HYDROGEN CHLORIDE OXIDATION REACTION CATALYST FOR PREPARING CHLORINE, AND PREPARATION METHOD TEREFOR

Abstract

The present invention relates to a catalyst for obtaining chlorine (Cl.sub.2) through an oxidation reaction of hydrogen chloride (HCl), and more particularly, to an oxidation reaction catalyst for preparing Cl.sub.2 from HCl by addition of a second heterogeneous material to a RuO.sub.2-supported catalyst using TiO.sub.2 as a support, and a preparation method therefor. According to an embodiment of the present invention, a hydrogen chloride oxidation reaction catalyst for use in a method for preparing chlorine by oxidizing hydrogen chloride includes a support and a heterogeneous material in an active ingredient. The catalyst according to the present invention has both increased catalytic activity at a low temperature and enhanced thermal stability, and thus a catalyst having improved durability such as thermal stability at a high temperature is provided. Therefore, since thermal stability is secured, the performance of the catalyst is maintained for a long time even at a high temperature.

Claims

1. A method for preparing chlorine through oxidation of hydrogen chloride in the presence of a hydrogen chloride oxidation reaction catalyst, whererin the hydrogen chloride oxidation reaction catalyst includes 0.5-10 parts by weight of a heterogeneous material, 1-10 parts by weight of ruthenium oxide as an active ingredient, and 80-99 parts by weight of a support, based on 100 parts by weight of the total catalyst after drying.

2. The method of claim 1, wherein the heterogeneous material includes at least one selected from ceria, alumina, and silica.

3. The method of claim 1, wherein the support includes at least one selected from alumina, titania, and zirconia.

4. The method of claim 1, wherein the support has a specific surface area of 5-300 m.sup.2/g.

5. The method of claim 1, wherein the hydrogen chloride oxidation reaction catalyst is at least one selected from a powder form, a particle form, and a pellet form.

Description

Example 1

[0070] A solution prepared by dissolving 0.5 g of cerium nitrate hydrate in 5.0 g of DIW was impregnated with 10.0 g of titania powder and then dried in air at 100 C. for 4 hours. The dried solid was calcined at 350 C. for 3 hours in an electric furnace under air flow and gradually cooled to room temperature. The obtained solid was added to a solution prepared by dissolving 1.08 g of ruthenium nitrosyl nitrate dissolved in a nitric acid solution in 320.0 g of DIW, stirred at room temperature for 5 hours, and then dried by using a rotary evaporator. The dried solid was calcined at 350 C. for 3 hours in an electric furnace under air flow and gradually cooled to room temperature to finally obtain a RuO.sub.2CeO.sub.2/TiO.sub.2 catalyst in which ruthenium oxide was included in an amount of 2.0 parts by weight and ceria was included in an amount of 2.0 parts by weight.

Example 2

[0071] A catalyst was prepared in the same manner as in Example 1 by using 0.13 g of cerium nitrate hydrate to finally obtain a RuO.sub.2CeO.sub.2/TiO.sub.2 catalyst in which ruthenium oxide was included in an amount of 2.0 parts by weight and ceria was included in an amount of 0.5 parts by weight.

Example 3

[0072] A catalyst was prepared in the same manner as in Example 1 by using 0.25 g of cerium nitrate hydrate to finally obtain a RuO.sub.2CeO.sub.2/TiO.sub.2 catalyst in which ruthenium oxide was included in an amount of 2.0 parts by weight and ceria was included in an amount of 1.0 parts by weight.

Example 4

[0073] A catalyst was prepared in the same manner as in Example 1 by using 1.25 g of cerium nitrate hydrate to finally obtain a RuO.sub.2CeO.sub.2/TiO.sub.2 catalyst in which ruthenium oxide was included in an amount of 2.0 parts by weight and ceria was included in an amount of 5.0 parts by weight.

Comparative Example 1

[0074] A solution prepared by dissolving 0.4 g of ruthenium chloride hydrate in 5.0 g of DIW was impregnated with 10.0 g of titania powder (Sakai Co., Ltd.) and then dried in air at 100 C. for 4 hours. The dried solid was calcined at 350 C. for 3 hours in an electric furnace under air flow and gradually cooled to room temperature to finally obtain a RuO.sub.2/TiO.sub.2 catalyst in which ruthenium oxide was included in an amount of 2.0 parts by weight.

[0075] Experimental Example 1 for evaluating catalytic activity and Experimental Example 2 for evaluating thermal stability were carried out under the following conditions.

Experimental Example 1Evaluation of Catalytic Activity

[0076] 1.35 g of the prepared catalyst was diluted with 6.75 g of a titania powder and charged into a nickel reaction tube (a tube having an outer diameter of 1 inch). A catalyst layer was heated to a temperature of 300 C. in the reaction tube, and a reaction was performed while hydrogen chloride and oxygen gas were supplied under normal pressure at a rate of 100 mL/min. After 2 hours from the start of the reaction, the gas at the outlet of the reaction tube was passed through a 15% aqueous potassium iodide solution to perform sampling for 10 minutes. Subsequently, the amount of chlorine prepared was measured by an iodine titration method, and the space time yield (STY) of hydrogen chloride was calculated by the following equation. Results of Experimental Example 1 are shown in Table 1 below.

[00001]$\begin{array}{cc}\mathrm{Space}\mathrm{time}\mathrm{yield}\left(\mathrm{STY}\right)=\frac{\mathrm{Amount}\mathrm{of}\mathrm{chlorine}\mathrm{gas}\mathrm{generated}({\mathrm{gcl}}_2}{\mathrm{Amount}\mathrm{of}\mathrm{catalyst}\left(g_{\mathrm{cat}}\right)\mathrm{Reaction}\mathrm{time}\left(\mathrm{hr}\right)}& \left[\mathrm{Equation}1\right]\end{array}$

Experimental Example 2Evaluation of Thermal Stability

[0077] After the reaction was performed for 24 hours under the conditions of Experimental Example 1, the amount of chlorine prepared was measured to calculate a hydrogen chloride conversion rate A. After that, the catalyst layer was heated to a temperature of 380 C. and the reaction was performed for 24 hours under the same flow rate condition. After the temperature of the catalyst layer was lowered to 300 C., and the reaction was performed for 2 hours under the same flow rate condition. The amount of chlorine prepared was measured to calculate a hydrogen chloride conversion rate B. The thermal stability of the catalyst was compared by calculating the degree of deterioration as shown in the following equation by using the ratio of the conversion rate B to the conversion rate A. Results thereof are shown in Table 2.

[00002]$\begin{array}{cc}\mathrm{Degree}\mathrm{of}\mathrm{deterioration}\left(\%\right)=100-\left(\frac{\mathrm{Conversion}\mathrm{rate}B}{\mathrm{Conversion}\mathrm{rate}A}100\right)& \left[\mathrm{Equation}2\right]\end{array}$

TABLE-US-00001 TABLE 1 Comparative Classification Example Example 1 Example 2 Example 3 Example 4 Catalyst information 2 parts by weight of 2 parts by weight of 2 parts by weight of 2 parts by weight of 2 parts by weight of RuO.sub.2/TiO.sub.2 RuO.sub.2 - 2 RuO.sub.2 - 0.5 RuO.sub.2 - 1 RuO.sub.2 - 5 parts by weight of parts by weight of part by weight of parts by weight of CeO.sub.2/TiO.sub.2 CeO.sub.2/TiO.sub.2 CeO.sub.2/TiO.sub.2 CeO.sub.2/TiO.sub.2 STY 2.05 1.47 2.57 2.14 1.19

TABLE-US-00002 TABLE 2 Comparative Classification Example Example 1 Example 4 Catalyst information 2 parts by weight of 2 parts by weight of 2 parts by weight of RuO.sub.2/TiO.sub.2 RuO.sub.2 - 2 RuO.sub.2 - 5 parts by weight of parts by weight of CeO.sub.2/TiO.sub.2 CeO.sub.2/TiO.sub.2 Degree of deterioration 34% 30% 7%

[0078] It can be confirmed from the results of Table 1 and Table 2 that it can have superior activity and durability, compared with the existing ruthenium oxide catalyst, according to the amount of cerium oxide added.

[0079] In particular, it can be confirmed that the catalytic activity is at the same level or higher in the range of 2 parts by weight of RuO.sub.2 and 0.5-1 part by weight of CeO.sub.2/TiO.sub.2. Furthermore, it can be confirmed that the degree of deterioration is improved in the range of 2 parts by weight of RuO.sub.2 and 2-5 parts by weight of CeO.sub.2/TiO.sub.2, compared with Comparative Example.

[0080] Accordingly, it can be confirmed that the catalyst according to the present invention has an effect of enhancing catalytic activity at a low temperature according to the content of the heterogeneous metals and enhancing thermal stability to improve durability such as thermal stability at a high temperature. Therefore, improved durability can be confirmed in that the thermal stability is secured and thus the performance of the catalyst can be maintained for a long time even at a high temperature.

[0081] While the present invention has been described by particular matters such as specific components and limited embodiments and drawings, this is provided only for helping the comprehensive understanding of the present invention. The present invention is not limited to the above-described embodiments, and it will be understood by those of ordinary skill in the art that various modifications and variations can be made thereto without departing from the scope of the present invention.

[0082] Therefore, it will be understood that the spirit of the present invention should not be limited to the above-described embodiments and the claims and all equivalent modifications fall within the scope of the present invention.