Note: Claims are shown in the official language in which they were submitted.
CLAIMS
1. A method of synthesizing a zirconium-stabilized calcium oxide nanoparticle
sorbent, comprising:
a) forming a calcium oxide nanoparticle by treating calcium compounds in a
calcium compound treatment comprising:
i) dissolving a calcium alkoxide in a mixed aromatic and alcoholic solvent
to form a calcium alkoxide solution;
ii) adding water to the calcium alkoxide solution to form a liquid calcium
hydroxide alcogel;
iii) drying the calcium hydroxide alcogel, to provide a calcium oxide
nanoparticle composition; and,
b) admixing a zirconium compound with one or more of the calcium compounds
in the calcium compound treatment, to form the zirconium-stabilized calcium
oxide
nanoparticle sorbent;
wherein the zirconium-stabilized calcium oxide nanoparticle sorbent has a BET
suiface area of at least 100 m2/g, an average particle size of between 100 and
500
nm, and a carbon dioxide capture capacity of at least 10 mole/kg sorbent.
2. The method of claim 1, wherein the calcium alkoxide has the formula
(R0)3Ca, and
wherein each R is a straight chain alkyl group.
3. The method of claim 2, wherein each R is a methyl or ethyl group.
4. The method of any one of claims 1 to 3, wherein the zirconium compound is a
zirconium alkoxide.
5. The method of claim 4, wherein the zirconium alkoxide is zirconium(IV)
ethoxide
(Zr(ethoxide)4)1 zirconium(IV) propoxide (Zr(propoxide)4) or zirconium(IV)
tertiary
butoxide (Zr(t-Butoxide)4).
6. The method of any one of claims 1 to 3, wherein admixing the zirconium
compound
comprises one or more of (1) mixing a zirconium stabilizer precursor with the
calcium
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alkoxide in step (i) or (ii), so that the liquid calcium hydroxide alcogel
comprises
zirconium; or, (2) incipient wetness impregnation (IWI) of the calcium oxide
nanoparticle composition with a zirconium stabilizer precursor solution; or
(3) shelling
the calcium oxide nanoparticle composition surface, before or after calcining
the
calcium oxide nanoparticle composition, in a core-shell treatment with a core-
shell
surfactant.
7. The method of claim 6, wherein the zirconium stabilizer precursor is a
zirconium
alkoxide.
8. The method of claim 7, wherein the zirconium alkoxide is zirconium(IV)
ethoxide
(Zr(ethoxide)4)1 zirconium(IV) propoxide (Zr(propoxide)4) or zirconium(IV)
tertiary
butoxide (Zr(t-Butoxide)4).
9. The method of any one of claims 6 to 8, wherein mixing the zirconium
stabilizer
precursor with the calcium alkoxide in step (i) or (ii), comprises dissolving
the
zirconium stabilizer precursor in the mixed aromatic and alcoholic solvent.
10. The method of claim 6, wherein shelling comprises adding a mesoporous
zirconia to calcined calcium oxide nanoparticles by the core-shell treatment
using the
core-shell surfactant.
11. The method of claim 6 or 10, wherein the core-shell surfactant is P123 or
TMA.
12. The method of any one of claims 1 to 11, wherein admixing the zirconium
compound comprises adding zirconium tertiary butoxide to calcium methoxide in
the
mixed aromatic and alcoholic solvent.
13. The method of claim 12, wherein zirconium tertiary butoxide and calcium
methoxide are added to the mixed aromatic and alcoholic solvent in a ratio of
0.05-0.1
moles of Zr(t-Butoxide)4 per mole of Ca(CH30)2.
14. The method of any one of claims 1 to 13, wherein adding water comprises
adding 2-5 moles of H20 per mole of calcium alkoxide.
15. The method of any one of claims 1 to 14, further comprising mixing the
calcium
hydroxide alcogel for an alcogel aging period to provide an aged alcogel and
drying
the calcium hydroxide alcogel comprises drying the aged alcogel.
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16. The method of any one of claims 1 to 15, wherein the calcium alkoxide
solution
comprises zirconium in an opaque slurry.
17. The method of any one of claims 1 to 16, wherein the liquid calcium
hydroxide
alcogel comprises zirconium and is clear and colorless.
18. The method of any one of claims 1 to 17, wherein drying the calcium
hydroxide
alcogel comprises supercritical drying and vacuum dehydration.
19. The method of any one of claims 1 to 17, wherein the calcium hydroxide
alcogel
comprises zirconium and drying the calcium hydroxide alcogel comprises a
thermal
dehydration of zirconium-calcium hydroxide nanoparticles to provide dehydrated
zirconium-calcium hydroxide nanoparticles.
20. The method of claim 19, wherein the thermal dehydration is carried out
at least
partially under a dehydrating vacuum pressure.
21. The method of claim 19 or 20, wherein the thermal dehydration is
carried out
at a dehydration temperature of at least 450 C.
22. The method of any one of claims 19 to 21, further comprising calcining
the
dehydrated zirconium-calcium hydroxide nanoparticles to provide a calcined
mixed
zirconia-calcium oxide sorbent.
23. The method of claim 22, wherein calcining is carried out at a
temperature of at
least 850 C.
24. The method of any one of claims 1 to 23, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has a carbon dioxide capture capacity of at
least
5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 5 mole/kg sorbent.
25. The method of any one of claims 1 to 24, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has a carbon dioxide capture capacity that
loses
no more than 10, 9, 8, 7, 6, 5, 4, 3 or 2% carbon dioxide capture capacity
after 20
cycles.
26. The method of any one of claims 1 to 25, wherein active Ca0 conversion
by
carbon dioxide capture of the zirconium-stabilized calcium oxide nanoparticle
sorbent
is at least 90, 91, 92, 93, 94, 95, or 96% in a first carbon capture cycle.
27. The method of any one of claims 1 to 26, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has a BET surface area of at least 140
m2/g, 150
m21g, 160 m21g, 170 m2/g, 180 m2/g or 190 m2/g.
28. The method of any one of claims 1 to 27, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has an average particle size of less than
500nm,
400 nm, 350nm, 300nm1 250nm, 200nm, 150nm1 100nm or 90nm.
29. The method of any one of claims 1 to 28, further comprising pelletizing
the
zirconium-stabilized calcium oxide nanoparticle sorbent, to provide a
pelletized
zirconium-stabilized calcium oxide nanoparticle sorbent.
30. The zirconium-stabilized calcium oxide nanoparticle sorbent produced by
the
method of any one of claims 1 to 28, or the pelletized zirconium-stabilized
calcium
oxide nanoparticle sorbent produced by the method of claim 29_
31. Use of the zirconium-stabilized calcium oxide nanoparticle sorbent
produced
by the method of any one of claims 1 to 28 as a carbon dioxide sorbent.
32. Use of the pelletized zirconium-stabilized calcium oxide nanoparticle
sorbent of
claim 29, as a carbon dioxide sorbent in a fixed-bed calcium looping process.
33. Use of a zirconium-stabilized calcium oxide nanoparticle composition as
a
carbon dioxide sorbent, wherein the composition comprises intermixed zirconium
and
calcium oxide nanoparticles in a solid zirconium-calcium oxide sorbent having
a BET
surface area of at least 100 m2/g with average particle size of between 100
and 500
nm.
34. The use according to claim 33, wherein the zirconium-stabilized calcium
oxide
nanoparticle sorbent has a carbon dioxide capture capacity of at least 51 6,
7, 8, 91 10,
11, 12, 13, 14 or 5 mole/kg sorbent
35. The use according to claim 33 or 34, wherein the zirconium-stabilized
calcium
oxide nanoparticle sorbent has a carbon dioxide capture capacity that loses no
more
than 10, 9, 8, 7, 6, 5, 4, 3 or 2% carbon dioxide capture capacity after 20
cycles.
36. The use according to any one of claims 33 to 35, wherein active CaO
conversion by carbon dioxide capture of the zirconium-stabilized calcium oxide
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nanoparticle sorbent is at least 90, 91, 92, 93, 94, 95, or 96% in a first
carbon capture
cycle.
37. The use according to any one of claims 33 to 36, wherein the zirconium-
stabilized calcium oxide nanoparticle sorbent has a BET surface area of at
least 140
m2/g, 150 m21g, 160 m21g, 170 m2/g, 180 m2/g or 190 m2/g.
38. The use according to any one of claims 33 to 37, wherein the zirconium-
stabilized calcium oxide nanoparticle sorbent has an average particle size of
less than
500nm, 400 nm, 350nm1 300nm, 250nm, 200nm, 150nm1 100nm or 90nm.
39. A method of adsorbing carbon dioxide, comprising exposing a carbon
dioxide
gas to a zirconium-stabilized calcium oxide nanoparticle composition, wherein
the
composition comprises intermixed zirconium and calcium oxide nanoparticles in
a
solid zirconium-calcium oxide sorbent having a BET surface area of at least
100 m2/g
with average particle size of between 100 and 500 nm.
40. The method of claim 39, wherein the zirconium-stabilized calcium oxide
nanoparticle sorbent has a carbon dioxide capture capacity of at least 5, 6,
7, 8, 91 10,
11, 12, 13, 14 or 5 mole/kg sorbent.
41. The method of claim 39 or 40, wherein the zirconium-stabilized calcium
oxide
nanoparticle sorbent has a carbon dioxide capture capacity that loses no more
than
10, 9, 8, 7, 6, 5, 4, 3 or 2% carbon dioxide capture capacity after 20 cycles.
42. The method of any one of claims 39 to 41, wherein active Ca0 conversion
by
carbon dioxide capture of the zirconium-stabilized calcium oxide nanoparticle
sorbent
is at least 90, 91, 92, 93, 94, 95, or 96% in a first carbon capture cycle.
43. The method of any one of claims 39 to 42, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has a BET surface area of at least 140
m21g, 150
m21g, 160 m21g, 170 m2/g, 180 m2/g or 190 m2/g.
44. The method of any one of claims 39 to 43, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has an average particle size of less than
500nm,
400 nm, 350nm, 300nm, 250nm, 200nm, 150nm, 100nm or 90nm.
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45. The method of any one of claims 39 to 44, wherein the sorbent reversibly
adsorbs CO2 at 650-700 C to form CaCO3.
46. The method of claim 45, wherein the sorbent is regenerated from CaCO3
at
850-900 C with the release of CO2.
47. A zirconium-stabilized calcium oxide nanoparticle composition, wherein
the
composition comprises intermixed zirconium and calcium oxide nanoparticles in
a
solid zirconium-calcium oxide sorbent having a BET surface area of at least
100 m2/g
with average particle size of between 100 and 500 nm.
48. The composition of claim 47, wherein the zirconium-stabilized calcium
oxide
nanoparticle sorbent has a carbon dioxide capture capacity of at least 5, 6,
7, 8, 9, 10,
11, 12, 13, 14 or 5 mole/kg sorbent.
49. The composition of claim 47 or 48, wherein the zirconium-stabilized
calcium
oxide nanoparticle sorbent has a carbon dioxide capture capacity that loses no
more
than 10, 9, 8, 7, 6, 5, 4, 3 or 2% carbon dioxide capture capacity after 20
cycles.
50. The composition of any one of claims 47 to 49, wherein active Ca0
conversion
by carbon dioxide capture of the zirconium-stabilized calcium oxide
nanoparticle
sorbent is at least 90, 91, 92, 93, 94, 95, or 96% in a first carbon capture
cycle.
51. The composition of any one of claims 47 to 50, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has a BET surface area of at least 140
m21g, 150
m2/g, 160 m21g, 170 m2/g, 180 m2/g or 190 m2/g.
52. The composition of any one of claims 47 to 51, wherein the zirconium-
stabilized
calcium oxide nanoparticle sorbent has an average particle size of less than
500nm,
400 nm, 350nm, 300nm1 250nm, 200nm, 150nm1 100nm or 90nm.
53. The composition of any one of claims 47 to 52, wherein the sorbent
reversibly
adsorbs CO2 at 650-700 C to form CaCO3.
54. The composition of claim 53, wherein the sorbent is regenerated from
CaCO3
at 850-900 C with the release of CO2.
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