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US4336102A
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Method for recovery and reuse of ammonia in ammonia-base sulfite cooking liquors
Assignee: Alstom Power Inc
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Filing: 1980-10-06
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Granted: 1982-06-22
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Expires: 2000-10-06
Abstract
Abstract A method for recovering ammonia from spent ammonia-base sulfite pulping liquor includes steam stripping spent ammonia and condensing the resulting vapor to produce a dilute ammonia or ammonium hydroxide solution. This dilute solution is passed through a cation exchange column to produce an ammonium sulfite-ammonium bisulfite solution which is delivered to a sulfur dioxide absorption tower to thereby produce a concentrated ammonia-base sulfite cooking liquor. The residual liquor from the stripping step and the non-condensable gases are burned as fuel and the waste gases from this burning, which contain a small percentage of sulfur dioxide, are delivered to the absorption tower and subsequently discharged to the atmosphere free of sulfur dioxide and ammonia.
Inventors
- 👤 Lawrence J. Jacobs
- 👤 Carl R. Bozzuto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:45
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/06; D21C11/02; Y; Y10; Y10S; Y10S210/00; Y10S210/928; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
A process for the recovery and reuse of ammonia in ammonia-base sulfite cooking liquors comprising the steps of: steam stripping spent ammonia-base sulfite cooking liquor to produce a vapor and a liquor residue; condensing the vapor formed during the steam stripping to form a dilute aqueous solution comprising ammonia or ammonium hydroxide in water; burning the liquor residue produced during steam stripping and non-condensed gases from the condensing step to produce an exhaust gas containing sulfur dioxide; passing the dilute aqueous solution produced during the condensing step through a cation exchange column charged with sulphurous acid to thereby form an ammonium sulfite containing solution; delivering the exhaust gases produced during the step of burning and the ammonium sulfite containing solution to a fortifying tower; and fortifying the ammonium sulfite containing solution with sulfur dioxide from the exhaust gases of the burning step to produce an ammonia-based sulfite cooking liquor concentrate.
Claim 2
Dependent Claim
150 words
A process for the recovery and reuse of ammonia in ammonia-base sulfite cooking liquors comprising the steps of: steam stripping spent ammonia-base sulfite cooking liquor to produce a vapor and a liquor residue; condensing the vapor formed during the steam stripping to form a dilute aqueous solution comprising ammonia or ammonium hydroxide in water; burning the liquor residue produced during steam stripping and non-condensed gases from the condensing step to produce an exhaust gas containing sulfur dioxide; passing the dilute aqueous solution produced during the condensing step through a cation exchange column charged with sulphurous acid to thereby form an ammonium sulfite containing solution; delivering the exhaust gases produced during the step of burning and the ammonium sulfite containing solution to a fortifying tower; and fortifying the ammonium sulfite containing solution with sulfur dioxide from the exhaust gases of the burning step to produce an ammonia-based sulfite cooking liquor concentrate.
Claim 3
Dependent Claim
14 words
The process of claim 1 further comprising: delivering make-up ammonia to the fortifying tower.
Claim 4
Dependent Claim
27 words
The process of claim 2 further comprising: burning a sulfur containing material to produce additional sulfur dioxide; and delivering the additional sulfur dioxide to the fortifying tower.
Claim 5
Dependent Claim
27 words
The process of claim 1 further comprising: burning a sulfur containing material to produce additional sulfur dioxide; and delivering the additional sulfur dioxide to the fortifying tower.
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) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |