2009 R&D 100 Winner
A significant amount of the anthropogenic mercury in the environment comes from flue gas produced when coal is burned in electric utility boilers. The National Energy Technology Laboratory’s (Pittsburgh, Pa.) Thief Process for the Removal of Mercury from Flue Gas is a new, low-cost method of removing this mercury—a well-known toxin—from the flue gas. The process involves extracting a small portion of the partially burned coal from the combustion unit using a suction pipe called a “thief” and injecting it in the flue gas downstream of the boiler. Here, the partially burned coal acts like activated carbon to soak up mercury in the flue gas. The key to the Thief Process is that it reduces mercury remediation costs by using a small portion of the coal already on hand—and actually in the combustion unit—instead of expensive activated carbon. Thief technology has been proven effective from the laboratory scale to the demonstration scale, matching the performance of activated carbon for a small fraction of the cost. The process can also be added on or retrofitted to existing power plant combustion units.
Technology
Process to remove mercury from flue gas
Developer
National Energy Technology Laboratory