Method and apparatus for removing mercury species from hot flue gas

A method of removing mercury from flue gas containing mercury and particulate solids emanating from a fossil-fuel energy conversion plant and passing through a flue gas duct, said method comprising the following steps:

• (a) contacting the mercury in the flue gas with a solution containing at least one chloride-containing salt dissolved in a solvent by injecting the solution into the flue gas duct at an injection location, in order to oxidize mercury into HgCl2;
• (b) heating the solution to at least about 300° C. by either (b1) selecting the injection location so that the flue gas temperature in the flue gas duct at the injection location is from about 370° C. to about 650° C., and heating the solution to at least about 300° C. prior to injecting the solution into the flue gas duct, or (b2) selecting the injection location so that the flue gas temperature in the flue gas duct at the injection location is from about 650° C. to about 980° C., thereby rapidly heating the solution to at least about 300° C. upon injection of the solution into the flue gas duct;
• and
• (c) removing oxidized mercury from the flue gas with means for removing particulate solids from the flue gas.