SU1685512A1 - Method for preparing catalysis for chemical processes - Google Patents

Abstract

This invention relates to catalytic chemistry, in particular to the preparation of a catalyst for chemical processes. The goal is to increase the activity of the catalyst L to reduce its material consumption. The preparation is carried out by mixing the aluminum component with chromic anhydride in a mass ratio of 1: (0.68-1.0) in an aqueous medium at elevated temperature, adding to the resulting mixture additionally activated carbon, manganese oxide or carbonate, and / or zirconium oxide or hydroxide at a certain mass ratio within 1-3 hours. The process is carried out with the subsequent mixing of the obtained catalyst base with double carbonate salts of copper and zinc at a certain mass ratio, molding and heat treatment at 80-2 80 ° C. Preferably, the catalyst base is mixed with nickel carbonate at a mass ratio in terms of oxides: catalyst base: nickel oxide - 1: (0.5-0.7) The new catalyst provides gas cleaning at low temperatures of 120-130 ° C due to partial reduction by 10-20% of the nickel component and chromium oxide. 1 hp f-ly, 2 tab. sl C

Description

The invention relates to the chemical industry, to the technology of producing mixed catalysts for the conversion of carbon monoxide with steam, for hydrogenation, in particular for the purification of hydrogen and hydrogen-containing gas from oxygen and oxygen-containing impurities.

The purpose of the invention is to increase the activity of the catalyst and reduce its material consumption.

The method is carried out as follows.

The aluminum component, chromic anhydride, activated carbon, manganese and / or zirconium compounds are loaded into a mixing apparatus according to the ratios, moistened according to the ratios with water, the temperature is raised and mixed for a specified time - a catalyst base is obtained (mixture No. 1).

A measured amount of a copper – ammonium carbonate solution is poured into a heated reactor, loaded according to the required amount of zinc oxide catalyst composition, the temperature is raised to 70–99 ° C, and double salts of copper and zinc are precipitated to contain ammonia in the solution not exceeding 20 g / l, filtered and dried - get a mixture of N 2.

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The basis of the catalyst (mixture No. 1) is mixed with double salts of copper and zinc or with a carbonate form of nickel at a given temperature and humidity for a certain time and molded into granules by extrusion or rolled into balls with the subsequent process of their heat treatment.

Example 1. Chromic anhydride, manganese oxide and activated carbon are added to a mixing apparatus at the rate of 0.4 kg calculated as base oxides (mixture No. 1) alumina or alumina obtained by calcining aluminum hydroxide at 450-500 ° C. when the ratio of components in terms of oxides is chromium oxide (): aluminum oxide A1203): activated carbon (C) manganese oxide (Mn02) 1: 1: 0.04: 0.04, the components are mixed, filled with water and at a ratio m: W -1: 1 raise the temperature to 50 ° C and mix for 1.5 h - get the basis of the cat alizator (mixture No. 1).

The ammonium carbonate solution of copper and zinc oxide are mixed in a given ratio in terms of metal oxides — copper oxide: zinc oxide 1: 0.5; the precipitate is separated and aired from ammonia in air flow at 80-130 ° C — mixture No. 2

The basis of the catalyst (mixture No. 1) is mixed with double carbonate salts of copper and zinc (mixture No. 2) at 50 ° C for 0.5 h and molded into granules by extrusion, heat treated at 150 ° C — a catalyst with bulk density 0 is obtained , 9 kg / dm3. The catalyst is reduced by the converted gas and is tested in the carbon monoxide conversion process at 200-220 ° C, a steam: gas ratio of 0.6, a space velocity of 6000, a pressure of 2.8 MPa (28 atm) on the converted gas with a monoxide content (% by volume) carbon 3.5-4, carbon dioxide 10-15, (СЙ4 + А g) - up to 1, H2 12-17, the rest is nitrogen,

The degree of carbon monoxide conversion at the beginning of the test is 96%, through. 168 h 92%.

Example 2. A catalyst sample was tested in the process of medium-temperature conversion of carbon monoxide on the composition of a gas containing 7-14 vol.% Of carbon monoxide at 360-400 ° C. The degree of carbon monoxide conversion at the beginning of the test was 85%, after 168 hours of testing 84%.

Examples 3-5. Catalyst samples are prepared as in Example 1, according to the ratio proposed in the method, are tested under the conditions of Example 1.

Examples 6 and 7. Samples of the catalyst are prepared as in example 1, but instead of carbonate double salts of copper and zinc, nickel carbonates are used, and the samples are tested during the purification of hydrogen-containing gas from oxygen-containing compounds — methanation. As an indicator of activity, the minimum temperature (° C) is taken, providing a volume fraction of carbon monoxide at the output of no more than 1-10%, at a pressure of 3.0 MPa, volume rate h, volume fraction in the source gas 0.3-1.0% and 0.00- 0.03% CO2 after pre-heating the catalyst for 10 hours at 550 ° C.

This figure corresponds to the accepted method for determining activity for methanation catalysts: NMK-1, NKM-4A; TO-2.

On the basis of the experimental work carried out, the optimal parameters of the preparation process were determined, the optimal ratios of the catalyst components, the physical characteristics of the catalyst were determined.

The technological parameters of catalyst preparation and the ratio of components are given in Table. 1. Physical properties, catalyst composition and activity indicators are given in table. 2

The accepted standards of the technological mode of preparation of the catalyst base (N; 1 mixture) make it possible to synthesize acid-cement adhesive cement, the aluminum and coal components being the suppliers of cations, and the additions of manganese and / or zirconium provide the catalytic redox synthesis of cement-cement.

The double salts of copper and zinc synthesized by known methods ensure that the sphericity of the components is no more than 150A, and when mixed with the catalyst base (mixture No. 1), the dispersion of the active components is not only preserved, but even increased by partial abrasion and the formation of solid solutions up to 80-100A . A similar dispersion is achieved in the preparation of the catalyst for mahanirvana using nickel carbonate salt.

The process of extrusion molding and subsequent heat treatment of the granules in the indicated temperature ranges can significantly reduce the energy intensity of the process by changing the heat treatment process from 400–450 to 180–280 ° С (this

method), to reduce the material consumption of the catalyst by reducing the bulk density from 1.1-1.6 to 0.7-1.0 kg / dm3 to the fed-in method.

Preliminary synthesis of the catalyst base by introducing at given temperature, humidity, ratios allows plasticity of the mass to be achieved, while chromic acid borrows part of aluminum and carbon cations, and manganese and / or zirconium oxides are good carriers of anions from chromic acid and catalyze redox synthesis of cement based on the combination of chromium and aluminum and the addition of coal, manganese and / or zirconium to the base (mixture No. 1). When isomorphous copper and zinc salts or nickel carbonates are mixed, the parameters in the specified parameters of the catalyst synthesis process preserve the fine amorphous nature of the active components and provide increased activity, the degree of conversion at the stage of low-temperature conversion of carbon monoxide under test conditions of the catalyst is 95- 98%, and after testing for 168 hours, it is 92-95%.

The selected mixing temperature of 30–70 ° C of the catalyst base with active components inhibits the setting of the mass and facilitates the process of forming the catalyst into granules, and the heat treatment of the granules in the temperature range of 80–280 ° C ensures not only the setting of the granules 10-20% of the coal introduced into the composition, as well as predetermines the increased performance characteristics of the catalyst.

In the process of purification of hydrogen-containing gas from oxygen-containing compounds, the catalyst prepared according to this technology ensures gas purification at low temperatures of 120-130 ° C, due to partial reduction of the nickel component and chromium oxide by 10-20%.

Claims (1)

1. A method for preparing a catalyst for chemical processes by mixing in an aqueous medium at elevated temperatures the aluminum component with chromic anhydride, double carbonate salts of copper and zinc, drying and molding, characterized in that, in order to increase the activity of the catalyst and reduce its material intensity, mixing the aluminum component with chromic anhydride is blown up in a mass ratio of 1: 0.68-1.0, additionally activated carbon, manganese oxide or carbonate and / or oxide or hydroxide q is introduced into the mixture horses at a mass ratio in terms of oxides: chromium oxide: aluminum oxide: activated carbon: manganese oxide and / or zirconium oxide 1: 0.4-2.5: 0.01-0.12: 0.01-0.12 within 1-3 hours, followed by mixing the obtained catalyst base with double carbonate salts of copper and zinc at a mass ratio in terms of oxides: catalyst base: copper oxide: zinc oxide 1: 0.4-1.4: 0.4- 1.0, molding the mixture into granules and heat treating them at 80-280 ° C. 2, the method according to claim 1, characterized in that the catalyst base is mixed with nickel carbonate at a mass ratio in terms of oxides: catalyst base: nickel oxide 1: 0.5-07. Table 1  The catalyst was prepared for medium-temperature oxide-carbon conversion. A sample of catalyst I 2 is tested in a process of low carbon conversion of carbon monoxide. 1 Sample catalyst by a known method. table 2