Particulate absorbent materials and methods for making same

• US 20050230659A1
• Filed: 11/24/2004
• Published: 10/20/2005
• 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
• Granted Patent: US 7,732,372 B2
• Time in Patent Office: Days
• US Class Current: 252/189
• 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, 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;

(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.

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

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 material comprises a metal oxide.

7. A particulate absorbent material as recited in claim 1, wherein said absorbent material comprises a metal oxide selected from Group 1 and Group 2 metal oxides.

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

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

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

11. A particulate absorbent material as recited in claim 1, wherein said absorbent material comprises a misch metal.

12. 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.

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

14. 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.

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

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

MgO.

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

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

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

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

21. 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.

22. 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.

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

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

25. 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.

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

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

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

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

30. 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.

31. 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.

32. 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.

33. 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.

34. A particulate absorbent material as recited in claim 1, wherein said absorbent material is adapted to absorb CO₂ and has an absorption capacity of at least about 20 grams CO₂ per 100 grams of unreacted absorbent material.

35. A particulate absorbent material as recited in claim 34, wherein said absorbent compound maintains said absorption capacity over at least 100 cycles.

36. A particulate absorbent material as recited in claim 1, wherein said absorbent material is adapted to absorb CO₂ and has an absorption capacity of at least about 30 grams CO₂ per 100 grams of unreacted absorbent material.

37. A particulate absorbent material as recited in claim 1, wherein said absorbent material comprises an absorbent compound having an absorption capacity of at least about 70 mol. %.

38. A particulate absorbent material as recited in claim 1, wherein said absorbent material comprises an absorbent compound having an absorption capacity of at least about 90 mol. %.

39. A particulate absorbent material as recited in claim 37, wherein said absorbent compound maintains said absorption capacity over at least 100 cycles.

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

41. 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 and a metal oxide that is different than said first absorbent compound, and wherein said particulate absorbent material has a surface area of at least about 5 m²/g.

42. A particulate absorbent material as recited in claim 41, wherein said absorbent compound is selected from Group 1 and Group 2 metal oxides.

43. A particulate absorbent material as recited in claim 41, wherein said absorbent compound is a calcium compound.

44. A particulate absorbent material as recited in claim 41, wherein said metal oxide is selected from the group consisting of Al₂O₃, MgO, SiO₂ and TiO₂.

45. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent material is in the form of substantially spherical particles.

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

47. A particulate absorbent material as recited in claim 41, wherein said surface area is at least about 15 m²/g.

48. A particulate absorbent material as recited in claim 41, wherein said surface area is at least about 30 m²/g.

49. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent material has a pore volume of at least about 0.01 cm³/g.

50. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent material has a pore volume of at least about 0.04 cm³/g.

51. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent material has a pore volume of at least about 0.15 cm³/g.

52. A particulate absorbent material as recited in claim 41, wherein said metal oxide comprises from about 1 wt. % to 50 wt. % of said particulate absorbent material.

53. A particulate absorbent material as recited in claim 41, where said metal oxide comprises from about 5 wt. % to about 25 wt. % of said particulate absorbent material.

54. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent compound has an absorption capacity of at least about 50 mol. % for at least one selected chemical species.

55. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent compound has an absorption capacity of at least about 70 mol. % for at least one selected chemical species.

56. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent compound has an absorption capacity of at least about 90 mol. % for at least one selected chemical species.

57. A particulate absorbent material as recited in claim 41, wherein said absorbent compound has an absorption capacity of at least about 50 mol. % for at least one selected chemical species after at least 100 cycles.

58. A particulate absorbent material as recited in claim 41, wherein said absorbent compound has an absorption capacity of at least about 70 mol. % for at least one selected chemical species after at least 100 cycles.

59. A particulate absorbent material as recited in claim 41, wherein said absorbent compound has an absorption capacity of at least about 90 mol. % for at least one selected chemical species after at least 100 cycles.

60. A particulate absorbent material as recited in claim 41, wherein said particulate absorbent material is pelletized.

61. A method for the fabrication of a particulate absorbent material, comprising the steps of:

(a) atomizing a liquid-containing precursor solution to form precursor droplets, said precursor solution comprising at least a first precursor to an absorbent compound;

(b) heating said precursor droplets to form dried precursor droplets; and

(c) converting said dried precursor droplets to an absorbent material comprising an absorbent compound.

62. An absorbent material as recited in claim 61, wherein said heating step and said converting step occur sequentially in a spray pyrolysis.

63. An absorbent material as recited in claim 61, 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.

64. A method as recited in claim 61, wherein said first precursor is at least partially soluble in said precursor solution.

65. A method as recited in claim 61, wherein said first precursor is selected from the group consisting of metal oxalates and metal hydroxides.

66. A method as recited claim 61, wherein said first precursor is selected from the group consisting of calcium nitrate, calcium acetate, calcium oxalate and calcium hydroxide.

67. A method as recited claim 61, wherein said first precursor comprises calcium oxalate.

68. A method as recited claim 61, wherein said heating step comprises heating said droplets in the presence of an oxygen-containing gas.

69. A method as recited claim 61, wherein said precursor solution further comprises a morphology-enhancing agent.

70. A method as recited claim 61, 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.

71. A method as recited claim 61, wherein said precursor solution further comprises a second precursor, said second precursor being selected to form a compound selected from the group consisting of aluminum oxides, magnesium oxides, silicon oxides and titanium oxides.

72. A method as recited claim 61, wherein said precursor solution further comprises a second precursor, said second precursor being selected to form magnesium oxide.

73. A method as recited claim 61, wherein said precursor solution further comprises a second precursor comprising magnesium nitrate.

74. A method as recited claim 61, wherein said precursor solution further comprises a second precursor, said second precursor being selected to form alumina.

75. A method as recited claim 61, wherein said precursor solution further comprises a second precursor comprising particulate alumina.

76. A method as recited claim 61, wherein said precursor solution further comprises a second precursor, said second precursor being selected to form a metal selected from the group consisting of Mg, Ni, Zn and Cu.

77. A method as recited claim 61, wherein said heating step comprises heating said precursor droplets to a temperature of at least about 300°

C.

78. A method as recited in claim 61, wherein said converting step comprised heating said intermediate compound.

79. A method as recited claim 61, wherein said atomizing step comprises atomizing said precursor solution using a spray nozzle.

80. A method as recited claim 61, wherein said atomizing step comprises atomizing said precursor solution using ultrasonic transducers.

81. A method as recited claim 61, wherein said particles have an average size of from about 1 μ

m to about 50 μ

m.

82. A method as recited claim 61, further comprising the step of pelletizing said particulate absorbent material.

83. A method as recited claim 61, further comprising the step of coating said particulate absorbent material on a support structure.

84. A method as recited claim 61, wherein said particulates have substantially spherical morphology.

85. A method as recited in claim 61, wherein said absorbent material comprises CaO.

86. A method as recited claim 61, wherein said absorbent material comprises ZnO.

87. A method as recited claim 61, wherein said absorbent material comprises MnO:

ZrO₂.

88. A method as recited claim 61, wherein said absorbent material comprises CeO₂:

ZrO₂.

89. A method as recited claim 61, wherein said absorbent material comprises a metal hydride.

90. A method for the fabrication of a particulate NO_x absorbent material, comprising the steps of:

(a) providing a precursor solution comprising at least a first precursor to a NO_x absorbent compound;

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

(c) heating said precursor droplets to form dried precursor droplets;

and

(d) converting said dried precursor droplets to an absorbent material comprising an absorbent compound.

91. An absorbent material as recited in claim 90, wherein said heating step and said converting step occur sequentially in a spray pyrolysis.

92. An absorbent material as recited in claim 90, 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.

93. A method as recited claim 90, wherein said NO) absorbent compound comprises a compound selected from the group consisting of the oxides, hydroxides or carbonates of the alkali metals, alkaline earth metals and lanthanide metals.

94. A method as recited claim 90, wherein said NO_x absorbent compound comprises an oxide, hydroxide or carbonate of a metal selected from Na, K, Ca or Ba.

95. A method as recited claim 90, wherein said NO_x absorbent compound comprises MnO:

ZrO₂.

96. A method as recited claim 90, wherein said NO_x absorbent compound comprises CeO₂.

97. A method as recited claim 90, wherein said NO_x absorbent compound comprises a Y—

Ba—

Cu—

O compound.

98. A method for the fabrication of a particulate H₂S absorbent material, comprising the steps of:

(a) providing a precursor solution comprising at least a first precursor to a H₂S absorbent compound;

(b) atomizing said precursor solution to form precursor droplets; and

(c) heating said precursor droplets to form a particulate NO_x absorbent compound.

(d) converting said dried precursor droplets to an absorbent material comprising an absorbent compound.

99. An absorbent material as recited in claim 98, wherein said heating step and said converting step occur sequentially in a spray pyrolysis.

100. An absorbent material as recited in claim 98, 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.

101. A method as recited in claim 98, wherein said H₂S absorbent compound comprises CaO.

102. A method as recited in claim 98, wherein said H₂S absorbent compound comprises ZnO.

103. A method for the fabrication of a reversible hydrogen storage material, comprising the steps of:

(a) providing a precursor solution comprising at least a first precursor to a hydrogen storage compound;

(b) atomizing said precursor solution to form precursor droplets; and

(c) heating said precursor droplets to form dried precursor droplets;

and

(d) converting said dried precursor droplets to an absorbent material comprising an absorbent compound.

104. An absorbent material as recited in claim 103, wherein said heating step and said converting step occur sequentially in a spray pyrolysis.

105. An absorbent material as recited in claim 103, 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.

106. A method as recited in claim 103, wherein said hydrogen storage compound comprises a misch metal.

107. A method as recited in claim 103, wherein said hydrogen storage compound comprises a misch metal selected from the group consisting of LaNi₅, Mg₂Ni, Mg₂Fe, TiFe, and ZrMn₂.

108. A method as recited in claim 103, wherein said hydrogen storage compound comprises a metal hydride.

109. A method as recited in claim 103, wherein said hydrogen storage compound comprises a metal hydride selected from the group consisting of NaBH₄, AlH₃, LiAlH₄ and Mg(AlH₄)₂.

110. A method as recited in claim 103, wherein said hydrogen storage compound comprises an alkali metal nitride.