RU1660278C - Method of preparing catalyst for fuel combustion - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular the preparation of a catalyst for burning fuel. The aim is to increase the activity of the catalyst while reducing emissions of nitrogen oxides during heat treatment. For this, the carrier, AI O, is impregnated with solutions of iron nitrate and oxalic ammonium molar ratio of "1: (3-3.2), followed by drying and heat treatment. In this case, the activity of the obtained catalyst in the oxidation of carbon monoxide is higher than known. Thus, a 50% oxidation state is achieved at 270-280 °; C vs. 349 ° With a reduction in nitrogen oxide emissions from 50 to 0.06 g / s. 1 tab

Description

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The invention relates to the field of chemistry, in particular to the production of chemistry, in particular to the production of eluene-oxide catalysts used, for example, for the combustion of fuels, industrial emissions, and can be used in the chemical and petrochemical industries.

The aim of the invention is to obtain a catalyst with increased activity and reduction of nitrogen oxide emissions at the heat treatment stage by using a solution containing as an oxalic component ammonium oxalate in a specific molar ratio with iron nitrate.

Example 1. Alumina (Pruritus 230 mg / g, P 24 MPa, water capacity 0.47 ml / g, sphere 1.6 - 2.0 mm) is impregnated in the water tank with a solution containing ammonium oxalate and iron nitrate in a ratio of 3 :1. The solution is prepared as follows: a weighed portion of iron nitrate (ReMO3 / s x 9 Hz O) 266.7 g is dissolved in 400 ml of distilled water. Then, 278.4 g of ammonium oxalate are added to the resulting solution with stirring. The volume of the finished solution is 1 liter.

After impregnation, the catalyst is dried at 30-110 ° C under an infrared lamp until it is free-flowing and calcined in a stream of air 500 at 350 ° C for 4 hours.

The catalytic activity is determined in a flow-through setup in a model CO oxidation reaction. Test conditions:

Temperature, ° С150-600

CO concentration

air, vol.% 1,0

Gas consumption, l / h СО0,4

Air39.6

Circulation speed, l / h1000

Weighed catalyst, g1,0

Granule size - corresponds to the granule size of the test samples, mm1.6-2.0

The method for separately determining the concentration of nitric oxides (N0 and N02) formed during the heat treatment of catalysts is based on the oxidation of nitric oxide to dioxide using an oxidizing mixture (49

ML НзР04 (CONC.) + 10 ML H2S04 (CONC.) I- 41

ml Н20 + 0.5 g KMnO / i) absorption of nitrogen dioxide with a solution of potassium iodide and colorimetric determination of the nitrite ion by the Griss-Iolosv reaction. Sensitivity of determination: 0.3 µg N02 in the analyzed volume of the solution.

The temperature is taken as a measure of activity to achieve a 50% degree of CO conversion. The concentration of nitrogen oxides released was calculated in mg per gram of catalyst. The results of the analysis and catalytic activity are shown in the table.

Example 2. Similar to example 1, but the ratio of ammonium oxalic acid and iron nitrate is 3.2: 1. The properties of the catalyst are shown in the table.

Example 3. Similar to example 1, but the ratio of ammonium oxalic and iron nitrate is 2.6: 1. The properties of the catalyst are shown in the table,

Example 4 (prototype). Alumina is impregnated for moisture capacity with a solution containing iron nitrate and oxalic acid in a ratio of 1: 3. The solution was prepared as follows. A portion of iron nitrate (ReMOZ) s 9N20) 266.7 g.

dissolved in 200 ml of distilled water. Then 247 g of oxalic acid (H 2 ClO x x 2H20) is dissolved in 440 ml of hot distilled water and a hot solution of oxalic acid is added to the solution

iron nitrate with vigorous stirring.

After impregnation, the catalyst is dried at 30-110 ° C under an infrared lamp until free-flowing and calcined in a stream of air 500 at 500 ° C for 4 hours.

Thus, the use of ammonium oxalate in an impregnating solution makes it possible to obtain alumina – iron oxide catalysts with increased catalytic activity in CO oxidation, to lower the heat treatment temperature, and to reduce emissions of nitrogen oxides at the heat treatment stage. During the heat treatment of the catalyst obtained by the prototype method, the emissions of nitrogen oxides are 50 g / s, which significantly exceeds the permissible norms (0.06 g / s). The use of the inventive method allows to reduce N02 emissions below normal.

(56) Copyright certificate of the USSR No. 1295566, cl. B 01 J 23 / 86.1985

USSR author's certificate N 1536569 class B 01 J 37 / 00.1988.

 - Prototype, - Beyond.

Claims (1)

The claims METHOD FOR PREPARING A CATALYST FOR FUEL BURNING by impregnating an alumina support with a solution containing iron nitrate and an oxalic acid component, followed by drying and heat treatment, characterized in that, in order to obtain . catalyst with increased activity and | reduce nitrogen oxide emissions at the heat treatment stage, use a solution containing ammonium as an oxalic acid component Oxalate in molar ratio with iron nitrate (3 - 3.2): 1.