US5135729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lignosulfonate-modified calcium hydroxide for SO2 control during furnace injection
Assignee: Environmental Protection Agency
•
Filing: 1990-04-03
•
Granted: 1992-08-04
•
Expires: 2010-04-03
Abstract
Abstract A method is provided for removing sulphur-containing gases from fossil fuel-fired combustors comprising the step of introducing sorbent particles modified with lignosulfonates into the exhaust gases.
Inventors
- 👤 David A. Kirchgessner
- 👤 Jeffrey M. Lorrain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:52
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/508; B01J; B01J20/00; B01J20/02; B01J20/04; B01J20/041; B01J20/22; B01J20/24; B01J20/30; B01J20/3078; B01J2220/00; B01J2220/40; B01J2220/48; B01J2220/4812; B01J2220/4825; B01J2220/4831
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A method for removing sulphur-containing gases from exhaust gases of a fossil fuel-fired combustor comprising the steps of introducing into said exhaust gases at a temperature in the range of about 65° to 1315° C. sorbent particles capable of reacting with said sulphur containing gases, said particles comprising a surface-modified sorbent selected from the group consisting of alkali metal lignosulfonate-modified calcium hydroxide and alkali metal lignosulfonate-modified calcium magnesium hydroxide, wherein said alkali metal lignosulfonate comprises up to 5% by weight of the total dry weight of said surface-modified sorbent.
Claim 2
Independent Claim
89 words
A method for removing sulphur-containing gases from exhaust gases of a fossil fuel-fired combustor comprising the steps of introducing into said exhaust gases at a temperature in the range of about 65° to 1315° C. sorbent particles capable of reacting with said sulphur containing gases, said particles comprising a surface-modified sorbent selected from the group consisting of alkali metal lignosulfonate-modified calcium hydroxide and alkali metal lignosulfonate-modified calcium magnesium hydroxide, wherein said alkali metal lignosulfonate comprises up to 5% by weight of the total dry weight of said surface-modified sorbent.
Claim 3
Dependent Claim
18 words
The method according to claim 1 wherein said sorbent comprises calcium hydroxide and said surfactant comprises calcium lignosulfonate.
Claim 4
Dependent Claim
16 words
A method according to claim 2 wherein said particles comprise from 0.5 to 2% calcium lignosulfonate.
Claim 5
Dependent Claim
25 words
A method according to claim 3 wherein the particle size distribution of said particles is finer than the distribution of a corresponding non-surfactant modified sorbent.
References Cited (Backward Citations)
US4786485A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |