GB949388A - Process for preparing melamine - Google Patents
Process for preparing melamineInfo
- Publication number
- GB949388A GB949388A GB35538/60A GB3553860A GB949388A GB 949388 A GB949388 A GB 949388A GB 35538/60 A GB35538/60 A GB 35538/60A GB 3553860 A GB3553860 A GB 3553860A GB 949388 A GB949388 A GB 949388A
- Authority
- GB
- United Kingdom
- Prior art keywords
- ammonia
- reactor
- carbon dioxide
- melamine
- stage
- 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
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/56—Preparation of melamine
- C07D251/60—Preparation of melamine from urea or from carbon dioxide and ammonia
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/56—Preparation of melamine
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
<PICT:0949388/C2/1> <PICT:0949388/C2/2> <PICT:0949388/C2/3> Melamine is prepared by heating urea in a first stage at from 250 to 500 DEG C. at a pressure above 10 atmospheres, followed by heating in the presence of ammonia and in the absence of gaseous carbon dioxide. The process may be continuous and the temperature and pressure conditions may be the same as the first stage, for example, from 340 to 400 DEG C. at a pressure from 40 to 150 atmospheres and both the carbon dioxide and ammonia may be removed after the first stage and further ammonia added, or the carbon dioxide alone may be removed and the residual melamine and ammonia heated in the second stage. Apparatus is described (Fig. 1) comprising a reactor A, in which melamine is formed from the urea, S a separator which removes the carbon dioxide and A2 a second reactor to which ammonia recovered from S or additional thereto is added; (Fig. 2) a reactor A1R, a separating cyclone SC, and a column C in which the product is countercurrent to ammonia and a second reactor A2 into the base of which ammonia is introduced; and (Fig. 3) in which the gaseous phase ammonia and carbon dioxide is separated and removed from the top of reactor A2 and in which ammonia is passed countercurrent to the down flowing liquid and the melamine is removed at M.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT1761859 | 1959-10-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB949388A true GB949388A (en) | 1964-02-12 |
Family
ID=11150511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB35538/60A Expired GB949388A (en) | 1959-10-22 | 1960-10-17 | Process for preparing melamine |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE596270A (en) |
| CH (1) | CH409982A (en) |
| ES (1) | ES261878A1 (en) |
| GB (1) | GB949388A (en) |
| SE (1) | SE300210B (en) |
-
1960
- 1960-10-17 GB GB35538/60A patent/GB949388A/en not_active Expired
- 1960-10-17 CH CH1159860A patent/CH409982A/en unknown
- 1960-10-21 ES ES0261878A patent/ES261878A1/en not_active Expired
- 1960-10-21 BE BE596270A patent/BE596270A/en unknown
- 1960-10-21 SE SE10073/60A patent/SE300210B/xx unknown
Also Published As
| Publication number | Publication date |
|---|---|
| SE300210B (en) | 1968-04-22 |
| BE596270A (en) | 1961-04-21 |
| ES261878A1 (en) | 1961-04-01 |
| CH409982A (en) | 1966-03-31 |
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