Onsite Powder Activated Carbon Production Using Hot Oxygen and Utility Supplied Coals

摘要

Powder activated carbon (PAC) injection has been shown to be effective in capturing mercury from many coal-fired power plants. For some coals, such as many bituminous coals, a standard (undoped) activated carbon can be used. Effective mercury capture for plants firing sub-bituminous or lignite coals typically requires doped activated carbons. Although these carbons are currently commercially available, their current production is relatively limited compared to the anticipated quantities required for mercury control. A rapid increase in production capacity may be difficult since PAC production is a complicated, energy and capital intensive process. Chunks of feedstock are typically pyrolized over long residence times in rotary kilns. The resultant coke is then activated in a second processing step using either steam or chemicals. Finally the activated material is pulverized to very fine sizes to produce the final PAC. Doping is typically done after the material has been produced in another processing step.