US3764464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing cellulose pulp by alkaline oxygen digestion of wood in the presence of alkali metal carbonate or bicarbonate
Assignee: Mo och Domsjo AB
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Filing: 1971-06-18
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Granted: 1973-10-09
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Expires: 1991-06-18
Abstract
Abstract CELLULOSE PLUP IS PREPARED FROM WOOD BY ALKALINE OXYGEN DIGESTION IN THE PRESENCE OF ALKALI METAL CARBONATE OR BICARBONATE. A GAS PHASE INCLUDING UNREACTED OXYGEN GAS AND CARBON DIOXIDE IS FORMED DURING THE DIGESTION, AND THE CARBON DIOXIDE IS SEPARATED FROM THE GAS PHASE BY ABSORPTION WHILE OXYGEN GAS FROM WHICH THE CARBON DIOXIDE HAS BEEN SEPARATED IS RECYCLED FOR SUBSEQUENT DIGESTION OF WOOD.
Inventors
- 👤 H Samuelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:38
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |