Process for purifying flue gas

US4620492A · kind A · utility

Assignee

• Kernforschungszentrum Karlsruhe GmbH · DE

Inventors

• Hubert Vogg · Karlsruhe, DE
• Hartmut Braun · Karlsruhe, DE
• Gabriele Jindra · Graben-Neudorf, DE

Key dates

• Filing date: Jul 23, 1985
• Grant date: Nov 4, 1986
• Expiry date: Jul 23, 2005

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D53/70
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the purification of flue gas generated during the combustion of waste materials has a first embodiment wherein soluble heavy metals are precipitated and recovered in a compact form and wherein the soluble heavy metal-free extraction residue is returned to the combustion system where noxious organic substances are pyrolyzed. In another embodiment, substantially all of the heavy metals from the flue gas are collected in a single solid residue, which residue may be thermally treated to recover mercury and the treated residues subsequently returned to the combustion system wherein noxious organic substances are pyrolyzed or combined in a hazardous waste stabilizing substance. In yet another embodiment of the process, heavy metals present in an acidic condensate solution from a condensation/scrubbing step are precipitated and the precipitated heavy metals are thermally treated, together with the flue ash, to remove mercury, after which the remaining solids may be returned to the combustion system to pyrolyze noxious organic substances contained therein or may be combined with a hazardous waste stabilization substance.