Method for separating dichlorophenol mixture by cross-current dissociation extraction

Abstract

The invention discloses a method for separating dichlorophenol mixture by cross-current dissociation extraction. The method includes the following steps that: the dichlorophenol mixture as a material is dissolved in organic solvent to prepare mixed dichlorophenol solution, aqueous inorganic alkali solution is adopted as an extracting agent, and after cross-current dissociation extraction, the organic layer is distilled, so that 2, 4-dichlorophenol is obtained. Since the method adopts cross-current dissociation extraction to separate the dichlorophenol mixture, the technique and equipment are simple, the usages of the organic solvent and the alkali is small, the consumption of material and energy is reduced, 98 percent of 2, 4-dichlorophenol can be obtained, meanwhile, the recovery rate of2, 4-dichlorophenol is more than 95 percent, and the recovery rate of the organic solvent exceeds 99 percent.

Description

technical field

[0001] The invention relates to a chemical separation method of mixed dichlorophenols, in particular to a cross-flow dissociation extraction separation method of mixed dichlorophenols. Background technique

[0002] An important use of 2,4-dichlorophenol is to produce dichlorophenoxy acid and its ester herbicides. At present, most of these products use mixed dichlorophenol with a 2,4-dichlorophenol content of about 90%, of which more than 90% is produced by the enterprise itself by the direct chlorination of phenol. When the chlorination of phenol reaches a certain depth, the chlorinated product is mainly 2,4-dichlorophenol (about 90%), and the main impurities are 2,6-dichlorophenol and 2,4,6-trichlorophenol. Due to the low purity of 2,4-dichlorophenol, the yield of dichlorophenoxy acid and its ester herbicides produced is low and the amount of three wastes is large. With the increasing emphasis on environmental protection and the requirement for the purity ...

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