JP2004254761A - Gasification method of environmental pollutant and apparatus therefor, and decomposition treatment method and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide gasification and decomposition methods and apparatuses therefor which enable the efficient decomposition and removal of the environmental pollutants such as dioxin or PCB hard to decompose along with a low degree of dissolution into water and high in environmental persistence. <P>SOLUTION: In a gasification method of the environmental pollutants and an apparatus therefor, the PCB or other environmental pollutants are adsorbed by the activated charcoal and separated as gas components from the activated charcoal using the superheated steam and a decomposition treatment method, and in a method and apparatus for decomposition treatment of environmental pollutant, the gas components are subjected to the decomposition treatment by the superheated steam. The material to be decomposed with a higher water content contaminated by the PCB or other environmental pollutants is separated into liquid and solid components by a solid/liquid separation means, the PCB or other environmental pollutants contained in the liquid components are adsorbed by the activated charcoal and separated as the gas components from the activated charcoal using the superheated vapor. The gas components thus obtained are subjected to the decomposition treatment by the superheated steam. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gasification method and apparatus for a hardly decomposable environmental pollutant, and a decomposition treatment method and apparatus therefor, and in particular, adsorbs environmental pollutants such as PCB (polychlorinated biphenyl) and dioxin on activated carbon, and superheated steam. The present invention relates to a gasification method and apparatus for separating the activated carbon as a gas component, and a method and apparatus for decomposing environmental pollutants as separated gas components using superheated steam.
[0002]
[Prior art]
PCB is a collective term for biphenyl hydrogen replaced with chlorine. In Japan, production began in 1954, making use of its excellent electrical characteristics, nonflammability, and chemical stability to make various capacitors and transformers. It is used in insulation oil for ceramics, ballasts such as fluorescent lamps, pole transformers, heat transfer media, lubricating oil, and pressure sensitive paper. This PCB is highly degradable and has high environmental persistence, low solubility in water, but high fat solubility, so it is easy to accumulate in adipose tissue, and is semi-volatile and has volatilization mobility that moves through the atmosphere. Yes, toxicities such as carcinogenicity and effects on the immune system have been confirmed.
[0003]
Non-Patent Document 1 summarizes the outline of this PCB problem. For example, conventionally known methods for treating liquid PCBs include thermal decomposition at a high temperature of 1100 ° C. or higher, dechlorination in which chlorine in PCBs is replaced with hydrogen by chemical reaction and decomposed into non-PCB materials. Method, hydrothermal oxidative decomposition method that decomposes PCB with high-temperature and high-pressure water, and catalytic oxidation that desorbs carbon of high-temperature molten metal by putting oxygen and PCB into high-temperature molten metal (Ni-Cu) in reducing atmosphere Reduction thermochemical decomposition method that decomposes into carbon, carbon dioxide and hydrochloric acid, photodegradation method (UV catalytic method) in which PCB and alkaline agent are mixed, dechlorinated by ultraviolet irradiation, and decomposed by catalyst or PCB decomposition bacteria is there.
[0004]
Further, as a method for treating solid PCBs, the above-described thermal decomposition method at high temperature, hydrothermal oxidative decomposition method in which organic matter impregnated / attached with PCB by high-temperature and high-pressure water is decomposed, and PCB decomposed by heating contaminants is reduced. There are a reductive thermochemical decomposition method that decomposes thermally / chemically at room temperature, a vacuum heating separation method that separates PCB by heating PCB contaminants in a vacuum state, a solvent cleaning method that cleans using an organic solvent, and the like.
[0005]
On the other hand, according to Patent Document 1, the applicant of the present application previously heated a solvent to generate a solvent vapor, further heated the solvent vapor to a predetermined temperature to form a solvent superheated vapor, and brought the solvent superheated vapor to a predetermined temperature. Supply continuously into a heated normal pressure (or slightly negative pressure) reactor, supply the material to be decomposed into the reactor in the atmosphere of the solvent superheated steam, and pass it over a predetermined reaction time. In this way, a method and apparatus for decomposing an environmental pollutant that decomposes an object to be decomposed has been proposed. According to such a decomposition treatment method, environmental pollutants such as chlorofluorocarbon gas are vaporized together with the solvent and then heated to become superheated vapor whose temperature only rises at normal pressure (or slightly negative pressure), and a predetermined reaction is caused in the reactor. When passing over time, it is decomposed, and the superheated steam is liquefied and discharged. Since these reactions are all closed systems in the reaction apparatus, there is an effect that no secondary contamination occurs.
[0006]
In the case of an environmental pollutant containing a solid component, the inside of the reaction apparatus is transferred by a transfer device and decomposed, and the solid component remaining after the decomposition process is discharged from the reaction apparatus. By arbitrarily setting the reaction time and temperature, the degree of decomposition can be controlled. During processing, a 100% decomposition rate can be obtained in a short time of 1 second or less to several tens of seconds, and the processing temperature can be set arbitrarily. The activation energy required to start decomposition can be selected and the solvent vapor can be arbitrarily selected depending on the substance to be decomposed, so the decomposition rate, decomposition rate, etc. are stable, and most organic compounds can be decomposed. .
[0007]
[Patent Document 1]
Japanese Patent No. 3219689 [Non-Patent Document 1]
Trends in PCB issues (Summary of amendments to Topics Environmental Corporation Law), http: // www. jama-net. or. jp / Japanes / jyuden / pcb62. htm
[0008]
[Problems to be solved by the invention]
However, each of the various processing methods for the liquid or solid PCB requires a high processing cost. Therefore, in addition to the difficulty in cost, the conventional method is to burn the material to be decomposed. Therefore, there is a problem that PCB may be re-synthesized during cooling even if it is once decomposed. Moreover, although the processing method of about 1 to 3% of PCB contained as a liquid has a track record, there is almost no track record about the processing method of solid PCB.
[0009]
Furthermore, the high-temperature incineration method has a problem of measures against dioxins and the like generated in the residue, and in other treatment methods, it is difficult to change the reaction process depending on the material to be decomposed, and a dedicated device is required. The running cost and the initial cost are high, and there is a disadvantage that there is no versatility.
[0010]
Accordingly, the present invention solves the above problems in a system for decomposing difficult-to-decompose environmental pollutants such as PCB and dioxin, and adsorbs environmental pollutants such as PCB on activated carbon to efficiently remove the activated carbon. A method for gasifying and decomposing environmental pollutants such as PCBs, in which environmental pollutants such as PCBs attached to the substrate are separated from the activated carbon as gas components using superheated steam, and gas components are further decomposed using superheated steam, and The object is to provide such a device.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention adsorbs PCBs and other environmental pollutants on activated carbon and separates them from the activated carbon as gas components using superheated steam, an apparatus for gasifying the environmental pollutants, and an apparatus therefor obtained. We provide an environmental pollutant decomposition method and apparatus for decomposing gas components with superheated steam. Highly water-decomposed materials contaminated with PCBs and other environmental pollutants are separated into liquid and solid components by solid-liquid separation means, and the PCB and other environmental pollutants contained in the liquid components are adsorbed on activated carbon. The activated carbon is separated from the activated carbon as a gas component using superheated steam, and the obtained gas component is decomposed with superheated steam. In addition, the high-water-decomposition material contaminated with PCB and other environmental pollutants is separated into a liquid component and a solid component by solid-liquid separation means, and superheated steam is used to remove PCB and other environmental pollutants contained in the solid component. It isolate | separates as a gas component with the used gasifier, and decomposes | disassembles the obtained gas component by superheated steam.
[0012]
Further, PCBs and other environmental pollutants contained in the material to be decomposed with a low water content are separated as gas components by a gasifier using superheated steam, and the obtained gas components are decomposed by superheated steam. PCBs and other environmental pollutants contained in oil are converted into gas components by a gasifier using superheated steam, and the obtained gas components are decomposed by superheated steam. PCB and other environmental pollutants adhering to the solid component are converted into gas components by a gasifier using superheated steam, and the obtained gas components are decomposed by superheated steam.
[0013]
According to such an environmental pollutant gasification method and apparatus, and its decomposition treatment method and apparatus, PCB and other environmental pollutants are adsorbed on activated carbon and separated from the activated carbon as gas components using superheated steam. In addition, the obtained gas component can be decomposed with superheated steam. Accordingly, it is possible to provide a gasification / decomposition method and apparatus capable of efficiently decomposing and removing environmental pollutants such as PCB which are hardly decomposable and have low water solubility and high environmental persistence.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A specific embodiment of a method and apparatus for gasifying an environmental pollutant and a decomposition method and apparatus for the same according to the present invention will now be described with reference to the drawings, taking PCB gasification and decomposition as an example. FIG. 1 is a flowchart of PCB pollutant processing to which the present invention is applied. When PCB pollutants are [1] high water content, [2] low water content, [3] PCB-containing oil ] [4] Treatment of PCB adhered to solid] [5] Treatment of PCB adsorbed activated carbon]
[0015]
[(1) Case of high water content] and [(5) Treatment of PCB-adsorbed activated carbon]
As shown in Step 1, when the material to be decomposed is, for example, PCB-contaminated soil having a high moisture content, first, in Step 2, solid-liquid separation processing of the PCB-contaminated soil is performed by solid-liquid separation means. A liquid component is obtained and a solid component is obtained in step 4. The liquid component is adsorbed on the activated carbon in Step 5 to remove the PCB, and discharged as the liquid cleaned in Step 6. The activated carbon that has adsorbed PCB in step 5 is treated as PCB adsorbed activated carbon shown in step 24 when the adsorption amount reaches a saturated state. By supplying the superheated steam 8 to the PCB-adsorbed activated carbon shown in step 24, the PCB is separated from the PCB-adsorbed activated carbon as a gas component, and is supplied to the decomposition apparatus in step 11 to be decomposed by the superheated steam 8. The activated carbon from which the PCB has been removed can be reused.
[0016]
Further, the gas component that has been decomposed in step 11 is cooled in step 12 to obtain a gas component in step 13 and a liquid component in step 14. The gas component obtained in step 13 is subjected to an adsorption process again with activated carbon in step 15 and then exhausted as a safe gas in step 16. The liquid component obtained in step 14 is subjected to an adsorption process again with activated carbon in step 17. To remove the PCB and discharge as the liquid cleaned in step 18. The adsorption treatment with activated carbon in step 15 and step 17 is performed as a fuel safe means in order to completely remove PCB in the system, and the decomposition itself is completed in step 11. Therefore, step 15 and step 17 can be omitted depending on the properties of the object to be decomposed.
[0017]
On the other hand, the solid component obtained in step 4 is sent to the gasifier in step 7 and superheated steam 8 is supplied to obtain a gas component in step 9 and a residue component in step 10. The gas component obtained in step 9 is decomposed by superheated steam 8 in step 11. Thereafter, the gas components separated and decomposed from the PCB-adsorbed activated carbon are processed through steps 12 to 18 in the same manner.
[0018]
[▲ 2 ▼ When moisture content is low]
If the material to be decomposed is PCB contaminated soil having a low water content, as shown in step 19, the solid-liquid separation process in step 2 is omitted and immediately sent to the gasifier in step 7, where superheated steam 8 Thereafter, the same processing is performed to perform safe gas exhaust processing and processing of the residue from which the PCB has been removed.
[0019]
[▲ 3 ▼ In case of oil containing PCB]
When the material to be decomposed is, for example, oil containing PCB as shown in step 20, the solid-liquid separation process is omitted as in step 19, and the gas is fed into the gasifier in step 7 and gasified with superheated steam. Process in the same manner as above.
[0020]
[(4) Treatment of PCB attached to solid]
As shown in step 21, when the material to be decomposed is PCB attached to a solid, for example, the residue is treated by heating at about 500 ° C. and when the residue can be gasified without residue. . First, the solid component that remains as a residue that is difficult to gasify by heating at about 500 ° C. shown in Step 22 is sent to the gasifier in Step 7 and supplied with superheated steam 8, and the gasified component is decomposed in Step 11. After the decomposition process with the superheated steam 8 is performed in the apparatus, the process is performed as described above to perform a safe gas exhaust process and the discharge of the cleaned liquid. On the other hand, the solid component which can be gasified without any residue by heating at about 500 ° C. shown in Step 23 is directly supplied to the decomposition apparatus in Step 11 and subjected to the decomposition treatment with the superheated steam 8 and then the treatment as described above. Do.
[0021]
FIG. 2 is a system diagram showing an embodiment for carrying out [(1) High moisture content] and [(5) PCB adsorbed activated carbon treatment] in the PCB pollutant treatment flowchart of FIG. The main components are as follows. 25 is a vapor compression dehydrator, 26 is a boiler, 27 is a liquid tank, 28 is a gasifier, 29 is a residue tank, 30 and 31 are activated carbon towers, 32 is a heater, 33 is a decomposition device, 34 is a cooler, 35 is an activated carbon tower, and 36 is a neutralization washing tower.
[0022]
The operation mode of the system diagram will be described. First, the PCB contaminated soil 40 as the material to be decomposed is put into the vapor compression dehydrator 25 using a slurry pump, and the water 41 as the solvent is heated by the boiler 26 and put into the vapor compression dehydrator 25. The PCB-contaminated soil 40 and the water 41 as the solvent are sufficiently mixed by the stirrer 43 while the vacuum pump 42 is operated. Then, the valve 44 is opened to allow the liquid component to flow down to the liquid tank 27, and the concentrated sludge solid component is introduced into the gasifier 28 using the valve 45 and the slurry pump 46.
[0023]
The liquid component stored in the liquid tank 27 is sent into the activated carbon towers 30 and 31 filled with activated carbon through the valves 48 and 49 by the operation of the pump 47, and is adsorbed and removed by the activated carbon. At this time, valves 51 and 52 for supplying superheated steam to be described later are closed. The liquid components rendered harmless by passing through the activated carbon towers 30 and 31 pass through valves 53 and 54 and are discharged from the discharge end 55.
[0024]
When the adsorption capacity of the activated carbon stored in the activated carbon towers 30 and 31 is saturated, the valves 48 and 49 are closed, the supply of liquid components is stopped, and the process of separating the adsorbed PCB from environmental pollutants is performed. First, the activated carbon towers 30 and 31 are preheated to 400 ° C. to 500 ° C. by the heaters 30a and 31a, and at the same time, superheated steam 50 obtained by a superheated steam generator (not shown) is supplied to both activated carbons via valves 51 and 52. Feed into towers 30,31.
[0025]
A superheated steam generator is a steam generator heated to 200 ° C to 300 ° C by operating a heater to generate a mixed steam of 100 ° C or higher by evaporating a solvent such as water or methanol. When this mixed steam is generated Since the specific volume increases, a pressure is generated, resulting in a pressure of several kg / cm ² , and this steam pressure generates the mixed steam by being transferred to a spiral pipe disposed in the superheated steam generator. This superheated steam generator is heated by a heater to a predetermined temperature for making superheated steam necessary for decomposing the material to be decomposed. Since the temperature of the superheated steam necessary for the decomposition treatment varies depending on the object to be decomposed, it is set according to each object to be decomposed. In order to separate the PCB adsorbed on the activated carbon, superheated steam at about 400 ° C. to 600 ° C. is appropriate.
[0026]
The gas component containing PCB separated from the activated carbon towers 30 and 31 by the superheated steam 50 is sent to the heater 32 through valves 56 and 57. The heater 32 is supplied with air 58 and steam 59 heated to about 500 ° C., mixed and heated with a gas component containing PCB, and sent to the decomposition apparatus 33.
[0027]
The decomposition apparatus 33 is heated and held in advance so as to maintain the temperature of the superheated steam 50 by driving a heater (not shown). That is, it is appropriate that the cracking device 33 is heated to substantially the same temperature as the superheated steam generator. A predetermined reaction time is maintained by superheated steam while a gas component containing PCB passes through the decomposition apparatus 33, the PCB is decomposed and rendered harmless, and is sent into the cooler 34 of the next stage.
[0028]
The inside of the decomposition apparatus 33 is not pressurized, and is set to a substantially normal pressure with the discharge port side opened. That is, a blower or the like is installed at the discharge port, and the pressure in the pipe is a slight negative pressure. Therefore, unlike the conventional high-pressure hydrothermal reactor, the decomposition apparatus 33 can decompose environmental pollutants under a slight negative pressure.
[0029]
The cooler 34 supplies the cooling water from the inlet 34a of the cooling water and flows it out of the outlet 34b, so that the gas of the decomposition target decomposed in the pipe communicating with the decomposition apparatus 33 is cooled and liquefied. . The temperature in the cooling device may be any temperature that can liquefy the decomposed gas. By liquefying in this way, generation of by-products is prevented, and there is no concern about secondary contamination due to release in the gaseous state and scattering into the atmosphere. The waste liquid is again adsorbed with components including residual PCB by the activated carbon tower 35 and sent to the neutralization washing tower 36, and only safe gas components are diffused into the atmosphere through the blower 60. As described above, the activated carbon tower 35 is installed as a fuel safe means in order to completely remove PCB in the system, and the activated carbon tower 35 can be omitted depending on the object to be decomposed.
[0030]
Next, the processing method of the solid component separated into solid and liquid by the vapor compression dehydrator 25 will be described. As described above, the solid component containing PCB is introduced into the gasifier 28 through the valve 45 and the slurry pump 46. The The gasifier 28 is preheated to 400 ° C. to 500 ° C. by the heaters 61 and 62, and is supplied with superheated steam 50 obtained by a superheated steam generator not shown. Then, the PCB 63 attached to the solid component is separated as a gas component by the superheated steam 50 while the solid component is transferred by rotating the screw 63 arranged in the gasifier 28 by the screw drive motor 64, It is sent to the heater 32 as a steam flow through the valve 65, and thereafter is decomposed based on the operation mode described above. The solid component remaining in the gasifier 28 is stored in the residue tank 29 through the valve 66 and discarded as a harmless substance.
[0031]
FIG. 3 is a system diagram showing an embodiment for carrying out [(3) case of oil containing PCB] and [(4) treatment of PCB attached to solid] in the PCB pollutant treatment flowchart of FIG. 1 described above. Since the basic configuration is almost the same as the system diagram of FIG. 2, the same reference numerals are given. In FIG. 3, reference numeral 70 denotes a batch tank that contains a solid adsorbed by PCB.
[0032]
The oil 71 containing PCB flows into the gasifier 28 which is preheated to 400 ° C. to 600 ° C. together with the superheated steam 50 and is transferred by the superheated steam 50 while being transferred by the screw 63 driven by the screw drive motor 64. Becomes a gas component and is sent as a vapor stream to the heater 32 through the valve 65, decomposed by the heater 32 and the decomposition device 33 based on the above-described operation mode, and decomposed in a pipe communicating with the decomposition device 33. The gas of the decomposed material to be decomposed is cooled and liquefied by the cooler 34, and the component containing PCB in the drainage is adsorbed by the activated carbon towers 30 and 31, and is passed through the valves 53 and 54 to the neutralization washing tower 36. It is sent and safe gas components are diffused into the atmosphere through the blower 60. The solid component remaining in the gasifier 28 is stored in the residue tank 29 through the valve 66 and discarded as a harmless substance. As described above, the activated carbon tower 35 is installed as a fuel safe means in order to completely remove PCB in the system, and the activated carbon tower 35 can be omitted depending on the object to be decomposed.
[0033]
The batch tank 70 is preheated to 400 ° C. to 600 ° C. by the heater 70a, and the PCB adhering to the solid becomes a gas component by supplying the superheated steam 50. 32, and is disassembled based on the above-described operation mode.
[0034]
When the adsorption capacity of the activated carbon stored in the activated carbon towers 30 and 31 is saturated, the valves 48 and 49 are closed, the supply of liquid components is stopped, and the process of separating the adsorbed PCB from environmental pollutants is performed. First, the activated carbon towers 30 and 31 are preheated to 400 ° C. to 500 ° C. by the heaters 30a and 31a, and at the same time, superheated steam 50 obtained by a superheated steam generator (not shown) is supplied to both activated carbons via valves 51 and 52. Feed into towers 30,31.
[0035]
The gas component containing PCB separated from the activated carbon towers 30 and 31 by the superheated steam 50 is sent to the heater 32 through valves 56, 57 and 67. The heater 32 is supplied with air 58 and steam 59 heated to about 500 ° C., mixed and heated with a gas component containing PCB, and sent to the decomposition apparatus 33.
[0036]
Here, the solvent for generating the superheated steam 50 will be described. As the solvent, water, methanol, and hydrogen peroxide can be used. In the case of water, the reaction proceeds mainly by hydrolysis. When the solvent is methanol, methanol itself is thermally decomposed at about 300 ° C., and CH ₃ OH → H ₂ O + H ₂ + C.
Since the hydrolysis proceeds simultaneously by reductive decomposition reaction and H _{2 O} by H _2, only hydrolysis is effectively applicable to the reaction rate or can not be decomposed very slowly under decomposition products. If sufficient decomposition time is not taken, organic substances may be formed as by-products.
[0037]
When the solvent is hydrogen peroxide, it is easily decomposed by heat and 2H ₂ O ₂ → 2H ₂ O + O ₂
Therefore, hydrolysis and oxidation reaction proceed simultaneously. Furthermore, oxidation in a water vapor atmosphere is called wet combustion, and reacts with organic carbon to become CO ₂ , which is an exothermic reaction, and thus a decomposition reaction proceeds in a chain manner.
[0038]
4 shows the treatment data of the sludge containing PCB when the present invention is applied. The PCB sludge prepared in step 80 (water content 81%, soil 19 kg, water 81 kg, soil specific gravity 1.14, volume 97). 7L, PCB 500 ppm = 50 g) was subjected to solid-liquid separation with a vapor compression dehydrator in step 81, and the water content in the dehydrated liquid in step 82 was 99.99% (water 66.7 kg, soil 4 g, PCB 3.148 ppm = The water content of the dehydrated sludge in Step 83 was 42.95% (Soil 18.996 kg, Water 14.3 kg, PCB 1493.441 ppm = 49.79 g).
[0039]
Next, when the properties of the activated carbon after passing through the dehydrating liquid were observed in step 84, the activated carbon was 1000 g (4 g of soil, 43.5 g of water, PCB 20.0.477 ppm = 0.21 g), and the state of the liquid after passing through the activated carbon in step 85 As shown in the figure, there is no soil, water 66.6565 kg, PCB is less than 0.0005 mg / l. Therefore, it can be seen that PCB is efficiently removed by the adsorption force of the activated carbon.
[0040]
The dehydrated sludge was gasified using the gasifier in Step 86, and the properties of the residue after gasification were observed in Step 87. As a result, the water content was 10.31% (2.66085 kg of soil (47% loss on ignition)). 0.83%), water 0.3 kg, and PCB 0.0007 mg / l) were found to be below the standard value of 0.003 mg / l. Further, when the gas components obtained by the gasifier were decomposed in a decomposition apparatus using a superheated steam at 600 ° C. in an oxygen atmosphere in step 88, the properties of the activated carbon after adsorption were observed in step 89. 11.3 g, water 271.5 g, PCB 0.63 ppm = 0.527 g), and the decomposition rate was found to be 99.994%. When the properties of the exhaust gas cleaning water were examined in Step 90, the gas cleaning water was 20 kg (condensed water 1.7 kg), and the PCB was less than 0.0005 mg / l. As described above, the cleaned gas component passes through the blower 60 and is diffused into the atmosphere as a safe exhaust gas.
[0041]
FIG. 5 shows decomposition processing data of the PCB-containing oil when the present invention is applied. The insulating oil 495 g (PCB 5 g = 1%) contaminated with the PCB prepared in step 91 is flowed at 1 kg / h in step 92. In the gasifier 28 heated to 550 ° C. by the heater in step 93, 600 ° C. superheated steam was added to the cracker 33 heated to 1000 ° C. in step 93 while adding 600 ° C. air at a flow rate of 150 Nl / min. After adding and decomposing at a flow rate of 1 kg / h, cooling with the cooler 34 in step 94, and examining the properties of the activated carbon obtained in step 95, the activated carbon 1000g (water 36g, PCB 0.115ppm = 0.00012g) And the decomposition rate was found to be 99.998%. The gas component after the activated carbon adsorption is sent to the neutralization washing tower 36, and the safe gas component is diffused into the atmosphere through the blower 60. As a result of examining the properties of the cleaning liquid in Step 96, it was found that PCB was less than 0.0005 mg / l with 20 kg of gas cleaning liquid and 1 kg of condensate. In this data, the process of the heater 32 shown in FIG. 3 is omitted, and the insulating oil contaminated with the gasified PCB is directly supplied to the decomposition apparatus 33. Of course, it may be supplied and heated in advance.
[0042]
FIG. 6 shows cleaning processing data of activated carbon that has adsorbed PCB. In step 100, cleaning steam is put into a heater 68 heated to 600 ° C. at a flow rate of 1 kg / h, and activated carbon in which PCB is adsorbed in step 101. Is heated to 600 ° C. by a heater, and overheated steam at 600 ° C. is added at a flow rate of 1 kg / h while adding air at 600 ° C. at a flow rate of 150 Nl / min into the decomposition apparatus 33 heated to 1000 ° C. in step 102. Then, after cooling in the cooler 34 in Step 103 and examining the properties of the activated carbon obtained in Step 104, 500 g of the original activated carbon adsorbed PCB (2 g of soil, 21.75 g of water, 200.4 ppm of PCB) = 0.105 g) is 500 g of activated carbon (2 g of soil, 16.8 g of water, PCB is <0.0005 mg / l). It can be seen that the PCB from coal has been removed. The gas component containing PCB separated from the activated carbon is decomposed by the decomposition apparatus 33 by superheated steam, the decomposed gas component is sent to the neutralization washing tower 36, and the safe gas component is diffused into the atmosphere through the blower 60. The As a result of examining the properties of the cleaning liquid in Step 105, it was found that 20 kg of gas cleaning water, 1 kg of condensed water, and PCB were less than 0.0005 mg / l, and the decomposition rate was 99.99% or more.
[0043]
【The invention's effect】
As described above in detail, according to the present invention, environmental pollutants can be efficiently adsorbed and removed from activated substances by using the activated substances such as PCB and dioxin which are environmental pollutants. The PCB adsorbed on the activated carbon or the PCB adhering to the solid component can be gasified using superheated steam, and further decomposed by the superheated steam. In particular, not only the decomposition treatment of about 1 to 3% of PCB contained as a liquid but also a solid PCB treatment method can provide a great effect.
[0044]
As described above, the conventional high-temperature incineration method has a problem of measures against dioxins and the like generated in the residue, and in other treatment methods, it is difficult to change the reaction process depending on the material to be decomposed, and a dedicated device is used. On the other hand, the present invention has a lower processing cost than various conventional processing methods for liquid or solid PCBs, has low running costs and low initial costs, is advantageous in terms of cost, and is subject to decomposition treatment. There is no problem such as recombination of PCBs decomposed by not burning the product.
[0045]
Furthermore, according to the present invention, since the process proceeds at a low pressure, the material of the constituent member can be arbitrarily selected as long as it can withstand a predetermined high temperature, and it can withstand mechanical strength and tensile stress or thermal stress. Therefore, there is an effect that versatility is wide.
[0046]
Therefore, according to the present invention, it is possible to efficiently decompose and remove environmental pollutants such as dioxins and PCBs that are hardly decomposable and have low water solubility and high persistence. A decomposition method and an apparatus thereof can be provided.
[Brief description of the drawings]
FIG. 1 is a flowchart of PCB contaminant processing to which the present invention is applied.
FIG. 2 is a system diagram showing an embodiment for implementing a pollutant processing flowchart.
FIG. 3 is a system diagram showing gasification and decomposition treatment of PCB attached to oil and solids containing PCB.
FIG. 4 is an explanatory diagram showing treatment data of sludge containing PCB when the present invention is applied.
FIG. 5 is an explanatory diagram showing decomposition processing data of oil containing PCB when the present invention is applied.
FIG. 6 is an explanatory diagram showing cleaning processing data of activated carbon that has adsorbed PCB.
[Explanation of symbols]
25 ... Vapor compression dehydrator 26 ... Boiler 27 ... Liquid tank 28 ... Gasifier 29 ... Residue tanks 30, 31, 35 ... Activated carbon tower 32 ... Heater 33 ... Decomposition device 34 ... Cooler 36 ... Neutralization washing tower 40 ... PCB contaminated soil 42 ... Vacuum pump 46 ... Slurry pump 50 ... Superheated steam 60 ... Blower 70 ... Batch tank 71 ... PCB oil reference number P3587

Claims (17)

A method for gasifying an environmental pollutant comprising adsorbing PCB and other environmental pollutants on activated carbon, and separating the activated carbon from the activated charcoal as a gas component using superheated steam. A high-water-content decomposed material contaminated with PCB and other environmental pollutants is separated into a liquid component and a solid component by solid-liquid separation means, and the PCB and other environmental pollutants contained in the liquid component are adsorbed on activated carbon. A method for gasifying an environmental pollutant, wherein the activated carbon is separated from the activated carbon as a gas component using superheated steam. A high-water-content decomposed material contaminated with PCB and other environmental pollutants is separated into a liquid component and a solid component by solid-liquid separation means, and superheated steam is used for PCB and other environmental pollutants contained in the solid component. A method for gasifying an environmental pollutant, wherein the gas component is separated as a gas component by a gasifier. A method for gasifying an environmental pollutant, characterized in that PCBs and other environmental pollutants contained in a material to be decomposed with a low water content are separated as gas components by a gasifier using superheated steam. A method for gasifying an environmental pollutant, characterized in that a PCB or other environmental pollutant contained in oil is used as a gas component by a gasifier using superheated steam. A method for gasifying environmental pollutants, characterized in that PCBs and other environmental pollutants attached to solid components are converted into gas components by a gasifier using superheated steam. Solid-liquid separation means that separates the high-water-degraded material contaminated by PCB and other environmental pollutants into liquid and solid components, and activated carbon as PCB and other environmental pollutants contained in the obtained liquid components An environmental pollutant gasification apparatus comprising: adsorption means for adsorbing; and separation means for separating PCB and other environmental pollutants from the activated carbon as gas components using superheated steam. The gasifier for an environmental pollutant according to claim 7, wherein a vapor compression dehydrator is used as the solid-liquid separation means. Solid-liquid separation means for separating a high-moisture-decomposed material contaminated by PCB and other environmental pollutants into liquid components and solid components, and PCB and other environmental pollutants contained in the obtained solid components as gas components And a gasifier using superheated steam that is separated as an environmental pollutant gasifier. PCB or other environmental pollutants are adsorbed on activated carbon, separated from the activated carbon as a gas component using superheated steam, and the resulting gas component is decomposed by superheated steam. Processing method. A high-water-content decomposed material contaminated with PCB and other environmental pollutants is separated into a liquid component and a solid component by solid-liquid separation means, and the PCB and other environmental pollutants contained in the liquid component are adsorbed on activated carbon. A method for decomposing an environmental pollutant, wherein the activated carbon is separated from the activated carbon as a gas component by using superheated steam, and the resulting gas component is decomposed by superheated steam. A high-water-content decomposed material contaminated with PCB and other environmental pollutants is separated into a liquid component and a solid component by solid-liquid separation means, and superheated steam is used for PCB and other environmental pollutants contained in the solid component. A method for decomposing an environmental pollutant, wherein the gas component is separated as a gas component by a gasifier, and the obtained gas component is decomposed by superheated steam. It is characterized by separating PCB and other environmental pollutants contained in the material to be decomposed with a low water content as gas components by a gasifier using superheated steam, and subjecting the resulting gas components to decomposition treatment with superheated steam. To decompose environmental pollutants. A method for decomposing environmental pollutants, characterized in that PCB and other environmental pollutants contained in oil are converted into gas components by a gasifier using superheated steam, and the obtained gas components are decomposed by superheated steam. A method for decomposing an environmental pollutant characterized in that a PCB or other environmental pollutant adhered to a solid component is converted into a gas component by a gasifier using superheated steam, and the resulting gas component is decomposed by superheated steam. . Solid-liquid separation means that separates the high-water-degraded material contaminated by PCB and other environmental pollutants into liquid and solid components, and activated carbon as PCB and other environmental pollutants contained in the obtained liquid components An adsorption means for adsorbing, a separation means for separating PCB and other environmental pollutants from the activated carbon as a gas component using superheated steam, and a decomposition means for decomposing the obtained gas component with superheated steam. An apparatus for decomposing environmental pollutants, characterized in that Solid-liquid separation means that separates the high-water-decomposed material contaminated by PCB and other environmental pollutants into liquid and solid components, and superheated steam from PCBs and other environmental pollutants contained in the obtained solid components An apparatus for decomposing environmental pollutants, comprising: separation means for separating gas components using a gasifier using a gas; and decomposing means for decomposing the obtained gas components with superheated steam.

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