Method for separating p-aminodiphenyl amine reduction solution

Abstract

The present invention is a method for separating p-aminodiphenylamine reducing liquid, which belongs to the field of crude product material separation, and the problem to be solved is to reduce the consumption of crude product material separation; the present invention mainly includes the following steps: solvent distillation, centrifugal separation, inorganic phase concentration, For processes such as organic phase distillation, by adding solvent distillation steps and using centrifugal separation to replace the extraction unit in production, the amount of extraction agent used in the system is greatly reduced, thereby greatly reducing energy consumption by more than 60%.

Description

technical field

[0001] The invention relates to a treatment method for p-aminodiphenylamine reducing liquid, in particular to a method for separating p-aminodiphenylamine reducing liquid, and belongs to the field of crude product material separation. Background technique

[0002] At present, the advanced method of synthesizing p-aminodiphenylamine in the world is the nitrobenzene method. The method has high product quality and mild reaction conditions. The main process steps are condensation process, reduction process and separation process. Among them, the first two processes are reaction processes. , and the main energy consumption and difficulty of this process lies in the separation process. This is because the methanol solvent in the reducing solution is a stabilizer, which makes the inorganic phase and the organic phase in the system evenly distributed. Therefore, when processing, it is necessary to add a large amount of water to extract and separate the inorganic phas...

Examples

Embodiment 1

[0032] Distill 300ml of p-aminodiphenylamine reducing solution in a water bath at 70°C, and distill and separate the solvent in the system to obtain a reducing solution that removes the solvent. Send the reducing solution and soft water with a volume ratio of 1:0.2 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a 70°C water bath, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 15%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.

Embodiment 2

[0034] Distill 300ml of p-aminodiphenylamine reducing solution in a water bath at 80°C, distill and separate the solvent in the system to obtain a reducing solution from which the solvent has been removed, and send the reducing solution and soft water with a volume ratio of 1:0.4 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a water bath at 80°C, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 20%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.

Embodiment 3

[0036] Distill 300ml p-aminodiphenylamine reducing solution in a water bath at 90°C, distill and separate the solvent in the system to obtain a reducing solution from which the solvent has been removed, and send the reducing solution and soft water with a volume ratio of 1:06 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a 90°C water bath, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 25%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.

technical field

[0001] The invention relates to a treatment method for p-aminodiphenylamine reducing liquid, in particular to a method for separating p-aminodiphenylamine reducing liquid, and belongs to the field of crude product material separation. Background technique

[0002] At present, the advanced method of synthesizing p-aminodiphenylamine in the world is the nitrobenzene method. The method has high product quality and mild reaction conditions. The main process steps are condensation process, reduction process and separation process. Among them, the first two processes are reaction processes. , and the main energy consumption and difficulty of this process lies in the separation process. This is because the methanol solvent in the reducing solution is a stabilizer, which makes the inorganic phase and the organic phase in the system evenly distributed. Therefore, when processing, it is necessary to add a large amount of water to extract and separate the inorganic phas...

Examples

Embodiment 1

[0032] Distill 300ml of p-aminodiphenylamine reducing solution in a water bath at 70°C, and distill and separate the solvent in the system to obtain a reducing solution that removes the solvent. Send the reducing solution and soft water with a volume ratio of 1:0.2 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a 70°C water bath, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 15%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.

Embodiment 2

[0034] Distill 300ml of p-aminodiphenylamine reducing solution in a water bath at 80°C, distill and separate the solvent in the system to obtain a reducing solution from which the solvent has been removed, and send the reducing solution and soft water with a volume ratio of 1:0.4 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a water bath at 80°C, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 20%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.

Embodiment 3

[0036] Distill 300ml p-aminodiphenylamine reducing solution in a water bath at 90°C, distill and separate the solvent in the system to obtain a reducing solution from which the solvent has been removed, and send the reducing solution and soft water with a volume ratio of 1:06 into In the centrifugal separator, the inorganic phase and the organic phase are separated, and the inorganic phase obtained by the above centrifugal separation is subjected to vacuum distillation and concentration in a 90°C water bath, and the soft water is distilled out of the system, and concentrated to obtain a high-concentration catalyst solution with a content of 25%. The organic phase obtained by the above centrifugal separation is subjected to vacuum rectification in an oil bath, and the raw material aniline, p-aminodiphenylamine with a content of 99.61% and by-product residues are separated.