GB795639A - A process for recovering amines from the residues in the production of aromatic isocyanates - Google Patents

A process for recovering amines from the residues in the production of aromatic isocyanates

Info

Publication number
GB795639A
GB795639A GB27646/56A GB2764656A GB795639A GB 795639 A GB795639 A GB 795639A GB 27646/56 A GB27646/56 A GB 27646/56A GB 2764656 A GB2764656 A GB 2764656A GB 795639 A GB795639 A GB 795639A
Authority
GB
United Kingdom
Prior art keywords
water
distillation residue
distillation
alkali
per cent
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
GB27646/56A
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.)
Bayer AG
Original Assignee
Bayer 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 Bayer AG filed Critical Bayer AG
Publication of GB795639A publication Critical patent/GB795639A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/82—Purification; Separation; Stabilisation; Use of additives
    • C07C209/84—Purification
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/82—Purification; Separation; Stabilisation; Use of additives
    • C07C209/86—Separation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C211/00—Compounds containing amino groups bound to a carbon skeleton
    • C07C211/43—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
    • C07C211/44—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton having amino groups bound to only one six-membered aromatic ring
    • C07C211/49—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton having amino groups bound to only one six-membered aromatic ring having at least two amino groups bound to the carbon skeleton
    • C07C211/50—Compounds containing amino groups bound to a carbon skeleton having amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton having amino groups bound to only one six-membered aromatic ring having at least two amino groups bound to the carbon skeleton with at least two amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Aromatic amines are recovered from the distillation residue obtained in the production of aromatic isocyanates by phosgenation of aromatic amines, by heating the distillation residue with water at 160 DEG -250 DEG C. The distillation residue is preferably mixed with the same amount by weight of water and heated for about two to four hours under sufficient pressure to keep at least part of the water used in a liquid state. Preferably up to 1 per cent of an alkali, e.g. calcium oxide, sodium hydroxide or other alkali or alkaline earth metal hydroxides or carbonates, are added to the distillation residue-water mixture. The resultant aqueous reaction material may be salted out while still warm with e.g. caustic soda solution, sodium chloride or sodium sulphate. The amine may then be removed by siphoning or filtering. Separation may also be effected by extraction with organic solvents preferably hydrocarbon mixtures or chlorinated hydrocarbon mixtures. The cyclic ureas remaining in the residue may be worked up by heating with concentrated alkaline solutions to form the corresponding ortho-diamines. The aromatic amines may also be isolated by venting the gas from the pressure vessel whilst the latter is hot thereby removing a large amount of the water present. The amine may then be obtained by direct distillation. The distillation residue may also be mixed with 15-25 per cent of water of and up to 1 per cent by weight of alkali to obtain a suspension. This mixture is then heated and the reaction mixture so obtained may be worked up by direct distillation. Examples are given illustrating the recovery of 2,4-toluylene diamine, 2,6-toluylene diamine and aniline, after the phosgenation process.
GB27646/56A 1955-09-09 1956-09-10 A process for recovering amines from the residues in the production of aromatic isocyanates Expired GB795639A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE795639X 1955-09-09

Publications (1)

Publication Number Publication Date
GB795639A true GB795639A (en) 1958-05-28

Family

ID=6710778

Family Applications (1)

Application Number Title Priority Date Filing Date
GB27646/56A Expired GB795639A (en) 1955-09-09 1956-09-10 A process for recovering amines from the residues in the production of aromatic isocyanates

Country Status (1)

Country Link
GB (1) GB795639A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3128310A (en) * 1955-09-09 1964-04-07 Bayer Ag Recovery of amines
US3225094A (en) * 1962-06-15 1965-12-21 Du Pont Preparation of polyamines by steam hydrolysis of polyisocyanate reaction products
US3246035A (en) * 1962-11-28 1966-04-12 Fmc Corp Preparation of non-vicinal aromatic diamines
US3314996A (en) * 1963-05-21 1967-04-18 Lummus Co Process for separating vicinal and non-vicinal toluene diamines
US3331876A (en) * 1964-03-23 1967-07-18 Mobay Chemical Corp Recovery of tolylenediamines
US4319046A (en) * 1977-07-22 1982-03-09 The Sherwin-Williams Company Preparation of 1,2 diaminobenzene by high pressure acid hydrolysis of benzemidazolone
US8063241B2 (en) 2006-12-18 2011-11-22 Bayer Materialscience Ag Process for the preparation of toluene-diisocyanate
WO2014009342A1 (en) 2012-07-11 2014-01-16 Bayer Materialscience Ag Method for working up distillation residues from isocyanate production
US9688619B2 (en) 2013-08-19 2017-06-27 Covestro Deutschland Ag Process for obtaining organic isocyanates from distillation residues from isocyanate preparation
WO2018114846A1 (en) 2016-12-21 2018-06-28 Covestro Deutschland Ag Process for preparing an isocyanate
CN111183131A (en) * 2017-12-27 2020-05-19 旭化成株式会社 Method for recovering organic amine
EP3960728A1 (en) 2020-08-24 2022-03-02 Covestro Deutschland AG Method for producing isocyanate with thermal oxidative recycling

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3128310A (en) * 1955-09-09 1964-04-07 Bayer Ag Recovery of amines
US3225094A (en) * 1962-06-15 1965-12-21 Du Pont Preparation of polyamines by steam hydrolysis of polyisocyanate reaction products
US3246035A (en) * 1962-11-28 1966-04-12 Fmc Corp Preparation of non-vicinal aromatic diamines
US3314996A (en) * 1963-05-21 1967-04-18 Lummus Co Process for separating vicinal and non-vicinal toluene diamines
US3317606A (en) * 1963-05-21 1967-05-02 Lummus Co Process for separating vicinal and nonvicinal toluene diamines
US3331876A (en) * 1964-03-23 1967-07-18 Mobay Chemical Corp Recovery of tolylenediamines
US4319046A (en) * 1977-07-22 1982-03-09 The Sherwin-Williams Company Preparation of 1,2 diaminobenzene by high pressure acid hydrolysis of benzemidazolone
US8063241B2 (en) 2006-12-18 2011-11-22 Bayer Materialscience Ag Process for the preparation of toluene-diisocyanate
WO2014009342A1 (en) 2012-07-11 2014-01-16 Bayer Materialscience Ag Method for working up distillation residues from isocyanate production
US9688619B2 (en) 2013-08-19 2017-06-27 Covestro Deutschland Ag Process for obtaining organic isocyanates from distillation residues from isocyanate preparation
WO2018114846A1 (en) 2016-12-21 2018-06-28 Covestro Deutschland Ag Process for preparing an isocyanate
US10703713B2 (en) 2016-12-21 2020-07-07 Covestro Deutschland Ag Process for preparing an isocyanate
CN111183131A (en) * 2017-12-27 2020-05-19 旭化成株式会社 Method for recovering organic amine
CN111183131B (en) * 2017-12-27 2022-06-28 旭化成株式会社 Method for recovering organic amine
US11578030B2 (en) 2017-12-27 2023-02-14 Asahi Kasei Kabushiki Kaisha Organic amine collection method
EP3960728A1 (en) 2020-08-24 2022-03-02 Covestro Deutschland AG Method for producing isocyanate with thermal oxidative recycling
WO2022043291A1 (en) 2020-08-24 2022-03-03 Covestro Deutschland Ag Process for preparing isocyanate and recycling, thermal oxidative recovery

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