Patent US4316748A successfully refreshed from Google Patents.
US4316748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the acid hydrolysis of waste cellulose to glucose
Assignee: New York University
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Filing: 1980-03-18
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Granted: 1982-02-23
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Expires: 2000-03-18
Abstract
Abstract A process and apparatus for the acid hydrolysis of waste cellulose to glucose of the type wherein waste cellulose is continuously fed into an inlet port of a twin screw extruder, water is continuously fed into reaction zone in the extruder downstream of the inlet port, the cellulose is continuously reacted with water in the presence of an acid catalyst at elevated temperature and pressure in the reaction zone while continuously conveying same to an outlet port of the extruder and the reacted cellulose is discharged from the extruder the elevated temperature and pressure in the reaction zone is maintained, has the elevated pressure is maintained by forming a dynamic seal zone at the upstream end of the reaction zone by providing an unthreaded and radially recessed discontinuity in the screws.
Inventors
- 👤 Barry A. Rugg
- 👤 Robert Stanton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:23
CPC Classifications
C; C13; C13K; C13K1/00; C13K1/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
In a process for the acid hydrolysis of waste cellulose to glucose of the type wherein waste cellulose is continuously fed into an inlet port of a twin screw extruder, the cellulose is continuously reacted in the presence of a dilute sulfuric acid catalyst at elevated temperature and pressure in the reaction zone by the continuous injection of steam or superheated water at elevated pressure downstream of the inlet port while being continuously conveyed to an outlet port of the extruder while the extruder temperature and pressure in the reaction zone is maintained by forming a dynamic seal zone at the upstream end of the reaction zone and valving at the downstream end, the improvement wherein the step of forming a dynamic seal zone at the upstream end of the reaction zone comprises providing an unthreaded and radially recessed discontinuity in the screws.
Claim 2
Dependent Claim
143 words
In a process for the acid hydrolysis of waste cellulose to glucose of the type wherein waste cellulose is continuously fed into an inlet port of a twin screw extruder, the cellulose is continuously reacted in the presence of a dilute sulfuric acid catalyst at elevated temperature and pressure in the reaction zone by the continuous injection of steam or superheated water at elevated pressure downstream of the inlet port while being continuously conveyed to an outlet port of the extruder while the extruder temperature and pressure in the reaction zone is maintained by forming a dynamic seal zone at the upstream end of the reaction zone and valving at the downstream end, the improvement wherein the step of forming a dynamic seal zone at the upstream end of the reaction zone comprises providing an unthreaded and radially recessed discontinuity in the screws.
Claim 3
Dependent Claim
38 words
The process according to claim 1, wherein the discontinuity is formed by providing an unthreaded element in the dynamic seal zone having a smaller diameter than the remaining screw upstream thereof and downstream thereof in the reaction zone.
Claim 4
Dependent Claim
36 words
The process according to claim 1 or claim 2, wherein the step of valving further comprises continuously discharging the reacted material downstream of the outlet port in response to a selected pressure in the reaction zone.
Claim 5
Dependent Claim
27 words
The process according to claim 3, wherein the step of continuously feeding the cellulose waste material comprises continuously feeding a dry cellulose material into the inlet port.
Claim 6
Dependent Claim
17 words
The process according to claim 4, further comprising adding water just upstream of the dynamic seal zone.
Claim 7
Dependent Claim
20 words
The process according to claim 1, further comprising the step of pretreating the cellulose waste material by irradiation before feeding.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-22 | 1985-08-24 | 1986-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-22 | 1989-08-24 | 1990-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-22 | 1993-08-24 | 1994-02-23 | $7700.00 | Window Closed / Lapsed |