SU709163A1 - Method of obtaining catalyst for carbon monoxide conversion - Google Patents

Description

I

The invention relates to the field of chemical industry, mainly, to the technology of producing solid substances consisting of oxide metal compounds, and can be used to obtain displaced catalysts based on oxide metal compounds — copper, zinc, aluminum.

In modern chemical industry, for the production of catalysts, methods are used that consist of the following basic operations: obtaining a solution of nitric acid, sulfate, hydrochloric acid, formic acid, and other metal salts; obtaining a solution precipitator; mixing the obtained solutions of metal salts and precipitator; separating and washing the obtained precipitate; drying, calcining and shaping (tabletting) with a mass cation aggregate; restoration (activation) of the catalyst before its use in the catalytic process.

Known methods for the preparation of catalysts in which oxalic acid is used as a precipitant, and the catalyst mass after the introduction of the precipitant is

a suspension of oxalate of copper and zinc in a solution of aluminum nitrate 1 or aluminum nitrate and nitric acid 12. During the heat treatment of the catalyst mass, aluminum nitrate is decomposed with significant qualities of harmful nitrogen oxides.

The closest to the proposed method, according to the technical essence and the achieved effect, is a method for preparing a catalyst for the conversion of carbon monoxide by mixing a solution of copper, zinc and aluminum nitrate salts with a precipitating solution, which is alkali metal carbonate and / or bicarbonate, followed by separation and washing the obtained precipitate from the soluble salt, molding, drying, calcining and recovering 3.

However, this method does not allow for the uniform distribution of insoluble metal compounds in the sediment, since most of these compounds precipitate at different pH. In addition, most

Alkali metal catalysts are an undesirable impurity or even a home.

The aim of the invention is to increase the activity and decrease the amount of wastewater during the preparation of the catalyst.

The goal is achieved in the method of producing catalysts by mixing a solution of nitrate salts of copper, zinc and aluminum with a solution of a precipitator, followed by separating and washing the resulting precipitate from the soluble salt, molding, drying, calcining and recovering the precipitator using an aqueous solution containing 10 -30 weight.h. aluminum hydroxide and 26-36 weight. ammonium oxalate, and the deposition is carried out from a solution containing, by weight. including:

Nitrate 1e25

Zinc nitrate15-30

Aluminum nitrate 20-60

A distinctive feature of the invention is the use as an precipitant of an aqueous solution of ammonium hydroxide and ammonium oxalate with a certain ratio between the components.

In the process of the invention, all metals are in the sediment in the form of sparingly soluble oxalates and hydroxides, and the separable filter is a solution of ammonium nitrate, which can be used as a fertilizer.

The use of a complex precipitant — an aqueous solution of ammonia and ammonium oxalate — provides simultaneous precipitation of all metals in the precipitate regardless of the pH of the medium and does not require thorough washing of insoluble metal compounds (hydroxides and oxalates) from the ammonium salt (ammonium nitrate), since the latter is easily decomposed or sublimated during heat treatment of sediment.

The proposed complex precipitant does not contain alkali metals, and the concentration of ammonium ions in it is such that it does not allow some metals (copper zinc) to be converted again into solution in the form of soluble ammonia complexes.

Example 1. Preparing a solution of 25 wt. including copper nitrate salts, 19, wt. including zinc, 40 wt. including aluminum and 480 wt. including water and ravor precipitator containing 20 wt. am ammonium hydroxide, 30 wt. ammonium oxalate and 280 weight. h of water. Both solutions are mixed, the precipitated precipitate is separated by filtration from the mother liquor, separated from ammonium nitrate, dried at 110 ° C and calcined at 400 ° C. Get the catalyst composition, wt.%: Copper oxide 38

Zinc Oxide28

Aluminum oxide 34

which is mixed with 2 wt.% graphite and tableted into 4x6 mm tablets.

The catalyst is tested in the process of conversion of CO with water vapor on a model plant under: conditions: volume of catalyst 400 pressure 28 atm; temperature 220 ° С. volumetric rate 5000 vapor / gas ratio 0.7 and. the composition of the source gas, vol.%: WITH 2.4; CO2 21.6; SS + Ag 1; N 18.0; Hj 57.0.

Test result: residual content of carbon monoxide in the converted gas is 0.15% by volume. The amount of wash water per 1 kg of catalyst is 19 kg.

Example 2. The catalyst receive and test as in example 1, only the solution of metal salts consists of 25 weight. h. C (N03) 30 wt. h, Zn (NO3) 2, 20 wt. including A (N03) 3 and 200 weight. including water, and a solution of complex osalitel consists of 10 wt. h., 36 weight. including (NN4) 20204 and 400 wt. h of water. The calcined catalyst mass has a composition, wt.%: CuO 38; ZnO 45; AljOa 17.

Example 3. The catalyst receive and test as in example 1, only the solution of metal salts consists of 25 weight. h. C (N03) 2 15 wt. h. 2p (MOZ) 2, 60 wt. including AI (NO3) 3 and 430 weight. including water, and the solution of the complex precipitator consists of 30 weight. including NN4OH, 26 wt. including (MH4) 2C204 and 170 weight. h of water. The calcined catalyst mass has a composition, wt.%: CuO 34, ZnO 20, A1203 46.

Example 4. The catalyst receive and test as in example 1, only the solution of metal salts consists of 25 parts by weight C (MOZ) 2 15 wt. including Zn (NO3) 2, 20 wt. h. A1 (BOD) s 140 weight. including water, and the solution of a complex precipitator consists of 10 ъ. including NN4OH, 26 wt. including (NH4.) 2C2O4 and 200 weight. h of water. The calcined mass is precipitated, wt.%: CuO 48, ZnO 30, AlaOj 22.

The catalyst samples according to examples 2, 3, 4 when testing have results similar to example I.

The catalyst content obtained in the prototype method under the conditions of Example 1 is 0.36 at.% CO, a is the amount of wash water when preparing the prototype catalyst is 48 kg per 1 kg of catalyst.

Thus, the present method allows to obtain catalysts, the activity of which is more than 2 times higher than the activity of catalysts obtained by a known method. In addition, the proposed method allows reducing the quantity of wash water by more than 2 times and is easy to dispose of using, for example, ammonium nitrate as a mineral fertilizer.

5 7091636

Claims (3)

The formula of the invention and 26-36 weight. ammonium oxalate, and precipitation A method for producing a catalyst for copper enver-nitrate 25 these carbon monoxide by mixing a solution of zinc nitrate 15-30 nitrate salts of copper, zinc and aluminum N Aluminum nitrate 20-60 with a precipitator solution followed by a department — information sources, by washing and washing the obtained sediment ot rasted taken into account during the examination vorimo salt molded by drying, calcined-1. USSR Copyright Certificate № 413704, and restoration, distinguishing-cl. B 01 3 37/02, 1970. so that in order to increase actuality 2. USSR author's certificate N 269152, and reducing the amount of wastewater, in qual. On 01 J 37/04, 1969. water precipitator is used as a precipitator; 3. UK application No. 1366367, holding 10-30 weight. including ammonium hydroxide class. In 1 E, 1971 (prototype). carried out from a solution containing weight. including: