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Circulating ammonolysis technique for o-phenylenediamine mother liquid

A technology of o-phenylenediamine mother liquor and process method, which is applied in the field of circular ammonolysis process of o-phenylenediamine mother liquor, can solve problems such as heavy ammonia smell, influence on operating environment, occupational hazards, etc., and achieve the effect of reducing ammonia residue

Inactive Publication Date: 2017-01-04
ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The production of o-phenylenediamine is mainly obtained from the ammoniation of o-nitrochlorobenzene, reduction with sodium sulfide, crystallization, and centrifugation; during the separation process of o-phenylenediamine and mother liquor, due to the large amount of ammonia The smell of ammonia on the site is heavy, which will lead to an increase in ammonia consumption, and affect the operating environment and cause occupational hazards.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] A cyclic ammonolysis process method for o-phenylenediamine mother liquor, the method mainly includes: (1) after the reduction and recovery of o-nitroaniline in sodium sulfide solution is completed, the temperature of the material is controlled at 90°C, and the Feed nitrogen in the still, and nitrogen is passed into by the pipeline that inserts the reduction kettle bottom, and nitrogen feed rate is controlled at 5 liters / second, and the time is controlled at 15 minutes; (2) water pump is connected with the bottom of reduction kettle, utilizes 500m 3 The / h water flushing pump ensures that the reduction kettle is in a state of slight negative pressure. The discharged nitrogen and ammonia gas enter the two-stage series absorption tower from the top of the reduction kettle to recover ammonia gas. The adsorption filler in the absorption tower is water, and the adsorption is completed. Afterwards, desorption is carried out, and the obtained ammonia gas is recycled for use in a...

Embodiment 2

[0019] A cyclic ammonolysis process method for o-phenylenediamine mother liquor, the method mainly includes: (1) after the reduction and recovery of o-nitroaniline in sodium sulfide solution is completed, the temperature of the material is controlled at 100 ° C, to the reduction Nitrogen is introduced into the still, and the nitrogen is introduced by a pipeline inserted into the bottom of the reduction still. The nitrogen feeding speed is controlled at 10 liters / second, and the time is controlled at 15 minutes; 3 The / h water flushing pump ensures that the reduction kettle is in a state of slight negative pressure. The discharged nitrogen and ammonia gas enter the two-stage series absorption tower from the top of the reduction kettle to recover ammonia gas. The adsorption filler in the absorption tower is water, and the adsorption is completed. Afterwards, desorption is carried out, and the obtained ammonia gas is recycled for use in ammonolysis cycle.

[0020] Through the abo...

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PUM

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Abstract

The invention discloses a circulating ammonolysis technique for o-phenylenediamine mother liquid. The circulating ammonolysis technique mainly includes: (1), after reductive recycling of o-nitroaniline in a sodium sulfide solution is finished, controlling material temperature to 80-100 DEG C, feeding nitrogen into a reduction kettle, and controlling nitrogen feeding speed to 5-10L / s and time to 10-15min; (2), utilizing a water flushing pump of 500m3 / h to ensure a micro negative pressure state in the reduction kettle, and recycling ammonia from discharged nitrogen and ammonia through absorbing towers in two-stage series connection for ammonolysis circulating. After gas driving, ammonia content of about 11-13g / L in the mother liquid can be lowered to below 5-6g / L; o-phenylenediamine liquid ammonia unit consumption per ton is lowered to below 0.265t / t from 0.28t / t, so that pollution is greatly reduced, and operation environment is improved.

Description

technical field [0001] The invention relates to the ammonolysis of the o-phenylenediamine mother liquor, in particular to a cyclic ammonolysis process for the o-phenylenediamine mother liquor. Background technique [0002] O-phenylenediamine is also called 1,2-diaminobenzene and 1,2-phenylenediamine. Those separated from water are white to light yellow leaf-shaped crystals, those separated from chloroform are prismatic crystals. It is easy to change color when exposed to the air, from white to yellow, brown, purple, and finally black. The relative density is 1.2698. The melting point is 103-104°C. The boiling point is 256-258°C. Slightly soluble in cold water, easily soluble in hot water, ethanol, ether, chloroform and benzene. It reacts with inorganic acid to generate water-soluble salt; reacts with carbon disulfide in aqueous solution to generate 2-mercaptobenzimidazole; reacts with carbon dioxide under pressure to generate benzimidazolone. This product is poisonous....

Claims

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Application Information

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IPC IPC(8): C07C209/36C07C211/51
CPCC07C209/36C07C211/51
Inventor 王先武陈建平熊珊珊王前胜
Owner ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD