GB851863A - Improvements in the manufacture of melamine - Google Patents

Improvements in the manufacture of melamine

Info

Publication number
GB851863A
GB851863A GB10864/57A GB1086457A GB851863A GB 851863 A GB851863 A GB 851863A GB 10864/57 A GB10864/57 A GB 10864/57A GB 1086457 A GB1086457 A GB 1086457A GB 851863 A GB851863 A GB 851863A
Authority
GB
United Kingdom
Prior art keywords
flow
temperature
melamine
ammonia
continuously
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
GB10864/57A
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.)
Wyeth Holdings LLC
Original Assignee
American Cyanamid Co
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 American Cyanamid Co filed Critical American Cyanamid Co
Publication of GB851863A publication Critical patent/GB851863A/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
    • 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
    • B01J10/00—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor
    • 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
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/0053—Details of the reactor
    • B01J19/006—Baffles
    • 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
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • 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
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/18—Details relating to the spatial orientation of the reactor
    • B01J2219/182—Details relating to the spatial orientation of the reactor horizontal
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/19—Details relating to the geometry of the reactor
    • B01J2219/194—Details relating to the geometry of the reactor round
    • B01J2219/1941—Details relating to the geometry of the reactor round circular or disk-shaped
    • B01J2219/1943—Details relating to the geometry of the reactor round circular or disk-shaped cylindrical

Abstract

Melamine is continuously prepared from urea or its thermal decomposition products in the presence of minimal quantities of ammonia by providing a continuously flowing stream comprising ammonia gas at a temperature above 425 DEG C. under a pressure of at least 750 p.s.i.; preheating as feed material urea or it's thermal decomposition products to a temperature above its melting point but below its decomposition point; continuously introducing a flow of preheated molten feed into the heated pressurised ammonia stream under a pressure of at least 750 p.s.i.; controlling the rates of flow of feed and gas such that the combined flows have a temperature of from at least 425 DEG C. to 550 DEG C., thereby forming a mixture comprising melamine and ammonia vapours; thereafter introducing at least one additional flow of preheated molten feed into said combined flow; controlling the temperature of said combined flow and the rate and temperature of each said additional flow such that a temperature of 425-550 DEG C. is maintained at all times; adjusting the rate and number of said additional flows such that the rate of said combined flow is sufficient to retain the reaction products in suspension; continuously withdrawing ammonia gas and melamine, and recovering melamine therefrom. Specified starting materials, other than urea, are biuret, triuret, cyanic acid and ammonium cyanate.
GB10864/57A 1956-04-25 1957-04-03 Improvements in the manufacture of melamine Expired GB851863A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US851863XA 1956-04-25 1956-04-25

Publications (1)

Publication Number Publication Date
GB851863A true GB851863A (en) 1960-10-19

Family

ID=22190000

Family Applications (1)

Application Number Title Priority Date Filing Date
GB10864/57A Expired GB851863A (en) 1956-04-25 1957-04-03 Improvements in the manufacture of melamine

Country Status (1)

Country Link
GB (1) GB851863A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11213978B2 (en) * 2015-03-04 2022-01-04 Safedon Limited Stripping of a dip-moulded glove from a former

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11213978B2 (en) * 2015-03-04 2022-01-04 Safedon Limited Stripping of a dip-moulded glove from a former

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