Abstract: An exemplary embodiment of the present invention provides a method of controlling a PAC-to-particulate ratio in a potion of an exhaust system from a furnace. The method comprises measuring a second amount of particulate exiting a particulate removal system, and controlling a first amount of particulate removed by the particulate removal system based in part on the measured second amount of particulate, such that a desired ratio of PAC-to-particulate is obtained in the portion of the exhaust system.

Abstract: An exemplary embodiment of the present invention provides a method of controlling a PAC-to-particulate ratio in a potion of an exhaust system from a furnace. The method comprises measuring a second amount of particulate exiting a particulate removal system, and controlling a first amount of particulate removed by the particulate removal system based in part on the measured second amount of particulate, such that a desired ratio of PAC-to-particulate is obtained in the portion of the exhaust system.

Abstract: Methods and apparatuses are described for removing a contaminant, such as a vaporous trace metal contaminant like mercury, from a gas stream. In one embodiment, a primary particulate collection device that removes particulate matter is used. In this embodiment, a sorbent filter is placed within the housing of the primary particulate collection device, such as an electrostatic precipitator or a baghouse, to adsorb the contaminant of interest. In another embodiment, a sorbent filter is placed within or after a scrubber, such as a wet scrubber, to adsorb the contaminant of interest. In some embodiments, the invention provides methods and apparatuses that can advantageously be retrofit into existing particulate collection equipment. In some embodiments, the invention provides methods and apparatuses that in addition to removal of a contaminant additionally remove particulate matter from a gas stream.