US4168299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic method for hydrolyzing urea
Assignee: FERTILIZER INDUSTRIES Inc
•
Filing: 1978-03-20
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Granted: 1979-09-18
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Expires: 1998-03-20
Abstract
Abstract A method for hydrolyzing urea in aqueous solutions such as waste-water streams which comprises heating the aqueous solution containing urea in the presence of a catalytic amount of vanadium pentoxide for sufficient time and at sufficient temperatures to effect hydrolysis of substantially all of the urea to ammonia and carbon dioxide.
Inventors
- 👤 Lorenz P. Schell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:39
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/02; C02F1/025; C01; C01C; C01C1/00; C01C1/02; C01C1/08; C01C1/086; C01C1/10; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/908
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
33 words
In the process of hydrolyzing urea to carbon dioxide and ammonia, the improvement which comprises carrying out said urea hydrolysis in the presence of a catalytic amount of V 2 O 5 .
Claim 2
Dependent Claim
33 words
In the process of hydrolyzing urea to carbon dioxide and ammonia, the improvement which comprises carrying out said urea hydrolysis in the presence of a catalytic amount of V 2 O 5 .
Claim 3
Dependent Claim
51 words
A process for hydrolyzing urea contained in an aqueous solution which comprises heating said aqueous solution in the presence of a catalytic amount of V 2 O 5 for sufficient time and at sufficient temperatures to effect hydrolysis of at least a portion of said urea to ammonia and carbon dioxide.
Claim 4
Dependent Claim
51 words
A process for hydrolyzing urea contained in an aqueous solution which comprises heating said aqueous solution in the presence of a catalytic amount of V 2 O 5 for sufficient time and at sufficient temperatures to effect hydrolysis of at least a portion of said urea to ammonia and carbon dioxide.
Claim 5
Dependent Claim
15 words
The process of claim 2 wherein said ammonia is then separated from said aqueous solution.
Claim 6
Dependent Claim
27 words
The process of claim 2 wherein the amount of said urea in said aqueous solution is from about 0.01% to 20% by weight of said aqueous solution.
Claim 7
Dependent Claim
21 words
The process of claim 4 wherein said hydrolysis temperature is in the range from about 70° C. to about 200° C.
Claim 8
Dependent Claim
18 words
The process of claim 5 wherein said aqueous solution is the waste-water stream from a urea production process.
Claim 9
Dependent Claim
18 words
The process of claim 6 wherein said hydrolysis occurs within an ammonia desorber in a urea production process.
Claim 10
Dependent Claim
21 words
The process of claim 6 wherein said urea hydrolysis occurs in a carbon dioxide recovery system in an ammonia production process.
Claim 11
Dependent Claim
33 words
The process of claim 8 wherein said catalytic amount of V 2 O 5 is in the range of about 0.02% to about 1.0% by weight (expressed as vanadium) of said waste-water solution.
Claim 12
Dependent Claim
63 words
The process of claim 9 wherein the hydrolysis temperature is from about 90° C. to about 160° C. and the catalytic amount of V 2 O 5 is from about 0.05% to 0.5% by weight (expressed as vanadium) of said waste-water stream and the amount of urea in said waste-water stream is from about 0.5% to about 10% by weight of said stream.
Claim 13
Dependent Claim
13 words
The process of claim 2 wherein substantially all of said urea is hydrolyzed.
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) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |