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GB953760A - Improvements in or relating to the preparation of melamine - Google Patents

Improvements in or relating to the preparation of melamine

Info

Publication number
GB953760A
GB953760A GB3388761A GB3388761A GB953760A GB 953760 A GB953760 A GB 953760A GB 3388761 A GB3388761 A GB 3388761A GB 3388761 A GB3388761 A GB 3388761A GB 953760 A GB953760 A GB 953760A
Authority
GB
United Kingdom
Prior art keywords
stage
melamine
ammonia
stages
catalyst
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
Application number
GB3388761A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Evonik Operations GmbH
Original Assignee
SKW Trostberg AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by SKW Trostberg AG filed Critical SKW Trostberg AG
Publication of GB953760A publication Critical patent/GB953760A/en
Expired legal-status Critical Current

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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Melamine is made by heating urea, and/or its pyrolysis products, at ordinary pressure in the presence of a catalyst, in a first stage at 200-400 DEG C., in a stream of ammonia which is insufficient to carry off the resultant melamine, although the NH3/CO2 mixture formed by the reaction is swept out of the reaction zone, and in a second stage at 250-400 DEG C., in a more intensive stream of ammonia, sufficient to discharge the melamine from the catalyst, the melamine being separated as a sublimate by cooling the gas. Preferably the ammonia flow rate in the second stage is from 50 to 150 times greater than that of the first stage. Examples are given illustrating the invention using alumina and silica gel as catalysts, and also comparative experiments in which the process is carried out in one stage; in two stages without ammonia in the first stage: and in two stages with nitrogen replacing ammonia in the first stage. Specifications 915,234 and 937,561 are referred to. Reference has been directed by the Comptroller to Specification 767,344.
GB3388761A 1960-09-27 1961-09-21 Improvements in or relating to the preparation of melamine Expired GB953760A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1960S0070574 DE1138785B (en) 1960-09-27 1960-09-27 Process for the production of melamine.

Publications (1)

Publication Number Publication Date
GB953760A true GB953760A (en) 1964-04-02

Family

ID=7501831

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3388761A Expired GB953760A (en) 1960-09-27 1961-09-21 Improvements in or relating to the preparation of melamine

Country Status (5)

Country Link
BE (1) BE607672A (en)
CH (1) CH417614A (en)
DE (1) DE1138785B (en)
FR (1) FR1298276A (en)
GB (1) GB953760A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1212545B (en) * 1964-04-20 1966-03-17 Basf Ag Process for the production of melamine from urea

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE944490C (en) * 1952-01-12 1956-06-14 Monsanto Chemicals Process for the production of melamine
GB718934A (en) * 1952-01-17 1954-11-24 American Cyanamid Co Improvements relating to the preparation of cyanamide and cyanamide polymers from urea

Also Published As

Publication number Publication date
BE607672A (en) 1961-12-18
DE1138785B (en) 1962-10-31
FR1298276A (en) 1962-07-13
CH417614A (en) 1966-07-31

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