Particulate absorbent materials

• US 7,732,372 B2
• Filed: 11/24/2004
• Issued: 06/08/2010
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: Cabot Corporation
• Original Assignee: Cabot Corporation
• Inventors: Brewster, James, Atanassova, Paolina, Hampden-Smith, Mark J., Kyrlidis, Agathagelos, Shen, Jian-Ping, Napolitano, Paul
• Primary Examiner(s): Johnson; Edward M
• Application Number:
  US10/996,672
• Publication Number:
  US 20050230659A1
• Time in Patent Office: 2,022 Days
• Field of Search: 502/407, 502/414, 502/415, 502/439
• US Class Current: 502/407
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/0425 In-situ adsorption process during hydrogen production
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/0844 the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
• CPC Class Codes: C01B 2203/1005 Arrangement or shape of catalyst
• CPC Class Codes: C01B 2203/1023 Catalysts in the form of a monolith or honeycomb
• CPC Class Codes: C01B 2203/1047 Group VIII metal catalysts
• CPC Class Codes: C01B 2203/1241 Natural gas or methane
• CPC Class Codes: C01B 2203/142 At least two reforming, decomposition or partial oxidation steps in series
• CPC Class Codes: C01B 2203/148 involving a recycle stream to the feed of the process for making hydrogen or synthesis gas
• CPC Class Codes: C01B 2203/82 Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
• CPC Class Codes: C01B 3/326 characterised by the catalyst
• CPC Class Codes: C01B 3/40 characterised by the catalyst
• CPC Class Codes: C01B 3/56 by contacting with solids; Regeneration of used solids C01B3/508 takes precedence
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

Solid absorbent materials that are useful for absorption of chemical species from a fluid, such as a gas stream or a liquid stream. The absorbent materials are formed by spray processing and posses a well-defined chemical composition and microstructure. The absorbent materials can have a high absorption capacity for a chemical species such as H₂S, CO₂, NO_x, and H₂ and have a high recylability, such that the chemical species can be absorbed and desorbed over a large number of cycles.

Claims

1. A particulate absorbent material for the absorption of a chemical species from a fluid, wherein said absorbent material is fabricated by a process comprising the steps of:

(a) providing a precursor solution comprising at least a first precursor to an absorbent compound selected from Group 1 and Group 2 metal oxides;

(b) atomizing said precursor solution to form precursor droplets comprising said first precursor;

(c) heating said precursor droplets remove liquid therefrom and form dried precursor droplets; and

(d) converting said dried precursor droplets to a particulate absorbent material comprising said absorbent compound, wherein said particulate absorbent material is adapted to absorb CO₂ and has a CO₂ mass absorption capacity of at least about 20 grams CO₂ per 100 grams unreacted absorbent material.

2. An absorbent material as recited in claim 1, wherein said heating step and said converting step occur sequentially in a spray pyrolysis reactor.

3. An absorbent material as recited in claim 1, wherein said heating step forms an intermediate compound capable of being post-processed to form a particulate absorbent material, and wherein said converting step comprises heating said intermediate compound to form said particulate absorbent material.

4. A particulate absorbent material as recited in claim 1, wherein said first precursor is selected from the group consisting of a metal nitrate, a metal acetate, a metal oxalate and a metal hydroxide.

5. A particulate absorbent material as recited in claim 1, wherein said first precursor comprises a metal oxalate.

6. A particulate absorbent material as recited in claim 1, wherein said absorbent compound comprises a metal oxide selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide and barium oxide.

7. A particulate absorbent material as recited in claim 1, wherein said absorbent compound comprises calcium oxide.

8. A particulate absorbent material as recited in claim 1, wherein said precursor solution comprises a metal salt of a Group 1 or a Group 2 metal selected from the group consisting of a metal oxalate salt and a metal hydroxide salt.

9. A particulate absorbent material as recited in claim 1, wherein said heating step comprises heating said droplets in the presence of an oxygen-containing gas.

10. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a morphology-enhancing agent.

11. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a morphology-enhancing agent selected from the group consisting of lactic acid, glycine, alcohols, ammonium nitrate, polymers and carbohydrazide.

12. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a precursor to a second compound selected from the group consisting of aluminum oxide, magnesium oxide, silicon oxide and titanium oxide.

13. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material comprises CaO:

MgO.

14. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a precursor to magnesium oxide.

15. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises magnesium nitrate.

16. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a precursor to alumina.

17. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises particulate alumina.

18. A particulate absorbent material as recited in claim 1, wherein said precursor solution further comprises a precursor to a metal selected from the group consisting of Mg, Ni, Zn and Cu.

19. A particulate absorbent material as recited in claim 1, wherein said heating step comprises heating said precursor droplets to a temperature of at least about 300°

C.

20. A particulate absorbent material as recited in claim 1, wherein said atomizing step comprises atomizing said precursor solution using a spray nozzle.

21. A particulate absorbent material as recited in claim 1, wherein said atomizing step comprises atomizing said precursor using ultrasonic transducers.

22. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has an average size of from about 1 μ

m to about 50 μ

m.

23. A particulate absorbent material as recited in claim 1, further comprising the step of pelletizing said particulate absorbent material.

24. A particulate absorbent material as recited in claim 1, further comprising the step of coating said particulate absorbent material on a support structure.

25. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has a substantially spherical morphology.

26. A particulate absorbent material as recited in claim 1, further comprising the step of heating said particulate absorbent material.

27. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has a pore volume of at least about 0.04 g/cm³.

28. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has a pore volume of at least about 0.15 g/cm³.

29. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has a surface area of at least about 15 m²/g.

30. A particulate absorbent material as recited in claim 1, wherein said particulate absorbent material has a surface area of at least about 30 m²/g.

31. A particulate absorbent material as recited in claim 1, wherein said absorbent compound maintains said CO₂ mass absorption capacity over at least 100 cycles.

32. A particulate absorbent material as recited in claim 1, wherein said absorbent material has a CO₂ mass absorption capacity of at least about 30 grams CO₂ per 100 grams of unreacted absorbent material.

33. A particulate absorbent material as recited in claim 1, wherein said absorbent compound has a CO₂ molar absorption capacity of at least about 70 mol. %.

34. A particulate absorbent material as recited in claim 1, wherein said absorbent compound has a CO₂ molar absorption capacity of at least about 90 mol. %.

35. A particulate absorbent material as recited in claim 33, wherein said absorbent compound maintains said CO₂ molar absorption capacity over at least 100 cycles.

36. A particulate absorbent material as recited in claim 1, wherein said heating step comprises heating said droplets in a spray dryer.

37. A particulate absorbent material adapted for the absorption of a chemical species from a fluid, wherein said particulate absorbent material comprises an intimate mixture of at least a first absorbent compound selected from Group 1 and Group 2 metal oxides and at least a first metal oxide inert additive that is different than said first absorbent compound, wherein said particulate absorbent material has a surface area of at least about 5 m²/g and wherein said particulate absorbent material comprises not greater than 50 wt. % metal oxide inert additives.

38. A particulate absorbent material as recited in claim 37, wherein said absorbent compound is a calcium compound.

39. A particulate absorbent material as recited in claim 37, wherein said first metal oxide inert additive is selected from the group consisting of Al₂O₃, MgO, SiO₂ and TiO₂.

40. A particulate absorbent material as recited in claim 37, wherein said particulate absorbent material is in the form of substantially spherical particles.

41. A particulate absorbent material as recited in claim 37, wherein said surface area is at least about 10 m²/g.

42. A particulate absorbent material as recited in claim 37, wherein said surface area is at least about 15 m²/g.

43. A particulate absorbent material as recited in claim 37, wherein said surface area is at least about 30 m²/g.

44. A particulate absorbent material as recited in claim 37, wherein said particulate absorbent material has a pore volume of at least about 0.01 cm³/g.

45. A particulate absorbent material as recited in claim 37, wherein said particulate absorbent material has a pore volume of at least about 0.04 cm³/g.

46. A particulate absorbent material as recited in claim 37, wherein said particulate absorbent material has a pore volume of at least about 0.15 cm³/g.

47. A particulate absorbent material as recited in claim 37, wherein said first metal oxide inert additive comprises from about 1 wt. % to 50 wt. % of said particulate absorbent material.

48. A particulate absorbent material as recited in claim 37, where said first metal oxide inert additive comprises from about 5 wt. % to about 25 wt. % of said particulate absorbent material.

49. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 50 mol. % for at least one selected chemical species.

50. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 70 mol. % for at least one selected chemical species.

51. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 90 mol. % for at least one selected chemical species.

52. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 50 mol. % for at least one selected chemical species after at least 100 cycles.

53. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 70 mol. % for at least one selected chemical species after at least 100 cycles.

54. A particulate absorbent material as recited in claim 37, wherein said first absorbent compound has an absorption capacity of at least about 90 mol. % for at least one selected chemical species after at least 100 cycles.

55. A particulate absorbent material as recited in claim 37, wherein said particulate absorbent material is pelletized.