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US3972990A
Expired / Lapsed
US
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Method of preparing low density-high micropore volume refractory inorganic oxide particles
Assignee: Universal Oil Products Co
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Filing: 1975-05-30
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Granted: 1976-08-03
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Expires: 1995-05-30
Abstract
Abstract A method of preparing spheroidal refractory inorganic oxide particles characterized by low bulk density in combination with high micropore volume is disclosed. The particles, especially low bulk density - high micropore volume alumina particles, are useful as a support or carrier material for catalytically active materials to yield an improved hydrocarbon conversion catalyst.
Inventors
- 👤 Kenneth D. Vesely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:50
CPC Classifications
B; B01; B01J; B01J2/00; B01J2/02; B01J2/06; B01J2/08; B01J21/00; B01J21/02; B01J21/04; B01J35/00; B01J35/60; B01J35/63; B01J35/635; B01J35/638; B01J35/64; B01J35/647
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
203 words
A method of preparing spherical particles of alumina having an average bulk density of from about 0.1 to about 0.6 grams per cubic centimeter, with from about 0.7 to about 5.0 cubic centimeters per gram of the total pore volume being associated with pores having an average diameter of less than about 600 Angstroms, said method comprising the steps of: a. effecting the gelation of a hydrosol of said alumina in admixture with ammonia in a hot oil bath to form hydrogel spheres; b. percolating a water-miscible alcohol through said hydrogel spheres at a temperature of from about 20° to about 50° C. until the effluent alcohol is substantially free of acquired water; c. thereafter evaporating the resulting water-alcohol solution from the hydrogel spheres at a pressure of from about 300 to about 600 millimeters of mercury and at a temperature substantially equivalent to the boiling point of said alcohol-water solution at said pressure; d. further drying said spheres in a substantially water-free atmosphere to produce spheres characterized by less than about 10 wt. % loss on ignition at 900° C.; and e. calcining the dried spheres at a temperature of from about 425° to about 750° C. in a substantially water-free atmosphere.
Claim 2
Independent Claim
203 words
A method of preparing spherical particles of alumina having an average bulk density of from about 0.1 to about 0.6 grams per cubic centimeter, with from about 0.7 to about 5.0 cubic centimeters per gram of the total pore volume being associated with pores having an average diameter of less than about 600 Angstroms, said method comprising the steps of: a. effecting the gelation of a hydrosol of said alumina in admixture with ammonia in a hot oil bath to form hydrogel spheres; b. percolating a water-miscible alcohol through said hydrogel spheres at a temperature of from about 20° to about 50° C. until the effluent alcohol is substantially free of acquired water; c. thereafter evaporating the resulting water-alcohol solution from the hydrogel spheres at a pressure of from about 300 to about 600 millimeters of mercury and at a temperature substantially equivalent to the boiling point of said alcohol-water solution at said pressure; d. further drying said spheres in a substantially water-free atmosphere to produce spheres characterized by less than about 10 wt. % loss on ignition at 900° C.; and e. calcining the dried spheres at a temperature of from about 425° to about 750° C. in a substantially water-free atmosphere.
Claim 3
Dependent Claim
46 words
The method of claim 1 further characterized with respect to step (a) in that said hydrosol is an acidic alumina hydrosol containing from about 10 to about 14 wt. % aluminum in from about a 1:1 to about a 1.5:1 ratio with acid anion content thereof.
Claim 4
Dependent Claim
37 words
The method of claim 2 further characterized with respect to step (a) in that said ammonia is derived from hexamethylenetetramine utilized in an amount to effect substantially complete neutralization of the acid anion contained in said mixture.
Claim 5
Dependent Claim
40 words
The method of claim 2 further characterized with respect to step (a) in that said ammonia is derived from hexamethylenetetramine utilized in from about a 1:4 to about a 2:4 mole ratio with the acid anion contained in said mixture.
Claim 6
Dependent Claim
20 words
The method of claim 1 further characterized with respect to step (a) in that said ammonia is derived from hexamethylenetetramine.
Claim 7
Dependent Claim
21 words
The method of claim 1 further characterized with respect to step (a) in that said hydrosol is an aluminum hydroxyhalide sol.
Claim 8
Dependent Claim
30 words
The method of claim 1 further characterized with respect to step (a) in that said oil bath is maintained at a temperature of from about 50° to about 105° C.
Claim 9
Dependent Claim
41 words
The method of claim 1 further characterized with respect to step (b) in that said alcohol wash is effected at a temperature of from about 20° to about 50° C. and at a pressure to maintain substantially liquid phase aging conditions.
Claim 10
Dependent Claim
19 words
The method of claim 1 further characterized with respect to step (b) in that said alcohol is ethyl alcohol.
Claim 11
Dependent Claim
43 words
The method of claim 1 further characterized with respect to step (c) in that said water-alcohol solution is evaporated at a reduced pressure of from about 5 to about 10 psig and at a temperature of from about 10° to about 50° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |