Patent ID: 7497172

Claim:
A method of removing mercury and NO x from flue gas produced by combustion devices burning mercury and chlorine containing fuel, the flue gas passing from a combustion zone in which the temperature exceeds 2600° F., through a first temperature zone in which the temperatures range from 1750° F. to 2100° F., through a second temperature zone in which the temperatures range from 900° F. to 1450° F., and through a particle removal device, the method comprising: selecting a reburn fuel containing carbon; preparing a slurry of the reburn fuel and water wherein a ratio of water to reburn fuel is such that when the slurry is injected into the flue gas prior to the first temperature zone where the temperature exceeds 2100° F. and combustion is occurring, a first portion of the reburn fuel will gasify and then will combine with a portion of the NO x in the flue gas and a second portion of the reburn fuel will form activated carbon particles; injecting the slurry into the flue gas prior to the first temperature zone where the temperature exceeds 2100° F. and combustion is occurring, where the first portion of the reburn fuel gasifies and subsequently combines with a portion of the NO x in the flue gas and a second portion of the reburn fuel forms activated carbon particles; passing the flue gas and activated carbon particles through the second temperature zone where the mercury and chlorine present in the flue gas as a result of combustion of the mercury and chlorine containing fuel will combine because of the presence of the activated carbon particles to form HgCl 2 and at least a portion of the HgCl 2 will bind to the activated carbon particles; and directing the flue gas to the particle removal device for removal of the activated carbon particles.