US4442080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid bed SOX/NOX process--"hydrated calcine absorption"
Assignee: GEA Process Engineering AS
•
Filing: 1982-06-01
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Granted: 1984-04-10
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Expires: 2002-06-01
Abstract
Abstract A process for removal of nitrogen oxides and sulfur oxides from waste gases by contacting the waste gases with a particulate material comprising an alkaline earth based absorbent for sulfur oxides. Essential features are a reaction temperature of 85 DEG -145 DEG C., a maximum value of 3 for the ratio of nitrogen oxides to sulfur oxides, and the presence of oxygen and moisture. In its preferred form the process comprises a spray drying-absorption reaction followed by particle separation in a bag house. Removal efficiency is improved by the presence of minor amounts of sodium sulfite together with the alkaline earth based absorbent. Also a special conveyance of material may be applied to improve efficiency.
Inventors
- 👤 James R. Donnelly
- 👤 Karsten S. Felsvang
- 👤 Per Morsing
- 👤 Preston L. Veltman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:03
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/60; B01J; B01J20/00; B01J20/02; B01J20/04; B01J8/00; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
155 words
A process for treating a gaseous mixture containing SO x and NO x wherein the molar ratio of NO x to SO x is 3 or below and wherein both SO x and NO x are removed which comprises: a. providing a reactor for particulate material wherein the particles are in motion relative to each other; b. said particles having a surface comprising alkaline earth hydroxide reactable with said SO x and NO x , in admixture with the reaction products of said SO x and NO x and alkaline earth hydroxide; c. contacting the particles in said reactor with the gaseous mixture at a temperature of between about 85° C. and about 150° C. in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; d. thereby substantially reducing the amount of SO x and NO x in the gaseous mixture.
Claim 2
Dependent Claim
155 words
A process for treating a gaseous mixture containing SO x and NO x wherein the molar ratio of NO x to SO x is 3 or below and wherein both SO x and NO x are removed which comprises: a. providing a reactor for particulate material wherein the particles are in motion relative to each other; b. said particles having a surface comprising alkaline earth hydroxide reactable with said SO x and NO x , in admixture with the reaction products of said SO x and NO x and alkaline earth hydroxide; c. contacting the particles in said reactor with the gaseous mixture at a temperature of between about 85° C. and about 150° C. in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; d. thereby substantially reducing the amount of SO x and NO x in the gaseous mixture.
Claim 3
Dependent Claim
52 words
A process in accordance with claim 1 in which the surface of the particles is in substantial part formed within the bed by reaction of SO x and NO x with substantially anhydrous alkaline earth hydroxide formed on the particles by dehydration of a preformed solution or dispersion of alkaline earth hydroxide.
Claim 4
Dependent Claim
15 words
A process according to claim 1 in which the alkaline earth reagent is calcium hydroxide.
Claim 5
Dependent Claim
47 words
A process in accordance with claim 1 in which the surface of the particles is in substantial part formed within the reactor by reaction of an alkaline earth oxide introduced to the reactor and water vapor, oxygen and SO x and NO x of the gaseous mixture.
Claim 6
Dependent Claim
34 words
A process in accordance with claim 1 in which the surface of the particles is in substantial part formed within the reactor by reaction of calcium oxide introduced to the reactor and water vapor,
Claim 7
Dependent Claim
50 words
A process in accordance with claim 1 in which the surface of the particles is in substantial part formed within the reactor by reaction of a preformed hydrated alkaline earth oxide introduced to said reactor with the oxygen, water vapor and SO x and NO x of the gaseous mixture.
Claim 8
Dependent Claim
209 words
A process for treating a gaseous mixture containing SO x and NO x wherein the molar ratio of NO x to SO x is 3 or below and wherein both SO x and NO x are removed which comprises: a. providing in a reactor a bed of particulate material wherein the particles are in motion relative to each other; b. said particles having a surface comprising hydrated alkaline earth oxide in admixture with the reaction products of SO x and NO x and said oxide; c. contacting the particles in said bed with the gaseous mixture at a temperature of between about 85° C. and about 150° C. in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; d. to thereby substantially reduce the amount of SO x and NO x in the gaseous mixture; e. removing reacted particulate material from the bed on a continuous basis; f. abrading the surfaces of at least part of the removed particles, and returning at least part of the abraded particles to the reactor on a continuous basis; g. sizing the particles to remove both fines and coarse fractions therefrom and returning the mid cut to the reactor.
Claim 9
Dependent Claim
209 words
A process for treating a gaseous mixture containing SO x and NO x wherein the molar ratio of NO x to SO x is 3 or below and wherein both SO x and NO x are removed which comprises: a. providing in a reactor a bed of particulate material wherein the particles are in motion relative to each other; b. said particles having a surface comprising hydrated alkaline earth oxide in admixture with the reaction products of SO x and NO x and said oxide; c. contacting the particles in said bed with the gaseous mixture at a temperature of between about 85° C. and about 150° C. in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; d. to thereby substantially reduce the amount of SO x and NO x in the gaseous mixture; e. removing reacted particulate material from the bed on a continuous basis; f. abrading the surfaces of at least part of the removed particles, and returning at least part of the abraded particles to the reactor on a continuous basis; g. sizing the particles to remove both fines and coarse fractions therefrom and returning the mid cut to the reactor.
Claim 10
Dependent Claim
14 words
A process in accordance with claim 16 in which the bed is fluidized bed.
Claim 11
Dependent Claim
25 words
A process in accordance with claim 7 in which the particles comprise an abrasion resistant non-porous core upon which the alkaline earth hydroxide is deposited.
Claim 12
Dependent Claim
31 words
A process in accordance with claim 7 in which particulates are continuously removed from the bed, reaction products are separated from the core and the core is returned to the bed.
Claim 13
Dependent Claim
178 words
A process for treating a gaseous mixture containing both sulfur oxides and nitrogen oxides wherein the molar ratio of NO x to SO x is below 3 and wherein both SO x and NO x are removed which comprises: a. providing a fluidizable bed of particles comprising an inert nonporous material; b. passing a heated waste gas comprising sulfur oxides and nitrogen oxides through the bed of particulates to maintain a temperature between about 85° C. and 150° C. and to fluidize the particles; c. dispersively introducing a solution or dispersion of an alkaline earth hydroxide to the bed, said solution or dispersion contacting the heated surfaces of the fluidized particles whereby water is evaporated, said alkaline earth hydroxide is deposited on the particles and absorption reactions with the sulfur and nitrogen oxides occur in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; and d. passing effluent gases from the fluidized bed to a particle separation device to remove particulates from said gases.
Claim 14
Dependent Claim
178 words
A process for treating a gaseous mixture containing both sulfur oxides and nitrogen oxides wherein the molar ratio of NO x to SO x is below 3 and wherein both SO x and NO x are removed which comprises: a. providing a fluidizable bed of particles comprising an inert nonporous material; b. passing a heated waste gas comprising sulfur oxides and nitrogen oxides through the bed of particulates to maintain a temperature between about 85° C. and 150° C. and to fluidize the particles; c. dispersively introducing a solution or dispersion of an alkaline earth hydroxide to the bed, said solution or dispersion contacting the heated surfaces of the fluidized particles whereby water is evaporated, said alkaline earth hydroxide is deposited on the particles and absorption reactions with the sulfur and nitrogen oxides occur in the presence of at least 0.5% by volume oxygen and water vapor but in the absence of a substantial quantity of liquid water; and d. passing effluent gases from the fluidized bed to a particle separation device to remove particulates from said gases.
Claim 15
Dependent Claim
36 words
A process according to claim 11 in which a portion of the particulates are withdrawn from the bed, reaction products are removed therefrom and at least a portion of the particles are returned to the bed.
Claim 16
Dependent Claim
41 words
A process according to claim 11 in which the alkaline earth hydroxide is calcium hydroxide and is formed within the bed by introduction of calcium oxide which reacts with water vapor contained in the gaseous mixture to form said calcium hydroxide.
Claim 17
Dependent Claim
29 words
A process according to claim 20 in which the alkaline earth hydroxide is calcium hydroxide and is preformed by hydration of CaO and then is introduced to the bed.
Claim 18
Dependent Claim
22 words
A process according to claim 11 in which the temperature of the bed is maintained between about 110° C. and 120° C.
Claim 19
Dependent Claim
59 words
A process according to claim 20 in which the mols of alkaline earth hydroxide employed is between 0.9 and 1.5 mols reagent to the SO x in waste gas, the oxygen content of the waste gas is at least 1.5 volume percent and the content of water vapor is at least the equivalent of a 40° C. dew point.
Claim 20
Dependent Claim
94 words
A process according to claims 1 or 11 in which the particulates comprising the bed are formed in situ by reaction between the alkaline earth hydroxide and SO x and NO x of the gaseous feed mixture, and the bed is maintained under equilibrium operating conditions by continuously removing a portion of the bed material, removing part of the solid reaction products therefrom and returning at least part of the said portion to the bed for further contact with the SO x and NO x content of the gaseous mixture feed to the process.
Claim 21
Dependent Claim
34 words
A process according to claims 1 or 11 in which the waste gases contain fly ash and a substantial amount of said fly ash is captured with reaction product particles formed in the bed.
Claim 22
Dependent Claim
48 words
A process according to claims 1 or 11 in which the waste gases contain fly ash and said fly ash is captured with particles formed in the bed and a portion of the said fly ash is recovered in a particulate recovery device disposed downstream from the bed.
Claim 23
Dependent Claim
49 words
A process according to claims 1 or 11 in which finely divided liquid water is introduced into the bed, and is therein vaporized as a temperature control means before it can react with either SO x and NO x of the feed mixture or with the alkaline earth hydroxide.
Claim 24
Dependent Claim
27 words
A process according to claims 1 or 11 in which the temperature of the bed is controlled by heat exchange between the particles and an external medium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |