Process for synthesis of toluenediamine by low pressure hydrogenation of dinitrotoluene, catalyst and preparation method of catalyst

A technology of dinitrotoluene and toluenediamine, which is used in physical/chemical process catalysts, Raney-type catalysts, preparation of amino compounds, etc., can solve the problems of external solvent, difficult reaction, and high reaction pressure.

Inactive Publication Date: 2014-09-17
SEDIN ENG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] In order to achieve the above-mentioned purpose, the present invention breaks through the shackles of conventional technical cognition that nickel-based catalysts need to add solvents and reaction pressures up to 2MPa in the hydrogenation reaction of dinitrotoluene, and through a large number of catalyst modification experiments, activity evaluation experiments and mechanism research Analyzed and screened and compared various nickel-based catalysts, and successfully developed a Raney nickel catalyst with activity similar to noble metal catalysts at a low pressure of about 1MPa and without an external solvent; and according to the developed Raney nickel catalyst. Catalytic performance , strength and settling properties, thr

Method used

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  • Process for synthesis of toluenediamine by low pressure hydrogenation of dinitrotoluene, catalyst and preparation method of catalyst
  • Process for synthesis of toluenediamine by low pressure hydrogenation of dinitrotoluene, catalyst and preparation method of catalyst
  • Process for synthesis of toluenediamine by low pressure hydrogenation of dinitrotoluene, catalyst and preparation method of catalyst

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Effect test

Embodiment 1

[0053] Mix 6 μm nickel powder, 5 μm aluminum powder and 8 μm additive metal Fe powder with a mass fraction of Ni55wt%—Al40wt%—Fe5wt%, and place it in a crucible with a funnel at the bottom and surrounded by SiC. / min speed heating to 1600 ℃ melting, after 0.8MPa Ar gasification and atomization to obtain alloy powder, the cooling rate is 1.0×10 6 K / s; mix the alloy powder and NaOH powder at a mass ratio of 1:1, add distilled water 3 times the volume of the alloy powder into the container dropwise at room temperature, and the dropping speed keeps the material wet evenly but does not form a liquid phase; After the dropwise addition, the suspension was sonicated at 20kHZ and 70°C for 40min, and then washed with distilled water to obtain a catalyst, which was stored in water for future use. The catalyst prepared by this embodiment is used for the specific operational route and reaction conditions of the hydrogenation of dinitrotoluene as follows:

[0054] a. the prepared Raney-Ni ...

Embodiment 2

[0059] Mix 5 μm nickel powder, 7 μm aluminum powder and 7 μm auxiliary metal powder with a mass fraction of Ni53wt%—Al43wt%—auxiliary 4wt%, and place it in a crucible with a funnel at the bottom and surrounded by SiC. Heating at the speed of ℃ / min to 1550 ℃ for melting, and then vaporized and atomized by 0.9MPa Ar to obtain alloy powder, the cooling rate is 1.2×10 6 K / s; mix the alloy powder and NaOH powder at a mass ratio of 1.1:1, add distilled water 4 times the volume of the alloy powder into the container dropwise at room temperature, and the dropping speed keeps the material wet evenly but does not form a liquid phase; After the dropwise addition, the suspension was ultrasonicated for 35 minutes at 30kHZ and 60°C, washed with distilled water to obtain the target catalyst, and stored in water for later use. The catalyst prepared by this embodiment is used for the specific operational route and reaction conditions of the hydrogenation of dinitrotoluene as follows:

[0060]...

Embodiment 3

[0065] Mix 4 μm nickel powder, 9 μm aluminum powder and 6 μm auxiliary metal powder with a mass fraction of Ni53wt%—Al45wt%—auxiliary 2wt%, and place it in a crucible with a funnel at the bottom and surrounded by SiC, and microwave at 60 The speed of ℃ / min is heated to 1500 ℃ for melting, and the alloy powder is obtained after gasification and atomization by 1.0MPa Ar, and the cooling rate is 1.3×10 6 K / s; mix the alloy powder and NaOH powder at a mass ratio of 1:2, add distilled water 5 times the volume of the alloy powder into the container dropwise at room temperature, and the dropping speed keeps the material wet evenly but does not form a liquid phase; After the dropwise addition, the suspension was ultrasonicated for 30 minutes at 50kHZ and 60°C, and then washed with distilled water to obtain a catalyst, which was stored in water for future use. The catalyst prepared by this embodiment is used for the specific operational route and reaction conditions of the hydrogenatio...

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Abstract

A process for synthesis of toluenediamine (TDA) by low pressure hydrogenation of dinitrotoluene (DNT) is as follows: preparing a fresh Raney nickel catalyst and DNT into fresh catalyst slurry, adding the fresh catalyst slurry into a hydrogenation reactor; respectively adding raw material DNT and hydrogen into the hydrogenation reactor for reaction, leading a liquid reaction product into a catalyst separator I for separation, sending an upper clear liquid to a catalyst separator II, sending a gas phase into a purge gas separator, and returning settled catalyst slurry to the hydrogenation reactor; and filtering a clear liquid in the central part of the catalyst separator II with a filter to obtain a crude TDA product. The process has the advantages of low equipment investment, low energy consumption, and synthesis of the toluenediamine (TDA) by hydrogenation of the dinitrotoluene in the absence of an externally added solvent and under the low pressure condition of 1MPa.

Description

technical field [0001] The invention belongs to a process for industrially synthesizing toluene diamine, a catalyst and a preparation method of the catalyst, in particular to a process for synthesizing toluene diamine through low-pressure hydrogenation of dinitrotoluene, a Raney nickel catalyst used and a preparation method of the catalyst. Background technique [0002] Toluenediamine (TDA), also known as diaminotoluene, is an important chemical raw material and chemical intermediate, which is usually synthesized by hydrogenation of dinitrotoluene (DNT) in the presence of an external organic solvent and catalyst. At present, there are two main DNT hydrogenation technologies in the industry: the first is the American DuPont technology using supported Pd+Pt / C noble metal catalysts, which has the advantages of low reaction pressure (1MPa), high catalyst activity and no need for additional solvents. However, there are the disadvantages that the catalyst is difficult to separate,...

Claims

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Application Information

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IPC IPC(8): C07C211/50C07C209/36B01J25/02
CPCY02P20/584
Inventor 范辉李改英王月玲
Owner SEDIN ENG
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