Preparation of catalyst and use for high yield conversion of methane to ethylene

• US 20070055083A1
• Filed: 11/09/2006
• Published: 03/08/2007
• Est. Priority Date: 04/29/2003
• Status: Active Grant

• Current Assignee: Abbas Hassan, Aziz Hassan, Dr. Ebrahim Bagherzadeh
• Original Assignee: Abbas Hassan, Aziz Hassan, Dr. Ebrahim Bagherzadeh
• Inventors: Hassan, Abbas, Hassan, Aziz, Bagherzadeh, Ebrahim
• Granted Patent: US 7,250,543 B2
• Time in Patent Office: Days
• US Class Current: 570/237
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/02 of the alkali- or alkaline earth metals or beryllium
• CPC Class Codes: B01J 23/14 of germanium, tin or lead
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/11 Lithium
• CPC Class Codes: B01J 2523/12 Sodium
• CPC Class Codes: B01J 2523/22 Magnesium
• CPC Class Codes: B01J 2523/23 Calcium
• CPC Class Codes: B01J 2523/24 Strontium
• CPC Class Codes: B01J 2523/25 Barium
• CPC Class Codes: B01J 2523/43 Tin
• CPC Class Codes: B01J 2523/47 Titanium
• CPC Class Codes: B01J 27/08 Halides
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: B01J 37/08 Heat treatment B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: C01G 23/003 Titanates C01G23/001 takes precedence
• CPC Class Codes: C01G 23/006 Alkaline earth titanates
• CPC Class Codes: C01P 2002/34 perovskite-type (ABO3)
• CPC Class Codes: C01P 2002/72 : by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C04B 2235/3208 : Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3215 : Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3236 : Alkaline earth titanates
• CPC Class Codes: C04B 35/63424 : Polyacrylates; Polymethacrylates
• CPC Class Codes: C04B 35/636 : Polysaccharides or derivatives thereof
• CPC Class Codes: C07C 11/04 : Ethylene
• CPC Class Codes: C07C 2/84 : catalytic
• CPC Class Codes: C07C 2521/06 : Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
• CPC Class Codes: C07C 2523/02 : of the alkali- or alkaline earth metals or beryllium
• CPC Class Codes: C07C 2527/06 : Halogens; Compounds thereof
• CPC Class Codes: C07C 2527/10 : Chlorides
• CPC Class Codes: Y02P 20/141 : Feedstock
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts
• CPC Class Codes: Y10S 502/525 : Perovskite

Abstract

A perovskite catalyst is prepared using a ceramic sol-sol methodology comprising preparing slurry in water of an alkaline earth metal salt, a powdered metal salt and a powdered transition metal oxide, adding a polymeric binder to form a paste, drying and comminuting the paste into a powder and heating the powder with a temperature profile to calcination temperatures. In one embodiment the slurry is formed of titanium oxide with barium carbonate and tin chloride in deionized water, and more specifically by a mixture according to Ba (1−0.05x)+TiO2+SnCl2(0.05x) where x is in moles. The perovskite catalyst is preferably used in a process for oxidative coupling of methane. Catalyst performance is enhanced through the addition of halides to the feed gas in the reaction.

Claims

1. A method of oxidative coupling of methane for the formation of heavier hydrocarbons, the method comprising the steps of:

producing a perovskite catalyst, the catalyst produced by a process comprising;

forming an aqueous slurry comprising an alkaline earth metal salt, a powdered metal salt and a powdered transition metal oxide;

adding a polymeric binder to the slurry to form a paste;

drying the paste for forming a powder;

heating the powder at increasing temperatures at a predetermined profile commensurate with the polymeric binder; and

calcining the heated powder; and

contacting a feed gas stream containing methane and oxygen in an oxidative coupling reactor under oxidative coupling conditions in the presence of the perovskite catalyst.

2. The method of claim 1, further comprising adding either a halogen or carbon dioxide into the feed gas stream, and wherein the halogen is added at timed intervals during the oxidative coupling.

3. The method of claim 2, wherein the halogen is chloride.

4. The method of claim 3, wherein the chloride in the gas stream is selected from the group consisting of methane chloride, ethane chloride, chlorine gas, chloroform, stannous chloride (SnCl₂), hydrochloric acid (HCl), or carbon tetrachloride (CCl₄).

5. The method of claim 4, wherein the chloride in the gas stream is carbon tetrachloride (CCl₄).

6. The method of claim 3, further comprising the step of reacting the higher hydrocarbons with one or more compounds selected from the group consisting of the higher hydrocarbons, ethylene, propylene, butylene, benzene, styrene, chlorine, oxygen, and olefins.

7. The method of claim 1, wherein the alkaline earth metal salt is selected from the group consisting of barium, calcium and strontium salts.

8. The method of claim 7, wherein the metal oxide is titanium oxide.

9. The method of claim 7, wherein the slurry comprises a mixture including Ba (0.5x−

1x)+TiO₂, wherein x is in moles.

10. The method of claim 7, wherein the slurry comprises a mixture including Ba (0.5x−

1x)+TiO₂ and either Ca_x or Sr_x, wherein x is in moles.

11. The method of claim 9, wherein the slurry is formed by a mixture according to Ba (0.5−

0.95x)+TiO₂+R(0.05−

0.5x), wherein x is in moles, and wherein R is selected from the group consisting of BaCl₂, LiCl, MgCl₂, NaCl, and SnCl₂.

12. The method of claim 9, wherein the slurry comprises a mixture including Ba (0.5x−

0.95x)+TiO₂+SnCl₂(0.05x), wherein x is in moles.

13. The method of claim 10, wherein the slurry is formed by a mixture according to Ba (0.95x)+TiO₂+SnCl₂(0.05x), wherein x is in moles.

14. The method of claim 7, wherein the polymeric binder is selected from the group of polymer binders consisting of vinyl acetate dibutyl acrylate and methyl hydroxylethyl cellulose.

15. The method of claim 14, further comprising sizing the catalyst to a size suitable for the oxidative coupling reactor.

16. A method of oxidative coupling of methane for the formation of heavier hydrocarbons, the method comprising the steps of:

producing a perovskite catalyst, the catalyst produced by a process comprising;

forming an aqueous slurry comprising an alkaline earth metal salt, a powdered transition metal salt and a powdered transition metal oxide;

drying the slurry to form a powder;

heating the powder at increasing temperatures at a predetermined profile; and

calcining the heated powder to produce the perovskite catalyst, wherein the perovskite catalyst comprises a mixture including Ba+TiO₂+R, wherein R is Sn; and

contacting a feed gas stream containing methane and oxygen in an oxidative coupling reactor under oxidative coupling conditions in the presence of the perovskite catalyst.

17. The method of claim 16, further comprising adding either a halogen or carbon dioxide into the feed gas stream, and wherein the halogen is added at timed intervals during the oxidative coupling.

18. The method of claim 17, wherein the halogen is chloride.

19. The method of claim 18, wherein the chloride in the gas stream is selected from the group consisting of methane chloride, ethane chloride, chlorine gas, chloroform, stannous chloride (SnCl₂), hydrochloric acid (HCl), or carbon tetrachloride (CCl₄).

20. The method of claim 19, wherein the chloride in the gas stream is carbon tetrachloride (CCl₄).

21. The method of claim 17, further comprising the step of reacting the higher hydrocarbons with one or more compounds selected from the group consisting of the higher hydrocarbons, ethylene, propylene, butylene, benzene, styrene, chlorine, oxygen, and olefins.