Abstract: In a method of removing metals such as mercury from flue gas produced by combustion devices, water or water including a calcium-containing component or water including Cl? anion formers or water including both a calcium-containing component and Cl? anion formers is injected into the flue gas in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature from about 250° F. to about 350° F. to retain the mercury within the aqueous phase. After the water evaporates, the oxidized mercury is retained on the dry flyash particles present in the flue gas. These flyash particles bound with the oxidized mercury are removed from the flue gas by a particulate removal device, such as an electrostatic precipitator, baghouse filter or cyclone.

Abstract: In a method of removing metals such as mercury from flue gas produced by combustion devices, water or water including a calcium-containing component or water including Cl? anion formers or water including both a calcium-containing component and Cl? anion formers is injected into the flue gas in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature from about 250° F. to about 350° F. to retain the mercury within the aqueous phase. After the water evaporates, the oxidized mercury is retained on the dry flyash particles present in the flue gas. These flyash particles bound with the oxidized mercury are removed from the flue gas by a particulate removal device, such as an electrostatic precipitator, baghouse filter or cyclone.

Abstract: In a method for removing mercury from flue gas produced by combustion devices burning coal and other fuels that contain mercury and chlorine the combustion process is controlled to generate a flue gas comprising fly ash containing at least 0.25% unburned carbon, and preferably at least 5.0% unburned carbon. In addition the flue gas is rapidly cooled from a temperature within the range of 1450° F. to 900° F. to a temperature below 900° F. at a rate of at least 1000° F. per second. This step will enhance the concentrations of Cl-atoms and Cl2, which accelerates the rates of mercury oxidation in both the gas phase and on particle surfaces. Finally, the flue gas is directed to the particle removal device for removal of the fly ash to which some of the mercury is bound, and also directed to a wet scrubber for retention of the oxidized mercury vapor in wastewater and solid effluents.