Separation and purification system and method for phenol and hydrogen peroxide hydroxylation reaction mixed liquid

Abstract

The invention provides a separation and purification system and method for a phenol and hydrogen peroxide hydroxylation reaction mixed liquid. The system comprises a double-effect dehydration flash evaporator, a first-effect dehydration flash evaporator, a double-effect dehydration rectifying tower, a first-effect dehydration phenol removal tower, a catechol removal tower, a catechol crude distillation tower, a catechol rectifying tower, a tar crude distillation and dilution evaporation assembly and a m-hydroquinone / hydroquinone separation tower which are connected in series, the resorcinol rectifying tower and the hydroquinone rectifying tower are respectively connected with the upper part and the lower part of the m / hydroquinone separating tower. During separation and purification, the reaction liquid is sequentially subjected to the procedures of double-effect flash dehydration, double-effect rectification dehydration, first-effect dehydration and dephenolization, catechol removal, catechol crude distillation and rectification, tar crude distillation and mixed diphenol separation, and through the procedures, the product energy consumption is reduced, and meanwhile, the product requirements of high-end customers in the market are met; and the operation is simple and convenient and the production is stable.

Description

technical field [0001] The invention belongs to the technical field of chemical separation, and in particular relates to a separation and purification system and method for a mixed liquid of phenol and hydrogen peroxide hydroxylation reaction. Background technique [0002] Hydroquinone, the molecular formula is C 6 H 6 O 2 , with three isomers: ortho, meta and para, all three isomers are used as important chemical raw materials and intermediates, and have a wide range of applications: [0003] Catechol, also known as catechol, is a compound formed after two ortho-position hydrogens of benzene are replaced by hydroxyl groups. It is an important basic organic chemical raw material and an important intermediate in the pharmaceutical industry. It is widely used in the production of dyes and light stabilizers. , photosensitive materials, fragrances, preservatives, accelerators, special inks, electroplating materials, raw lacquer flame retardants, in addition, is a widely used ...

AI Technical Summary

Problems solved by technology

[0010] However, these technologies still inevitably have certain defects: Although the latter patent of Tianjin University has optimized energy saving and consumption reduction and the purity of hydroquinone products compared with the former, there are still problems such as high energy consumption in the dehydration tower and satisfactory quality of catechol products. It does not meet the defects required by high-end customers in the market; at the same time, the product in the tar is extracted by a deep steamer in its process, and there is more hydroquinone in the tar due to the expansion of the tar

The patent CN101054340A of Shanghai Huayi Acrylic Acid Co., Ltd. puts the tar in the final step of separation. The tar stays for a long time and is easy to expand, carbonize, and crack. It cannot be produced normally and the purity of the product is polluted.

[0011] Although the patents of Rhone Planck Company and Rhodea Chemical Company use a wiped film evaporator in the tar extraction, the content of hydroquinone in the tar is reduced, but due to the characteristics of the tar, the content of hydroquinone in the tar is still high 4%, and the viscosity of tar is high, and the difficulty of discharge will easily lead to production obstruction, high energy consumption for dehydration and dephenolization, and the quality of catechol products cannot meet the requirements of high-end customers in the market; in addition, the melting crystallizer is used in the patent of Rhodia Chemical Obtaining resorcinol and hydroquinone is difficult to operate and has relatively high requirements for public works

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