WO2009127591A2 - Verfahren zur aufarbeitung von rückständen aus der produktion von isocyanaten - Google Patents
Verfahren zur aufarbeitung von rückständen aus der produktion von isocyanaten Download PDFInfo
- Publication number
- WO2009127591A2 WO2009127591A2 PCT/EP2009/054287 EP2009054287W WO2009127591A2 WO 2009127591 A2 WO2009127591 A2 WO 2009127591A2 EP 2009054287 W EP2009054287 W EP 2009054287W WO 2009127591 A2 WO2009127591 A2 WO 2009127591A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- amine
- water
- residues
- bases
- production
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C263/00—Preparation of derivatives of isocyanic acid
- C07C263/10—Preparation of derivatives of isocyanic acid by reaction of amines with carbonyl halides, e.g. with phosgene
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/62—Preparation of compounds containing amino groups bound to a carbon skeleton by cleaving carbon-to-nitrogen, sulfur-to-nitrogen, or phosphorus-to-nitrogen bonds, e.g. hydrolysis of amides, N-dealkylation of amines or quaternary ammonium compounds
-
- 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
Definitions
- the invention relates to a process for the workup of isocyanate adducts, such as polyurethanes, residues from isocyanate production, in particular distillation residues from the production of tolylene diisocyanate (TDI) or hexamethylene isocyanate (HDI).
- isocyanate adducts such as polyurethanes
- residues from isocyanate production in particular distillation residues from the production of tolylene diisocyanate (TDI) or hexamethylene isocyanate (HDI).
- Isocyanate adducts fall in the art in large quantities as waste.
- Examples are polyurethane foams, here for example production waste or foams from decommissioned equipment, motor vehicles or furniture.
- isocyanate adducts are production wastes, in particular distillation residues, from the production of polyisocyanates, especially of tolylene diisocyanate (TDI) or hexamethylene isocyanate (HDI).
- TDI tolylene diisocyanate
- HDI hexamethylene isocyanate
- TDI is used in large quantities for the production of polyurethanes, in particular flexible polyurethane foams.
- the preparation of TDI is usually carried out by reacting toluenediamine (TDA) with phosgene. This method has long been known and widely described in the literature.
- the TDA is reacted with phosgene in a conventional two-stage phosgenation.
- the residue may contain up to 70%, preferably up to 50%, particularly preferably up to 30% TDI.
- the residue may contain up to 70%, preferably up to 50%, particularly preferably up to 30% TDI.
- a frequently practiced possibility to recover at least part of the TDI contained in the distillation residue consists in the further removal of the TDI from the residue, for example by means of an extruder.
- Suitable apparatuses are, for example, the so-called list dryers. These are special paddle dryers from List, which are frequently used in isocyanate production.
- the amount of TDI in the distillation residue can be significantly lowered.
- hydrolysis One such possibility of recovery is the reaction of the residue with water, the so-called hydrolysis. Such methods are described many times. The hydrolysis of the residue is favored by bases or acids. Amines also favor hydrolysis. The hydrolysis can be used to denature the TDI distillation residue, as described, for example, in US-A 4 091 009. Another possibility is the recovery of TDA, which can then be converted again with phosgene to TDI. Such methods are described for example in DE-A 29 42 678, JP-A 5 8201 751 and DE-A 19 62 598.
- DE-A 27 03 313 describes a hydrolysis process which can be carried out both batchwise in an autoclave and continuously in a tubular reactor.
- the hydrolysis of the solid TDI residue is carried out with aqueous ammonia solution, solutions of primary or secondary amines in water or aqueous TDA solution.
- WO 2006/134137 describes a process for working up isocyanate residues, in which monomeric isocyanate is first separated off from the residue in a cunning dryer and the residue obtained is treated with ammonia; in this process, too, there is no complete recovery of the valuable substances ammonia is difficult to handle.
- the object could be achieved by first adding the residue to a hydrolysis and then the reaction product of the hydrolysis a mixer with heat transfer surface, preferably an extruder or kneader is supplied.
- the invention accordingly provides a process for working up residues from the production of isocyanates, comprising the steps
- step b) feeding the reaction product from step a) into a mixer with heat transfer surface, preferably a kneader or an extruder,
- step b) By separating a part of the products from the reaction mixture, the amount of the product treated in step b) can be reduced, thereby making it possible to make the reaction apparatuses used in step b) smaller.
- the amount of separated amine and / or water should only be so great that the mixture remains pumpable and can be easily transported by the apparatus used in step b). Typically, therefore, the viscosity of the mixture should be below 500 mPas.
- step a), step b) or both steps can be carried out in the presence of a base.
- This base is different from the amine which is the target product of the process of the invention.
- the base in step a) should have a base strength which is greater than that of the amine which is the target product of the process according to the invention.
- the base strength of the base used in step b) should also be greater than that of the amine which is the target product of the process according to the invention. If a base has already been used in step a) in this embodiment of the process according to the invention, the base strength of the base used in step b) should be greater than that of all bases used in step a).
- the bases used in steps a) and b) may be basic oxides or hydroxides of metals. Preferably, it is oxides or hydroxides of alkali and / or alkaline earth metals, especially hydroxides of alkali and / or alkaline earth metals. Particularly preferably, potassium or sodium hydroxide are used as solid or concentrated alkalis.
- nitrogen-containing compounds are used as bases. These are preferably selected from the group containing primary, secondary or tertiary amines, ammonia, and heterocyclic nitrogen compounds, such as imidazoles.
- the base can be added in both steps before or during the reaction.
- mixtures of distillation bottoms from an amine production are used as base, alone or in combination with further of the abovementioned bases, amine-containing mixtures.
- amine-containing mixtures are preferably residues from the production of the amines which are used for the preparation of the isocyanates from which the residues used in step a) are derived.
- These amine residues are obtained in particular during the distillative workup of the amines, as described, for example, in EP 1 706 370. But other amine-containing streams are possible.
- the amine residues are preferably used in conjunction with other bases. If the basicity of the amine residues is lower than that of the amine formed on hydrolysis, a stronger base, preferably from the above-mentioned group, is present.
- the process is preferably designed so that the strongest base is used last and organic base before the alkaline base.
- the hydrolysis can be carried out both continuously and discontinuously. The decision on this depends above all on the amount of residues produced in the particular isocyanate production.
- the reaction of the isocyanate adducts with water is preferably carried out at a temperature in the range between 100 and 500 ° C., preferably 100 to 400 ° C., more preferably 100 to 250 ° C. and a pressure in the range between 20 and 500 bar, preferably 30 to 400 bar and particularly preferably 30 and 380 bar performed.
- the water must be at least equimolar with respect to the bond to be cleaved. It is preferably used in an at least 10% molar excess. Since the composition of the residues is highly dependent on the reaction conditions in the production process and can not be determined analytically, the quantity of the water in the following is in wt .-%. Preferably, the water content of the starting components of the process according to the invention in the range of 10 wt .-% up to 90 wt .-%, preferably 30 to 70 wt .-%, based on the reaction mixture of the hydrolysis.
- reaction product of step a) is usually taken from the reactor continuously and worked up. In the preferred solvent-free process, the reaction product is single-phase when fully reacted.
- the reaction can be carried out in tubular reactors, in boilers or in stirred tank cascades.
- the residence time is preferably between 30 seconds and 7 hours, preferably between 10 minutes and 5 hours.
- step a The reaction product from step a), optionally after the above-described separation of water and amine, in the mixer with heat transfer surface, preferably a kneader or extruder of step b) transferred. There, the residue is further reduced.
- Single-screw, twin-screw, ring, multi-shaft or planetary roller extruders, single-shaft or twin-screw kneaders or paddle dryers can be used as extruders or kneaders.
- One or two-shaft kneaders such as those manufactured by List and Buss-SMS, are suitable. Also suitable are compounding extruders from Coperion.
- the reaction with the base in the mixer with heat transfer surface is carried out at 20 to 900 mbar in vacuo and at 100 to 250 0 C.
- the reaction is carried out at 20 to 10 mM and 150 to 245 ° C.
- the residence time of the product is 10 minutes to 5 hours.
- the amine and, if still present, the water is separated off. This can be done for example by distillation.
- the separated amine or amine / water mixture can, if necessary, be sent to a further workup. This includes, for example, the separation of the remaining water and other volatile constituents. This is preferably done by distillation.
- the worked-up amine can be used again in the process for the preparation of isocyanates.
- the residue remaining after the separation of amine and water is discharged and can be landfilled or incinerated.
- the residues from the production of isocyanates in particular toluene diisocyanate (TDI) and hexamethylene diisocyanate (MDI) can be worked up.
- TDI toluene diisocyanate
- MDI hexamethylene diisocyanate
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Processing Of Solid Wastes (AREA)
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09731507A EP2280939A2 (de) | 2008-04-14 | 2009-04-09 | Verfahren zur aufarbeitung von rückständen aus der produktion von isocyanaten |
CN2009801130372A CN102007096A (zh) | 2008-04-14 | 2009-04-09 | 来自异氰酸酯生产的残留物的后处理方法 |
JP2011504429A JP2011516593A (ja) | 2008-04-14 | 2009-04-09 | イソシアネートの製造で生じる残渣を処理する方法 |
US12/936,080 US8440856B2 (en) | 2008-04-14 | 2009-04-09 | Method for treating residues from the production of isocyanates |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP08154471 | 2008-04-14 | ||
EP08154471.0 | 2008-04-14 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2009127591A2 true WO2009127591A2 (de) | 2009-10-22 |
WO2009127591A3 WO2009127591A3 (de) | 2009-12-17 |
Family
ID=40904127
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2009/054287 WO2009127591A2 (de) | 2008-04-14 | 2009-04-09 | Verfahren zur aufarbeitung von rückständen aus der produktion von isocyanaten |
Country Status (6)
Country | Link |
---|---|
US (1) | US8440856B2 (de) |
EP (1) | EP2280939A2 (de) |
JP (1) | JP2011516593A (de) |
KR (1) | KR20110009111A (de) |
CN (1) | CN102007096A (de) |
WO (1) | WO2009127591A2 (de) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010130652A2 (de) * | 2009-05-11 | 2010-11-18 | Basf Se | Hydrolyse von isocyanataddukten mit 1-alkylimidazol |
WO2019131855A1 (ja) | 2017-12-27 | 2019-07-04 | 旭化成株式会社 | 有機アミンの回収方法 |
WO2023080257A1 (ja) | 2021-11-08 | 2023-05-11 | 旭化成株式会社 | イソシアネート化合物の製造方法、カルバメート化合物の製造方法、アミン化合物の回収方法、イソシアネート組成物 |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5416830B2 (ja) | 2009-04-24 | 2014-02-12 | ビーエーエスエフ ソシエタス・ヨーロピア | 色の安定なmdaとmdiの製造方法 |
ES2532761T3 (es) | 2009-06-26 | 2015-03-31 | Basf Se | Procedimiento de producción de isocianatos, preferentemente diisocianatos y poliisocianatos con recirculación de disolvente |
WO2011015541A1 (de) * | 2009-08-04 | 2011-02-10 | Basf Se | Verfahren zur herstellung von isocyanaten |
HUE031803T2 (en) | 2012-07-11 | 2017-08-28 | Covestro Deutschland Ag | Process for processing distillation residues from the production of isocyanate |
CN114539072B (zh) * | 2022-03-05 | 2023-12-19 | 福州大学 | 焦油渣胺解联产二氨基甲苯和乙烯脲类衍生物的方法 |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3128310A (en) * | 1955-09-09 | 1964-04-07 | Bayer Ag | Recovery of amines |
US3331876A (en) * | 1964-03-23 | 1967-07-18 | Mobay Chemical Corp | Recovery of tolylenediamines |
US4091009A (en) * | 1976-08-16 | 1978-05-23 | Olin Corporation | Process for deactivating toluene diisocyanate distillation residue |
JPS58201751A (ja) * | 1982-05-17 | 1983-11-24 | Mitsui Toatsu Chem Inc | アミン化合物を回収する方法 |
WO1999065868A1 (de) * | 1998-06-18 | 1999-12-23 | Basf Aktiengesellschaft | Verfahren zur aufarbeitung von destillationsrückständen aus der synthese von toluylendiisocyanat |
WO2004108656A1 (en) * | 2003-06-09 | 2004-12-16 | Hanwha Chemical Corporation | Method for recovering toluene diamine from high boiling tar residue discharged from toluene diisocyanate preparation process |
EP1935877A1 (de) * | 2006-12-18 | 2008-06-25 | Bayer MaterialScience AG | Verfahren zur Herstellung von Toluylendiisocyanat |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3636030A (en) | 1968-12-16 | 1972-01-18 | Du Pont | Recovery of aromatic dhsocyanates from still residues |
DE2703313A1 (de) | 1977-01-27 | 1978-08-03 | Bayer Ag | Verfahren zur herstellung von organischen polyaminen |
DE2942678A1 (de) | 1979-10-23 | 1981-05-07 | Bayer Ag, 5090 Leverkusen | Verfahren zur aufarbeitung von vernetzten, harnstoffgruppenhaltigen isocyanatdestillationsrueckstaenden und verwendung der verfahrensprodukte als ausgangskomponenten bei der herstellung von kunststoffen |
US4654443A (en) * | 1985-03-11 | 1987-03-31 | The Dow Chemical Company | Hydrolysis of isocyanate distillation bottoms |
JPS62114984A (ja) * | 1985-11-14 | 1987-05-26 | Kawasaki Steel Corp | 無水フタル酸蒸留残渣からの無水フタル酸回収方法 |
EP0267531A3 (de) * | 1986-11-12 | 1989-02-01 | List AG | Eindampfverfahren für hochviskose Produkte |
DE4416571C1 (de) * | 1994-05-11 | 1995-12-07 | Eberhard Dr Giebeler | Verfahren und Vorrichtung zur Rückgewinnung von Aminen aus Aminwaschlösungen und Verwendung spezieller verfahrensmäßig erhaltbarer Rückstände bei der Herstellung von Zement oder als Düngemittelkomponente |
JP2002173471A (ja) * | 2000-12-07 | 2002-06-21 | Kobe Steel Ltd | イソシアネート系分解対象化合物の分解回収方法 |
DE102004001456A1 (de) * | 2004-01-08 | 2005-08-11 | Basf Ag | Verfahren zur destillativen Aufbereitung von Toluylendiamin |
DE102005027814A1 (de) | 2005-06-15 | 2006-12-21 | Basf Ag | Verfahren zur Aufarbeitung von Isocyanataddukten |
DE102005032430A1 (de) * | 2005-07-12 | 2007-01-25 | Bayer Materialscience Ag | Verfahren zur Herstellung von Toluylendiamin |
US9061971B2 (en) * | 2005-09-29 | 2015-06-23 | Basf Aktiengesellschaft | Method for purifying residues containing isocyanates |
-
2009
- 2009-04-09 WO PCT/EP2009/054287 patent/WO2009127591A2/de active Application Filing
- 2009-04-09 US US12/936,080 patent/US8440856B2/en not_active Expired - Fee Related
- 2009-04-09 JP JP2011504429A patent/JP2011516593A/ja active Pending
- 2009-04-09 CN CN2009801130372A patent/CN102007096A/zh active Pending
- 2009-04-09 KR KR1020107023567A patent/KR20110009111A/ko not_active Application Discontinuation
- 2009-04-09 EP EP09731507A patent/EP2280939A2/de not_active Withdrawn
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3128310A (en) * | 1955-09-09 | 1964-04-07 | Bayer Ag | Recovery of amines |
US3331876A (en) * | 1964-03-23 | 1967-07-18 | Mobay Chemical Corp | Recovery of tolylenediamines |
US4091009A (en) * | 1976-08-16 | 1978-05-23 | Olin Corporation | Process for deactivating toluene diisocyanate distillation residue |
JPS58201751A (ja) * | 1982-05-17 | 1983-11-24 | Mitsui Toatsu Chem Inc | アミン化合物を回収する方法 |
WO1999065868A1 (de) * | 1998-06-18 | 1999-12-23 | Basf Aktiengesellschaft | Verfahren zur aufarbeitung von destillationsrückständen aus der synthese von toluylendiisocyanat |
WO2004108656A1 (en) * | 2003-06-09 | 2004-12-16 | Hanwha Chemical Corporation | Method for recovering toluene diamine from high boiling tar residue discharged from toluene diisocyanate preparation process |
EP1935877A1 (de) * | 2006-12-18 | 2008-06-25 | Bayer MaterialScience AG | Verfahren zur Herstellung von Toluylendiisocyanat |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010130652A2 (de) * | 2009-05-11 | 2010-11-18 | Basf Se | Hydrolyse von isocyanataddukten mit 1-alkylimidazol |
WO2010130652A3 (de) * | 2009-05-11 | 2011-04-21 | Basf Se | Hydrolyse von isocyanataddukten mit 1-alkylimidazol |
WO2019131855A1 (ja) | 2017-12-27 | 2019-07-04 | 旭化成株式会社 | 有機アミンの回収方法 |
EP3872062A1 (de) | 2017-12-27 | 2021-09-01 | Asahi Kasei Kabushiki Kaisha | Verfahren zur entnahme von organischen aminen |
US11578030B2 (en) | 2017-12-27 | 2023-02-14 | Asahi Kasei Kabushiki Kaisha | Organic amine collection method |
WO2023080257A1 (ja) | 2021-11-08 | 2023-05-11 | 旭化成株式会社 | イソシアネート化合物の製造方法、カルバメート化合物の製造方法、アミン化合物の回収方法、イソシアネート組成物 |
Also Published As
Publication number | Publication date |
---|---|
CN102007096A (zh) | 2011-04-06 |
WO2009127591A3 (de) | 2009-12-17 |
EP2280939A2 (de) | 2011-02-09 |
JP2011516593A (ja) | 2011-05-26 |
US8440856B2 (en) | 2013-05-14 |
KR20110009111A (ko) | 2011-01-27 |
US20110021836A1 (en) | 2011-01-27 |
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