Experimental Research Of AC/DC Streamer Plasmas In Flue Gas Desulfurization

This research aims at developing a novel streamer plasma flue gas desulfurization technological process by use of a gas discharge plasma and chemical method. Its creative points lie in (1) Using power supplies with DC superimposed with AC (AC/DC) to generate well spatially distributed streamer plasmas in industrially scaled reactors. The development of AC/DC power supply, makes the plasma generator no longer limited by the pulse power device and its large-scale industrial application possible.(2) Using a partitioned wet reactive technological process to separate the multi-cycled thermal chemical absorption region of SO2with NH3from the plasma radical chain reaction region. The absorption of SO2mainly take place in the thermal chemical absorption region, while the enhanced absorption of remainder SO2, the oxidation of ammonium sulfites, the NH3slip control and the SO3mist removal be performed in the successive plasma region.(3) Using the plasmas to oxidize the sulfites in the concentrated solution to covert the sulfites into sulfates. By use of the partitioned wet reactor the electric discharge power is concentrated to act on the concentrated sulfite solution from the absorption region, so that the oxidation speed can be increased. Through semi-industrial scaled flue gas desulfurization tests under the conditions of initial SO2concentrations within500～1000μl·L-1the desulfurization efficiency greater than95%, one-cycle oxidation efficiency of ammonium sulfite of1～3mol-L-1within20%～60%, molar energy consumption less than20Wh·mol-1, energy consumption less than3.5Wh-Nm-3, ammonia slip less than5μl·L-1and a byproduct of qualified agricultural fertilizer are obtained. The wet reactive technological process avoided the problem of the solid byproducts sticking to the walls of the plasma reactor, and the entire technological process can be kept steady and continuous. That demonstrates that the desulfurization technological process with the streamer plasma ammonia method has a favorable prospect in industrial applications.