Industrial experiments on pulse corona simultaneous removal of NO x and SO2 from flue gas

The corona-induced simultaneous removal of NO_x and SO ₂ from flue gas is based on the application of narrow voltage pulses to an electrode structure similar to that of an electrostatic precipitator. The free electrons of the corona discharge, having energy up to 20 eV, originate active radicals which lead to the transformation of NO_x and SO₂ into their acids which can be neutralized to salt particulate by adding to the gas a basic compound such as ammonia and calcium hydroxide. The process has been investigated with a test rig installed in the slipstream of the flue gas duct of a coal-fired thermal power plant. The experiments were performed with three reactor modules of different geometries. Further experiments are necessary to assess the effect of different electrode geometries of the reactor, the efficiency of the process attainable with an improved coupling of narrow pulse power set to the reactor, and the practical ways for integrating the DeNO_x and DeSO₂ corona process with the solid particle collection system