The PCO process for photochemical removal of mercury from flue gas

A promising technology has been developed to capture and remove elemental mercury species from coal-fired power plants. Powerspan Corp. has licensed the technology and initiated a bench and pilot test program to develop the Photochemical Oxidation, or PCO™, process for commercial application with subbituminous and lignite fuels. ocess has the potential to serve as a low cost mercury oxidation technology that will facilitate elemental mercury removal in a downstream SO2 scrubber, wet electrostatic precipitator (WESP), or baghouse. It uses 254-nm (nanometer) ultraviolet light from a mercury lamp to produce an excited state mercury species in the flue gas, leading to oxidation of elemental mercury. This paper presents results of Powerspanʹs initial bench-scale testing on a simulated flue gas stream. Preliminary testing conducted in Powerspanʹs bench-scale facility showed greater than 90% oxidation and removal of elemental mercury. The process also has potential to serve as a low cost method for the removal of mercury from waste incinerator flue gases.