KR100954205B1 - Preparation method of complex catalyst for ozone deodorization - Google Patents

Abstract

The present invention relates to a complex ozone catalyst capable of decomposing sulfide compounds with high efficiency and a method for preparing the same. More specifically, the ozone catalyst reaction using a complex ozone catalyst in which a composite metal composed of cobalt, nickel and iron is supported on activated carbon is Compared to the decomposition of organic pollutants using ozone alone without using a catalyst, the oxidizing power is significantly increased, and thus the sulfide compound causing odor can be economically and environmentally friendly.

Complex ozone catalyst, cobalt, nickel, iron, activated carbon, sulfide

Description

Preparation method of complex catalyst for ozone deodorization reaction

The present invention relates to a complex ozone catalyst capable of economically and environmentally friendly decomposition of sulfide compounds that cause odor due to a significant increase in oxidizing power compared to decomposition of organic pollutants using ozone alone, and a method for preparing the same.

Odor-induced sulfides are sensory pollutants that are unpleasant to humans, unlike other air pollutants, and are themselves harmful air pollutants. Sulphide compounds are the major pollutants regulated by law as air pollutants that directly affect the living environment. However, sulfide compounds have a wide range of sources and types of triggers and a variety of sources.

In addition, sulfide compounds have recently caused social problems such as controversy about human hazards in industrial facilities, and they remain in the atmosphere for a long time without being destroyed by chemical conversion or self-purification of the troposphere due to low reactivity with other substances.

In general, sulfide compounds generated in industrial facilities of scale are removed by treatment methods such as combustion, adsorption, absorption, and low temperature condensation and prevention facilities such as biofilters, RTO, RCO, activated carbon adsorption, and cleaning methods. Many sources of odorous substances, such as laundry, can not have a treatment facility.

Livestock farmers contain higher concentrations of organic matter, nutrients such as nitrogen and phosphorus than other pollutants, and the odor intensity is stronger than that of other emission facilities. The methods currently used to reduce such odors include chemical treatment, adsorption, masking, and biological deodorization. On the other hand, there is a method of adding a deodorant or a microbial agent to contaminants. Processing efficiency is not very high.

In addition, the wet deodorization apparatus using water washing or liquid-liquid cleaning is composed of a complex system to improve the treatment performance, it is necessary to treat the drainage or discharge liquid, and the operation operation is not necessarily easy. Therefore, in order to deal with the sources of these small and small businesses, a simple and economical prevention facility is needed.

Ozone reacts with all chemicals and, in theory, the high oxidizing power of ozone itself oxidizes the material completely to water and carbon dioxide. However, not all substances are highly reactive, and some are less reactive with ozone.

While the research and development of the dry ozone deodorizer which removes major odors by using solid catalysts to remove odors and remove organic volatile substances (VOCs) using ozone, the resolution of a particular compound is not so large, the cause of certain compounds, especially odor There is an urgent need to develop catalysts that can selectively decompose sulfide compounds that are recognized as substances.

In particular, since sulfide compounds have a slow reaction rate with ozone, sufficient deodorizing effects cannot be obtained in a short contact time, and thus, they are not easily removed in a general odor removing apparatus.

Accordingly, the present inventors have completed the present invention by developing a compacted complex ozone catalyst capable of economically and environmentally friendly treatment of odorous substances, particularly sulfide compounds, generated in small-scale factories, barns, and food resource recycling facilities.

Accordingly, an object of the present invention is to provide a complex ozone catalyst capable of economically and environmentally friendly decomposition of sulfide compounds.

In order to achieve the above object, the present invention provides a composite ozone catalyst, characterized in that the composite metal consisting of cobalt, nickel and iron supported on the activated carbon.

Ozone is a highly oxidizing substance after fluoride in nature. Odor can be decomposed by the oxidizing power and easily deodorizing device can be configured, but the reaction rate is very slow in the low concentration area where odor pollution is a problem.

For example, ozone and hydrogen sulfide are each reacted at 1 ppm, and the half-life is 9,000 minutes, and the half-life is about 220 minutes in methyl mercaptan, which is relatively fast.

However, the present invention has been completed in view of the fact that when the ozone catalyst is used together to accelerate the deodorization reaction, sufficient reaction can be obtained in a very short time to obtain the effect of deodorization.

The deodorization mechanism using ozone proceeds as follows.

O ₃ + M (catalyst) ----> O ₂ + MO (activated catalyst)

MO + organic matter (odorous substance) ----> oxidation product of M + odorous substance

Hereinafter, the present invention will be described in more detail.

In the composite ozone catalyst of the present invention, the composite metal preferably contains cobalt, nickel, and iron in a weight ratio of 1 to 2: 1 to 2: 1 to 2, and includes cobalt, nickel, and iron in a 2: 2: 1 ratio. It is more preferable to include by weight ratio. If the metal is out of the above range, the removal efficiency may be lowered.

The present invention comprises the steps of dissolving cobalt, nickel and iron in an aqueous hydrochloric acid solution; Immersing the obtained composite metal solution in activated carbon; Reducing the composite metal immersed in the activated carbon; And it provides a method for producing a composite ozone catalyst characterized in that it comprises a step of washing and drying the composite metal from which activated carbon has been removed.

The dissolving step is based on 100 parts by weight of aqueous hydrochloric acid, 0.01-0.1 parts by weight of cobalt, 0.01-0.1 parts by weight of nickel and 0.01-0.1 parts by weight of iron, preferably 0.03-0.06 parts by weight of cobalt, 0.02-0.04 parts by weight of nickel and Dissolve 0.03 parts by weight of iron.

In addition, the immersion step is to decompress the composite metal while decompressing the gas present in the activated carbon pores by reducing the pressure with a vacuum pump.

At this time, the composite metal is immersed in 0.1 to 1.0 parts by weight, preferably 0.46 to 0.75 parts by weight based on 100 parts by weight of activated carbon. If the complex metal is immersed in a small amount out of the above range, the deodorization reaction rate of ozone is very slow, and if the complex metal is immersed in a large amount, the deodorization reaction rate of ozone is saturated and there is an uneconomic problem.

The composite ozone catalyst of the present invention can efficiently treat sulfide compounds such as hydrogen sulfide, methyl sulfide, methyl disulfide and the like.

The ozone catalyst reaction using the complex ozone catalyst according to the present invention is capable of economically and environmentally friendly decomposition of sulfide compounds that cause odor due to a significant increase in oxidizing power compared to the decomposition of organic pollutants using ozone alone without using a catalyst. have.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

<Examples 1 to 4> Preparation of complex ozone catalyst

The catalyst used in the experiment was prepared using granulated activated carbon (SZ-35, Φ 3.5, Shin Ki Chemical Co., Ltd.) as a carrier. The process of preparing activated carbon supported catalyst was carried out with 20% -HCl aqueous solution of CoCl ₂ , FeCl ₃ and NiCl ₃ in 1: 1: 1 molar ratio, 2: 1: 1 molar ratio, 1: 2: 1 molar ratio, and 2: 2: 1 molar ratio, respectively. It was dissolved in 20 L, put into a sealed container with 3500 g of circular granular activated carbon, and decompressed with a vacuum pump to immerse each metal while extracting the gas present in the activated carbon macropore.

In order to reduce the immersed metal ions it was reduced to metal using NaBH ₄ as a reducing agent. In order to remove the activated carbon and other foreign matter in the fine powder of the prepared catalyst, it was sufficiently washed with distilled water, and dried at 100 ± 5 ℃ for 2 hours to prepare a composite metal catalyst.

The composite ozone catalyst prepared in this example is shown in FIG. 2.

Experimental Example 1 Catalyst Analysis

Surface observation of the catalyst prepared in Example was performed by scanning electron microscopy (Scanning electron microscopy, SEM, S-3000N, HITACHI) (see Fig. 3).

As a result, Figure 4 shows the surface of the activated carbon before immersing cobalt, nickel, iron, Figure 5 shows the SEM image after supporting the cobalt, nickel, iron.

In addition, the metal content of the composite ozone catalyst prepared in Example and the metal concentration at the carrier surface are shown in Table 1.

Ingredient CoNiF1 CoNiF2 CoNiF3 CoNiF4 1: 1: 1 2: 1: 1 1: 2: 1 2: 2: 1 C 89.03 88.43 89.56 89.42 O 7.42 7.33 7.02 7.04 Mg 0.60 0.32 0.09 0.05 Si 0.59 0.28 0.11 0.05 K 0.37 0.70 0.69 0.22 Ca 0.15 0.61 0.17 0.05 Co 0.62 1.1 0.62 1.32 Ni 0.61 0.62 1.13 1.24 Fe 0.61 0.61 0.61 0.61 total 100 100 100 100

< Experimental Example  2> Review of catalytic activity

In order to examine the reactivity and treatment efficiency of the sulfide compound of the composite ozone catalyst prepared in Example, experiments should be directly performed using hydrogen sulfide, methyl sulfide, and methyl disulfide as target substances. All three materials exist in the gaseous state at room temperature, are not commercially available at appropriate concentrations, and have conditions that are not easy to set up an experimental device.

Therefore, it was judged that it was almost impossible to test the efficiency of the catalyst with pure sulfide compound, and it was decided to use benzene and toluene as inflow gas.

Benzene and toluene were considered to be the most suitable compounds to identify indirectly the efficiency of catalysts because they are the most frequently generated, simple to use and easy to measure.

Therefore, in this experiment, benzene and toluene were used as sample gas and the removal efficiencies of the complex ozone catalysts were measured according to the tower column residence time. At this time, the removal efficiency measurement analysis was used GC / MS (Varian Saturn 2200, USA) (see Figure 6).

In order to eliminate the removal efficiency error due to the adsorption of activated carbon, the experiment was performed by first supplying a sample gas to check the breakthrough point of activated carbon and then supplying ozone. Measurement results are as shown in Figs.

More specifically, FIG. 7 shows an initial concentration of 48-52 ppm of benzene and a 14-144 second ballast retention time, FIG. 8 shows an initial concentration of 97-102 ppm of benzene and a 14-144 second tower length of benzene, and FIG. 9 shows an initial concentration of toluene 47 -52ppm and tower residence time 14-144 seconds, Figure 10 was toluene initial concentration 97-103ppm and tower residence time 14-144 seconds.

As shown in FIGS. 7 to 10, it was found that the removal efficiency of CoNiF4 having the highest cobalt content was the highest among the four types of complex ozone catalysts (CoNiF1, CoNiF2, CoNiF3, CoNiF4) used in the present experiment.

In addition, it was found that the removal efficiency of toluene was higher than that of benzene when tested under the same conditions. In addition, the removal efficiency was found to be higher at 100 ppm than at 50 ppm in both benzene and toluene.

Therefore, through this experiment, the composite ozone catalyst used in this experiment was predicted that the higher the cobalt content, the higher the initial odor concentration, the higher the removal efficiency.

1 is a flow chart showing the manufacturing process of the composite metal catalyst of the present invention,

Figure 2 shows a composite metal catalyst prepared according to an embodiment of the present invention,

Figure 3 shows a scanning electron microscope used for the surface observation of the composite metal catalyst of the present invention,

4 and 5 are SEM pictures of the surface of the activated carbon before or after the immersion of the composite metal,

Figure 6 shows the GC-MS used for the catalytic activity review of the present invention,

7 to 10 show the results of the performance test of the composite metal catalyst of the present invention for benzene or toluene.

Claims (5)

delete delete Dissolving cobalt, nickel and iron in an aqueous hydrochloric acid solution; Immersing the obtained composite metal solution in activated carbon; Reducing the composite metal immersed in the activated carbon; And Washing and drying the composite metal from which activated carbon has been removed Method for producing a composite catalyst for ozone deodorization reaction comprising a. The complex catalyst for ozone deodorization according to claim 3, wherein the dissolving step dissolves 0.01-0.1 parts by weight of cobalt, 0.01-0.1 parts by weight of nickel and 0.01-0.1 parts by weight of iron with respect to 100 parts by weight of an aqueous hydrochloric acid solution. Manufacturing method. The method of claim 3, wherein the immersion step is to decompress the composite metal while decompressing the gas present in the activated carbon pores by reducing the pressure with a vacuum pump.

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