US4008169A
Expired / Lapsed
US
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Preparation of iron oxide sorbent for sulfur oxides
Assignee: Individual
•
Filing: 1975-03-07
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Granted: 1977-02-15
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Expires: 1995-03-07
Abstract
Abstract A highly sorbent iron oxide for use in the purification of dilute sulfur and oxygen-bearing gases is prepared by a two step process which involves a low temperature decomposition of iron sulfate and a low temperature oxidation of the intermediate product.
Inventors
- 👤 Patrick John McGauley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:14
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/60; B; B01; B01J; B01J20/00; B01J20/02; B01J20/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A process for the preparation of an improved iron oxide sorbent active for use in the purification of sulfur and oxygen-containing gases comprising: a. providing a quantity of iron sulfate-bearing solids, b. advancing said solids to a decomposition zone, c. contacting the solids with hot reducing gas at a temperature of from about 300° to about 700° C. under conditions to produce both a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, d. separating the above magnetite-bearing solids from the gas, and e. oxidizing said magnetite-bearing solids at a temperature below about 450° C. to form an iron oxide-bearing solid sorbent.
Claim 2
Dependent Claim
109 words
A process for the preparation of an improved iron oxide sorbent active for use in the purification of sulfur and oxygen-containing gases comprising: a. providing a quantity of iron sulfate-bearing solids, b. advancing said solids to a decomposition zone, c. contacting the solids with hot reducing gas at a temperature of from about 300° to about 700° C. under conditions to produce both a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, d. separating the above magnetite-bearing solids from the gas, and e. oxidizing said magnetite-bearing solids at a temperature below about 450° C. to form an iron oxide-bearing solid sorbent.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the magnetite-bearing solids are oxidized by contacting with a sulfur and oxygen-bearing gas in an absorption zone.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the concentration of reducing agent in the hot reducing gas in the reaction zone is in equilibrium composition with magnetite in the decomposition product.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the iron sulfate-bearing solid is principally iron sulfate.
Claim 6
Dependent Claim
149 words
A process for preparing iron oxide-bearing sorbent that are active for use in the purification of sulfur and oxygen-bearing gases comprising: a. providing a quantity of prepared iron oxide-bearing solids that contain iron sulfates and are suitable in particle size and mechanical properties for contacting with gases, b. advancing said solids to a decomposition zone, c. contacting the above solids in the decomposition zone with hot reducing gases to produce a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, the temperature in the decomposition zone being between about 300° and 700° C. d. separating the magnetite containing solids from the product gas, e. recovering the product gas containing sulfur dioxide and reducing agents, and f. oxidizing the magnetite-bearing solids at a temperature below about 450° C. to form a highly active iron oxide-bearing sorbent for sulfur from sulfur and oxygen-bearing gases.
Claim 7
Dependent Claim
149 words
A process for preparing iron oxide-bearing sorbent that are active for use in the purification of sulfur and oxygen-bearing gases comprising: a. providing a quantity of prepared iron oxide-bearing solids that contain iron sulfates and are suitable in particle size and mechanical properties for contacting with gases, b. advancing said solids to a decomposition zone, c. contacting the above solids in the decomposition zone with hot reducing gases to produce a solid that contains magnetite and a product gas that contains both sulfur dioxide and reducing agents, the temperature in the decomposition zone being between about 300° and 700° C. d. separating the magnetite containing solids from the product gas, e. recovering the product gas containing sulfur dioxide and reducing agents, and f. oxidizing the magnetite-bearing solids at a temperature below about 450° C. to form a highly active iron oxide-bearing sorbent for sulfur from sulfur and oxygen-bearing gases.
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) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |