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

• US 7,291,321 B2
• Filed: 04/28/2004
• Issued: 11/06/2007
• Est. Priority Date: 04/29/2003
• Status: Expired due to Fees

• Current Assignee: HRD Corporation, Petrochemical Research & Technology Company
• Original Assignee: HRD Corporation
• Inventors: Bagherzadeh, Ebrahim, Hassan, Abbas, Hassan, Aziz
• Primary Examiner(s): Vanoy; Timothy C.
• Application Number:
  US10/833,735
• Publication Number:
  US 20040220053A1
• Time in Patent Office: 1,287 Days
• Field of Search: 423/593.1, 423/598, 423/594.9, 423/594.15, 423/594.16, 502/344, 502/350, 502/340, 502/352, 502/525, 502/439, 501/135, 501/136, 501/137
• US Class Current: 423/593.1
• 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 producing a perovskite catalyst comprising:

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

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 to form the perovskite catalyst.

2. the method of claim 1, wherein the aqueous slurry is formed by:

dispersing a powdered alkaline earth metal salt in water,

adding the powdered metal salt to the water; and

adding the powdered transition metal oxide to the water.

3. The method of claim 2 wherein the alkaline earth metal salt is selected from the group consisting of barium, calcium and strontium salts.

4. The method of claim 2 wherein the metal oxide is titanium oxide.

5. The method of claim 3, wherein the slurry comprises a mixture including Ba (0.5x-1x)+TiO2, wherein x is in moles.

6. The method of claim 3, wherein the slurry comprises a mixture including Ba (0.5x -1x)+TiO2 and either Ca_x or Sr_x, wherein x is in moles.

7. The method of claim 5, 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.

8. The method of claim 7, wherein the slurry comprises a mixture including Ba (0.5x-0.95x)+TiO₂+SnCl₂(0.05x), wherein x is in moles.

9. The method of claim 8, wherein the slurry is formed by a mixture according to Ba (0.95x)+TiO₂+SnCl₂(0.05x), wherein x is in moles.

10. The method of claim 3, wherein the polymeric binder is selected from the group of polymer binders consisting of vinyl acetate dibutyl acrylate and methyl hydroxyl ethyl cellulose.

11. The method of claim 10, further comprising sizing the catalyst to a size suitable for a catalytic reactor.

12. The method of claim 11, wherein the powder is heated by raising the temperature of the powder in a temperature profile comprising a series of successive ramping and holding stages up to the calcining temperature.

13. The method of claim 12, wherein the temperature is raised to the calcining temperature at an increasing rate ranging from about 200°

to about 400°

C. per hour.

14. The method of claim 12, wherein the temperature profile further comprises:

ramping the temperature from ambient to about 200°

C. for about ¼

hour and holding for a hold period;

ramping the temperature to about 400°

C. over about a further ¼

hour and holding for a hold period;

ramping the temperature to about 600°

C. over about a further ¼

hour and holding for a hold period;

ramping the temperature to the calcination temperature over about a further ¼

hour and holding for ranging from about 8 hours to about 24 hours.

15. The method of claim 14, wherein each hold period ranges from about ¼

hour to about 1 hour.

16. The method of claim 15, wherein the hold period is about ¼

hour.

17. The method of claim 14, wherein the calcining temperature is between about 700°

C. to about 1000°

C.

18. The method of claim 17, wherein the calcining temperature is held for between about 8 hours to about 12 hours.

19. The method of claim 12, further comprising:

ramping the temperature from ambient to about 100°

C. for about ¼

hour and holding for about a further ¼

hour;

ramping the temperature to about 200°

C. over about a further ¼

hour and holding the temperature for about a further ¼

hour;

ramping the temperature to the calcining temperature over about a further ¼

hour; and

holding the temperature at the calcining temperature for over about 8 hours.

20. The method of claim 19, wherein the calcining temperature is between about 800°

C. to about 1000°

C.

21. The method of claim 20, wherein the calcining temperature is held for between about 8 hours to about 12 hours.