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Method for recovering hydroquinone from dihydric phenol waste residues

A technology of hydroquinone and dihydric phenol, which is applied in the field of recovery of hydroquinone, can solve the problems of environmental pollution, volatile, waste of resources, etc., achieve considerable economic benefits, simple operation, and reduce environmental pollution

Active Publication Date: 2014-01-22
QINGDAO UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is no good way to deal with this kind of waste residue at present, and the method of incineration can only be used.
There are great disadvantages when incinerating dihydric phenol waste residue: firstly, the hydroquinone contained in the dihydric phenol waste residue has not been rationally utilized, resulting in the waste of a large amount of resources; secondly, due to the existence of hydroquinone, the combustion process It will produce a large amount of toxic gas and cause environmental pollution, and because hydroquinone is easier to volatilize than other components in the waste residue, even if it is not burned, it will cause a certain degree of pollution to the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Firstly, the solid dihydric phenol waste residue discharged from the production process of hydroquinone is crushed to 60 meshes, and the organic solvent glycerin is added to the waste residue, and the mass ratio of the added glycerol to waste residue is 1.0, so that the dihydric phenol waste residue is fully dissolved in glycerol; then adopt intermittent vacuum rectification to steam hydroquinone together with glycerin from the top of the tower, the top pressure is controlled at 10kPa, the reflux ratio at the top of the tower is 3, and the rectification time is 0.6 hour; finally Add extractant diethyl ether to extract hydroquinone in the overhead distillate, the mass ratio of extractant and distillate is 1.0, after adding diethyl ether, the solution is stirred, the stirring speed is 150r / min, the extraction time is 40min, and the extraction temperature is 25°C, after the extraction is completed, let the solution stand at room temperature for 30 minutes, after layering, t...

Embodiment 2

[0016] First, the solid dihydric phenol waste residue is crushed to 80 meshes, and the organic solvent glycerin is added to the waste residue. Pressure rectification distills hydroquinone and glycerol from the top of the tower, the top pressure is controlled at 10kPa, the top reflux ratio is 4, and the rectification time is 1 hour; Hydroquinone was extracted with diethyl ether, the mass ratio of extractant to distillate was 1.5, the solution was stirred after adding diethyl ether, the stirring speed was 200r / min, the extraction time was 40min, the extraction temperature was 30°C, and the solution was cooled to room temperature after the extraction was completed. After standing still for 50 min, the extract phase was separated and evaporated and crystallized at 80°C to obtain the hydroquinone product.

[0017] The total recovery rate of hydroquinone in this example reaches 91%, which shows that this scheme can well achieve the effect of hydroquinone recovery.

Embodiment 3

[0019] Firstly, the solid dihydric phenol waste residue is crushed to 80 meshes, and the organic solvent glycerin is added to the waste residue. Pressure rectification distills hydroquinone and glycerol from the top of the tower, the top pressure is controlled at 5kPa, the top reflux ratio is 5, and the rectification time is 1.5 hours; Hydroquinone was extracted with isopropyl ether, the mass ratio of extractant to distillate was 1.3, the solution was stirred after adding isopropyl ether, the stirring speed was 200r / min, the extraction time was 60min, the extraction temperature was 35°C, and the extraction was completed Afterwards, the solution was allowed to stand at room temperature for 30 minutes, and after the layers were separated, the extract phase was evaporated and crystallized at 80° C. to obtain the hydroquinone product.

[0020] The total recovery rate of hydroquinone in this example reaches 85%, which shows that this scheme can well achieve the effect of hydroquino...

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Abstract

The invention relates to a method for recovering hydroquinone from dihydric phenol waste residues, which comprises the following steps of: firstly crushing the solid dihydric phenol waste residues and adding glycerol serving as an organic solvent into the waste residues, so that the dihydric phenol waste residues are fully dissolved; then steaming the hydroquinone and the glycerol from the top of a tower by adopting intermittent vacuum distillation, controlling the pressure of the top of the tower to be within the range of 4-60 kPa, the temperature reflux ratio of the top of the tower to be within the range of 2-7 and the distillation time to be within the range of 0.5-2 hours and discharging residual tar waste residues from the bottom of the tower to be used as fuel; and finally adding ether or isopropyl ether serving as an extracting agent into distillate at the top of the tower to extract the hydroquinone, agitating solution after the extracting agent is added, standing the solution at a room temperature after the completion of extraction and carrying out evaporation and crystallization on extract phase at a temperature of 50-100 DEG C after layering to obtain a dihydric phenol product. The method has the beneficial effects that the operation is simple; the recovery rate of the hydroquinone can reach above 80 percent; and not only are the waste residues treated, and is the environmental pollution reduced, but also the considerable economic benefits can be obtained.

Description

Technical field: [0001] The invention relates to a method for recovering hydroquinone from dihydric phenol waste residue, in particular to a method for recovering hydroquinone from dihydric phenol waste residue discharged from the hydroquinone production process. Background technique: [0002] With the continuous improvement of my country's hydroquinone production technology, the production capacity of hydroquinone has been increasing year by year. In the process of hydroquinone production and product separation, since dihydric phenol is a heat-sensitive substance, it is very easy to oxidize and condense to form tar by-products. The dihydric phenol waste residue discharged after production contains 8.0% hydroquinone. Moreover, the amount of dihydric phenol waste residue discharged every year also shows an increasing trend year by year. However, there is no good way to deal with this kind of waste residue at present, and the method of incineration can only be used. There ar...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C39/08C07C37/70
Inventor 项曙光孙晓岩夏力
Owner QINGDAO UNIV OF SCI & TECH
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