SU980810A1 - Charge for producing granulated catalyst for oxidazing carbon oxide - Google Patents

Description

The invention relates to the preparation of catalysts for the oxidation of carbon monoxide and can be used for the disposal of industrial gases.

A granular copper-chromium catalyst for the oxidation of carbon monoxide to dioxide is known, which is obtained by precipitating copper oxides and chromium in an alkaline medium, the starting material being nitrogen nitrate and ammonium chromate or ammonium bichromate. The copper-chromium catalyst is prepared as follows way: the initial solutions are precipitated, washed, filtered, the resulting copper chromates are dried, crushed, calcined and reduced, then the catalyst powder is mixed with alumina powder, phosphoric acid is added, and dried Wash by weight to a moisture content of 5-8%, pelletized and calcined at 420-450®С l.

However, during the precipitation and washing of copper chromates, waste water containing chromium salts is formed, and during calcination, nitrogen oxides and ammonia.

The closest to the invention in its technical essence and the effect achieved is a mixture for the preparation of a granulated catalysts, lysators for the oxidation of carbon monoxide, including copper-containing component - copper nitrate, chromium oxide (III) and aluminum oxide in the following ratio, wt.%: copper nitrate 57, chromium (III) oxide 29, If aluminum oxide 10 13,3 2.

However, such a mixture of copper nitrate is poorly plasticized, and the resulting catalysts are not strong enough. Besides

Moreover, during the preparation process, catalysts, when heated to 600 ° C, there is a significant release of toxic nitrogen oxides. When in the reaction zone reaches 50%

20 The degree of conversion of carbon monoxide to carbon dioxide with a space velocity of 15,000 catalyst prepared from a mixture of known composition, which indicates insufficient activity.

The aim of the invention is to increase the plasticity of the charge and increase the activity of the catalyst.

The goal is achieved

30 topics / that the mixture for the preparation of a granular catalyst for the oxidation of carbon monoxide contains a copper-containing component — copper powder, chromium oxide — chromic anhydride and alumina in the following ratio, wt.%: Copper powder 2.8–8.2 Chromic anhydride12 , 7-21.1 aluminum Else The proposed mixture for the preparation of the catalyst in comparison with the known leads to an increase in the plasticity of the mass and an increase in the activity of the catalyst. Thus, using the proposed mixture, it is possible to obtain a granular catalyst with a temperature of 50% —the degree of conversion of carbon monoxide into dioxide is 180 ° C, i.e. 35 ° C lower than in the case of the known charge. According to the invention, a mixture of alumina powders with a particle size of 1 µm and copper is moistened with a solution of chromic anhydride, the mass is rubbed until it acquires a plastic state, and then formed into granules by extrusion. This mixture is well molded, which makes it possible to obtain strong catalysts. The resulting catalysts are heated in air at 400-800 ° C. Example 1. 76.1 g of highly dispersed alumina with particle sizes of 1 micron and less, specific surface 140-170, calcined at 930–9 ° C, and 2.8 g of copper powder are thoroughly mixed. The mixture of powders is moistened with an aqueous solution of chromic anhydride, 21.1 with 42 ml of water, and then triturated to form a plastic mass. The obtained 1 plastic t mass is formed into granules, which are kept at room temperature for 24 hours, and then dried at b, after which they are heated to 400 s and kept at this temperature for 4 hours. Oxidation of carbon monoxide is carried out in a flow-through installation in a temperature range of 150-350 ° C and a space velocity of 18,000 hours for a gas mixture containing,%: CO 3.2; water vapor 10, OJ oxygen 12.3; the rest is nitrogen. At the reaction temperature of the oxidation of carbon monoxide, the degree of conversion of CO is 50%, and at - 100%. Example 2. Of 77.1 g of highly dispersed alumina, 4.1 g of copper powder and a solution of 18.8 g of chromic anhydride in 44 ml of water, the catalyst is prepared and tested as in Example 1. 50% oxidation temperature WITH 210®S and 100%. Example 3. From a mixture of 79.1 g of highly dispersed aluminum oxide, 8.2 g of copper powder, a solution of 12.7 g of chromic anhydride and 63 ml of water, a catalyst was prepared as in example 1. The test was carried out under the same conditions as and in example 1. The temperature of 50% oxidation of CO is 205 ° C, and 100% is 235 ° C. The test results of catalysts prepared from the proposed mixture are given in table. 1. The results of the evaluation of thermal stability of the most active sample obtained from the mixture of composition, as in example 1 and from the mixture of composition - a prototype, are given in table. 2. Table

The proposed 123.0, 2.58

21,176,1

131,02,49

18,877.1

77,02,61

12,779.1

Prototype

CuiNOj) Cr OjAljOg

57,629,115,3

230 245 235

215

MA and oxide-alumina, oh. so that, in order to increase the plasticity of the mixture and increase the activity of the catalyst, the mixture contains copper powder as the copper-containing component, and chromic anhydride as the chromium oxide in the following ratio of components, wt.%:

Sources of information accepted. Attention in the examination

1- USSR Copyright Certificate 386663, cl. B 01 J 23/86, 1971,

2. Patent CIUA 3870658, cl. 260-680, 01 J 23/86, published. 1975 (prototype).

Claims (1)

Claim The mixture for the preparation of a granular catalyst for the oxidation of carbon monoxide, including a copper-containing component, chromium oxide and alumina, about. which, in order to increase the plasticity of the mixture and increase the activity of the catalyst, the mixture contains copper powder as a copper-containing component, chromic anhydride as chromium oxide in the following ratio of components, May. %: Copper powder 2.8-8.2 Chromic anhydride 12.7-21.1 Oxide thirty aluminum Rest