煤浆催化氧化法烟气脱硫研究

基于液相催化氧化原理,以煤浆做洗涤介质进行烟气脱硫。此法起催化作用的Fe2+/Fe3+离子通过SO2、O2和煤中的黄铁矿作用而现场产生。实验过程控制模拟烟气中的SO2摩尔分率和O2浓度范围分别为760×10-6￣3200×10-6和3%￣20%。实验表明,反应温度约在40℃以上时,脱硫率即达90%以上。二氧化硫浓度增大,脱硫率呈下降趋势,与石灰/石灰石脱硫过程类似。在实验范围内,pH值和氧气浓度对脱硫率基本没有影响,实际烟气中的O2浓度完全满足催化氧化反应的需要。随烟气脱硫过程的进行,脱硫浆液中的总铁含量不断增加,说明煤中黄铁矿被不断浸出,故此法在脱除烟气中的二氧化硫的同时也降低了煤中的黄铁矿硫。

Flue Gas Desulfurization through Catalytic Oxidation of Coal Slurry

Based on the principle of aqueous catalyzed oxidation,coal slurries were used as SO2 scrubbing medium.The catalyst Fe2+/Fe3+ was produced in situ through the reaction of coal pyrite with SO2 and O2.Experimental concentration ranges of SO2 and O2 in the gas were 760Х10-6～ 3200Х10-6 and 3%～20% respectively.SO2 removal efficiency was more than 90% when the reaction temperature was above 40℃.SO2 removal efficiency decreased as SO2 concentration increased,which was similar as the wet lime/limestone flue gas desulfurization process.No significant effects were observed of pH value and O2 concentration on SO2 removal within the experimental range,and O2 concentration in actual flue gas was enough for the catalyzed oxidation.Total iron ion concentration in the slurry increased as the desulfurization reaction proceeded,which showed that the coal pyrite was being leached.This method can not only achieve high flue gas desulfurization efficiency but also reduce pyretic sulphur from coal.