US4367211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma arc process for the reduction of sulfur dioxide to sulfur
Assignee: Pfizer Inc
•
Filing: 1982-02-01
•
Granted: 1983-01-04
•
Expires: 2002-02-01
Abstract
Abstract A continuous process for the reduction of sulfur dioxide to sulfur in which a gas stream containing sulfur dioxide is contacted with a carbon source in the form of particulate coal at a temperature of at least 600 DEG C. in a plasma arc reaction zone generated by a rotating direct current arc.
Inventors
- 👤 William G. Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:15
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/0473; C01B17/0482
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
39 words
A continuous process for the reduction of sulfur dioxide to sulfur, which comprises contacting a gas stream containing sulfur dioxide with a carbon source in a plasma arc reaction zone at a temperature of at least about 600° C.
Claim 2
Dependent Claim
39 words
A continuous process for the reduction of sulfur dioxide to sulfur, which comprises contacting a gas stream containing sulfur dioxide with a carbon source in a plasma arc reaction zone at a temperature of at least about 600° C.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said carbon source is concurrently introduced with said sulfur dioxide into said zone in the form of particulate coal.
Claim 4
Dependent Claim
26 words
The process of claim 2 wherein the molar ratio of said sulfur dioxide to the carbon equivalent of said coal is from about 0.5 to 2.0.
Claim 5
Dependent Claim
11 words
The process of claim 3 wherein said ratio is about 1.0.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein the concentration of said sulfur dioxide in said gas stream is at least about 5 volume percent.
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein said zone is generated by a rotating direct current arc.
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) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |