Lowering the Cost of Mercury Removal from Flue Gases

Emissions of mercury and other air toxics from fossil fuel combustion have recently become a major concern. If they become regulated, it could have large economic effects on the electric utility industry. Activated carbon injection is the dominant method of dedicated mercury control. The activated carbons used for mercury control, however, are very expensive. A method of recycling injected activated carbon back into the flue gas stream is proposed. Any carbons used would be injected along with a new SO2-control sorbent that the Proposers have developed, called "supported-sorbent." This new sorbent is designed to be injected into the ash-free flue gas after the primary particulate control device and collected in a smaller, second device, such as a high-ratio baghouse.