Novel catalytic process for flue gas conditioning in electrostatic precipitators of coal-fired power plants.

One of the most important environmental protection problems for coal-fired power plants is prevention of atmospheric pollution of flying ash. The ash particles are typically removed from flue gases by means of electrostatic precipitators, for which the efficiency may be significantly increased by lowering the resistance of fly ash, which may be achieved by controlled addition of microamounts of sulfur trioxide (SO3) into the flue gases. This paper describes the novel technology for production of SO3 by sulfur dioxide (SO2) oxidation using the combined catalytic system consisting of conventional vanadium catalyst and novel platinum catalyst on the base of silicazirconia glass-fiber supports. This combination provides highly efficient SO, oxidation in a wide temperature range with achievement of high SO, conversion. The performed pilot tests have demonstrated reliable and stable operation, excellent resistance of the novel catalytic system to deactivation, and high overall efficiency of the proposed process. The scale of the plant was equivalent to the commercial prototype; therefore, no further scale-up of the oxidation process is required.