Sorbent and sorbent composition for mercury removal

A system for removing mercury from combustion gas. The system includes a combustion device, a stack, and a duct system that couples the combustion device to the stack. The system further comprises an injection system that is coupled to the duct system. The injection system injects sorbents including alkali-based sorbents and carbon-based sorbents into the duct system. Preferably the sorbent comprises from about 70% - 95% alkali-based sorbent which include sodium-based sorbents, in particular trona (hydrated sodium bicarbonate carbonate). Preferably the carbon based sorbents include activated-carbon. A particulate filter may be provided downstream of the injection point.