SILVER-BASED SORBENTS

• US 20080283446A1
• Filed: 04/30/2008
• Published: 11/20/2008
• Est. Priority Date: 05/01/2007
• Status: Abandoned Application

• Current Assignee: Auburn University
• Original Assignee: Auburn University
• Inventors: Yang, Hongyun, Tatarchuk, Bruce, Nair, Sachin
• Application Number:
  US12/112,700
• Publication Number:
  US 20080283446A1
• Time in Patent Office: Days
• US Class Current: 208/246
• 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 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2257/30 Sulfur compounds
• 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 20/0211 Compounds of Ti, Zr, Hf
• CPC Class Codes: B01J 20/0233 Compounds of Cu, Ag, Au
• 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 20/28014 characterised by their form
• 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 20/28076 being more than 1.0 ml/g
• CPC Class Codes: B01J 20/28078 Pore diameter
• CPC Class Codes: B01J 20/3021 : Milling, crushing or grinding
• 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 20/3236 : containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 20/3295 : Coatings made of particles, nanoparticles, fibers, nanofibers
• CPC Class Codes: B01J 20/3433 : of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3441 : Regeneration or reactivation by electric current, ultrasound or irradiation, e.g. electromagnetic radiation such as X-rays, UV, light, microwaves
• 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: B01J 2220/42 : Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: B01J 2220/56 : Use in the form of a bed
• CPC Class Codes: B01J 2220/62 : In a cartridge
• CPC Class Codes: B01J 2220/66 : Other type of housings or containers not covered by B01J2220/58 - B01J2220/64
• CPC Class Codes: C10G 2300/202 : Heteroatoms content, i.e. S, N, O, P
• CPC Class Codes: C10G 25/003 : Specific sorbent material, not covered by C10G25/02 or C10G25/03
• CPC Class Codes: C10G 25/12 : Recovery of used adsorbent

Abstract

Disclosed are sorbent compositions that include a porous titanium dioxide support impregnated with a silver material. The sorbent compositions may be utilized in systems and methods for removing sulfur compounds from hydrocarbon streams such as jet fuel.

Claims

1. A sorbent composition comprising porous titanium dioxide particles impregnated with a silver material, wherein the impregnated particles comprise about 80-99.9% titanium dioxide (w/w) and about 0.1-20% silver material (w/w).

2. The sorbent composition of claim 1, comprising about 95-99% titanium dioxide (w/w) and about 1-5% silver material (w/w).

3. The sorbent composition of claim 1, wherein the silver material is selected from a group consisting of silver metal, silver oxide, silver salt, and mixtures thereof.

4. The sorbent composition of claim 1, wherein the silver material is silver metal, silver oxide, or a mixture thereof.

5. The sorbent composition of claim 1, wherein the silver material is in a nanocrystallite form.

6. The sorbent composition of claim 1, wherein the particles have a pore volume of about 0.1-3.0 cc/g.

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

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

9. The sorbent composition of claim 1, wherein the particles have an average diameter of about 20-250 microns.

10. The sorbent composition of claim 1, wherein the particles have an average pore diameter of about 1-20 nm.

11. The sorbent composition of claim 1, wherein the particles are in the form of powder, grains, pellets, extrudates, or combinations thereof.

12. The sorbent composition of claim 1 dispersed on a support material selected from a group consisting of silicon dioxide, aluminum oxide, and activated carbon.

13. The sorbent composition of claim 1, wherein the silver material comprises a dopant selected from a Group VIII metal or an oxide thereof and the ratio of silver material to dopant in the sorbent composition is about (7-3):

1.

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

15. The filter material of claim 14, wherein the fibers have an average diameter of about 2-20 microns and the particles have an average diameter of about 20-250 microns.

16. The filter material of claim 14, wherein the sorbent composition is bonded to the matrix of fibers.

17. The filter material of claim 16, wherein the fibers are ceramic fibers.

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

(a) impregnating porous titanium dioxide particles with a volume of silver precursor solution to provide wet impregnated particles, wherein the volume of silver precursor solution is no more than the pore volume of the titanium dioxide particles;

(b) drying and calcining the impregnated particles.

19. The method of claim 18, wherein step (b) comprises heating the wet impregnated particles to a temperature of about 100-400°

C. for at least about 2 hours.

20. The method of claim 18, wherein the silver precursor solution is a silver salt solution.

21. The method of claim 18, wherein the step of impregnating is performed by incipient wetness impregnating, spray impregnating, or a combination of both.

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

drying at a temperature range of about 22-250°

C.;

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

drying in the presence of flowing gas stream; and

a combination thereof.

23. The method of claim 22, wherein the flowing gas stream comprises a gas selected a group consisting of air, nitrogen, oxygen, argon, helium, and a combination thereof.

24. The method of claim 22, 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

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

27. The process of claim 26, wherein the sorbent composition is contained within a cartridge having a bottom and a top and the hydrocarbon stream passes from the bottom of the cartridge to the top of the cartridge.

28. The process of claim 27, further comprising removing sulfur compounds adsorbed to the sorbent composition and any retained hydrocarbons.

29. The process of claim 28, wherein the step of removing sulfur compounds adsorbed to the sorbent composition and any retained hydrocarbons is performed by heating the sorbent composition to a temperature between about 100-900°

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

30. The process of claim 27, further comprising removing sulfur compounds adsorbed to the sorbent composition and any retained hydrocarbons by heating the sorbent composition to a temperature between about 100-900°

C. and passing air over the sorbent composition in a direction from the top of the cartridge to the bottom of the cartridge.

31. The process of claim 28, further comprising recovering the removed sulfur compounds and any retained hydrocarbons through condensation.

32. A filtering system comprising:

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

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

33. The filtering system of claim 32 contained in a cartridge.

34. A fuel filter assembly comprising the filtering system of claim 32.