US3811916A
Expired / Lapsed
US
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Method for carbon impregnation of alumina
Assignee: Alcoa Corp
•
Filing: 1971-09-07
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Granted: 1974-05-21
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Expires: 1991-09-07
Abstract
Abstract Process for the preparation of selectively constituted carbon impregnated alumina through the thermal cracking of hydrocarbon in contact with a fluidized bed of particles of precoated high surface area alumina in a first zone to deposit carbon in situ thereon in conjunction with the deposition of residual crackable hydrocarbon from the first zone gaseous effluent on particles of uncoated high surface area alumina in a second zone and prior to their introduction into said first zone, and minimization of the amounts of free hydrogen attendant the resultant carbon impregnated product.
Inventors
- 👤 A Russell
- 👤 N Jarrett
- 👤 B Marshall
- 👤 J Remper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:36
CPC Classifications
B; B01; B01D; B01D7/00; B01D7/02; C; C01; C01F; C01F7/00; C01F7/48; C01F7/56; C01F7/58; C01F7/60; C01F7/62; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/51; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/10; C01P2006/20; C01P2006/80; Y; Y10; Y10S; Y10S264/00; Y10S264/19; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
22 words
Process according to claim 1 wherein the recovered carbon impregnated alumina has an average carbon content of about 15-24 percent by weight.
Claim 2
Dependent Claim
22 words
Process according to claim 1 wherein the recovered carbon impregnated alumina has an average carbon content of about 17-19 percent by weight.
Claim 3
Dependent Claim
41 words
Process according to claim 1 including the step of continuously removing from the first zone hydrogen produced by the cracking in amounts sufficient to render the average hydrogen content of said carbon impregnated alumina at less than about 0.5 percent weight.
Claim 4
Dependent Claim
26 words
Process according to claim 1 including the step of maintaining the average alumina temperature at the loci of cracking in the first zone between about 750-1,100*C.
Claim 5
Dependent Claim
31 words
Process according to claim 1 including the step of maintaining the temperature of said second zone between about 20-100*C to effect deposition of said residual crackable hydrocarbon on said alumina therein.
Claim 6
Dependent Claim
22 words
Process according to claim 1 wherein the pressure in each of the first and second zones is between about 0.1-10 atmospheres absolute.
Claim 7
Dependent Claim
20 words
Process according to claim 1 including the step of removing hydrogen values from the gaseous effluent of said cracking step.
Claim 8
Dependent Claim
26 words
Process according to claim 1 including the step of feeding at least a portion of the gaseous effluent from the second zone to the first zone.
Claim 9
Dependent Claim
43 words
Process according to claim 1 including the step of cracking said hydrocarbon in a heated fluidized bed of alumina in said first zone, and the step of depositing said residual crackable hydrocarbon in a cooled fluidized bed of alumina in said second zone.
Claim 10
Dependent Claim
44 words
Process according to claim 10 including the step of feeding fresh particles of alumina to the second zone in an amount corresponding to the amount of particles of alumina having residual crackable hydrocarbon deposited thereon conducted from said second zone to the first zone.
Claim 11
Dependent Claim
27 words
Process according to claim 1 wherein the alumina introduced into said second zone has an average alpha alumina content of less than about 5 percent by weight.
Claim 12
Dependent Claim
22 words
Process according to claim 12 wherein said alumina has an average loss on ignition of less than about 5 percent by weight.
Claim 13
Dependent Claim
51 words
Process according to claim 1 wherein the alumina has a total iron, silicon and titanium impurities content of less than about 0.5 percent by weight, a sodium impurities content no greater than about 1.0 percent by weight calculated as Na2O, and an average surface area of at least about 10 m2/g.
Claim 14
Dependent Claim
30 words
Process according to claim 1 wherein the alumina introduced into said second zone has a total iron, silicon and titanium impurities content of less than about 0.5 percent by weight.
Claim 15
Dependent Claim
29 words
Process according to claim 1 wherein the alumina introduced into said second zone has a sodium impurities content no greater than about 1.0 percent by weight calculated as Na2O.
Claim 16
Dependent Claim
24 words
Process according to claim 1 wherein the alumina introduced into said second zone has an average surface area of at least about 10 m2/g.
Claim 17
Dependent Claim
27 words
Process according to claim 1 wherein the alumina introduced into said second zone has an average loss on ignition of less than about 5 percent by weight.
Claim 18
Dependent Claim
26 words
Process according to claim 1 wherein said alumina in said second zone has an average alpha alumina content of less than about 3 percent by weight.
Claim 19
Dependent Claim
22 words
Process according to claim 1 wherein said alumina in said second zone has an average surface area of at least 80 m2/g.
Claim 20
Dependent Claim
137 words
Process according to claim 1 for the production of carbon impregnated particles of alumina in the form of coked alumina which comprises the steps of thermally cracking said crackable hydrocarbon in saId first zone in contact with a bed of particles of alumina maintained at a temperature sufficient to crack said hydrocarbon, depositing carbon produced by said thermal cracking in situ on the particles of alumina and removing hot gaseous effluent resulting from said thermal cracking which contains carbonaceous values including volatile crackable hydrocarbon and entrained carbonaceous particles from said first zone, contacting said hot gaseous effluent with a lower temperature bed of particles of alumina in said second zone to deposit at least a portion of said carbonaceous values thereon for precoating the same, and introducing such precoated particles of alumina into the first zone bed.
Claim 21
Dependent Claim
31 words
Process according to claim 21 including the step of cooling said hot gaseous effluent from the first zone prior to its contact with the particles of alumina in said second zone.
Claim 22
Dependent Claim
36 words
Process according to claim 21 including the step of maintaining said bed in said second zone at a temperature sufficient to cool the hot gaseous effluent to a degree to effect condensation of condensable hydrocarbons therein.
Claim 23
Dependent Claim
36 words
Process according to claim 21 including the step of transferring at least a portion of the cool gaseous effluent from said second zone to the bed in said first zone to assist in the fluidization thereof.
Claim 24
Dependent Claim
54 words
Process according to claim 21 including the steps of fluidizing the bed in said second zone by introduction of hydrocarbon-containing gas therein, and introducing at least a portion of the resultant mixed gaseous effluent from the bed in said second zone into the bed in said first zone to contribute to the fluidizing thereof.
Claim 25
Dependent Claim
168 words
Process according to claim 21 for the production of carbon impregnated particles of alumina in the form of coked alumina which comprises the steps of transferring particles of alumina from a cooled fluidized bed of such alumina in said second zone maintained at a temperature of about 20-100*C into a heated bed of alumina in said first zone maintained at a temperature of about 750-1,100*C, fluidizing said heated bed by upward passage of gas therethrough, thermally cracking crackable hydrocarbon in contact with the particles of said heated bed to deposit carbon in situ on the alumina particles therein, introducing the hot gaseous effluent containing crackable hydrocarbons and entrained carbonaceous particles from said first zone into the cooled bed in said second zone to condense at least a portion of the volatile hydrocarbons therein and to deposit such condensed hydrocarbons and entrained carbonaceous particles on particles of alumina in the cooled bed prior to transfer thereof to said heated bed, and recovering coked alumina particles from the heated bed.
Claim 26
Dependent Claim
74 words
Process according to claim 25 including the step of introducing hydrocarbon-containing gas into the cooled bed in said second zone to fluidize the same and introducing at least a portion of the gaseous effluent from the cooled bed comprising the remaining cooled gaseous effluent from said first zone and which still contains carbonaceous values therein and the hydrocarbon-containing fluidizing gas into the heated bed in said first zone to contribute to the fluidization thereof.
Claim 27
Dependent Claim
61 words
Process according to claim 25 including the step of injecting crackable hydrocarbon in liquid form into the heated bed for liquid contact with the particles of alumina therein in a quantity sufficient to provide coked alumina particles having an average carbon content of about 15-24 percent by weight and an average hydrogen content of less than about 0.5 percent by weight.
Claim 28
Dependent Claim
21 words
Process according to claim 28 wherein the average carbon content of the coked alumina particles is about 17-19 percent by weight.
Claim 29
Dependent Claim
28 words
Process according to claim 25 including the steps of maintaining the temperature of the cooled bed about 20-60*C, and maintaining the temperature of the heated bed about 750-950*C.
Claim 30
Dependent Claim
40 words
Process according to claiM 21 including the step of introducing said precoated particles of alumina into said first zone at a location permitting a rapid increase in the temperature thereof to the cracking temperature with minimal volatilization of said hydrocarbon.
Claim 31
Dependent Claim
28 words
Process according to claim 21 including the step of fluidizing the bed in said second zone by reintroducing at least a portion of the gaseous effluent therefrom thereinto.
Claim 32
Dependent Claim
22 words
Process according to claim 1 including the step of purging the carbon impregnated alumina with gas to reduce the hydrogen content thereof.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |