KR100270085B1 - Decomposition method for organic chloride compound - Google Patents

Abstract

PURPOSE: Disclosed is a decomposition method of organic chlorine compound using a catalyst, which is composed of Cu or Co as active species and activated carbon fiber as support. CONSTITUTION: The activated carbon fiber used as a catalyst support has a surface area of 700 m2/g and is a fitch-type material in isotropy. For Cu-impregnated catalyst, Cu of below 50 wt% is loaded on the fiber and the decomposition reaction is carried out at catalyst bulk density of 0.1 g/cm3 and space velocity of 1000 h-1. For Co-impregnated catalyst Co of 10 - 100 wt% is loaded on the fiber and the reaction is conducted at space velocity of 12000 h-1. In addition, the reaction temperature for respective catalysts is good at 200-500 deg.C and about 1000 ppm as concentration of organic chlorine compound is proper.

Description

Decomposition of Organic Chlorine Compounds Using Metal-Based Activated Carbon Fibers

The present invention relates to a method for decomposing and removing organochlorine compounds, and more particularly, to a method for more efficiently decomposing and removing organochlorine compounds using activated carbon fibers loaded with copper or cobalt.

Organochlorine compounds are toxic substances that are mixed with impurities in the manufacture of pesticides, or are produced during incineration of synthetic resins such as PW mainly in waste incinerators. , Polychlorobiphenyl (PCB) and tetrachloroethylene, etc., which can be decomposed when reacted at a high temperature of 700 ° C. or higher, but additional processing and energy are required to treat this high temperature. Therefore, it is possible to reduce the energy required to heat the reaction temperature to a low temperature of less than 300 ℃. In this regard, Cheirasphere, Vol. 19, Nos. 1-6, p. 361-366, 1989 discloses a method using a honeycomb-type platinum catalyst by Hiraoka et al., But the treatment cost is considerably high due to the characteristics of the catalyst. In addition, Hagemmaier et al. 0rganohalogen Compound 3, p65-68 discloses a method for removing dioxin using TiO ₂ catalyst at a temperature of 400 ℃ or less, which is difficult to effectively decompose due to the small specific surface area of the catalyst There is.

The present invention has been proposed to solve the above problems, and an object of the present invention is to use an organic carbon-supported activated carbon fiber as a catalyst, and to set the optimum reaction conditions more efficiently and economically organochlorine compound It is to provide a method that can decompose and remove.

According to the present invention, an organic chlorine compound is introduced by introducing an organic chlorine compound-containing gas into a reaction at a constant space velocity into an isotropic pitch-based activated carbon fiber catalyst having a specific surface area of 700 m ² / g or more at a reaction temperature of 200-500 ° C. A method of continuously decomposing and removing self is provided.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention uses a high specific surface area of the pitch-based activated carbon fibers to support the metal components on the surface of the activated carbon fibers to utilize the catalytic action of the metal and the activated carbon fibers themselves, compared to the case of using a catalyst composed only of the activated carbon fibers itself The present invention relates to a method for more effectively decomposing and removing organochlorine compounds.

In the present invention, the activated carbon fiber used as a catalyst in the decomposition of the organic chlorine compound is preferably made of isotropic pitch as a raw material. Activated fiber carbon can be produced by pitch and poly acrylonitrile (PAN), but the pitch is cheaper than the PAN system, it is preferable to produce activated carbon fiber with high yield and high specific surface area when manufacturing activated carbon fiber will be.

Moreover, in the present invention, a catalyst in which a metal is supported on isotropic pitch-based activated carbon fibers having a specific surface area of 700 m ² / g or more is used as the catalyst, and activated carbon fibers are more effective as the specific surface area is larger. If the specific surface area of activated carbon fiber is less than 700m ² / g as a catalyst, the activated carbon fiber with low activity level has a small catalytic reaction area according to the specific surface area, which does not activate the reaction effectively, so the specific surface area is more than 700m ² / g. Pitch-based activated carbon fibers are used.

Copper or cobalt is supported on the pitch-based activated carbon fibers and used as a catalyst.

When copper is supported on the pitch-based activated carbon fibers, copper is supported at 50% or less of the weight of the activated carbon fibers. When copper is supported on the pitch-based activated carbon fiber by 50% or more of the weight of the activated carbon fiber, copper is present at the pore inlet of the activated carbon fiber, thereby greatly reducing the specific surface area of the activated carbon fiber, despite the catalytic action of copper. In addition, since the specific surface area of the entire catalyst is reduced, the reaction is not effectively activated, but rather, the reaction efficiency is lowered, so that it is difficult to effectively decompose the organic chlorine compound. Therefore, it is preferable to support 50 wt% or less of copper on the activated carbon fiber.

In addition, when cobalt is supported on the pitch-based activated carbon fiber, cobalt is supported by 10-100% of the weight of the activated carbon fiber. When cobalt is supported on the isotropic pitch-based activated carbon fibers having a specific surface area of 700 m ² / g or more, less than 10% of the weight of the activated carbon fibers, the content of cobalt in the catalyst is low, so that the reaction is not activated efficiently. If the space velocity is increased, it is difficult to decompose the organic chlorine compound by more than 50%. On the other hand, in the case of supporting more than 100% of cobalt, like copper, cobalt closes pores of activated carbon fibers, thereby lowering the specific surface area of activated carbon fibers. When reacting at a rate, organochlorine compounds are difficult to decompose.

As described above, when the organic chlorine compound is decomposed by using activated carbon fiber carrying copper or cobalt as a catalyst, the reaction temperature during decomposition is preferably 200 to 500 ° C. This is because the organic chlorine compound does not decompose itself by the catalyst at a temperature of 200 ° C. or lower, and since the decomposition reaction starts even when the catalyst is not used above 500 ° C., there is no advantage of using the catalyst.

Under the decomposition reaction conditions as described above, based on the volume concentration of 1000 ppm of the organic chlorine gas in the gas and based on the apparent density of 0.1 g / cm 3 of the activated carbon fiber, copper containing the organic chlorine-containing compound to be decomposed the supported activated carbon fiber catalyst 8000h ^-1 or less, and the cobalt-supported catalyst, the activated carbon fiber is introduced at a space velocity of 12000h ^-1 or less.

The case of reaction with copper is introduced to 8000h ^-1 or more and a gas containing an organic chlorine compound to cobalt digested with a space velocity of 12000h ^-1 or more in the supported catalyst to the activated carbon fibers impregnated activated carbon fibers, the reaction catalyst contact time The reaction does not proceed efficiently because this layer is not divided, and the smaller the space velocity, the higher the decomposition efficiency of the organic chlorine compound.

It is to set the standard for limiting the space velocity in the reaction by defining the volume concentration of organic chlorine in the gas containing the organic chlorine compound to be decomposed to 1000 ppm and the apparent density of activated fiber carbon to 0.1 g / cm 3. When the volume concentration of is increased, the amount and space velocity of the catalyst can be adjusted according to the increase ratio.

Examples of organochlorine compounds that decompose themselves by the method according to the present invention include, but are not limited to, polychlorodibenzoparadioxin, polychlorodibenzofuran, polychlorobiphenyl, tetrachloroethylene and the like.

Hereinafter, the present invention will be described through examples.

Example I

Decomposition and Removal of Organochlorine Compounds Using Copper Supported Isotropic Pitch Activated Carbon Fiber Catalysts

Invention Example 1

After supporting the activated carbon fiber, the activated carbon fiber having an isotropic pitch system having a specific surface area of 1500m ² / g was treated with copper sulfate aqueous solution so that the copper supporting amount per 1g of activated carbon fiber was 0.2g. After removing the sulfide by heat treatment at 1 ° C. for 1 hour, a catalyst was used. According to Organohalogen Compound 3 of Hagennnier et al., P.65-68, tetrachloroethylene, a compound that is more difficult to decompose than PCDD as a model gas, was vaporized and maintained at 1000 ppm volume concentration, and reacted at 250 ° C. while supplying 400 cc / g of catalyst per minute. The composition of the gas was then analyzed continuously. The space velocity at this time was 2500 h ^-1 . As a result, it was 92% decomposed compared to the initial concentration of the feed gas.

Invention Example 2

After being supported on activated carbon fibers, activated carbon fibers with an isotropic pitch system having a specific surface area of 1500m ² / g were treated with copper sulfate aqueous solution so that the copper loading per 0.4g of activated carbon fibers was 0.4g. After removing the sulfide by heat treatment at 1 ° C. for 1 hour, a catalyst was used. Ethyl chloroethylene, a model gas, was maintained at a volume concentration of 1000 ppm, reacted at 250 ° C. while supplying 400 cc / g of catalyst per minute, and the composition of the gas was continuously analyzed after the reaction. The space velocity at this time was 2500 h ^-1 . The result shows 87% degradation compared to the initial concentration of the feed gas.

Invention Example 3

After supporting the activated carbon fiber, the activated carbon fiber with an isotropic pitch system having a specific surface area of 1500m ² / g was treated with copper sulfate aqueous solution to remove the water by drying under reduced pressure, so that the copper supporting amount per 1g of the activated carbon fiber was 0.2g. Heat treatment at 500 ° C. for 1 hour to remove sulfides was used as a catalyst. Tetrachloroethylene, a model gas, was vaporized and maintained at a volume concentration of 1000 ppm, and reacted at 350 ° C. while supplying 400 cc / g of catalyst per minute. The composition of the gas was continuously analyzed after the reaction. The space velocity at this time was 2500 h ^-1 . As a result, it showed 95% decomposition compared to the initial concentration of the feed gas.

Comparative Example 1

After supporting the activated carbon fiber, the activated carbon fiber with an isotropic pitch system having a specific surface area of 1500m ² / g is treated with copper sulfate aqueous solution to remove 1 minute of moisture after drying under reduced pressure, so that the amount of copper supported per 1g of activated carbon fiber is 1g. The sulfide removed by heat treatment at 1 hour was used as a catalyst. Tetrachloroethylene, a model gas, was vaporized and maintained at a 1000 ppm volume concentration, and reacted at 250 ° C. while supplying 400 cc / g of catalyst per minute. The composition of the gas was continuously analyzed after the reaction. The space velocity at this time was 2500 h ^-1 . The results showed 45% degradation compared to the initial concentration of the feed gas.

Comparative Example 2

Vaporized tetrachloroethylene was maintained at 1000 ppm volume concentration, and isotropic pitch-based activated carbon fibers having a specific surface area of 1500 m ² / g were used as catalysts and reacted at 200 ° C. while supplying 400 cc / g of catalyst per minute. Analyzed. The space velocity at this time was 2500 h ^-1 . As a result, it showed 72% degradation compared to the initial concentration of the feed gas.

Example II

Decomposition and Removal of Organochlorine Compounds Using Cobalt Supported Isotropic Pitch Activated Carbon Fiber Catalysts

Invention Example 4

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500 m ² / g with a cobalt nitrate solution [Co (NO ₃ ) ₂ · 6H ₂ O] so that the amount of cobalt supported per 0.2 g of activated carbon fibers was supported on activated carbon fibers. After the removal of moisture under reduced pressure conditions, the heat treatment was performed at 500 ° C. for 1 hour under an inert atmosphere to remove nitric oxide. According to Organo-halogen Compound 3 of Hagennnier et al., P. 65-68, tetrachloroethylene, a compound that is more difficult to decompose than PCDD as a model gas, was vaporized and maintained at 1000 ppm volume concentration, and was reacted at 250 ° C. while supplying 400 cc / g of catalyst per minute. After the reaction, the composition of the gas was analyzed continuously. The space velocity was 2500 h ^-1 . As a result, it showed 95% degradation compared to the initial concentration of the feed gas.

Invention Example 5

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500m ² / g with cobalt nitrate [Co (NO ₃ ) ₂ · 6H ₂ O] aqueous solution so that the amount of cobalt supported per 0.5g of activated carbon fibers after loading on activated carbon fibers After the removal of water under reduced pressure and heat treatment at 500 ℃ for 1 hour under inert atmosphere was used as a catalyst to remove the nitric oxide. As a model gas, tetrachloroethylene, a compound that is more difficult to decompose than PCDD, was vaporized and maintained at a volume concentration of 1000 ppm, and reacted at 250 ° C. while supplying 1000 cc / g of catalyst per minute. The composition of the gas was continuously analyzed after the reaction. The space velocity at this time was 6250h ^-1 . As a result, it showed 76% degradation compared to the initial concentration of the feed gas.

Invention Example 6

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500m ² / g with cobalt nitrate [Co (NO ₃ ) ₂ · 6H ₂ O] aqueous solution so that the amount of cobalt supported per 0.5g of activated carbon fibers after loading on activated carbon fibers After drying under reduced pressure to remove moisture, the resultant was heat-treated at 500 ° C. under inert atmosphere for 1 hour to remove nitric oxide. As a model gas, tetrachloroethylene, a compound that is more difficult to decompose than PCDD, was vaporized and maintained at a volume concentration of 1000 ppm, and reacted at 350 ° C while supplying 1000 cc / g of catalyst per minute, and the composition of the gas after the reaction was analyzed continuously. The space velocity at this time was 6250h ^-1 . The results showed 86% degradation compared to the initial concentration of the feed gas.

Invention Example 7

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500m ² / g with cobalt nitrate [Co (NO ₃ ) ₂ · 6H ₂ O] aqueous solution so that the amount of cobalt supported per 0.5g of activated carbon fibers after loading on activated carbon fibers After drying under reduced pressure to remove moisture, the resultant was heat-treated at 500 ° C. under inert atmosphere for 1 hour to remove nitric oxide. As a model gas, tetrachloroethylene, a compound that is more difficult to decompose than PCDD, was vaporized and maintained at a volume concentration of 1000 ppm, and reacted at 350 ° C. while supplying 1600 cc / g of catalyst per minute. The composition of the gas after the reaction was analyzed continuously. The space velocity at this time was 10000h ^-1 . As a result, it showed 56% decomposition compared to the initial concentration of the feed gas.

Comparative Example 3

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500 m ² / g with a cobalt nitrate solution [Co (NO ₃ ) ₂ · 6H ₂ O] so that the amount of cobalt supported per 1.5 g of activated carbon fibers after loading on activated carbon fibers After drying under reduced pressure to remove water, heat treatment was performed at 500 ° C. under inert atmosphere for 1 hour to remove nitric oxide. Tetrachloroethylene, a model gas, was vaporized and maintained at a 1000 ppm volume concentration, and reacted at 250 ° C. while supplying 400 cc / g of catalyst per minute. The composition of the gas was continuously analyzed after the reaction.

The space velocity at this time was 2500 h ^-1 . As a result, it showed 38% degradation compared to the initial concentration of the feed gas.

[Comparative Example 4]

Treated activated carbon fibers with an isotropic pitch system having a specific surface area of 1500 m ² / g with a cobalt nitrate solution [Co (NO ₃ ) ₂ · 6H ₂ O] so that the amount of cobalt supported per 1.5 g of activated carbon fibers after loading on activated carbon fibers After drying under reduced pressure to remove water, heat treatment was performed at 500 ° C. under inert atmosphere for 1 hour to remove nitric oxide. Tetrachloroethylene, a model gas, was vaporized and maintained at a volume of 1000 ppm, reacted at 350 ° C. while supplying 2000 cc / g of catalyst per minute, and the composition of the gas after the reaction was analyzed continuously. The space velocity at this time was 12500h ^-1 . The results showed a 43% degradation over the initial concentration of the feed gas.

Test conditions and decomposition rates of the organic chlorine compounds of Examples and Comparative Examples are shown in Table 1 below.

* Specific surface area of activated carbon fiber 1500m ² / g

From the examples and comparative examples described above, using a activated carbon fiber catalyst carrying less than 50% by weight of copper or 10-100% by weight of cobalt, a gas to be decomposed containing an organic chlorine compound under the reaction conditions defined in the present invention. In the case of decomposition and removal, toxic organochlorine compounds are non-hazardous substances and decompose themselves more than 50% more effectively.

Claims (3)

A method of self-decomposing and removing organic chlorine compounds by introducing organic chlorine-containing gas at a constant space velocity into an isotropic pitch-based activated carbon fiber catalyst having a specific surface area of 700 m ² / g or more at a reaction temperature of 200-500 ° C. . The catalyst according to claim 1, wherein the catalyst is an isotropic pitch-based activated carbon fiber having a specific surface area of 700 m ² / g or more supported by copper at 50% or less of the weight of the synthetic carbon fiber, and the organic chlorine compound-containing gas has an apparent density of 0.1 characterized in that it is introduced into the catalyst at a space velocity of 8000 h ⁻¹ or less, based on a volume concentration of 1000 ppm of gas containing g / cm 3 and an organochlorine compound. 2. The catalyst of claim 1, wherein the catalyst is an isotropic pitch-based activated carbon fiber having a specific surface area of 700 m ² / g or more supported by cobalt at 10-100% of the weight of the synthetic carbon fiber, and the organic chlorine-containing gas is the apparent density of the activated carbon fiber. Characterized in that it is introduced into the catalyst at a space velocity of 12000 h ⁻¹ or less, based on a volume concentration of 1000 ppm of the gas containing 0.1 g / cm 3 and the organochlorine compound.