ES238770A1 - Method for producing melamine - Google Patents
Method for producing melamineInfo
- Publication number
- ES238770A1 ES238770A1 ES0238770A ES238770A ES238770A1 ES 238770 A1 ES238770 A1 ES 238770A1 ES 0238770 A ES0238770 A ES 0238770A ES 238770 A ES238770 A ES 238770A ES 238770 A1 ES238770 A1 ES 238770A1
- Authority
- ES
- Spain
- Prior art keywords
- reaction
- pressure
- temperature
- melamine
- product
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
- B01J3/04—Pressure vessels, e.g. autoclaves
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Melamine is produced by reacting dicyandiamide, previously heated to between 100 DEG C. and its melting point, with gaseous ammonia under pressure, the pressure of ammonia being maintained throughout the reaction so as to be at least 50 kg./sq. cm. at the end of the reaction, this pressure being maintained during the cooling of the reaction product as long as its temperature is higher than about 250 DEG C. Preferably the pressure is maintained so as to reach about 80 kg./sq. cm. when the temperature of the melamine reaches 350 DEG C. It is advantageous for the dicyandiamide and the reaction vessel to be pre-heated as uniformly as possible, so that no point of the reaction mixture is at a temperature lower than the condensation temperature of ammonia under the operating pressure. It is also desirable that the size of the reaction vessel be such that the heat of reaction is dispersed without raising the temperature of the melamine substantially above 350 DEG C. Auxiliary compression means may be employed for attaining the final pressure of 50 kg./sq. cm. The reaction may be effected intermittently, e.g. inside a digester which may be enclosed in a container, the cooling being carried out in the digester, or continuously, e.g. by passing pre-heated dicyandiamide and gaseous ammonia into a first closed chamber, transferring the product in a liquid state into a second closed chamber, and feeding the product continuously or periodically into a third closed chamber where it is cooled. If desired, the final melamine product may be purified by recrystallization from hot water. The process is described with reference to drawings (not shown) illustrating the batchwise and continuous procedures.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR726577 | 1956-11-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
ES238770A1 true ES238770A1 (en) | 1958-05-16 |
Family
ID=8703974
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
ES0238770A Expired ES238770A1 (en) | 1956-11-28 | 1957-11-26 | Method for producing melamine |
Country Status (7)
Country | Link |
---|---|
BE (1) | BE562273A (en) |
CH (1) | CH362414A (en) |
DE (1) | DE1108701B (en) |
ES (1) | ES238770A1 (en) |
FR (1) | FR1161863A (en) |
GB (1) | GB814934A (en) |
IT (1) | IT581068A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3117969A (en) * | 1964-01-14 | Iwao arai | ||
US3254081A (en) * | 1966-05-31 | Production op melamine from dicyandiamide |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE752869C (en) * | 1938-01-30 | 1952-11-10 | Ig Farbenindustrie Ag | Process for the production of 2, 4, 6-triamino-1, 3, 5-triazine (melamine) |
DE943354C (en) * | 1941-07-29 | 1956-05-17 | Cassella Farbwerke Mainkur Ag | Process for the production of melamine |
-
0
- BE BE562273D patent/BE562273A/xx unknown
- IT IT581068D patent/IT581068A/it unknown
-
1956
- 1956-11-28 FR FR1161863D patent/FR1161863A/en not_active Expired
-
1957
- 1957-11-11 CH CH5253257A patent/CH362414A/en unknown
- 1957-11-12 GB GB3528057A patent/GB814934A/en not_active Expired
- 1957-11-26 ES ES0238770A patent/ES238770A1/en not_active Expired
- 1957-11-27 DE DES56036A patent/DE1108701B/en active Pending
Also Published As
Publication number | Publication date |
---|---|
BE562273A (en) | |
FR1161863A (en) | 1958-09-05 |
GB814934A (en) | 1959-06-17 |
CH362414A (en) | 1962-06-15 |
DE1108701B (en) | 1961-06-15 |
IT581068A (en) |
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