US3922222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for treatment of urea crystallizer condensate
Assignee: CF Industries Inc
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Filing: 1973-02-20
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Granted: 1975-11-25
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Expires: 1993-02-20
Abstract
Abstract Condensate from a urea crystallizer is directed to a low pressure boiler or heat exchanger and evaporated to accomplish thermal decomposition of urea and any biuret contained therein into ammonia and carbon dioxide which are subsequently removed and recycled to the urea plant, if desired, leaving substantially urea free water of sufficient quality to satisfy environmental regulations or guidelines or for use as boiler feed water.
Inventors
- 👤 Moorsel William H Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:29
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/04; C02; C02F; C02F1/00; C02F1/02; C02F1/025; C02F1/04; C02F1/048; C02F2101/00; C02F2101/30; C02F2101/38
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A process for removing nonvolatile contaminants such as urea and biuret from urea plant condensate comprising a mixture of condensed water and very small amounts of urea on the order of about 0.1% of the condensate, said process comprising the steps of introducing said condensate into a low pressure boiler, heating said condensate of water and the urea under conditions of times, low temperatures and pressures which are sufficient to thermally decompose urea essentially completely and thereby decomposing the urea in said condensate into ammonia and carbon dioxide essentially completely vaporizing said condensate, and thereafter separating substantial portions of the ammonia and carbon dioxide from resultant vaporized water of said condensate, by condensing at least a major portion of the vaporized condensate, and stripping ammonia and carbon dioxide from the water in said major portion.
Claim 2
Dependent Claim
135 words
A process for removing nonvolatile contaminants such as urea and biuret from urea plant condensate comprising a mixture of condensed water and very small amounts of urea on the order of about 0.1% of the condensate, said process comprising the steps of introducing said condensate into a low pressure boiler, heating said condensate of water and the urea under conditions of times, low temperatures and pressures which are sufficient to thermally decompose urea essentially completely and thereby decomposing the urea in said condensate into ammonia and carbon dioxide essentially completely vaporizing said condensate, and thereafter separating substantial portions of the ammonia and carbon dioxide from resultant vaporized water of said condensate, by condensing at least a major portion of the vaporized condensate, and stripping ammonia and carbon dioxide from the water in said major portion.
Claim 3
Dependent Claim
19 words
A PROCESS, AS DEFINED IN CLAIM 1, WHICH INCLUDES RECYCLING THE AMMONIA AND CARBON DIOXIDE TO THE UREA PLANT.
Claim 4
Dependent Claim
26 words
A process, as defined in claim 1, which includes utilizing the water from which the ammonia and carbon dioxide has been separated as boiler feed water.
Claim 5
Dependent Claim
39 words
A process, as defined in claim 1, wherein resultant water from said stripping contains a relatively small amount of ammonia, said process comprising the further step of heating said resultant water and venting the ammonia therefrom to the atmosphere.
Claim 6
Dependent Claim
31 words
A process as defined in claim 1, wherein the pressure at which the condensate is heated and vaporized in order to decompose the urea is on the order of 10 p.s.i.a.
Claim 7
Dependent Claim
14 words
A process as defined in claim 5 wherein said pressure is about 8.4 p.s.i.a.
Claim 8
Dependent Claim
20 words
The process as defined in claim 6 wherein the heating and vaporizing of said condensate is conducted at about 185*F.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |