US4256464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for desulfurization of coal
Assignee: Hamon Research Cottrell SA
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Filing: 1979-10-01
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Granted: 1981-03-17
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Expires: 1999-10-01
Abstract
Abstract Coal is oxidized by NO x in the presence of a liquid in which NO x is soluble. Oxidized sulfur species are removed by washing with water and dilute sulfuric acid. NO x is not consumed in the process and is recycled. More than 70% of sulfur in coal is removed.
Inventors
- 👤 Asim B. Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:55
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02; Y; Y10; Y10S; Y10S44/00; Y10S44/905
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A process for desulfurization of sulfur containing pulverized coal consisting essentially of the steps: suspending powdered sulfur containing coal in a liquid organic reaction medium generally inert to and a solvent for NO x , and while suspended, introducing NO and oxygen or an oxygen containing gas into the slurry; washing the reacted coal with water and then with a dilute solution of H 2 SO 4 or Na 2 CO 3 ; and thereafter drying the desulfurized coal.
Claim 2
Dependent Claim
79 words
A process for desulfurization of sulfur containing pulverized coal consisting essentially of the steps: suspending powdered sulfur containing coal in a liquid organic reaction medium generally inert to and a solvent for NO x , and while suspended, introducing NO and oxygen or an oxygen containing gas into the slurry; washing the reacted coal with water and then with a dilute solution of H 2 SO 4 or Na 2 CO 3 ; and thereafter drying the desulfurized coal.
Claim 3
Dependent Claim
29 words
The process defined in claim 1 wherein the reaction medium is selected from the group consisting of aliphatic or aromatic hydrocarbon, nitrated hydrocarbons, nitromethane or nitrobenzene, or halogenated hydrocarbons.
Claim 4
Dependent Claim
12 words
The process defined in claim 1 wherein the reaction medium comprises kerosine.
Claim 5
Dependent Claim
24 words
The process defined in claim 2 wherein the washing solution comprised 1% solution of H 2 SO 4 or Na 2 CO 3 .
Claim 6
Dependent Claim
28 words
The process defined in claim 1 wherein the mixture of NO and air consisted of NO 11.5% and air 88.5% by volume and the reaction stoichiometry was 3.30.
References Cited (Backward Citations)
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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) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |