GB838757A - Improvements in or relating to the preparation of urea - Google Patents
Improvements in or relating to the preparation of ureaInfo
- Publication number
- GB838757A GB838757A GB15843/58A GB1584358A GB838757A GB 838757 A GB838757 A GB 838757A GB 15843/58 A GB15843/58 A GB 15843/58A GB 1584358 A GB1584358 A GB 1584358A GB 838757 A GB838757 A GB 838757A
- Authority
- GB
- United Kingdom
- Prior art keywords
- column
- urea
- ammonia
- liquid
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
- C07C273/04—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds from carbon dioxide and ammonia
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A solution of ammonium carbamate (containing carbonate) is obtained in a process for the production of urea by heating under pressure in an autoclave carbon dioxide and a stoichiometric excess of liquid ammonia to form a melt containing urea, water, ammonium carbamate and free ammonia, in which process the melt is introduced into the top of the first of two rectifying columns and expanded to a pressure of 12-30 atm., the liquid in the bottom of this column being heated to 110-150 DEG C. and continuously discharged and the gases issuing from this column are washed with liquid ammonia in a second rectifying column from which the purified gaseous ammonia issues at the top while the liquid in the bottom of this second column is heated to 75-105 DEG C. and continuously discharged as a crystal-free ammonium carbamate solution. Water or an aqueous solution of ammonia or urea may also be introduced into the top of the second column. Specifications 753,386, 756,934 and 758,670 are referred to.ALSO:In the process for the production of urea by heating under pressure in an autoclave carbon dioxide and a stoichiometric excess of ammonia to form a melt containing urea, water, ammonium, carbamate and free ammonia, the melt is introduced into the top of the first of two rectifying columns and expanded to a pressure of 12-30 atm., the liquid in the bottom of this column being heated to 110-150 DEG C. and continuously discharged and the gases issuing from this column are washed with liquid ammonia in a second rectifying column from which the purified gaseous ammonia issues at the top while the liquid in the bottom of this second column is heated to 75-105 DEG C. and continuously discharged as a crystal-free carbamate solution. Water, or an aqueous solution of ammonia or urea may also be introduced into the top of the second column. Such a urea solution may contain biuret which is reconverted to urea provided the carbamate-urea solution discharged from the base of the column is returned to the synthesis autoclave. The carbamate solution is preferably returned to the autoclave separately from the liquefied top product (NH3) of the second column. Specifications 753,386, 756,934 and 758,670 are referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL838757X | 1957-05-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB838757A true GB838757A (en) | 1960-06-22 |
Family
ID=19843239
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB15843/58A Expired GB838757A (en) | 1957-05-18 | 1958-05-16 | Improvements in or relating to the preparation of urea |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB838757A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6978272B1 (en) * | 1999-11-29 | 2005-12-20 | Ncr Corporation | Method and apparatus for displaying instrumentation parameters in a database system |
-
1958
- 1958-05-16 GB GB15843/58A patent/GB838757A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6978272B1 (en) * | 1999-11-29 | 2005-12-20 | Ncr Corporation | Method and apparatus for displaying instrumentation parameters in a database system |
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