A pilot investigation on oxidation of ammonium sulfite by streamer corona plasma

For ammonia flue gas desulfurization (FGD), the sulfite to sulfate oxidation is very critical for industrial applications. This paper reports a novel corona plasma-induced oxidation technique to convert concentrated ammonium sulfites to sulfates in an aqueous solution. The streamer corona plasmas are generated with a dc superimposed ac power source. Ammonium sulfite solution is sprayed in a reactor by using two-phase nozzles. When the sulfite concentration is around 1–3 mol L−1, the oxidation efficiency after one-cycle processing is in the range of 20–60%. Multiple-cycle treatments can be used to improve the oxidation efficiency. The energy consumption is around 20 Wh mol−1. Based on the present investigations, we anticipate that an industrial plasma-assisted ammonium FGD can be applied in industries.