A method of producing a catalyst for decomposing harmful impurities

 

(57) Abstract:

The invention relates to inorganic chemistry and can be used in particular for the preparation of the catalyst used for the decomposition of ozone in production with his participation, namely: water treatment, wastewater treatment, processing of semiconductors in the electronics industry, sterilization in medicine and disinfection in agriculture; for the purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs and the emissions of industrial enterprises, for purification of exhaust gases of internal combustion engines, as well as for other industrial and environmental purposes. The described method of producing a catalyst comprising a mixture of manganese dioxide and copper oxide with a binder bentonite clay, molding granules, drying, grinding and heat treatment at 450-750C. the Proposed method allows to obtain a water-resistant catalyst of high activity in the decomposition of ozone and oxidation of carbon monoxide. table 1.

The invention relates to the field of inorganic chemistry and can be used in particular for the preparation of the catalyst used for the decomposition of ozone in production with his concerns sterilization in medicine and disinfection in agriculture; for the purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs and the emissions of industrial enterprises, for purification of exhaust gases of internal combustion engines, as well as for other industrial and environmental purposes.

A known method of producing a catalyst for decomposing harmful impurities, comprising a mixture of manganese dioxide, copper oxide and a binder (taluma) in the ratio(30-40):(20-30):(30-50), forming granules by extrusion of the mixture components in the matrix with subsequent extrusion of granules, their hydrothermal treatment at a temperature of 90-100oC for 2 hours and calcination at a temperature of 300oC for 3 hours (A. C. USSR N 1768247 from 29.12.90, CL 01 J 23/84, 53/36).

The disadvantage of this method is the low productivity of the production process for industrial preparation of catalyst due to the inability molding pellets in the auger granulator because of the low plasticity of the paste of the mixture components.

There is also known a method of producing a catalyst comprising a mixture of manganese dioxide and copper oxide with a binder (taumaranui 200-1000oC for 1-6 hours, molding pellets in the auger granulator, hydrothermal treatment, drying and calcination at a temperature of 300-400oC (U.S. Pat. RF N 2077947 from 04.04.95, CL 01 J 23/889, 37/04//(01 J 23/84, 101:62)).

The disadvantage of this method is the high cost industrial process for the preparation of the catalyst, due to significant wear of the dies in forming the granules, due to strong abrasive properties of the molded catalyst mass.

Closest to the proposed technical substance and the number of matching characteristics is a method of producing a catalyst comprising a mixture of manganese dioxide and copper oxide with a binder bentonite clay, manganese dioxide is mixed with copper oxide simultaneously with the preparation of the latter at a temperature of 50-95oC for 0.5 to 3.0 hours, and then manganese dioxide and copper oxide mixed with a binder, molding granules, drying the molded pellets at a temperature of 60-90oC for 10-15 hours, grinding and heat treatment at a temperature of 250-370oC (U.S. Pat. RF N 2083279 from 31.10.95, CL 01 J 23/889, 37/04//(01 J 23/84, 101:62)).

The disadvantage of this method is the instability of the granules obtained catalyst e, the invention is directed to the solution of the following problem: getting water-resistant catalyst, highly active in the decomposition of ozone and oxidation of carbon monoxide, which is achieved by the proposed method comprising a mixture of manganese dioxide and copper oxide with a binder bentonite clay, molding granules, drying, grinding and heat treatment.

The difference of the proposed method against known is that the heat treatment is conducted at a temperature of 450-750oC.

Of scientific and technical literature authors unknown process operation of the heat treatment of the molded pellets consisting of manganese dioxide, copper oxide and bentonite clay, at a temperature of 450-750oC.

The method is as follows.

Prepare aqueous suspension of manganese dioxide and add caustic sodium.

After dissolving the latter in a suspension of copper sulphate is added and keep stirring at a temperature of 50-95oC for 0.5 to 3.0 hours. Then the suspension is filtered and washed pasta from sulfate ions. The resulting paste is mixed with a binder bentonite clay, plastificated and formed into pellets by a screw granulator at a temperature of 100-110oC and a pressure of 35-45 ATM through a Spinneret hole diameter of 1.0-1.5 mm Formed granules are dried at the same time the round 450-750oC. the resulting catalyst has the following composition: manganese dioxide 50-70 wt.%, the copper oxide 10-25 wt. % bentonite clay 10-20 wt.%, impurity - rest. The catalytic activity of the obtained water-resistant catalyst in the oxidation of carbon monoxide was 1,68-2,13 mmol/g, the degree of purification from ozone was 95,4-99,6 %.

Example 1.

In a mixer equipped with heating and mixing devices, pour 4 liters of water, include a mixing device and load 4 kg of a paste of manganese dioxide with a humidity of 50%. Mixing lead for 30 minutes until a homogeneous aqueous suspension of manganese dioxide. Then in a mixer add 0,59 kg of sodium hydroxide and continue stirring for 20 minutes. After the dissolution of sodium hydroxide, setting the mixer temperature of 20oC and stopping stirring, the mixer gradually over 10 minutes add 4.2 l of copper sulfate solution with a concentration of 240 g/DM3. After adding copper sulphate stirring is continued for 30 minutes while maintaining the set temperature. After stirring the pasta mixture of manganese dioxide and copper oxide is filtered and washed from sulfate ions. The resulting paste with in sousage - bentonite clay and lead the process of plasticization of the paste at a temperature of 50oC for 0.7 hours to a moisture content of 30%. The resulting paste is unloaded and molded on to the screw granulator at a pressure of 40 ATM and a temperature of 110oC through a Spinneret hole diameter of 1.1 mm Molded granules are dried at a temperature of 80oC for 12 hours. The dried granules are crushed, sieved fraction of 1-3 mm, and conducting heat treatment at a temperature of 450oC. the resulting catalyst has the following composition: manganese dioxide 60 wt.%, the copper oxide 15 wt.%, bentonite clay 15 wt.%, impurity - rest. The catalytic activity of the obtained water-resistant catalyst in the oxidation of carbon monoxide was 2,13 mmol/g, the degree of purification from ozone amounted to 99.3 percent.

Example 2.

A process as in example 1 except that heat treatment temperature, which amounted to 600oC. the resulting catalyst has the following composition: manganese dioxide 60 wt.%, the copper oxide 15 wt.%, bentonite clay 15 wt. %, impurity - rest. The catalytic activity of the obtained water-resistant catalyst in the oxidation of carbon monoxide was 1.75 mmol/g, the degree of purification from ozone amounted to 97.8 per cent.

Example 3.

Wojenny the catalyst has the following composition: manganese dioxide 60 wt.%, the copper oxide 15 wt.%, bentonite clay 15 wt. %, impurity - rest. The catalytic activity of the obtained water-resistant catalyst in the oxidation of carbon monoxide was 1,68 mmol/g, the degree of purification from ozone amounted to 95.4 percent.

The results of research of influence of heat treatment temperature on the degree of purification from ozone and catalytic activity of the resulting catalyst in the oxidation of carbon monoxide in the table.

As follows from the data shown in the table, the high activity water-resistant catalyst in the decomposition of ozone and oxidation of carbon monoxide is observed when carrying out heat treatment at a temperature of 450-750oC. When the temperature of heat treatment is less than 450oC it is not possible to obtain a product having sufficient resistance to water. The increase in heat treatment temperature of more than 750oC leads to a noticeable decrease in the activity of the catalyst in the decomposition of ozone and oxidation of carbon monoxide.

The essence of the proposed method consists in the following. The high activity water-resistant catalyst in the decomposition of ozone and oxidation of carbon monoxide at conducting heat treatment at a temperature of 450-750oC due to the NCA acts as the active component, the copper oxide plays the role of promoter, enhancing the catalytic properties of the first, bentonite clay is the binder, providing a link between particles of the active component and promoter, and a plasticizer, promoting education in the process of mixing the components highly paste suitable for forming on a screw granulator. The main mineral bentonite clay is montmorillonite, which belongs to the layered minerals with expanding lattice. Mix in the aquatic environment leads to the fact that packet space of montmorillonite embedded water molecules and the lattice primary then expanded, contributing to increased binding and plasticizing properties. In addition, part of montmorillonite aluminate of calcium in the reaction of hydration water enters hydroalumination calcium and aluminium hydroxide. Since the dispersion of the bentonite clay is significantly higher than that of manganese dioxide and copper oxide, the formed pellet is a system that consists of particles of bentonite clay as a binder, forming a space frame comprising particles of the active component and promoter. In the inanem, strongly related to each other. Because compounds of this class are insoluble in water, and the granules obtained are water-resistant catalyst. Heat treatment temperature less than 450oC is insufficient for these reactions were in full and led to the formation of a rigid spatial structure, with sufficient resilience to water. On the other hand, carrying out heat treatment at a temperature of more than 750oC leads to a noticeable decrease in the activity of the resulting catalyst in the decomposition of ozone and oxidation of carbon monoxide, due to the fact that at these temperatures there is a restoration of tetravalent manganese in the composition dioxide to States of lower valency, which do not have any appreciable catalytic properties.

Thus, the proposed method allows to obtain a water-resistant catalyst having high activity in the decomposition of ozone and oxidation of carbon monoxide.

Implementation of the proposed method will significantly expand the scope of the catalyst used for the decomposition of ozone in production with his participation, namely: vodopodgotovitelnih in agriculture; for purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs and the emissions of industrial enterprises, for purification of exhaust gases of internal combustion engines, as well as for other industrial and environmental objectives that will provide an opportunity to effectively solve a wide range of environmental and technological problems.

From the above it follows that each of the signs stated together to a greater or lesser extent affect the solution of the problem, namely: obtaining water-resistant catalyst of high activity in the decomposition of ozone and oxidation of carbon monoxide, and the entirety is sufficient to characterize the claimed technical solution.

A method of producing a catalyst for decomposing harmful impurities, comprising a mixture of manganese dioxide and copper oxide with a binder bentonite clay, molding granules, drying, grinding and heat treatment, wherein the heat treatment is conducted at 450 - 750oC.

 

Same patents:

The invention relates to the production of catalysts for the process of low-temperature methanol synthesis

The invention relates to the production of catalysts for ammonia synthesis and can be used in the nitrogen industry

The invention relates to the production of catalysts for the process of low-temperature conversion of carbon monoxide with water vapor

The invention relates to the field of organic synthesis, in particular to a method of preparation of the catalyst to obtain vinylacetate (C. A.) from acetylene and acetic acid

The invention relates to gas cleaning from impurities and can be used in particular for the purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs, as well as for other industrial and environmental purposes
The invention relates to methods for solid sorbents and catalysts carriers, in particular for use in hydrogenation processes for cleaning oil fractions

The invention relates to the production of catalysts for the synthesis of methanol at low temperature and pressure

The invention relates to a catalyst and method of its preparation for the selective purification of gas mixtures containing nitrogen oxides, oxygen, and nitrogen dioxide

The invention relates to a method of preparing phosphoroclastic catalysts for processes of oligomerization of low molecular weight olefins and alkylation of benzene by propylene and can be used in refining and petrochemical industries
The invention relates to a method for preparing catalysts for medium-temperature conversion of carbon monoxide containing oxides of iron, copper, chromium, which is used in industry for preparation of nitric mixture for the synthesis of ammonia

The invention relates to methods of producing catalysts based on copper and zinc for the process of low-temperature steam reforming of carbon monoxide

The invention relates to the field of inorganic chemistry and can be used in particular for the preparation of the catalyst used for purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs in the emissions of industrial enterprises, for purification of exhaust gases of internal combustion engines, for the decomposition of ozone in production with his participation, namely: water treatment, wastewater treatment, processing of semiconductors in the electronics industry, sterilization in medicine and disinfection in agriculture, as well as for other industrial and environmental purposes

The invention relates to the production of sorbents and catalysts used in individual and collective means of protection for air purification from nitrogen oxides, and can be used in the industrial production of catalysts

The invention relates to catalytic chemistry, in particular to the preparation of catalysts for Hydrotreating petroleum fractions, and can be used in the refining industry

The invention relates to the field of inorganic chemistry and can be used in particular for the preparation of the catalyst used for purification of gas mixtures of carbon monoxide in the systems of collective and individual protection of respiratory organs in the emissions of industrial enterprises, for purification of exhaust gases of internal combustion engines, for the decomposition of ozone in production with his participation, namely: water treatment, wastewater treatment, processing of semiconductors in the electronics industry, sterilization in medicine and disinfection in agriculture, as well as for other industrial and environmental purposes
Up!