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US4131565A
Expired / Lapsed
US
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Process for reactivating spent activated-carbon
Assignee: Individual
•
Filing: 1975-04-07
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Granted: 1978-12-26
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Expires: 1995-04-07
Abstract
Abstract Spent activated-carbon is fluidized and directly heated at a temperature of 100° to 700° C in the first zone with an off gas from the second zone to remove volatiles from the spent carbon. The carbon so treated is then indirectly heated in the second zone at a temperature of 500° to 1000° C in the substantial absence of oxygen with a combustion gas while being fluidized with steam or a steam-containing inert gas to activate the carbon. The process ensures effective utilization of heat energy and substantially reduces the loss of carbon.
Inventors
- 👤 Masakazu Komori
- 👤 Kazuyuki Shiga
- 👤 Hajime Kitazato
- 👤 Hiroaki Okajima
- 👤 Yoshiharu Tanaka
- 👤 Shoiti Nojima
- 👤 Masashige Fukamachi
- 👤 Akinori Kurima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:35
CPC Classifications
B; B01; B01D; B01D15/00; C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/36; C02; C02F; C02F1/00; C02F1/28; C02F1/283
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
154 words
A process for the reactivation of spent activated-carbon, which comprises the steps of introducing spent activated carbon into a first devolatilization zone, fluidizing and directly heating said spent carbon in said first zone at a temperature between 100° and 700° C. with a gas from a second activation zone to remove volatiles from said spent carbon, transferring the carbon so treated to the second activation zone, indirectly heating said carbon in said second zone at a temperature between 500° to 1000° C. with a hot combustion gas while fluidizing said carbon in the substantial absence of oxygen with steam or a steam-containing inert gas to reactivate said carbon, the off gas from said indirect heating in said second zone being combined with the off gas from said reactivation in said second zone and used for fluidizing and heating said spent carbon in said first zone, and recovering the reactivated carbon from said second zone.
Claim 2
Dependent Claim
154 words
A process for the reactivation of spent activated-carbon, which comprises the steps of introducing spent activated carbon into a first devolatilization zone, fluidizing and directly heating said spent carbon in said first zone at a temperature between 100° and 700° C. with a gas from a second activation zone to remove volatiles from said spent carbon, transferring the carbon so treated to the second activation zone, indirectly heating said carbon in said second zone at a temperature between 500° to 1000° C. with a hot combustion gas while fluidizing said carbon in the substantial absence of oxygen with steam or a steam-containing inert gas to reactivate said carbon, the off gas from said indirect heating in said second zone being combined with the off gas from said reactivation in said second zone and used for fluidizing and heating said spent carbon in said first zone, and recovering the reactivated carbon from said second zone.
Claim 3
Dependent Claim
43 words
A process in accordance with claim 1 wherein the devolatilization in the first zone is carried out at a temperature of 100° to 500° C. and the activation in the second zone is carried out at a temperature of 600° to 1000° C.
Claim 4
Dependent Claim
39 words
A process in accordance with claim 2 wherein the retention time of the carbon in the first zone is 5 to 180 minutes and the retention time of the carbon in the second zone is 1 to 180 minutes.
Claim 5
Dependent Claim
39 words
A process in accordance with claim 1 wherein the retention time of the carbon in the first zone is 5 to 180 minutes and the retention time of the carbon in the second zone is 1 to 180 minutes.
Claim 6
Dependent Claim
32 words
A process in accordance with claim 1 wherein the temperature of the gas from the second activation is adjusted with a gas selected from the group consisting of a hot combustion gas,
Claim 7
Dependent Claim
30 words
A process in accordance with claim 1 which includes the additional step of quenching the reactivated carbon recovered from said second zone with steam, an inert gas or indirect cooling.
References Cited (Backward Citations)
US2933454A
Cited
US3816338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-25 | 1990-06-26 | 1990-12-26 | $7700.00 | Window Closed / Lapsed |