JP2000167392A - Adsorbing material regenerating apparatus and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for regenerating activated carbon not generating a drainage problem and not only moving an org. solvent capable of becoming a contaminant between media but fundamentally decomposing and purifying the same, and an adsorbing treatment apparatus utilizing the regeneration apparatus effectively. SOLUTION: The adsorbing material regenerating apparatus has a means for holding functional water containing a component generating the decomposition of a contaminant under the irradiation with light, a means 4 for irradiating this functional water with light, a means for holding an adsorbing material 1 adsorbing a contaminant, a means 5 for heating the adsorbing material 1 and a means for bringing the contaminant discharged from the adsorbing material 1 into contact with the functional water. The adsorbing material is regenerated by using this apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for desorbing and regenerating adsorbed and broken activated carbon in a solvent recovery apparatus and a deodorizing apparatus using activated carbon.

[0002]

2. Description of the Related Art Conventionally, activated carbon regeneration technology is generally performed by utilizing heating by steam or the like to remove trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, cis- Activated carbon is regenerated by removing organic solvents such as 1,2-dichloroethylene and chlorofluorocarbon.

[0003] Such a system comprises an activated carbon tower and a condenser, a decanter, connected to the discharge side of the activated carbon tower.
In addition, the condenser is provided with an aeration tank connected to the drain side of the decanter, and the condenser is set at a temperature of 10 to 30 ° C. to liquefy the adsorbed substance and vapor. Water and specific gravity were separated. Further, further on the lower side, the gas component and the wastewater are separated in the aeration tank, and discharged to the outside to complete the processing.

[0004]

However, this method may have the following problems. 1 A part of the collected solvent or the like as the substance to be adsorbed may be dissolved in the wastewater, and further wastewater treatment may be required. 2. When the object to be treated is a water-soluble solvent, it may be difficult to recover the solvent. 3 Further treatment of the organic solvent after recovery of the solvent in the decanter is required. Incineration may cause additional contamination, such as the generation of dioxins. 4. After separation of gas components and wastewater in the aeration tank, pollutants are discharged to the outside world.

Therefore, the object of the present invention is to prevent the problem of drainage from occurring,
An object of the present invention is to obtain a method and an apparatus for regenerating an activated carbon that fundamentally decomposes and purifies an activated carbon, instead of simply transferring an organic solvent that may become a pollutant between media. To get.

[0006]

According to the present invention, there is provided an activated carbon regenerating apparatus for retaining functional water containing a component which causes decomposition of pollutants under light irradiation; An apparatus for regenerating an adsorbed material, comprising: means for irradiating the contaminant with the functional water; means for irradiating the contaminant with the functional water; means for heating the adsorbed material adsorbing the contaminant;

Further, the method of the present invention for regenerating an adsorbed material comprises heating the adsorbed material to which the contaminant is adsorbed to discharge the contaminant; and decomposing the contaminant under light irradiation. A step of bringing the functional water containing the component to be contacted under light irradiation.

The operation is as follows.

In the method and apparatus for regenerating activated carbon of the present invention, activated carbon is disposed in a predetermined circulation path, and is heated in an activated carbon tower which forms a part of the circulation path. The substance to be adsorbed desorbed from the activated carbon by this heating is desorbed in a gaseous state. The adsorbed substance in the desorbed gas state reaches an equilibrium state with functional water in a functional water tank disposed in the circulation path.
That is, the substance to be adsorbed in the gas state dissolves in the functional water according to the equilibrium conditions. Here, when the functional water is irradiated with light, the dissolved substance to be absorbed is decomposed by the decomposing ability of the functional water. Then, the adsorbed substance in the gaseous state further dissolves in the functional water and is sequentially decomposed, and finally the adsorbed substance is desorbed from the activated carbon,
As the activated carbon is regenerated, the substance to be adsorbed from the activated carbon is also decomposed, and complete purification is performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 shows a system configuration of an activated carbon desorption system of the present invention. This system includes an activated carbon tank 2 in which activated carbon 1 to be treated is stored, a functional water tank 3, and a light irradiation unit 4 for irradiating the functional water with light. Here, in the present embodiment, the activated carbon tank 2 can be supplied with activated carbon to which the substance to be adsorbed has already been adsorbed. The activated carbon tank 2 is provided with a heater 5 as a means for heating the activated carbon 1.

In the activated carbon desorption system having this configuration, the activated carbon in the state of adsorbing the adsorbed substance and breaking through the adsorption is used.
The activated carbon 1 is stored in a predetermined position of the activated carbon tank 2, and the heater 5 is operated to heat the activated carbon 1, and the substance to be adsorbed is desorbed from the activated carbon 1 to regenerate the activated carbon 1. This step is called a regeneration step.

Further, the gas of the substance to be adsorbed is introduced into the functional water tank 3, and a part of the mixed gas g is dissolved in the functional water according to the equilibrium conditions. Further, the functional water is irradiated with light by a lamp as the light irradiating means 4 to decompose the adsorbed substance dissolved in the functional water. This step is called a dissolution / purification step.

[0014] Here, a pump may be used to promote the dissolution into the functional water. 6 is a functional water generator for supplying functional water to the functional water tank 3. The equilibrium is broken by the decomposition of the substance to be adsorbed dissolved in the functional water, and a part of the mixed gas g further dissolves in the functional water. This reaction proceeds continuously, and all the adsorbed substances finally desorbed from the activated carbon 1 are decomposed in the functional water, and the regeneration of the activated carbon is completed.

Each device will be described in further detail below.

(Activated Carbon 1 to be Treated) The activated carbon 1 that can be used in the present system may be any one, but it is desirable to select an appropriate one by a heating means. For example, in order to perform microwave heating, it is desirable that the electric resistance is large. The electrical resistance of pitch-based fibrous activated carbon is
Although it has a resistance of about 3Ω in the case of 150 mm, the electric resistance of the PAN-based fibrous activated carbon is much smaller, so that it is necessary to take another heating method, for example, a method of heating a heater or desorbing steam.

(Adsorbed object) The object to be treated includes trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, cis-1,2-dichloroethylene, H
Examples thereof include CFC, 13-fluorocarbon, and chloroform.

(Heater) The heater 5 attached to the outside of the activated carbon tank 2 is, for example, a microwave
450 MHz, 1.2 kW, which is usually used in household microwave ovens. The state of the microwave heating is such that the surface temperature of the activated carbon 1 is detected by the far-infrared distance thermometer 2a provided in the activated carbon tank 2, and the microwave irradiation energy is controlled.

An example of the surface temperature is 120 ° C. In this system, since steam is not used for heating, the system is a dry system. Since the entire activated carbon tower is not heated, the energy saving effect is large and the equipment is inexpensive.

(Functional water generator 6 and functional water) Functional water tank 3
The functional water used in is, for example, hydrogen ion concentration (pH value)
The oxidation-reduction potential when the working electrode is a platinum electrode and the reference electrode is silver-silver chloride is 800 mV or more and 1500 mV or less, preferably 1000 mV or more and 1300 mV or less, and the chlorine concentration is 1 or more and 4 or less, preferably 2 or more and 3 or less. It refers to water having a property of 5 mg / L or more and 150 mg / L or less, preferably 30 mg / L or more and 120 mg / L or less.

Such functional water can be obtained in the vicinity of its anode by dissolving an electrolyte (eg, sodium chloride or potassium chloride) in raw water and subjecting this water to electrolysis in a water tank having a pair of electrodes. it can. Here, the concentration of the electrolyte in the raw water before the electrolysis is, for example, preferably 20 mg / L to 2000 mg / L for sodium chloride, and more preferably 200 mg / L to 1000 mg / L.

When a diaphragm is arranged between the pair of electrodes at this time, it is possible to prevent mixing of the acidic water generated near the anode and the alkaline water generated near the cathode, and to reduce the decomposition of the organic compound. It is possible to obtain acidic water that can be efficiently performed.

As the diaphragm, for example, an ion exchange membrane is preferably used. As a means for obtaining such functional water, commercially available strongly acidic electrolyzed water generator (for example, trade name: Oasis Bio Half; manufactured by Asahi Glass Engineering Co., Ltd., trade name: strong electrolyzed water generator (Model FW- 200; manufactured by Amano Co., Ltd.).

Further, functional water generated from a device having no diaphragm can also be used for the decomposition of the organic compounds described above. For example, the oxidation-reduction potential is 300 mV or more and 1
100 mV or less, preferably 500 mV or more and 900 mV
And the chlorine concentration is 2 mg / L or more and 100 mg / L or less, preferably 20 mg / L or more and 80 mg / L or less.
~ 10, preferably 5-8 functional waters.

The acidic water having the above characteristics can be prepared not only by electrolysis but also by dissolving various reagents in raw water. For example, it can be obtained by adjusting the concentration of hydrochloric acid to 0.001N to 0.1N, sodium chloride to 0.005N to 0.02N, and sodium hypochlorite to 0.0001M to 0.01M.

The functional water having a pH of 4 or more can be prepared not only by electrolysis but also by dissolving various reagents in raw water. For example, it can be obtained by adjusting the concentration of hydrochloric acid to 0.001 N to 0.1 N, sodium hydroxide to 0.001 N to 0.1 N, and sodium hypochlorite to 0.0001 M to 0.01 M, and hypochlorite. Only, for example, sodium hypochlorite can be obtained by adjusting the concentration to 0.0001M to 0.01M.

Hydrochloric acid and hypochlorite can be used to prepare functional water having a pH of 4.0 or less and a chlorine concentration of 2 mg / L or more.

All of these functional waters can be used in the present invention, which exhibits a strong oxidizing ability upon irradiation with light and decomposes polluting organic substances.

(Light irradiating means 4) As the light irradiating means which can be used in the present invention, for example, a wavelength of 300 to 500 n
m, and more preferably 350 to 450 nm. The light irradiation intensity for the functional aqueous solution and the decomposition target is, for example, several hundred μW / cm ² (300 nm to 400 nm in a light source having a peak near a wavelength of 360 nm).
(Measurement is performed), the decomposition is practically sufficient.

As a light source of such light, natural light is used.
(Eg, sunlight) or artificial light (mercury lamp, black light, color fluorescent lamp, etc.) can be used.

[Embodiment 2] In the above embodiment, an example of an apparatus adopting the present invention which is used to regenerate activated carbon in a state in which an adsorbed substance is adsorbed and adsorbed and broken has been described. It is also possible to constitute a system that performs the adsorption treatment of the raw gas containing the object to be treated, and alternately removes the object to be treated by the activated carbon 1 and regenerates the activated carbon 1 in a closed loop.

FIG. 2 shows such an example. In this system, a pair of activated carbon towers 2 are provided, and a raw gas supply path 7 and a raw gas discharge path 8 are individually provided for these activated carbon towers 2. The functional water tank 3 is arranged so that the gas from the activated carbon tower 2 is supplied via the on-off valves 11a and 11b, and 6 is a functional water generator for supplying functional water to the functional water tank.

The operating state of the illustrated one will be described. The one disposed on the right is the one that is operating by removing the adsorbed material from the raw gas, and the one on the left is
Activated carbon is being regenerated.

The opening and closing of each of the on-off valves 11a and 11b alternately performs adsorption removal of the object to be treated and regeneration of the activated carbon. The raw material gas is supplied from the raw gas supply path 7 and enters the activated carbon tower 2a through the supply control valve 9 through 7a, where the adsorption treatment is performed. At this time, each on-off valve 11a is closed, and no gas flows into the functional water tank 3 from the activated carbon tower 2a.

The gas having undergone the adsorption treatment is discharged from the discharge passage 8 through the discharge control valve 10 through 8a. While the adsorption treatment is performed in the activated carbon tower 2a, the regeneration treatment is performed in the activated carbon tower 2b. In other words, the control valves 9, 10 are closed and 11b is opened, so that the activated carbon tower 2b and the functional water tank 3 are closed spaces. At this time, the heater 5b is operated to heat the activated carbon 1b, and the object to be adsorbed is desorbed from the activated carbon 1b to regenerate the activated carbon 1b.

The gas to be adsorbed is introduced into the functional water tank 3 via the control valve 11b, and a part of the mixed gas g is dissolved in the functional water according to the equilibrium conditions. Further, the functional water is irradiated with light by a lamp as the light irradiation means 4 to decompose the gas to be adsorbed dissolved in the functional water. Using a blower or the like, a means for more positively promoting the dissolution of gas into the functional water may be taken.

By alternately performing the adsorption removal and the regeneration of the activated carbon, continuous treatment of pollutants and regeneration of the activated carbon became possible.

[0038]

The following is an example of experimentally confirming the present invention.

A plurality of 27.5 mL glass vials were prepared, each containing 2.0 g of activated carbon (granular, Kanto Kagaku), and sealed with a butyl rubber stopper with a Teflon (registered trademark) liner and an aluminum seal. Next, put 10mg in a glass vial.
Was added in a gaseous state to all the glass vials through a butyl rubber stopper with a gas-tight syringe, and then left for several hours.

Thereafter, the TCE concentration was measured, and it was confirmed that all the TCE gas in the glass vial was adsorbed on the activated carbon. The TCE concentration of the gas phase in the glass vial was measured by sampling the gas phase of the glass vial with a gas tight syringe and measuring the TCE concentration by gas chromatography (trade name: GC-14B (with FID detector)). The column was measured by Shimadzu Corporation, and the column was measured by J & W DB-624).

Next, the activated carbon 1 on which TCE was adsorbed was placed in the activated carbon tank 2 of the apparatus shown in FIG. The function tank 3 has a pH of 2.1,
100 mL of functional water having an oxidation-reduction potential of 1150 mV and a residual chlorine concentration of 54 mg / L was added. While the activated carbon was heated by an electric heater (silicon rubber heater) 5, the functional water tank was continuously irradiated with light of a black light fluorescent lamp 4 (trade name: FL10BLB; manufactured by Toshiba Corporation, 10W) for 24 hours.

Then, the activated carbon was taken out and immediately n-hexane
Put in a container containing 10 mL, stir for 10 minutes, then n-hexan
e layer was separated and TC was measured by ECD gas chromatography.
The E amount was measured.

As a result, no TCE was detected from n-hexane, and it was found that activated carbon was regenerated.

No TCE was detected from the gas phase of the functional water tank or the activated carbon tank, indicating that TCE was not only removed but also decomposed.

[0045]

According to the method and the apparatus for regenerating activated carbon of the present invention, no drainage problem occurs, and it is possible not only to transfer organic solvents which can be pollutants between media but also to purify them by radical decomposition. became.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an activated carbon regeneration device according to one embodiment of the present invention.

FIG. 2 is a schematic view of an activated carbon regeneration device according to another embodiment of the present invention.

FIG. 3 is a schematic view of an activated carbon regenerating apparatus used when the present invention has been experimentally confirmed.

[Explanation of symbols]

 Reference Signs List 1 activated carbon 2 (a, b) activated carbon tower, activated carbon tank 3 functional water tank 4 light irradiation means 5 (a, b) heater 6 functional water generator 7 a, b supply path 8 a, b discharge path 9 supply control valve 10 discharge control valve 11a, b On-off valve 12 Drain pipe 13 Pump

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 53/81 F-term (Reference) 4D002 AA17 AA21 AA22 BA04 BA08 BA09 BA20 CA07 DA02 DA03 DA26 DA35 DA37 DA41 DA70 EA05 EA07 EA08 GB02 GB08 GB09 GB20 4G066 AA05B CA33 DA03 GA02 GA03

Claims (25)

[Claims] Heating the adsorbed material on which the contaminant is adsorbed to discharge the contaminant; and converting the contaminant and functional water containing a component that causes the decomposition of the contaminant under light irradiation. Contacting under light irradiation. 2. The method according to claim 1, wherein the functional water contains hypochlorous acid.
3. The method for regenerating an adsorbed material according to 1. 3. The method of claim 1, wherein the functional water is generated by electrolysis of water containing an electrolyte. 4. The method for regenerating an adsorbed material according to claim 3, wherein the functional water is acidic water generated near an anode by electrolysis of water containing an electrolyte. 5. The method according to claim 3, wherein the electrolyte is at least one of sodium chloride and potassium chloride. 6. The functional water according to claim 2, further comprising an inorganic acid.
6. The method for regenerating an adsorbed material according to any one of items 5 to 5. 7. The method according to claim 1, wherein the inorganic acid is hydrochloric acid, hydrofluoric acid, oxalic acid,
The method for regenerating an adsorbed material according to claim 6, wherein the method is at least one selected from sulfuric acid, phosphoric acid, and boric acid. 8. The method according to claim 2, wherein the functional water is an aqueous solution of hypochlorite. 9. The method according to claim 8, wherein the hypochlorite is at least one of sodium hypochlorite and potassium hypochlorite. 10. The chlorine concentration of the functional water is 2 to 150 mg.
The method according to any one of claims 1 to 9, wherein the ratio is / L. 11. The functional water has a hydrogen ion concentration (pH value) of 1
11. The redox potential (working electrode: platinum electrode, reference electrode: silver-silver chloride electrode) of 800 to 1500 mV, and a chlorine concentration of 5 to 150 mg / L. The method for regenerating an adsorbed material according to the paragraph. 12. The functional water has a hydrogen ion concentration (pH value).
11. The composition according to any one of claims 1 to 10, which has a characteristic of 4 to 10, an oxidation-reduction potential (working electrode: platinum electrode, reference electrode: silver-silver chloride electrode) of 300 to 110 mV, and a chlorine concentration of 2 to 100 mg / L.
The method for regenerating the adsorbed material as described. 13. The method according to claim 1, wherein the light in the irradiation is 300 to 50.
13. The method for regenerating an adsorbed material according to claim 1, wherein the light is a light including a wavelength range of 0 nm. 14. The method according to claim 1, wherein the contaminant is a halogenated aliphatic hydrocarbon compound. 15. The method according to claim 14, wherein the halogenated aliphatic hydrocarbon compound is an aliphatic hydrocarbon compound substituted with at least one of chlorine and fluorine. 16. The halogenated aliphatic hydrocarbon compound may be trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, cis-1,2-dichloroethylene, H
16. The method for regenerating an adsorbed material according to claim 15, wherein the method is at least one of CFC, 11-fluorocarbon and chloroform. 17. The method according to claim 1, wherein the adsorption material is activated carbon.
17. The method for regenerating an adsorbed material according to any one of items 16 to 16. 18. A means for retaining functional water containing a component that causes decomposition of a contaminant under light irradiation; a means for irradiating the functional water with light; and a means for heating an adsorbing material that has adsorbed the contaminant. And an adsorbing material regenerating apparatus having means for bringing contaminants discharged from the adsorbing material by heating into contact with functional water. 19. The adsorptive material regenerating apparatus according to claim 1, wherein the functional water contains hypochlorous acid. 20. The adsorption material regenerating apparatus according to claim 18, wherein the functional water is generated by electrolysis of water containing an electrolyte. 21. The functional water is an acidic water generated in the vicinity of an anode by electrolysis of water containing an electrolyte.
An apparatus for regenerating an adsorbed material as described in the above. 22. The functional water has a hydrogen ion concentration (pH value) of 1
22. The method according to any one of claims 18 to 21, wherein the oxidation-reduction potential (working electrode: platinum electrode, reference electrode: silver-silver chloride electrode) is 800 to 1500 mV, and the chlorine concentration is 5 to 150 mg / L. An apparatus for regenerating an adsorbed material as described in the above. 23. The functional water has a hydrogen ion concentration (pH value).
22. The composition according to any one of claims 18 to 21, wherein the composition has characteristics of 4 to 10, an oxidation-reduction potential (working electrode: platinum electrode, reference electrode: silver-silver chloride electrode) of 300 to 2300 mV and a chlorine concentration of 2 to 100 mg / L. An apparatus for regenerating an adsorbed material as described in the above. 24. The light from the means for irradiating,
19. Light having a wavelength range of 300 to 500 nm.
24. The adsorption material reproducing apparatus according to any one of items 23 to 23. 25. The method according to claim 1, wherein the adsorption material is activated carbon.
25. The adsorption material reproducing apparatus according to any one of 8 to 24.