Patent · US Expired

Removing phenols from waste water

US4162902A · kind A · utility

45Cited by
6References
1Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 30, 1977
Grant dateJul 31, 1979
Priority date
Expiry dateSep 30, 1997

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S210/908
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A process for removing phenols from waste water resulting from the gasification or carbonization of coal and containing CO.sub.2, H.sub.2 S and NH.sub.3, comprising mixing the waste water with a low-boiling organic solvent, separating the mixture into a solvent layer and an aqueous layer, stripping off from the aqueous layer under superatmospheric pressure the vapors of CO.sub.2, H.sub.2 S and organic solvent contained therein, then stripping off from the aqueous layer the NH.sub.3 contained therein leaving a refined aqueous product layer suitable for discharge, scrubbing the stripped vapors under superatmospheric pressure with a portion of the cold refined product to remove organic solvent contained therein, condensing part of the solvent and separating it under superatmospheric pressure, and scrubbing the remaining acid gases still containing ammonia and solvent with recirculated cooled raw phenol to remove the ammonia and solvent.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.