Doped supported zinc oxide sorbents for regenerable desulfurization applications

• US 7,833,316 B2
• Filed: 04/30/2008
• Issued: 11/16/2010
• Est. Priority Date: 05/01/2007
• Status: Active Grant

• Current Assignee: Auburn University
• Original Assignee: Auburn University
• Inventors: Tatarchuck, Bruce, Dhage, Priyanka, Yang, Hongyun
• Primary Examiner(s): LAWRENCE JR, FRANK M
• Application Number:
  US12/112,707
• Publication Number:
  US 20080271602A1
• Time in Patent Office: 930 Days
• Field of Search: 961/21, 961/32, 961/35, 961/53, 961/54, 555/23, 555/27, 423/244.01, 423/594.14, 423/622, 502/407, 208/208.R, 95135-137
• US Class Current: 95/135
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/112 Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2253/306 Surface area, e.g. BET-specific surface
• CPC Class Codes: B01D 2253/308 Pore size
• CPC Class Codes: B01D 2253/311 Porosity, e.g. pore volume
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/306 Organic sulfur compounds, e.g. mercaptans
• CPC Class Codes: B01D 2257/308 Carbonoxysulfide COS
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 2259/40088 by heating
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01J 20/02 comprising inorganic material
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28016 Particle form
• CPC Class Codes: B01J 20/28028 Particles immobilised within fibres or filaments
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28069 Pore volume, e.g. total pore volume, mesopore volume, micropore volume
• CPC Class Codes: B01J 20/3078 : Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 20/3204 : Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3234 : Inorganic material layers
• CPC Class Codes: B01J 20/3236 : containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 20/3293 : Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers
• CPC Class Codes: B01J 20/3433 : of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3458 : in the gas phase
• CPC Class Codes: B01J 20/3483 : by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: Y10T 428/249969 : Of silicon-containing material [e.g., glass, etc.]
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]

Abstract

Disclosed are sorbent compositions that include a silicon dioxide porous support impregnated with a mixture comprising zinc oxide and copper material. The sorbent compositions may be utilized in systems and methods for removing sulfur compounds from gaseous streams.

Claims

1. A sorbent composition comprising a porous silicon dioxide particles having a pore volume of about 0.1-3.0 cc/g impregnated with a mixture comprising zinc oxide and copper material, wherein the mixture comprises about 80-99% zinc oxide (w/w) and about 1-20% copper material (w/w), the impregnated particles comprise about 5-40% of the mixture (w/w), and copper and zinc are present in the mixture at a doping ratio Cu_xZn_(1-x)O/SiO₂ wherein 0.05≦

x≦

0.3.

2. The sorbent composition of claim 1, wherein the copper material is selected from a group consisting of copper metal, copper oxide, and combinations thereof.

3. The sorbent composition of claim 1, wherein the silicon dioxide particles comprise MCM silicon dioxide.

4. The sorbent composition of claim 1, wherein the particles have a surface area of about 100-1000 m²/g.

5. The sorbent composition of claim 1, wherein the particles have an average diameter of about 30-6000 microns.

6. The sorbent composition of claim 1, wherein the particles have an average diameter of about 30-300 microns.

7. The sorbent composition of claim 1, wherein the particles have an average pore diameter of about 0.2-70 nm.

8. A filter material comprising the sorbent composition of claim 1 entrapped in a matrix of fibers.

9. The filter material of claim 8, wherein the fibers have an average diameter of about 2-20 microns and the particles have an average diameter of about 30-300 microns.

10. The filter material of claim 8, wherein the sorbent composition is bonded to the matrix of fibers.

11. The filter material of claim 10, wherein the sorbent composition is bonded to the matrix of fibers by performing a sintering process.

12. The filter material of claim 10, wherein the fibers have an average diameter of about 2-20 microns and the particles have an average diameter of about 30-300 microns.

13. The filter material of claim 10, wherein the fibers are ceramic fibers.

14. A method for preparing the sorbent composition of claim 1, the method comprising:

impregnating porous particles with a solution comprising dissolved zinc salt and dissolved copper salt, wherein the volume of the solution is no more than the pore volume of the porous particles;

drying and calcining the impregnated particles.

15. The method of claim 14, wherein step (b) comprises heating the impregnated particles to a temperature of about 20-400°

C. for at least about 2 hours.

16. The method of claim 14, wherein the zinc salt is selected from a group consisting of zinc nitrate, zinc acetate, and a mixture thereof;

and the copper salt is selected from a group consisting of copper nitrate, copper acetate, and a mixture thereof.

17. The method of claim 14, wherein the step of impregnating is performed by incipient wetness impregnating, spray impregnating, or a combination of both.

18. The method of claim 14, wherein the step of drying is performed by a step selected from a group consisting of:

drying at a temperature range of about 20-200°

C.;

drying in sub-atmospheric pressures of about 0.001-759 torr;

drying in the presence of flowing gas stream; and

a combination thereof.

19. The method of claim 18, wherein the flowing gas stream comprises a gas selected a group consisting of air, nitrogen, oxygen, argon, helium, and a combination thereof.

20. The method of claim 18, wherein calcining is performed by heating the dried particles to a temperature in a range of about 100-800°

C. for at least about 1 hour and contacting the dried particles with a flowing gas stream.

21. A process for removing sulfur compounds from a stream, the process comprising passing the stream through an effective amount of the sorbent composition of claim 1 for a sufficient period of time to reduce sulfur compounds in the stream to a level of no more than about 1 ppmw.

22. The process of claim 21, wherein the sorbent composition is contained within a cartridge having a top and a bottom and the stream passes from the top of the cartridge to the bottom of the cartridge.

23. The process of claim 21, further comprising removing sulfur compounds adsorbed to or retained by the sorbent composition.

24. The process of claim 23, wherein the step of removing sulfur compounds adsorbed to or retained by the sorbent composition is performed by heating the sorbent composition to a temperature between about 100-900°

C. and passing an oxidizing agent over the sorbent composition.

25. The process of claim 24, wherein the oxidizing agent is selected from a group consisting of air, pure oxygen, ozone, hydrogen peroxide, and a combination thereof.

26. A filtering system comprising:

a first sorbent composition according to claim 1, wherein the first sorbent composition preferentially adsorbs a first sulfur compound; and

a second sorbent composition according to claim 1, wherein the second sorbent composition preferentially adsorbs a second sulfur compound.

27. The filtering system of claim 26 contained in a cartridge.

28. A fuel filter assembly comprising the filtering system of claim 26.