Positive pulsed corona discharge process for simultaneous removal of SO/sub 2/ and NO/sub x/ from iron-ore sintering flue gas

Abstract

We investigated the application of pulsed corona discharge process to the removal of SO/sub 2/ and NO/sub x/ from industrial flue gas of an iron-ore sintering plant. The study was performed on a pilot scale, which is the most advanced demonstration of this process. The flow rate of 5000 m/sup 3//h of the flue gas was successfully treated. The electrode structure of the corona reactor is the same as that of the conventional electrostatic precipitator. We made use of magnetic pulse compression technology to produce repetitive high voltage pulses. The pulse width (full width at half maximum) was reduced to less than 1 /spl mu/s by connecting a resister in parallel with the corona reactor. An inductor was added to the resister in series to minimize the loss by restricting the current flowing through the resister. By this method, we were able to deliver pulse power with peak voltage of 110 kV and peak current of 2.3 kA to the corona reactor. Chemical additives such as ammonia (NH/sub 3/) and propylene (C/sub 3/H/sub 6/) were used to increase the removal efficiencies of SO/sub 2/ and NO/sub x/.