Patent ID: 6447740
Filing Date: 2002-09-10
Classification: B01D,Y02A

Abstract:
A process for oxidizing gaseous pollutants in a flue gas stream composed of flue gases, water vapour and one or more gaseous pollutants selected from the group consisting of SO2, NO, NO2, H2S, and mercury vapour, said oxidized form of the pollutants being more readily removable from the flue gas stream by water absorption than the non-oxidized form thereof, comprising:(a) injecting sufficient chlorine in a gaseous form, a liquid form, or as a chlorine water solution, into the flue gas stream while the flue gas stream is at a temperature greater than 100Â° C. to thereby react the chlorine with the pollutants to form an oxidized flue gas stream comprising flue gases, water vapour and oxidized gaseous pollutants is formed; (b) scrubbing the oxidized flue gas stream with water, or water solution of pH less than or equal to 7; and (c) adding sufficient alkali metal iodide salt to the water or water solution to precipitate the mercury from the water or water solution of pH less than or equal to 7.