US3725210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing unreacted materials remaining in urea synthesis effluent by plural stage distillation and co2 stripping
Assignee: Mitsui Toatsu Chemicals Inc
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Filing: 1970-08-18
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Granted: 1973-04-03
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Expires: 1990-08-18
Abstract
Abstract UREA SYNTHESIS EFFLUENT FROM WHICH THE MAJOR PORTION OF UNREACTED CARBON DIOXIDE AND AMMONIA HAVE BEEN REMOVED, IS COMPLETELY STRIPPED OF THE REMAINING UNREACTED MATERIALS BY PASSING THE EFFLUENT THROUGH A COLUMN HAVING A RECTIFICATION ZONE MAINTAINED AT A GAUGE PRESSURE OF 0 TO 5 KG./CM.2 AND A HEAD TEMPERATURE OF 60* TO 120*C., A HEATING ZONE MAINTAINED AT 100* TO 140*C. AND A STRIPPING ZONE WHEREIN CARBON DIOXIDE IS INTRODUCED AT THE RATE OF 0.01 TO 092 MOL PER MOL OF UREA CONTAINED IN THE EFFLUENT, WHEREBY THE UNREACTED MATERIALS ARE COMPLETELY REMOVED FROM THE UREA SYNTHESIS EFFLUENT. D R A W I N G
Inventors
- 👤 E Otsuka
- 👤 K Kanai
- 👤 S Inoue
- 👤 N Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:35
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/14; C07C273/16
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |