US4427642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for dry desulfurization of flue gas
Assignee: Mitsubishi Power Ltd
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Filing: 1982-01-13
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Granted: 1984-01-24
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Expires: 2002-01-13
Abstract
Abstract Sulfur oxides contained in the flue gas from coal-fired boiler are adsorbed by an adsorbent prepared by dry-distilling a portion of fuel coal, thereby producing semi-coke, and activating the semi-coke by steam, and then the sulfur oxides-adsorbed adsorbent is heated to desorb the adsorbed sulfur oxides at a high concentration. The desorbed sulfur oxides are passed through a bed of semi-coke before the activation to recover the sulfur oxides as elemental sulfur.
Inventors
- 👤 Norio Arashi
- 👤 Yukio Hishinuma
- 👤 Hidetoshi Akimoto
- 👤 Sadao Takahashi
- 👤 Fumito Nakajima
- 👤 Kenichi Gomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:06
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/0404; C01B17/0408; B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; C01B17/48; C01B17/50; C01B17/60; C01B32/00; C01B32/30; C01B32/312; C01B32/336; B01D2253/00; B01D2253/10; B01D2253/102; B01D2257/00; B01D2257/30; B01D2257/302; B01D2258/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
162 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting one portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing sulfur oxides; separately dry distilling a second portion of said coal to produce a semi-coke adsorbent; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the semi-coke while abrading another part of the adsorbent to produce waste adsorbent; conducting the effluent to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent as fuel in said boiler or furnace.
Claim 2
Dependent Claim
162 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting one portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing sulfur oxides; separately dry distilling a second portion of said coal to produce a semi-coke adsorbent; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the semi-coke while abrading another part of the adsorbent to produce waste adsorbent; conducting the effluent to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent as fuel in said boiler or furnace.
Claim 3
Dependent Claim
183 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting a portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing the sulfur oxides; separately dry distilling a second portion of said coal to produce a semi-coke adsorbent; moving the semi-coke adsorbent through a moving bed type desulfurization column from the top of the column downwards; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the adsorbent while abrading another part of the adsorbent to produce waste adsorbent; conducting the desorbed sulfur oxides to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent in the boiler or furnace as fuel.
Claim 4
Dependent Claim
183 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting a portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing the sulfur oxides; separately dry distilling a second portion of said coal to produce a semi-coke adsorbent; moving the semi-coke adsorbent through a moving bed type desulfurization column from the top of the column downwards; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the adsorbent while abrading another part of the adsorbent to produce waste adsorbent; conducting the desorbed sulfur oxides to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent in the boiler or furnace as fuel.
Claim 5
Dependent Claim
163 words
A process for dry desulfurization of flue gas, where sulfur oxides are removed from a flue gas produced by boilers or furnaces using coal capable of being converted to semi-coke as at least a part of the fuel, which comprises: adsorbing the sulfur oxides onto a semi-coke adsorbent prepared by dry distillation of a part of the same coal as that used in the furnace or boiler, thereby removing the sulfur oxides from the flue gas while abrading a portion of the adsorbent to produce waste adsorbent, then heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing the sulfur oxides at a high concentration and simultaneously regenerating the semi-coke adsorbent while abrading a portion of the adsorbent to produce waste adsorbent, and recyclically using the semi-coke in the adsorption, when conducting the desorbed sulfur oxides to a process for the recovery of elemental sulfur, and returning the waste adsorbent produced in the adsorption and desorption to the boilers or furnaces for combustion as fuel.
Claim 6
Dependent Claim
163 words
A process for dry desulfurization of flue gas, where sulfur oxides are removed from a flue gas produced by boilers or furnaces using coal capable of being converted to semi-coke as at least a part of the fuel, which comprises: adsorbing the sulfur oxides onto a semi-coke adsorbent prepared by dry distillation of a part of the same coal as that used in the furnace or boiler, thereby removing the sulfur oxides from the flue gas while abrading a portion of the adsorbent to produce waste adsorbent, then heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing the sulfur oxides at a high concentration and simultaneously regenerating the semi-coke adsorbent while abrading a portion of the adsorbent to produce waste adsorbent, and recyclically using the semi-coke in the adsorption, when conducting the desorbed sulfur oxides to a process for the recovery of elemental sulfur, and returning the waste adsorbent produced in the adsorption and desorption to the boilers or furnaces for combustion as fuel.
Claim 7
Dependent Claim
19 words
A process according to claim 2 or 3 wherein the dry distillation is conducted at 600° to 700° C.
Claim 8
Dependent Claim
19 words
A process according to claim 2 or 3 wherein the dry distillation is conducted in an N 2 atmosphere.
Claim 9
Dependent Claim
33 words
A process according to claim 1, 2 or 3 wherein a portion of the sulfur oxides in the effluent are reduced to elemental sulfur by using the semi-coke adsorbent as a reducing agent.
Claim 10
Dependent Claim
22 words
A process according to claim 6, wherein the sulfur oxides remaining in the effluent after reduction are subjected to the Claus reaction.
Claim 11
Dependent Claim
24 words
A process according to claims 1, 2 or 3 wherein the semi-coke is activated by steam and an oxygen-containing gas after the dry distillation.
Claim 12
Dependent Claim
25 words
A process according to claim 8, wherein the semi-coke is activated by steam and an oxygen-containing gas at a temperature of 700° to 900° C.
Claim 13
Dependent Claim
27 words
A process according to claim 6, wherein the reduction is conducted at a temperature of 600° to 800° C. produced by combusting a portion of the semi-coke.
Claim 14
Dependent Claim
63 words
A process according to claim 2, wherein a sulfur oxide concentration of the flue gas passing through the desulfurization column of moving bed type is detected at the inlet side and the outlet side of the desulfurization column, and a rate of withdrawing the semi-coke from the desulfurization column is adjusted at least by the respective detected signals and a set percent desulfurization.
Claim 15
Dependent Claim
46 words
A process according to claim 2, wherein the adjustment of the rate of withdrawing the semi-coke is made in view of actual operating conditions of the desulfurization column as information in addition to the detected signals of the sulfur oxide concentration and the set percent desulfurization.
Claim 16
Dependent Claim
40 words
A process according to claim 2, wherein the adsorbed semi-coke arriving at the bottom of the desulfurization column is supplied to a desorption column, and heated therein, thereby regenerating an adsorption activity, and then supplied again to the desulfurization column.
Claim 17
Dependent Claim
173 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting one portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing sulfur oxides; separately dry distilling a second portion of said coal at a temperature of 600°-700° C. in an N 2 atmosphere to produce a semi-coke adsorbent; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the semi-coke while abrading another part of the adsorbent to produce waste adsorbent; conducting the effluent to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent as fuel in said boiler or furnace.
Claim 18
Dependent Claim
173 words
A process for the dry desulfurization of flue gas containing sulfur oxides, comprising: providing fuel coal capable of being converted to semi-coke; combusting one portion of said coal as at least part of the fuel in a boiler or furnace to produce a flue gas containing sulfur oxides; separately dry distilling a second portion of said coal at a temperature of 600°-700° C. in an N 2 atmosphere to produce a semi-coke adsorbent; contacting the flue gas with the adsorbent to adsorb the sulfur oxides, thereby removing the sulfur oxides from the flue gas while abrading a part of the adsorbent to produce waste adsorbent; heating the sulfur oxides-adsorbed semi-coke adsorbent, thereby desorbing an effluent containing a high concentration of sulfur oxides and simultaneously regenerating the semi-coke while abrading another part of the adsorbent to produce waste adsorbent; conducting the effluent to a process for the recovery of elemental sulfur therefrom; recyclically using the regenerated semi-coke in the contacting step; and combusting all the waste adsorbent as fuel in said boiler or furnace.
Claim 19
Dependent Claim
30 words
A process according to claim 1, wherein heavy tarry matter is generated from the coal in the dry distilling step and is returned to said boiler or furnace as fuel.
Claim 20
Dependent Claim
33 words
A process according to claim 1, wherein a gas comprising hydrogen and methane is generated from the coal in the dry distilling step and is returned to said boiler or furnace as fuel.
Claim 21
Dependent Claim
31 words
A process according to claim 8, wherein a gas comprising hydrogen, carbon monoxide and carbon dioxide is generated from the semi-coke and is returned to said boiler or furnace as fuel.
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) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |