Recovery method of benzene series nitration waste acid

A recovery method and technology for nitrifying waste acid, applied in nitric acid, nitrogen oxides/oxyacids, chemical industry, etc., can solve problems such as serious equipment corrosion, a large amount of waste acid and organic acid wastewater, and the inability to meet sustainable development, etc. To achieve the effect of environmental protection in the process and simple treatment methods

Active Publication Date: 2016-08-17
QUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantage of this process is that a large amount of waste acid and organic acid wastewater will be produced in the process, which will seriously corrode the equipment and cannot meet the requirements of sustainable development.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Add 150.2g (1.63mol) toluene to a 1L four-port reactor equipped with mechanical stirring, a thermometer, and a condenser tube, start stirring, and raise the temperature so that the temperature of the reactor is controlled at 50°C. Slowly add 400g of mixed acid nitrating reagent dropwise. The composition of the nitrating reagent: the mass fraction of nitric acid is 27%, the mass fraction of sulfuric acid is 57%, and the balance is water. The dropping rate is controlled so that the mixed acid nitrating reagent is added dropwise in about 1.5 hours. To room temperature, about 547.48 g of reaction solution was obtained. The above reaction liquid was transferred to a separator, and 217.00 g of the upper organic liquid and 330.48 g of the lower aqueous phase were collected.

[0027] Collected upper layer organic liquid (acid nitrotoluene) 217.00g obtains 194.03g nitrotoluene product through water washing, alkali washing, rectification.

[0028] The lower aqueous phase enters ...

Embodiment 2

[0032] Add 312.0 g (4.00 mol) of benzene into a 1 L four-port reactor equipped with mechanical stirring, a thermometer, and a condenser tube, start stirring, and raise the temperature so that the temperature of the reactor is controlled at 55 ° C. Slowly add 575.22 g of mixed acid nitration reagent dropwise, Mixed acid nitration reagent composition: nitric acid mass fraction 46wt%, sulfuric acid mass fraction 48wt%, balance is water, control the dropping rate, make mixed acid nitration reagent dropwise in about 2.5 hours, dripping is completed and kept warm for 1h, after the reaction is completed, drop to At room temperature, about 879.72 g of the reaction solution was obtained. The above reaction liquid was transferred to a separator, and 483.52 g of the upper organic liquid and 396.20 g of the lower aqueous phase were collected.

[0033] 483.52 g of the collected upper layer organic liquid (acid nitrobenzene) was washed with water, alkali washed and rectified to obtain 422.8...

Embodiment 3

[0038] Add 450.24g (4.0mol) of chlorobenzene to a 1L four-port reactor equipped with mechanical stirring, a thermometer, and a condenser, start stirring, and raise the temperature to control the temperature of the reactor at 50°C, and slowly add 575.20g of mixed acid nitration reagent dropwise. , the composition of the mixed acid nitration reagent: nitric acid mass fraction 46wt%, sulfuric acid mass fraction 48wt%, the balance is water, control the dropping rate, make the mixed acid nitration reagent dropwise in about 3.0 hours, keep warm for 1h after dripping, and then heat up to 65°C Keep warm for 1 hour. After the reaction is completed, cool down to room temperature to obtain about 1017.48 g of reaction solution. The above reaction liquid was transferred to a separator, and 621.05 g of the upper organic liquid and 396.43 g of the lower aqueous phase were collected.

[0039] Collected upper layer organic liquid (acid nitrochlorobenzene) 621.05g obtains 545.28g mononitrochlor...

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PUM

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Abstract

The invention provides a recovery method of benzene series nitration waste acid. The recovery method includes: mixing waste acid from a benzene series nitration reaction process with activated carbon for decolorizing, adding decolorized waste acid and solid potassium nitrate into an intermittent reactive distillation column bottom sequentially, heating to 60-70 DEG C with stirring for 0.5-3 hours, performing rectification operation while reaction is conducted, collecting overhead distillate, namely recovery liquid, adding water into the intermittent reactive distillation column bottom, heating with stirring to dissolve residues in the bottom, regulating a pH value of 1.4-2.1 by a potassium hydroxide water solution, filtering immediately, naturally cooling filtrate to separate out solids, filtering to obtain potassium bisulfate and recycling mother liquor. The recovery method of the benzene series nitration waste acid has the advantages that the waste acid is utilized effectively to obtain nitric acid required by the reaction and the high-added-value potassium bisulfate, so that the whole technological process is more environment friendly.

Description

(1) Technical field [0001] The invention belongs to the technical field of chemical products, and in particular relates to a method for recovering waste acid produced in the nitration reaction process of benzene series such as benzene, toluene, chlorobenzene and the like. (2) Background technology [0002] Nitrobenzene series are an important class of fine chemical intermediates, which can be widely used in the synthesis of dyes, pesticides, medicines, plastics, and energetic materials. At present, nitric acid mixed acid nitration technology is commonly used in industry to produce nitrobenzene series. The advantages of this process are fast reaction speed, less side reactions, and large production capacity; the amount of nitric acid is close to the theoretical amount, and almost all nitric acid can be used; sulfuric acid The large heat capacity can effectively control the reaction temperature; concentrated sulfuric acid can dissolve most organic matter, increase the contact ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B21/46C01D5/02C07C201/08C07C205/06C07C205/11
CPCC01B21/46C01D5/02C07C201/08C07C205/06C07C205/11Y02P20/10
Inventor 许建帼李杰吕延文金懿胡向兵
Owner QUZHOU UNIV
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