Industrial experiments on pulse corona simultaneous removal of NOx and SO2 from flue gas

The corona-induced simultaneous removal of NO/sub x/ and SO/sub 2/ from flue gas, which is based on the application of narrow voltage pulses to an electrode structure similar to that of an electrostatic precipitator is studied. The free electrons of the corona discharge, having energy up to 20 eV, originate active radicals which lead to the transformation of NO/sub x/ and SO/sub 2/ into their acids, which can be neutralized to salt particulate by adding to the gas a basic compound, such as ammonia or calcium hydroxide. The process has been investigated with a test rig installed in the slipstream of the flue gas duct of a coal thermal power plant. The experiments were performed with three reactor modules of different geometries having a nominal gas flow rate of 1000 Nm/sup 3//h. The voltage pulses, generated with a fast switching experimental device, had a rise front less than 400 ns and a repetition frequency up to 300 Hz. The test results confirm the physical feasibility of the process.<>