon 13A, a primary slurry fine powder. Since the additive is added according to the fineness of the activated carbon 13B and then emulsified with a line mixer, the properties of the resulting emulsified slurry 26 are improved.
This is because only the finely divided primary slurry fine powder activated carbon 13B has a fine particle size, so that no matter how much additive is added, the fluidity of the slurry cannot be improved and it becomes difficult to flow.
For this reason, activated carbon of large particles (coarse particles) and small particles (fine powders) is obtained by making a mixture of primary slurry granular activated carbon 13A obtained by slurrying activated carbons having two different particle sizes and primary slurry fine powder activated carbon 13B. Thus, it is possible to obtain a good mixed slurry 23 by supplying water thereto.

Furthermore, additives 21A and 21B are added to the mixture of primary slurry granular activated carbon 13A and primary slurry fine powder activated carbon 13B according to the fine particle size (for example, solid concentration, oil concentration, particle size, etc.) of each primary slurry. Since it is added, the effect of adding the surfactant is further exhibited. Thereby, emulsification is accelerated | stimulated and supply stop of the emulsification slurry 28 can be avoided. As a result, the emulsified slurry 28 can be stably supplied to the hydrothermal oxidative decomposition apparatus continuously.
Further, even when the supply of slurry is stopped, since the coarse granular activated carbon is mixed, it is possible to speed up the return of the slurry supply.

Here, the mixing ratio of the primary slurry granular activated carbon 13A and the primary slurry fine powder activated carbon 13B is preferably a mixing ratio of 1: 1, but the observation result of the slurry monitoring means 15A, 15B shows the state of the slurry. This ratio may be changed as appropriate.
Further, the type and amount of the additive may be changed while confirming the load of the pump P ₅ for extruding the emulsified slurry 28 supplied from the secondary slurry tank 27 to the hydrothermal oxidative decomposition apparatus 120.

  The fine particle size of the slurry of the slurry monitoring means 15A, 15B is preferably 40 to 80% in the case of solid concentration, for example. In the case of oil concentration, it is preferably 5 to 10%, for example. In the case of the particle size, the 50% average particle size is preferably 30 to 100 μm, and the particle size distribution range is preferably 0.1 to 200 μm. The fine particle size is appropriately changed according to the type of activated carbon and the degree of pulverization of granular activated carbon, and the present invention is not limited to these.

  Further, the types of the additives 21A and 21B are not one type but need to be properly used from the dispersibility and fluidity of the processed material, and may be two or more types.

  Here, as additives 21A and 21B, for example, nonionic surfactants, fatty acid surfactants (for example, sucrose fatty acid ester), higher alcohol surfactants (for example, polyoxyethylene alkyl ether), alkylphenol-based interfaces An activator (for example, polyoxyethylene alkylphenyl ether) can be exemplified, but the present invention is not limited thereto.

  As an example of the slurry property of the emulsified slurry 28, the ratio of the activated carbon is 50 to 70% by weight, and 0.5 to 3% by weight is added as an additive thereto. The rest is water.

In order to slurry the activated carbon 11A adsorbed with harmful substances (for example, PCB) using such an activated carbon slurrying apparatus 10, a good emulsified slurry can be obtained by performing the following steps.
1) Pulverization step This pulverization step is a step of pulverizing with a pulverizing means after supplying water 12 to granular activated carbon (3-8 mm pellet form) 11A adsorbing harmful substances.
2) First primary slurrying step The first primary slurrying step is a step of converting the pulverized granular activated carbon into primary slurryed granular activated carbon 13A.
3) Second primary primary slurrying step In this second primary slurrying step, water 12 is supplied to finely powdered activated carbon (1 to 100 μm finely powdered) 11B that adsorbs harmful substances and primary slurryed finely powdered activated carbon 13B. It is a process.
4) Mixing Step This mixing step is a step of mixing the primary slurry granular activated carbon 13A and the primary slurry fine powder activated carbon 13B in the mixing unit 24 to obtain a mixed slurry 23.
5) Additive supply process In this additive supply process, the slurry state of the primary slurry granulated activated carbon 13A in the first primary slurry tank 14A and the slurry in the second primary slurry tank 14B are added to the mixed slurry 23. This is a step of supplying the additives 21A and 21B according to the slurry state of the primary slurry fine powder activated carbon 13B.
6) Mixing and stirring step This mixing and stirring step is a step of emulsifying the mixed slurry 23 to which the additives 21A and 21B have been added with a line mixer 25 (for example, 1000 to 3000 rpm) that is a mixing and stirring for emulsifying.
7) Secondary slurrying step In this secondary slurrying step, the emulsified slurry 26 mixed with the line mixer 25, which is the mixing and stirring means, is converted into a secondary slurry (formation of oil-in-water emulsion) by the stirring means. It is the process of holding. At this time, further additives, water and the like may be added as necessary.

According to the present invention, the granular activated carbon 11A and the finely powdered activated carbon 11B are each made into a slurry, mixed with each other, and according to the slurry situation, the additive 21A, 21B is supplied and the line mixer 25 which is a mixing and stirring device. Since emulsification is performed, an emulsified slurry 28 with good fluidity can be obtained.
Since this emulsified slurry 28 is in a good oil-in-water type (O / W type) emulsified state, clogging, clogging, etc. during feeding to the hydrothermal oxidative decomposition apparatus 120 are prevented, and a stable slurry is always obtained. Supply can be made.

FIG. 2 is a schematic diagram of a configuration of a hydrothermal oxidative decomposition apparatus for treating harmful substances.
Next, an example of the hydrothermal oxidative decomposition treatment of harmful substances will be described with reference to FIG. 2, but the present invention is not limited to this.
As shown in FIG. 2, the hydrothermal oxidative decomposition apparatus 120 includes a cylindrical primary reaction tower 122 and oil (or organic solvent), PCB, water (H ₂ O), and sodium hydroxide (NaOH) treatment liquids. (Oil 123a, emulsified slurry 28 containing PCB, NaOH 123c, water 123d), a pressure pump 124 for pressurizing, a preheater 125 for preheating the water, and a secondary reaction tower 126 having a configuration in which, for example, a pipe is spirally wound. And a cooler 127 and a pressure reducing valve 128. Further, a gas-liquid separator 129 and an activated carbon layer 130 are disposed downstream of the pressure reducing valve 127, exhaust gas (CO ₂ ) 131 is exhausted from the chimney 132, and drainage (H ₂ O, NaCl) 133 is It is stored in the discharge tank 134 and is drained separately if necessary.

Note that oil (or organic solvent), PCB, H ₂ O, and NaOH treatment liquids (oil 123a, emulsified slurry 28 containing PCB, NaOH 123c, and water 123d) are connected to pipes 136a to 136d from the treatment liquid tanks 135a to 135d. And a mixer 137 such as an ejector. Further, an oxidizing agent such as oxygen (O ₂ ) is supplied by a high-pressure oxygen supply facility 138, and the supply pipe 139 is directly connected to the primary reaction tower 122. The reason why oil (or organic solvent) is added is to promote the decomposition reaction of particularly high-concentration PCB and to raise the reaction temperature to the optimum temperature when the hydrothermal oxidative decomposition apparatus 120 is started. Further, the above PCB, H ₂ O and NaOH may be mixed as the treatment liquid and charged into the primary reaction tower 122.

In the above apparatus, the pressure in the primary reaction tower 122 is increased to, for example, 26 MPa by pressurization by the pressurization pump 124. The preheater 125 preheats H ₂ O to about 300 ° C., for example. Further, oxygen is spouted into the primary reaction tower 122, and the temperature is raised to 380 ° C. to 400 ° C. by the internal reaction heat. By this stage, for example, PCB has been dechlorinated and oxidatively decomposed and decomposed into NaCl, CO ₂ and H ₂ O. Next, in the cooler 127, the fluid from the secondary reaction tower 126 is cooled to about 100 ° C. and the pressure is reduced to atmospheric pressure by the pressure reducing valve 128 at the subsequent stage. Then, CO ₂ and water vapor and the treatment liquid are separated by the gas-liquid separator 129, and the CO ₂ and water vapor are discharged into the environment through the activated carbon layer 130.

By treating the emulsified slurry 28 containing PCB, which is a harmful substance, using such a hydrothermal oxidative decomposition apparatus 120, PCB is dechlorinated and dechlorinated products such as biphenyl ((C ₆ H ₅ ) ₂ ) and The biphenyl is completely detoxified into CO ₂ , H ₂ O and the like by the action of an oxidizing agent or the like.

  Therefore, according to the present invention, activated carbon adsorbing harmful substances such as PCB (granular activated carbon 11A, fine pine activated carbon 11B) is made into an emulsified slurry 28 in a good emulsified state containing PCB by the activated carbon slurrying apparatus 10, and this PCB. The emulsified slurry 28 contained in the hydrothermal oxidative decomposition apparatus 120 is not separated into particles or agglomerated for agglomeration, and stable activated carbon detoxification can be achieved.

10 activated carbon slurry generator 11A granular activated carbon 11B fine powder activated carbon 13A primary slurry granular activated carbon 14A first primary slurry tank 14B second primary slurry tank 15A first slurry monitoring means 15B second slurry monitoring means 21A, 21B Additives 23 Mixed slurry 25 Line mixer 26 Emulsified slurry 27 Secondary slurry tank 28 Emulsified slurry

Claims (2)

An activated carbon slurrying device for slurrying activated carbon that has adsorbed harmful substances,
And breaking means for pulverizng after supplying water to granular activated carbon with adsorbed harmful substances,
A first primary slurrying tank in which the pulverized granular activated carbon is used as the primary slurry granular activated carbon;
First slurry monitoring means for monitoring a slurry state of the primary slurry granular activated carbon in the first primary slurry tank ;
A second primary slurried tank for the primary slurrying finely powdered activated carbon to hazardous substances by supplying water to the fine powder activated carbon adsorption,
Second slurry monitoring means for monitoring the slurry state of the primary slurryed fine powder activated carbon in the second primary slurrying tank ;
Provided before feeding the added pressure agent, a mixing unit to mix the slurry product by mixing the primary slurry of granular activated carbon and primary slurried fine powdered activated carbon,
A first additive supply means for supplying an additive to the mixed slurry according to the fine particle size of the primary slurry granular activated carbon;
A second additive supply means for supplying an additive to the mixed slurry according to the fine particle size of the primary slurry fine powder activated carbon;
The mixture slurry product and mixing and stirring means for emulsification with the addition of additives,
An activated carbon slurrying apparatus, comprising: a secondary slurrying tank that holds an emulsified state of the emulsified slurry mixed by the mixing and stirring means. An activated carbon slurrying method for slurrying activated carbon that has adsorbed harmful substances,
A pulverization process in which water is supplied to granular activated carbon that has adsorbed harmful substances and then pulverized by a pulverizing means;
A first primary slurrying step in which the pulverized granular activated carbon is used as primary slurry granular activated carbon;
A second primary slurrying step in which water is supplied to finely powdered activated carbon adsorbing harmful substances to form primary slurryed finely powdered activated carbon;
A mixing step of mixing primary slurry granular activated carbon and primary slurry fine powder activated carbon into a mixed slurry,
An additive supply step for supplying an additive to the mixed slurry according to the fine particle size of the primary slurry granular activated carbon and an additive according to the fine particle size of the primary slurry fine activated carbon ;
The mixture slurry product and mixing and stirring step of emulsification with the addition of additives,
And a secondary slurrying step of maintaining the emulsified state of the emulsified slurry by mixing the emulsified slurry mixed in the mixing and stirring step with a stirring means.

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