SU1747144A1 - Catalyst for carbon dioxide conversion of methane - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular a catalyst (QD) for carbon dioxide conversion of methane. The goal is to increase the catalytic activity and resistance to carbonization. This is achieved by those. that CT contains, wt%: nickel oxide 7.0-12.0; calcium oxide 1.0-4.0; silica 19.0-52,0; potassium oxide 6.0-9.0 and alumina rest. This allows for V 4000 and 800 ° C to increase the methane conversion rate to 85 versus 60.3% for the known catalyst with the almost complete absence of carbonization. 1 tab.

Description

This invention relates to catalysts for the carbon dioxide conversion of methane and can be used in thermochemical energy conversion processes.

A known catalyst for carbon dioxide conversion of methane, RuSSS, obtained by applying the active component of ruthenium on a stainless steel carrier. The catalyst can operate at a temperature of 850 ° C. The content of residual methane in the converted gas is 6.3%

The disadvantages of the known catalyst are the small area of activity and the coking of the catalyst when the ratio of carbon dioxide to methane is less than three. Besides

Moreover, ruthenium itself is a rare and expensive metal.

A known catalyst for the steam carbonic acid conversion of a HIAA, containing the following components, in wt%:

Nickel oxide 23-26

Alumina 44-52

Magnesium oxide 13-17

Barium oxide 0.6-1.2

Calcium Oxide 6-13

The disadvantage of this catalyst is its inadequate stability at high temperatures, at which carbon dioxide conversion of methane takes place. In this case, a rapid carbon black is observed.

J

and disintegration of the catalyst and, as a consequence, a decrease in catalytic activity.

Thus, the use of a GIAP for carbon dioxide conversion without water vapor is practically impossible. The use of steam-carbon-acid conversion in energy conversion processes (nuclear and solar) is ineffective, as it is associated with additional energy consumption for water vaporization, and the efficiency of energy conversion in steam methane conversion processes is less than 80%. The combined conversion of methane with steam and carbon dioxide (steam-carbon conversion) will reduce the efficiency of carbon dioxide conversion, the theoretical efficiency of which reaches 100%.

- The closest to the proposed one is the catalyst of methane conversion by the company ICH, containing oxides of nickel calcium, silicon and aluminum in the following ratio, wt.%; nickel oxide 21; calcium oxide 11: silica 1 b; potassium oxide 7; magnesium oxide 13; alumina rest.

The disadvantages of the known catalyst are lower catalytic activity and resistance to carbonization. Thus, at V 400 4 m and a temperature of 800 ° C, the degree of conversion of the dry converted gas is 60.27% and within 5 hours due to rapid coking, it is destroyed during operation.

 The aim of the invention is to increase the catalytic activity and resistance to carbonization.

The goal is achieved by a catalyst containing oxides of nickel, calcium, silicon, potassium and aluminum in the following ratio, wt.%:

Nickel oxide 7.0-12.0

Calcium Oxide 1.0-4.0

Silica 19.0-52.0

Potassium Oxide 6.0-9.0

Alumina Rest

The invention allows to increase the catalyst activity from 0.61 to 0.85 X conversion) with a carbon dioxide to methane ratio of 1: 1. The catalyst is not coked during operation. EXAMPLE 1. 1.67 g of nickel nitrate nitrate Ni (N03) 2-6HaOtr aluminum oxide, 3 g of silicon oxide SiO2, 0.14 g of calcium carbonate CaCO3, and 0.51 g of potassium carbonate CAC03 are weighed out. All components are mixed by adding distilled water to obtain a cream; figurative homogeneous mass .. Then this. the mass is dried at 130 ° C until removed from it

moisture. The resulting mixture is thoroughly mixed by grinding to the smallest particles. Then the powder is pressed at a pressure of 3 t / cm into briquettes, which are pierced in a furnace for two hours, smoothly raising the temperature linearly at a rate of 10 ° C / min to 750 ° C.

Before operation, the briquettes are restored in a stream of hydrogen for 4 hours at 800 ° C. In this case, nickel oxide is reduced to metallic nickel. After that, the catalyst is ready for operation under conditions of carbon dioxide conversion of methane. The conversion is carried out at a volumetric rate of 4000

C 1

The resulting catalyst contains, wt%:

ЫЮ7,3

AlzOs34,1

SI0251.2

K2O6

CaO1,4

Tests of the proposed catalyst showed its high catalytic activity, which was assessed by the composition of the output reaction products and the degree of methane conversion. The catalyst was tested at a temperature of 800 ° C with a 1: 1 ratio of carbon dioxide to methane. As a result of chromatographic analysis, the composition of the reaction products was determined.

47.7

48.0

4.0

0.3

The degree of conversion was 0.85.

PRI mme R 2. Weigh out 1.98 g of nickel nitrate crystalline hydrate, 3.75 g of alumina, 1.25 g of silicon oxide, 0.37 g of calcium carbonate, and 0.79 g of potassium carbonate. Further operations and processing are performed as in Example 1, the resulting catalyst contains, in wt.%: NIO8.1

A1aOz60.0

ZUa20.0

CaO3,5

Kao-8.4

As a result, after the carbon dioxide conversion of methane using this catalyst, the following composition of the reaction products was obtained,%:

At .41.7

SO.50.3

From “47.9

COA0.1

and a conversion of 0.73.

Example 2.97 gaseous acid nickel, 3.75 g of alumina, 1.25 g of silica and oxide, 0.4 g of carbon dioxide and 0.84 g of potassium carbonate are weighed out. Further operations and processing are performed in the same way as in Example 1. The resulting catalyst contains, in wt.%;

N1011,6

A 20357.3

SI0219.1

K208,6

CaO3,4

As a result of the conversion, reaction products were obtained,%:

H2 41.9

SO51,6

CH46.3

S020,2

Conversion rate 0.78. PRI me R 4. Weighed, g:

NKN03) 2-6H201.98

A1203.5

SI022,5

СОСОз0,41

K2CO3.73

Further operations and processing are carried out in the same manner as in Example 1. The resulting catalyst contains, in wt.%: N10; 8.1

A 20-39.9

5LU239,9

CaO8.3

K20: 3.8

After a x-chromatographic analysis of the converted gas, the composition of reaction products was obtained,%:

H2 41.2

SO48,7

CH47,7

С022.4

Conversion rate 0.74. PRI me R 5. Weighed, g: Wi (N03) 2 6H202.48

A 202

Sf023

K2CO3.7

СОСОз0,3

Further operations and processing are performed in the same way. as in example 1. The resulting catalyst contains, wt%: N1010.3

A 20332.2

SI0248,2

CaO2,7

K206.6

After carbon dioxide conversion, reaction products were obtained,%:

H243.1

SO48,4

CH46.4

S022.1

Conversion rate 0.78. PRI me R 6. Weigh 2.06 g of nickel nitrate nitrate hydrate. Ni (N03) 2y 6X2O 2.5 g of alumina, A1203, 2.5 g of silicon oxide, SI02. 0.46 g calcium carbonate, СОСОз. 0.84 g of potassium carbonate, KgSO3. All components are mixed by adding distilled water until a creamy, smooth mass is obtained. This mass is then dried at 130 ° C until moisture is removed from it. The resulting mixture is thoroughly mixed by grinding to the smallest particles. Then the powder is pressed at a pressure of 3 g / cm into briquettes, which are calcined in a furnace for two hours, gradually raising the temperature linearly at a rate of 10 ° C / mmn to 750 ° C.

Before operation, the briquettes are restored in a stream of hydrogen for 4 hours at 800 ° C. In this case, nickel oxide is reduced to metallic nickel. After that, the catalyst is ready for operation under the conditions of carbon dioxide methane conversion. The resulting catalyst contains, wt%:

A120З39,4

8SU239,5

N108.1

CaO-4,0

feO9.0

Tests of the proposed catalyst showed its high catalytic activity, which was assessed by the composition of the output products and the degree of methane conversion. The catalyst was tested at 800 ° С and the ratio of carbon dioxide to methane 1: 1.8. The chromatographic analysis determined the composition of the reaction products,%:

H243.1

CO-49,5

CH45.3

S022.1

The degree of conversion was 0.81.

Example. Weighed, g: Nl (NOs) 2-6H201.6

A1203

$ 1022

СОСОз0.11

K2CO3.55

Further operations and processing are carried out in the same manner as in Example 1. The resulting catalyst contains, in wt.%:

A120z51.3

SIO234.3

NiO7.0

.0

CaO6,4

After chromatographic analysis of the converted gas, the composition of the reaction products was obtained,%:

Н245,1

SO47,4

CH44.1

Ssch23,4

Conversion rate 0.85. Example Weighed, g: M (MOH) 2 6N201.99

AlzOs2

8Yu23

 SASOz0,2

 K2CO3.56

   The dual operations and processing are carried out as in Example 1. The resulting catalyst contains, in wt.%:

A 20З32,0

. SJ252.0

MYU8.2

CaO1,7

K2O6,1

As a result of chromatographic analysis of the converted gas, the composition of the reaction products was obtained,%:

Н22,5

CO49,4

CH45.1

S023.0

Conversion rate 0.82. PRI me R 9. Weighed, g: M (1MOZ) 2 6N203.07

A 20z 3.75

Si021.25

СОСОз0.39

K2CO3.78

Further operations and processing of the catalyst are carried out as in Example 4. The resulting catalyst contains, in wt.%:

A120z. 57.5

19 12 3.3 8.2

As a result of carbon dioxide conversion

methane obtained reaction products,%:

H242.1

SO50.6

CH45.4

CO21,9

Conversion rate 0.81.

Comparative characteristics of the known catalysts are presented in the table.

The use of the invention allows carbon dioxide conversion without water vapor, and in the presence of the proposed catalyst using solar energy, each ton of methane is enriched by 15.48 106 kJ / g. , 1% more than with steam reforming.

Claims (1)

Invention Formula 0 five A catalyst for carbon dioxide conversion of methane containing oxides of nickel, calcium, silicon, potassium, and aluminum, characterized in that. In order to increase the catalytic activity and resistance to carbonization, the catalyst contains these components in the following ratio, wt%: Nickel Oxide 7-12 Calcium Oxide 1-4 Silica 19-52 Potassium Oxide 6-9 Alumina Rest -one Comparison of the activity of catalysts at a space velocity of 400 hours at 800 ° C, test time 50h -one