流光放电等离子体液相氧化亚硫酸铵

Oxidation of Ammonium Sulfite in Aqueous Solutions with Streamer Plasmas

在氨-硫铵法烟气脱硫中,一个关键环节是将副产物的四价硫S(IV)氧化为六价硫S(VI).采用可规模化的流光放电液相氧化技术,通过交直流叠加(AC/DC)电源,激发气体放电产生等离子体对氨法脱硫高浓度的亚硫酸铵进行氧化.实验测量了该氧化过程与溶液浓度、放电功率密度、溶液pH值、温度以及传质效率因子等各种参数的关系.研究表明,在亚硫酸铵摩尔浓度为3mol·L-1时,可以获得有实用价值的反应速率,摩尔能耗减低到50Wh·mol-1以下,显示出很好的应用前景.

A streamer corona plasma induced oxidation technique, which used the so called AC/DC power supply to convert high concentration ammonium sulfite to sulfate was reported. The results showed that the sulfite oxidation rate was significantly higher than that in the forced air oxidation process. Research of using streamer discharge plasmas, to oxidize high concentration ammonium sulfite in the liquid phase, has obtained a remarkable progress. On the basis of the experiment results, the following conclusions could be arrived at： （1） In contrast to the plasma-induced oxidation, the spontaneous oxidations gave negligible contributions to convert sulfite to sulfate. （2） When the initial sulfite concentration was within 1-3 mol·L^-1, plasma induced one-cycle oxidation efficiency was in the range of 20%-60%. The oxidation rate was faster than that at concentrations less than 1 mol·L^-1. To make the technique industrially applicable, the plasma induced oxidation process should be performed under the initial concentration more than 1 mol·L^-1. （3） With the increase of the power density, the molar energy consumption of ammonium sulfite oxidation increased faster than the oxidation efficiency did, which indicated that radical-radical termination reactions dominated the process.