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Preparation method of p-nitrophenol

A technology for p-nitrophenol and p-nitrochlorobenzene is applied in the field of preparation of p-nitrophenol, can solve the problems of large waste water discharge, high energy consumption of products, low production efficiency, etc. High efficiency and high rate of first-class products

Active Publication Date: 2010-06-30
ANHUI BAYI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, p-nitrophenol mostly uses p-nitrochlorobenzene, caustic soda, and hydrochloric acid as raw materials, and generates p-nitrophenol through hydrolysis reaction, crystallization, primary separation, pulping, acidification reaction, and secondary separation. In the reaction solution system The concentration of caustic soda is generally 130-135g / L, the production efficiency of a single set of equipment is low, the discharge of waste water is large, and the energy consumption of the product is high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The preparation method of p-nitrophenol comprises the following processing steps:

[0028] (1) Hydrolysis reaction: 2200kg of p-nitrochlorobenzene is dropped in the hydrolysis still, add water with the caustic soda solution of 32% concentration (percentage by weight), be made into caustic soda concentration and reach 250g / L (about 20% by weight percent concentration) Put 4827.43L of caustic soda solution into the hydrolysis kettle, first feed steam into the jacket of the hydrolysis kettle to raise the temperature in the kettle to 153°C, then stop the heating (that is, stop feeding steam into the jacket of the hydrolysis kettle), Then when the temperature in the kettle is naturally raised to 162°C, the remaining steam in the jacket is drained, and when the temperature in the kettle rises to 165°C and the pressure is 0.83MPa, cold water is put into the jacket of the hydrolysis kettle to keep the hydrolysis kettle warm, so that The temperature and pressure in the kettle we...

Embodiment 2

[0035] The preparation method of p-nitrophenol comprises the following processing steps:

[0036] (1) Hydrolysis reaction: 5700kg of p-nitrochlorobenzene is dropped in the hydrolysis still, add water with the caustic soda solution of 32% concentration (weight percent), be made into caustic soda concentration and reach 250g / L (weight percent concentration is about 20%) 12623.24L of caustic soda solution is thrown into the hydrolysis kettle, and steam is first passed into the jacket of the hydrolysis kettle to raise the temperature in the kettle to 153°C, then stop heating (that is, stop feeding steam into the jacket of the hydrolysis kettle), Then when the temperature in the kettle is naturally raised to 162°C, the remaining steam in the jacket is drained, and when the temperature in the kettle rises to 165°C and the pressure is 0.83MPa, cold water is put into the jacket of the hydrolysis kettle to keep the hydrolysis kettle warm, so that The temperature and pressure in the ket...

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Abstract

The invention relates to a preparation method of p-nitrophenol. The method comprises the following technological steps: (1) hydrolysis reaction: putting p-nitrochlorobenzene and caustic soda into a hydrolysis kettle with the molecule mol ratio of p-nitrochlorobenzene to caustic soda being 1:(2.16-2.18) and concentration of caustic soda being 180-300g / L, raising the temperature in the kettle to 150-155 DEG C, stopping raising, then letting natural temperature rise to 162-165 DEG C and pressure to 0.7-0.9MPa, preserving the temperature of the hydrolysis kettle, controlling the temperature in the kettle and pressure respectively at 163-173 DEG C and 0.7-0.9MPa for 2-4h, agitating continuously during reaction to obtain reactants; (2) crystallization; (3) primary separation; (4) slurry conditioning; (5) acidification; and (6) secondary separation. Compared with background technology, the preparation method in the invention has the advantages of high production efficiency, less waste water discharge and low energy consumption.

Description

technical field [0001] The invention relates to the technical field of chemical products, more specifically, the invention relates to a preparation method of p-nitrophenol. Background technique [0002] p-Nitrophenol, colorless to pale yellow crystalline powder, has a smell like bitter almonds, soluble in hot water, alcohol, ether, usually stable in structure, is an important fine chemical intermediate, mainly used as an intermediate in the production of paracetamol Body p-aminophenol, in addition to the manufacture of rubber antioxidants, photographic developers, sulfur dyes, azo dyes and fur dyes. In recent years, with the rapid development of downstream derivative products, the demand for p-nitrophenol has also increased rapidly. [0003] At present, p-nitrophenol mostly uses p-nitrochlorobenzene, caustic soda, and hydrochloric acid as raw materials, and generates p-nitrophenol through hydrolysis reaction, crystallization, primary separation, pulping, acidification react...

Claims

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Application Information

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IPC IPC(8): C07C205/22C07C201/12
Inventor 李德昌郑从钦刘峰孙健潘颖孙怀爱时召俊李启本
Owner ANHUI BAYI CHEM IND
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