US4220635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic method for hydrolyzing urea
Assignee: FERTILIZER INDUSTRIES Inc
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Filing: 1979-05-14
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Granted: 1980-09-02
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Expires: 1999-05-14
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 a vanadium compound for sufficient time and at sufficient temperatures to effect hydrolysis of at least a portion of the urea to ammonia and carbon dioxide.
Inventors
- 👤 Lorenz P. Schell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:47
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/02; C02F1/025; C01; C01C; C01C1/00; C01C1/02; C01C1/08; C01C1/086
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
31 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 a vanadium compound.
Claim 2
Dependent Claim
31 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 a vanadium compound.
Claim 3
Dependent Claim
50 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 a vanadium compound 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
50 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 a vanadium compound 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
29 words
The process of claim 2 wherein the amount of said urea in said aqueous solution is from about 0.01 percent to 2 percent by weight of said aqueous solution.
Claim 7
Dependent Claim
34 words
The process of claim 2 wherein said catalytic amount of the vanadium compound is in the range of about 0.02 percent to about 1.0 percent by weight (expressed by vanadium) of said waste-water solution.
Claim 8
Dependent Claim
18 words
The process of claim 2 wherein said aqueous solution is the waste-water stream from a urea production process.
Claim 9
Dependent Claim
21 words
The process of claim 2 wherein said hydrolysis temperature is in the range from about 70° C. to about 200° C.
Claim 10
Dependent Claim
66 words
The process of claim 2 wherein the hydrolysis temperature is from about 90° C. to about 160° C. and the catalytic amount of the vanadium compound is from about 0.05 percent to 0.7 percent 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 percent to about 10 percent by weight of said stream.
Claim 11
Dependent Claim
13 words
The process of claim 2 wherein substantially all of said urea is hydrolyzed.
Claim 12
Dependent Claim
13 words
The process of claim 2 wherein the vanadium compound is sodium ortho vanadate.
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) | 1983-09-02 | 1984-03-03 | 1984-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-02 | 1988-03-03 | 1988-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-02 | 1992-03-03 | 1992-09-02 | $7700.00 | Window Closed / Lapsed |