Process of extracting phenols from a phenol-containing waste water by means of a solvent mixture
US5716524A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1997 |
| Grant date | Feb 10, 1998 |
| Priority date | — |
| Expiry date | Feb 24, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/909
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Phenols are extracted from a phenol-containing waste water by means of two solvents A and B. The waste water is first of all passed through a first extraction zone, and then through a second extraction zone. To the first extraction zone a mixture of the solvents A and B is supplied, and into the second extraction zone at least one of the two solvents is introduced. From the first extraction zone, solvent-mixture loaded with phenols is withdrawn, phenols am separated therefrom, and the solvents are used again in at least one of the extraction zones. Solvent B is lower-boiling and has a lower water solubility at a temperature in the range from 10.degree. to 60.degree. C. than solvent A. Solvent B has a water solubility at 40.degree. C. of up to 2 wt.-% and a boiling point at 1 bar of 50.degree. to 100.degree. C., and it is miscible with solvent A. Solvent A has a boiling point at 1 bar of not more than 172.degree. C. and a water solubility at 40.degree. C. of not more than 5 wt.-%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.