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US4182780A
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Process and an apparatus for alkali-treatment of lignocellulosic material
Assignee: Boliden AB
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Filing: 1977-05-10
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Granted: 1980-01-08
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Expires: 1997-05-10
Abstract
Abstract A process for increasing the feed value of lignocellulosic materials by alkali-treatment and subsequent neutralization with an acid in a closed system under circulation of the treating agents. Said treating agents are supplied or prepared during the course of the treatment at a rate essentially corresponding to the liquid uptake of the lignocellulosic material, the quantities of residual solutions resulting from the treatment being kept at a minimum. Moreover, an apparatus for carrying such process into effect.
Inventors
- 👤 Gosta B. Lagerstrom
- 👤 Nils-Inge Nilsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:27
CPC Classifications
A; A23; A23K; A23K10/00; A23K10/30; A23K10/32; Y; Y10; Y10S; Y10S426/00; Y10S426/807
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
87 words
A process for increasing the feed value of lignocellulosic materials by alkali-treatment and subsequent neutralization with an acid in a closed system under circulation of the treating agents, which comprises sprinkling concentrated alkali onto a mass of the material followed by sprinkling water for dilution-absorption onto the mass at a rate essentially corresponding to the absorption of treating agent by the lignocellulosic material and supplying the acid for neutralization in the form of a concentrate, whereby the quantity of residual solution resulting from the treatment is minimized.
Claim 2
Dependent Claim
87 words
A process for increasing the feed value of lignocellulosic materials by alkali-treatment and subsequent neutralization with an acid in a closed system under circulation of the treating agents, which comprises sprinkling concentrated alkali onto a mass of the material followed by sprinkling water for dilution-absorption onto the mass at a rate essentially corresponding to the absorption of treating agent by the lignocellulosic material and supplying the acid for neutralization in the form of a concentrate, whereby the quantity of residual solution resulting from the treatment is minimized.
Claim 3
Dependent Claim
36 words
A process according to claim 1, comprising collecting liquid drained from the ligno-cellulosic material at a level below the ligno-cellulosic material, the level of the collected liquid being maintained essentially constant by controlled supply of liquid.
References Cited (Backward Citations)
US4048341A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |