RU2659078C1 - Catalyst, method of catalyst preparation and method of oxidative conversion of hydrocarbons, hydrogenation of carbon oxides and hydrocarbons - Google Patents

Abstract

FIELD: chemistry; metallurgy.

SUBSTANCE: invention relates to the conversion catalyst. Catalyst for the oxidative conversion of hydrocarbons and the hydrogenation of carbon oxides and/or hydrocarbons contains, as an active component, transition metals of the Periodic Table and the carrier, it is characterized in that, as a carrier, it contains monocrystalline alumina nanofibers, which have the diameter more than 3 nm and the length more than 100 nm. Method for the catalyst preparation, the method for the oxidative conversion of hydrocarbons, the method for hydrogenating carbon monoxide and/or carbon dioxide and/or hydrocarbons is claimed.

EFFECT: high activity, stability of the catalyst when carrying out these catalytic processes.

15 cl, 7 tbl, 13 ex

Description

The invention relates to a catalyst and processes for catalytic oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons. In particular, reactions such as steam, carbon dioxide conversion, partial oxidation, or autothermal reforming of hydrocarbons to produce synthesis gas are the basis of most large-scale processes in the chemical and petrochemical industries.

Improving the catalysts and optimizing the parameters of these processes have always been of strategic importance, contributing to resource and energy conservation.

Recently, much attention has also been paid to the problem of utilizing carbon oxides, primarily the capture and involvement of carbon dioxide, one of the main greenhouse gases leading to global warming. The catalytic conversion of CO ₂ in the fuel (e.g., receipt of synthetic natural gas, methanol, dimethyl ether, the synthesis gas) is regarded as a promising approach on its disposal. In particular, catalytic conversion can be used in the processing of biogas, simultaneously containing methane and carbon dioxide. In this regard, the development of active, selective and stable heterogeneous catalysts that minimize capital costs and operating costs during the above processes is an extremely important task.

Currently, catalysts and methods for carrying out catalytic reactions of oxidative conversion of hydrocarbons using supported ruthenium, platinum, rhodium, cobalt, and nickel catalysts are known (P.K. Cheekatamarla, CM Finnerty, Reforming catalysts for hydrogen generation in fuel cell applications // Journal of Power Sources, V. 160 Is. 1,2006, 490-499; EP 1586 535 A2; CN 102949994 (A); US 7449168, B01J 23/78, C01B 3/26, 11.11.2009). The disadvantages of the known catalysts are low activity, carbonization of the catalysts and sintering of dispersed metal particles under the conditions of a catalytic reaction.

Also known are catalysts and methods for the hydrogenation of carbon oxides and hydrocarbons (RU 2409878, НМ 8/06, 01/20/2011; SU No. 780881, B01J 37/02, 1980). In particular, methods for the catalytic conversion of carbon dioxide are known where transition metals, for example, Ru, Rh, Pt, Ni, Co supported on alumina, are used as catalyst (O.V. Krylov, A.Kh. Mamedov, Heterogeneous-catalytic carbon dioxide reactions // Uspekhi Khimii, 1995, Volume 64, Number 9, Pages 935-959). The disadvantages of the known catalysts are the low conversion of carbon dioxide, carbonization and reduced activity.

Basically, these drawbacks are caused by the structure of the support used in the catalysts, which usually consists of agglomerates of spherically similar nanosized particles, which do not ensure the preservation of high dispersion, the optimal phase composition of the supported metal particles during the preparation of the catalyst and under conditions of catalytic reactions.

As a prototype, 5 weight was selected. % Rh / Al ₂ O ₃ catalyst (J. Yu, Z. Zhang, F. Dallmann, J. Zhang, D. Miao, H. Xu, A. Goldbach, R. Dittmeyer, Facile synthesis of highly active Rh / Al ₂ O ₃ steam reforming catalysts with preformed support by flame spray pyrolysis // Applied Catalysis B: Environmental 198 (2016) 171-179).

The disadvantages are the low conversion of carbon dioxide, carbonization and decreased activity.

The problem to which the present invention is directed, is to increase the efficiency of the catalytic oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons by developing more efficient catalysts.

EFFECT: high activity, stability of the catalyst during these catalytic processes.

The problem is solved through the use of a catalyst containing, as an active component, transition metals of the Periodic system, preferably at least one transition metal selected from group VIII of the Periodic system, in an amount of not less than 0.01 wt. %, and a carrier, which is single-crystal alumina nanofibers, mainly having a diameter of more than 3 nm and a length of more than 100 nm (US Patent Application 2013/0192517 A1, C30B 9/00, 01/01/2013), which may contain transition metals in their composition and lanthanides.

The problem is also solved by the method of preparing a catalyst for the oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons by applying complex compounds of transition metals, preferably at least one transition metal selected from group VIII of the Periodic system, in an amount of at least 0.01 wt. %, on a carrier, which is single-crystal alumina nanofibers, mainly having a diameter of more than 3 nm and a length of more than 100 nm, which may contain transition metals and lanthanides in their composition.

The problem is also solved by the method of oxidative conversion of hydrocarbons in the presence of a catalyst described above, at a temperature above 20 ° C, at a pressure above 0.1 atm. Water and / or carbon dioxide and / or oxygen, which may be mixed with nitrogen, are predominantly used as an oxidizing agent; hydrogen, water, carbon monoxide, carbon dioxide, methane can be formed as the main reaction products.

The problem is also solved by the method of hydrogenation of carbon oxides and hydrocarbons in the presence of a catalyst described above, at a temperature above 20 ° C, at a pressure above 0.1 atm. Hydrogenation is predominantly used for hydrogenation, and methane is the main product.

On the prototype at 650 ° C, even with a flow of 196000 cm ³ g ^-1 h ^{-1 the} equilibrium distribution of products and the conversion of methane during the methane steam reforming reaction were not achieved. On the catalyst prepared according to example 2, an equilibrium distribution of products was achieved with flows up to 270,000 cm ³ g ^-1 h ^-1 . The result is achieved due to the high activity and stability of the catalyst, as illustrated by examples 11 and 12.

The invention is illustrated by the following examples for the preparation of catalysts and examples describing the test results of the catalysts in the oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons.

I. Preparation of catalysts

Example 1

Obtaining a sample of 0.3 wt. % Rh / Alumina Nanofibers.

0.100 g of rhodium (III) nitrate hydrate is dissolved in 75 ml of water, then 10 g of aluminum oxide nanofibers are placed in the solution, dried at 110 ° C and calcined at 400 ° C.

Example 2

Obtaining a sample of 37 wt. % Ni / Nano alumina.

5.7 g of [Ni (NO ₃ ) ₂ ⋅ 6H ₂ O] and 1.2 g of glycine are dissolved in 15 ml of water. 2 g of aluminum oxide nanofibers are placed in the resulting solution, after which they are placed in a furnace heated to 400 ° C for 30 minutes. Then restore at 700 ° C in a stream of 10% H ₂ in Ar for 4 hours

Example 3

Obtaining a sample of 37 wt. % Ni / Nanofiber of alumina with cerium content.

5.7 g of [Ni (NO ₃ ) ₂ ⋅ 6H ₂ O] and 1.2 g of glycine are dissolved in 15 ml of water. 2 g of aluminum oxide nanofibers containing 0.1 wt. % cerium, after which it is placed for 30 minutes in a furnace heated to 400 ° C. Then restore at 500 ° C in a stream of 10% H ₂ in Ar for 4 hours

Example 4

Obtaining a sample of 20 wt. % Ni / Nano alumina.

2.7 g of [Ni (NO ₃ ) ₂ ⋅ 6H ₂ O] are dissolved in 15 ml of water. 2 g of aluminum oxide nanofibers are placed in the resulting solution, after which they are placed in a furnace heated to 400 ° C for 30 minutes. Then restore at 500 ° C in a stream of 10% H ₂ in Ar for 4 hours

Example 5

Obtaining a sample of 15 wt. % Ni / Nano alumina with chromium content.

1.8 g of [Ni (NO ₃ ) ₂ ⋅ 6H ₂ O] are dissolved in 50 ml of water. 2 g of aluminum oxide nanofibers containing 1 wt. % chromium, and 17 ml of a 1 mol / L sodium hydroxide solution are added dropwise dropwise. After this, the nanofibers are removed from the solution and placed for 30 minutes in a furnace heated to 400 ° C. Then restore at 500 ° C in a stream of 10% H ₂ in Ar for 4 hours

Example 6

Obtaining a sample of 0.3 wt. % Pt-0.3 wt. % Co / Nanofiber of alumina.

0.080 g of sodium hexachloroplatinate and 0.10 g of cobalt (II) nitrate are dissolved in 75 ml of water, then 10 g of aluminum oxide nanofibers are placed in the solution, dried at 110 ° C and calcined at 400 ° C.

II. Catalyst Testing

Example 7

The oxidative conversion of hydrocarbons is illustrated by the example of steam methane conversion. The process is carried out with a catalyst prepared in accordance with example 2, at a temperature of 650 ° C, at a speed of 135,000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 33.3 vol. % CH ₄ and 66.7 vol. % H ₂ O. The results are shown in table 1.

Example 8

The process of hydrogenation of carbon dioxide in the presence of methane is carried out with a catalyst prepared in accordance with example 3, at a temperature of 410 ° C, at a speed of 34000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 8.2 vol. % CO ₂ , 38.2 vol. % H ₂ , 2 vol. % CH _4, 51.6 vol. % N ₂ . The results are shown in table 2.

Example 9

The process of hydrogenation of carbon dioxide is carried out with a catalyst prepared in accordance with example 3, at a temperature of 395 ° C, at a speed of 34000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 8.2 vol. % CO ₂ , 38.2 vol. % H ₂ , 53.6 vol. % N ₂ The results are shown in table 3.

Example 10

Process of hydrogenation of propane is conducted with the catalyst prepared according to Example 3 at a temperature of 400 ° C at a rate of 25,000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 10 vol. % C ₃ H ₈ , 50 vol. % CH ₄ , 30 vol. % H ₂ , 10 vol. % N ₂ . The results are shown in table 4.

Thus, as can be seen from the examples and tables, the present invention allows to effectively carry out the processes of oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons.

Example 11, which proves the achievement of high stability of the catalyst compared to the prototype

Example 11

The stability of the catalyst is illustrated by the example of methane steam reforming for 90 hours. The process is carried out with a catalyst prepared in accordance with Example 2 at a temperature of 650 ° C, at a speed of 135,000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 33.3 vol. % CH ₄ and 66.7 vol. % H ₂ O The results are shown in table 5.

Examples 12 and 13 prove the high activity of the catalyst in the hydrogenation of carbon oxides.

Example 12

The process of hydrogenation of carbon monoxide is carried out with a catalyst prepared in accordance with example 3, at a temperature of 300 ° C, at a speed of 29000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 2 vol. % СО, 98 vol. % H ₂ . The results are shown in table 6.

Example 13

The hydrogenation process of carbon monoxide and carbon dioxide is carried out with a catalyst prepared in accordance with example 3, at a temperature of 300 ° C, at a speed of 29,000 cm ³ g ^-1 h ^-1 and atmospheric pressure. The reaction gas mixture consists of: 1 vol. % CO, 1 vol. % CO ₂ , 98 vol. % H ₂ . The results are shown in table 7.

Thus, as can be seen from the examples and tables, the present invention allows to effectively carry out the processes of oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and hydrocarbons.

Claims (15)

1. The catalyst for the oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and / or hydrocarbons, containing as an active component transition metals of the Periodic system and a carrier, characterized in that it contains monocrystalline alumina nanofibers having a diameter of more than 3 nm and a length of more than 100 as a carrier nm 2. The catalyst according to claim 1, characterized in that it contains the active component in an amount of at least 0.01 wt. % 3. A method of preparing a catalyst for the oxidative conversion of hydrocarbons and hydrogenation of carbon oxides and / or hydrocarbons by applying the active component of the transition metals of the Periodic system to a support, characterized in that the catalyst is prepared by applying complex compounds of transition metals to single crystal alumina nanofibers having a diameter of more than 3 nm and length over 100 nm. 4. The method of preparation of the catalyst according to p. 3, characterized in that the active component is applied in an amount of not less than 0.01 wt. % 5. The method of oxidative conversion of hydrocarbons in the presence of a catalyst, characterized in that the catalyst used is the catalyst according to claims. 1, 2 or prepared according to paragraphs. 3, 4. 6. The method according to p. 5, characterized in that as the oxidizing agent use water and / or carbon dioxide and / or oxygen. 7. The method according to p. 5, characterized in that oxygen is used as an oxidizing agent in a mixture with nitrogen. 8. The method according to p. 5, characterized in that hydrogen and / or water and carbon monoxide and / or carbon dioxide and / or methane are formed as the main reaction products. 9. The method according to p. 5, characterized in that the process is carried out at a temperature above 20 ° C. 10. The method according to p. 5, characterized in that the process is carried out at a pressure above 0.1 atm. 11. The method of hydrogenation of carbon monoxide and / or carbon dioxide and / or hydrocarbons in the presence of a catalyst, characterized in that the catalyst used is the catalyst according to claims. 1, 2 or prepared according to paragraphs. 3, 4. 12. The method according to p. 11, characterized in that hydrogen is used for the hydrogenation. 13. The method according to p. 11, characterized in that the main hydrogenation product is methane. 14. The method according to p. 11, characterized in that the process is carried out at a temperature above 20 ° C. 15. The method according to p. 11, characterized in that the process is carried out at a pressure above 0.1 atm.