Streamer plasma induced ammonia flue gas desulfurization

A streamer plasma induced flue gas desulfurization (FGD) technique is reported. An AC/DC superposition electric source generated a spatially well distributed plasma in an industrial scale reactor. Instead of the traditional dry technique, a partitioned wet reactor system was adopted. A streamer plasma oxidation technique was developed to solve the problem in the oxidation of concentrated ammonium sulfite solution. The ammonia slip was well controlled. The liquid byproduct was dried up to form solid ammonium sulfate. Pilot test under the conditions of an initial concentration of 500-1000 μl·L^-1 of SO₂ demonstrated the desulfurization efficiency greater than 95%. The oxidation efficiency through one cycle reached 50%-70%, the energy consumption in the reactor was less than 3.5 W·h·m^-3, and the ammonia slip was less than 5 μl·L^-1. The byproduct was ammonium fertilizer. Under the conditions of using high concentration OH radicals excited with AC/DC streamer plasmas, an oxidation rate with practical value can be achieved at a sulfite concentration of over 3 mol·L^-1.