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CN-121986085-A - Method for producing MDA

CN121986085ACN 121986085 ACN121986085 ACN 121986085ACN-121986085-A

Abstract

The invention relates to a method for producing methylenedianiline and to a production unit for carrying out the method for producing methylenedianiline.

Inventors

  • Niedermeier, M.M.
  • T. Matko
  • S. Oren Schleig
  • J. A. Bauschinger
  • M. WAGNER

Assignees

  • 巴斯夫欧洲公司

Dates

Publication Date
20260505
Application Date
20241004
Priority Date
20231006

Claims (15)

  1. 1. A process for preparing methylenedianiline, the process comprising (I) Preparing a stream S1 comprising aminal, (i) comprising (I.1) providing a stream S01 comprising aniline; (i.2) providing an aqueous stream S02 comprising formaldehyde; (i.3) contacting at least a portion of S01 provided according to (i.1) with at least a portion of S02 provided according to (i.2) in a first reactor unit RU1 to obtain a mixture M1 having an organic phase comprising aminal and aniline and having an aqueous phase comprising water; (i.4) passing the M1 obtained according to (i.3) through a separation unit SU for separating the phases of M1, obtaining a stream S1 comprising the organic phase comprising aminal and aniline, and a stream S11 comprising the aqueous phase comprising water; (ii) Passing said stream S1 prepared according to (i) in a second reactor unit RU2, RU2 comprising heterogeneous catalyst C, and contacting S1 with C in RU2, obtaining a stream S2 comprising aminobenzylaniline; (iii) Contacting S2 obtained according to (ii) with a liquid mixture ML comprising bronsted acids, obtaining a stream S3 comprising S2 and ML; (iv) Passing S3 obtained according to (iii) into a third reactor unit RU3, and subjecting S3 to rearrangement conditions in RU3, obtaining a stream S4 comprising methylenedianiline.
  2. 2. The method according to claim 1, wherein 20 to 70 wt%, preferably 25 to 60wt%, more preferably 30 to 50wt% of S02 consists of formaldehyde.
  3. 3. The process according to claim 1 or 2, wherein contacting S01 provided according to (i.1) with S02 provided according to (i.2) in the first reactor unit RU1 is performed at a temperature in the range of 20 ℃ to 100 ℃, preferably in the range of 30 ℃ to 95 ℃, more preferably in the range of 40 ℃ to 90 ℃, according to (i.3); Wherein preferably, according to (i.3), the contacting of S01 provided according to (i.1) with S02 provided according to (i.2) is performed at a pressure in the range of 0.5 bar to 10 bar (absolute), more preferably in the range of 0.6 bar to 5 bar (absolute), more preferably in the range of 0.7 bar to 2 bar (absolute).
  4. 4. A process according to any one of claims 1 to 3, wherein the molar ratio of aniline to formaldehyde in RU1 is in the range of 1.5:1 to 10:1, preferably in the range of 1.8:1 to 6:1, more preferably in the range of 2:1 to 4:1.
  5. 5. The process according to any one of claims 1 to 4, wherein the second reactor unit RU2 comprises one or more fixed bed reactors.
  6. 6. The process according to any one of claims 1 to 5, wherein contacting S1 with C in RU2 according to (ii) is performed at a temperature in the range of 15 ℃ to 200 ℃, preferably in the range of 20 ℃ to 180 ℃, more preferably in the range of 30 ℃ to 160 ℃.
  7. 7. The process according to any one of claims 1 to 6, wherein the bronsted acid comprised in ML is one or more of hydrochloric acid, sulfuric acid and phosphoric acid, preferably hydrochloric acid.
  8. 8. The method of any one of claims 1 to 7, wherein the liquid mixture ML further comprises aminobenzyl aniline.
  9. 9. The method of claim 8, the method further comprising: preparing said liquid mixture ML comprising a bronsted acid, preferably HCl, and an aminobenzylaniline, said preparing comprising -Contacting aniline, preferably a portion of S01 provided in (i.1), with an aqueous solution of said bronsted acid, obtaining a liquid mixture M10 comprising aniline, water and said bronsted acid; -introducing M10 into the reactor unit RUA together with formaldehyde, preferably a part of S02 provided in (i.2); -reacting M10 with said formaldehyde in RUA to obtain said liquid mixture ML comprising aminobenzylaniline and said bronsted acid.
  10. 10. The method of claim 9, wherein prior to introducing into the RUA, the method further comprises heating M10 to a temperature in the range of 20 ℃ to 95 ℃, more preferably in the range of 30 ℃ to 90 ℃.
  11. 11. The method according to claim 9 or 10, wherein the molar ratio of aniline to formaldehyde in RUA is in the range of 1.5:1 to 4.5:1, preferably in the range of 1.6:1 to 4:1, more preferably in the range of 1.7:1 to 3:1.
  12. 12. The process according to any one of claims 9 to 11, wherein the reaction of M10 with the formaldehyde in RUA is carried out at a temperature in the range of 30 ℃ to 90 ℃, preferably in the range of 40 ℃ to 70 ℃; wherein preferably the reaction of M10 with said formaldehyde in RUA is carried out at a pressure in the range of 0.1 bar to 10 bar (absolute), more preferably in the range of 0.5 bar to 2 bar (absolute).
  13. 13. The method according to any one of claims 9 to 12, wherein in S3 the ratio of the mass of aminobenzylaniline (ABA) comprised in S2 to the mass of aminobenzylaniline (ABA) comprised in ML is in the range of 10:1 to 1:10, preferably in the range of 1:1 to 1:6, more preferably in the range of 1:2 to 1:4.
  14. 14. The method of any one of claims 1 to 13, wherein subjecting S3 to rearrangement conditions in RU3 comprises subjecting S3 to a temperature in the range of 80 ℃ to 200 ℃, preferably in the range of 100 ℃ to 160 ℃, more preferably in the range of 120 ℃ to 140 ℃; Wherein preferably subjecting S3 to rearrangement conditions in RU3 comprises subjecting S3 to a pressure in the range of 0.5 bar to 10 bar (absolute), more preferably in the range of 0.8 bar to 5 bar (absolute), more preferably in the range of 1 bar to 3 bar (absolute).
  15. 15. A production unit for carrying out a process for preparing methylenedianiline, preferably according to any of claims 1 to 14, the unit comprising A first reactor unit RU1; Means for introducing at least a portion of stream S01 into RU 1; means for introducing at least a portion of the aqueous stream S02 into RU 1; Means for removing mixture M1 from RU 1; A separation unit SU; A second reactor unit RU2, said second reactor unit RU2 comprising a heterogeneous catalyst C; Means for introducing stream S1 into RU 2; means for contacting stream S2 with liquid mixture ML; a reaction unit RU3; Means for introducing stream S3 into RU 3; Means for removing stream S4 from RU 3.

Description

Method for producing MDA The invention relates to a method for producing methylenedianiline and to a production unit for carrying out the method for producing methylenedianiline. Methylene diphenylamine or diaminophenylmethane (abbreviated as MDA) refers to individual methylene diphenylamine isomers, mixtures of methylene diphenylamine isomers and/or oligomers of methylene diphenylamine, which are intermediate products for the production of polyisocyanates and resins. Several methods of preparing MDA are known in the art. For example, WO01/74755 A1 discloses a process for preparing a mixture of methylenedianiline, the process comprising reacting aniline and formaldehyde in the absence of an acid catalyst to form aminal, and isomerizing the aminal in one or more reactors at a temperature of from 100 ℃ to 250 ℃ in the presence of a solid catalyst selected from zeolite and silica-alumina. WO2010/072504 A1 discloses a process for providing methylene bridged polyphenyl polyamines, the process comprising condensing aniline and formaldehyde to obtain a condensate, reacting the condensate with a solid catalyst at a temperature in the range of 30 ℃ to 100 ℃ to obtain an intermediate mixture, and converting the intermediate mixture to methylene bridged polyphenyl polyamines in the presence of a subsequent solid catalyst at a temperature in the range of 70 ℃ to 250 ℃. In addition, methods using acid catalysts such as HCl are also known in the art. For example, HCl may be added after the aminal is produced, as described in US2016068474 A1. Alternatively, HCl may be added to the aniline before or together with formaldehyde, as disclosed in EP 2145874 A1, EP 2000459 A1, DE10141620 and DE 19804915. Another process for preparing MDA is disclosed in EP 0109931 A2, which comprises mixing an aminal stream (uncatalysed condensation) with an acidic condensate (HCl catalyzed condensation) and finally rearranging the mixture. The goal of EP 0109931 is to minimize HCl consumption in the process. However, there is a disadvantage in using the method because the formation of by-products is increased. Accordingly, there is always a need to provide improved processes that avoid the problems encountered in previous processes and increase production capacity while being cost effective. In particular, the process of the present invention has been demonstrated to allow for increased yields of 4,4' -MDA while saving acid catalyst such as HCl. The present invention thus relates to a process for the preparation of methylenedianiline, which comprises (I) Preparing a stream S1 comprising aminal, wherein (i) comprises (I.1) providing a stream S01 comprising aniline; (i.2) providing an aqueous stream S02 comprising formaldehyde; (i.3) contacting at least a portion of S01 provided according to (i.1) with at least a portion of S02 provided according to (i.2) in a first reactor unit RU1 to obtain a mixture M1 having an organic phase comprising aminal and aniline and having an aqueous phase comprising water; (i.4) passing the M1 obtained according to (i.3) through a separation unit SU for separating the phases of M1, obtaining a stream S1 comprising an organic phase comprising aminal and aniline, and a stream S11 comprising an aqueous phase comprising water; (ii) Passing stream S1 prepared according to (i) in a second reactor unit RU2, RU2 comprising heterogeneous catalyst C, and contacting S1 with C in RU2, obtaining stream S2 comprising aminobenzylaniline; (iii) Contacting S2 obtained according to (ii) with a liquid mixture ML comprising bronsted acids, obtaining a stream S3 comprising S2 and ML; (iv) Passing S3 obtained according to (iii) into a third reactor unit RU3, and subjecting S3 to rearrangement conditions in RU3, obtaining a stream S4 comprising methylenedianiline. Preferably, the first reactor unit RU1 is one or more of a tank, stirred tank and plug flow reactor. Preferably, upstream of one or more of the tank, stirred tank and plug flow reactor, RU1 further comprises a mixing device, which is a static (nozzle) or dynamic mixer or a tee. Preferably, the aniline comprised in S01 is fresh aniline and/or recycled aniline. Preferably, the aniline-containing stream S01 is non-aqueous. Preferably, 20 to 70 wt%, more preferably 25 to 60 wt%, more preferably 30 to 50wt% of S02 consists of formaldehyde. Preferably, according to (i.3), contacting S01 provided according to (i.1) with S02 provided according to (i.2) in the first reactor unit RU1 is performed at a temperature in the range of 20 ℃ to 100 ℃, more preferably in the range of 30 ℃ to 95 ℃, more preferably in the range of 40 ℃ to 90 ℃. Preferably, according to (i.3), the contacting of S01 provided according to (i.1) with S02 provided according to (i.2) in the first reactor unit RU1 is performed at a pressure in the range of 0.5 bar to 10 bar (absolute), more preferably in the range of 0.6 bar to 5 bar (absolute), more preferably in the range of 0.7 bar to 2 bar (absolute). Preferably, the