KR20010018330A - Fabrication of catalyst for removal of dioxin - Google Patents

Abstract

PURPOSE: Disclosed is a preparation method of catalyst for removing dioxin. The used catalyst is composed of molybdenum and vanadium species and these ingredients are coated on the surface of honeycomb substrate. CONSTITUTION: V2O5 and (MH4)6Mo7O24·4H2O are dissolved with respective proper ratios to get a slurry solution. And then the prepared compound is coated on the surface of honeycomb monolith and calcined at 400-500deg.C for 5 hours.

Description

Fabrication of catalyst for dioxin removal {Fabrication of catalyst for removal of dioxin}

The present invention relates to a method for preparing a Mo-V-based catalyst for dioxin removal, and removes dioxin by coating Mo and V using a honey comb composed of Al ₂ O ₃ , SiO _2, and MgO. It relates to a method for producing a catalyst for.

In general, dioxin treatment generated in incinerator is divided into combustion process, dust collection process, and treatment process.The composition of the combustion atmosphere in the combustion chamber, that is, the retention time of more than 850 ℃ and the retention time of 2 seconds or more, stably decomposes dioxin that may be included in the waste. In order to prevent dioxin regeneration, it is cooled to 200 ° C. and the dioxin produced is still adsorbed and removed by lime and activated carbon through a semi-dry cleaning device. Dioxin removal methods include catalytic decomposition, photolysis, incineration pyrolysis, ozone decomposition, chemical decomposition, physicochemical decomposition, and biological decomposition.

Dioxin decomposition using a catalyst is a method of removing dioxins by oxidatively decomposing gas and air containing dioxins through a catalyst layer. Metal oxides (V ₂ O ₅ , TiO ₂ , WO _3, etc.) and precious metals (Pt, Pd) are used as catalysts, and Pt, Pd, etc. may be supported by TiO ₂ , SiO _2, etc. to increase decomposition efficiency. . Photolysis is a method of breaking chemical bonds using light. When light of a specific wavelength is irradiated, chemicals are decomposed by light energy. Dioxin photolysis is most effectively known as the ultraviolet wavelength. It is difficult to estimate how much it actually decomposes. Dioxin decomposition methods in fly ash include incineration and pyrolysis methods. Since incineration requires oxidative decomposition at high temperatures, the fly ash must be sufficiently in contact with the air, so the fly ash has a low organic matter content and thus generates a low calorific value. Therefore, it is necessary to use auxiliary fuel. In addition, for complete combustion, it is necessary to properly control the temperature distribution, oxygen concentration, and residence time in the combustion chamber. Chemical decomposition and physicochemical decomposition methods are used to decompose dioxins using heat and pressure. Dioxins in water using supercritical fluids are completely mixed with supercritical water and oxygen, and the oxidation rate of organic compounds increases. Oxidative decomposition treatment is under consideration.

Among the dioxins removal methods, the removal of the catalysts is a priority for developing catalysts to increase the removal efficiency.

The present invention relates to a method for producing a dioxin-removing Mo-V-based catalyst for decomposing dioxins using the catalyst among the above methods, to minimize the production of dioxins and emission to the atmosphere in urban waste incinerators. In order to improve the removal efficiency of dioxin, the present invention relates to a method for preparing a catalyst for dioxin removal by coating Mo and V using honeycomb composed of conventional Al ₂ O ₃ , SiO _2, and MgO.

Dioxin decomposition using a catalyst is a method of removing dioxins by oxidatively decomposing gas and air containing dioxins through a catalyst layer.

The present invention is to solve the above technical problem to prepare a catalyst using a honey comb consisting of Al ₂ O ₃ , SiO ₂ and MgO (vanadium pentoxide (V ₂ O ₅ ) and ammonium molybdate ((NH _{4 6} Mo ₇ O ₂₄ · 4H ₂ O) mixed dissolution in an appropriate ratio to prepare a carrier impregnation reagent, the reagent was dissolved by impregnating the honey comb carrier in a warm bath and evaporated to dryness with gentle stirring It is characterized by consisting of a step of sufficiently absorbing the carrier, the dried carrier is calcined while maintaining at 400 ~ 500 ℃ for 5 hours at a temperature rising rate of 100 ℃ / 1hr. Dioxin removal using such a catalyst has high efficiency.

As described above, the present invention provides Mo in the existing honeycomb form for the purpose of removing dioxin, which is the most problematic in the post-combustion zone of the incinerator, in order to minimize the production of dioxins in the municipal waste incinerator and to suppress the discharge to the atmosphere. And by coating V and maximizing the removal rate is emerging as a sharp social problem around the world, it is easy to accumulate in the human body and living organisms, it is effective to increase the efficiency of toxic dioxins removal of carcinogenicity.

Claims (1)

In the manufacturing method of Mo-V-based catalyst for dioxin removal, Preparing a catalyst impregnation reagent by mixing and dissolving vanadium pentoxide (V ₂ O ₅ ) and ammonium molybdate ((NH ₄ ) ₆ Mo ₇ O ₂₄ .4H ₂ O) in an appropriate ratio to prepare the catalyst, Impregnating the reagent with a honey comb carrier in a warm bath and evaporating to dryness with gentle stirring to sufficiently absorb the dissolved reagent into the carrier, Method of preparing a catalyst by baking the dried carrier while maintaining at 400 ~ 500 ℃ 5 hours at a temperature increase rate of 100 ℃ / 1hr.