Dephenolizing method for phenol-containing wastewater

Abstract

The invention provides a dephenolizing method for phenol-containing wastewater. The dephenolizing method for the phenol-containing wastewater comprises the following steps: a, mixing phenol-containing wastewater and an extracting agent which takes methyl terschyl ether as a main body and extracting in an extracting tower or a multi-stage mixer-settler to obtain a solvent phase and a raffinate aqueous phase; b, rectifying the solvent by a rectification process and recycling the solvent and coarse phenol, wherein the rectifying tower theoretical stage is 15 to 25, the reflux ratio is 0.1 to 1, the operating pressure is 0.1 to 0.91 MPa, the tower top operating temperature is 50 to 90 DEG C, and the tower bottom temperature is 150 to 300 DEG C; c, distilling the raffinate aqueous phase by a distillation solvent recovery process and recycling residual extracting solvent, wherein the tower top temperature is 62 to 90 DEG C, the tower bottom temperature is 100 to 130 DEG C, and the amount of a material which is distilled from the top of the tower is 1.5 to 5 percent of that of a fed material; d, recycling the extracting solvent. The dephenolizing method for the phenol-containing wastewater has the beneficial effects that the process flow is simple; the equipment investment is low; the solvent recycling energy consumption is low; the recycling rate of the phenol is high.

Description

technical field [0001] The invention relates to a method for dephenolizing waste water containing phenol. Background technique [0002] In the dry distillation, drying and gasification process of low-quality coal, a large amount of gasification wastewater will be produced, containing high concentrations of phenols and other pollutants. Phenols have strong biological toxicity and great harm. At the same time, phenols are also important chemical raw materials. Therefore, the efficient removal and recovery of phenolic substances in coal chemical wastewater is not only of environmental significance, but also of certain economic significance. [0003] At present, in industrial installations, liquid-liquid extraction is the most widely used, stable and mature dephenolization method. For coal chemical wastewater, currently commonly used extractants include diisopropyl ether, methyl isobutyl ketone, crude benzene, and medium oil. But these extractants all have their obvious defec...

AI Technical Summary

Problems solved by technology

But these extractants all have their obvious defects, such as the diisopropyl ether has weak extraction ability to polyphenols, the energy consumption of methyl isobutyl ketone is too high when solvent recovery is carried out, crude benzene and medium oil not only have low extraction rate, and only It can recover solvents by adopting back-extraction process with complex process and secondary pollution