Abstract: In a method for removing NOx from the flue gas using a coal water slurry, other carbon containing fuel and water, or unburned carbon existing in the furnace itself due to continuing combustion, the ratio of carbon to water is adjusted so that a portion of the carbon forms activated carbon after injection of the fuel slurry into the flue gas. The activated carbon is then available to collect mercury chloride from the flue gas which has been formed through the enhancement of the mercury and chlorine oxidation reaction, enhanced through the heterogeneous reaction mechanism of this same activated carbon in the primary combustion fuel.

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.

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: Ammonia and optionally carbon monoxide are injected into the flue gas containing metals such as mercury in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature of from 900° F. to 1,450° F. to oxidize the metals within the flue gas. The oxidized metals are then attracted to particulates present in the flue gas. Oxidation is facilitated by a reaction zone stabilizer through which the flue gas flows. The stabilizer provides a stable continuous ignition front. These particulates bound with oxidized metals are removed from the flue gas by a particulate removal device such as an electrostatic precipitator or baghouse. After the ammonia is injected, the flue gas can be rapidly cooled to a temperature below 500° F. to minimize decomposition of oxidized metals in the flue gas.

Abstract: A method is disclosed which overcomes the problems which tend to occur in the retrofitting of coal burners for low-NOx emission. A gaseous or volatile liquid fuel is introduced into the primary or secondary air with the amount ranging from 2% to 25% of the boiler energy input as necessary to achieve the necessary NOx reduction and improved load following without operational problems. Optionally gas can be injected through gas burners in an amount ranging from 2% to 50% of the boiler energy input.