冷冻干燥法制备改性电石渣同时脱硫脱硝研究

Research on simultaneous desulfurization and denitrification during the preparation of modified carbide slag by freeze-drying method

为了进一步提高对电石渣的资源化利用,本文以电石渣为原料,采用碳酸氢钾(KHCO_(3))浸渍与冷冻干燥法相结合制备改性电石渣用于烟气同时脱硫脱硝.结果表明与普通烘干相比,采用冷冻干燥法制备的改性电石渣具有更高的脱除效果,在反应前90 min内二氧化硫(SO_(2))脱除率保持在100%,SO_(2)脱除的有效时间增加15 min;一氧化氮(NO)的脱除效率提高15%,有效时间增加35 min,反应活化能降低5.69 kJ·mol^(-1).材料的SO_(2)和NO吸附容量分别提高到1.18和2.05倍.通过物理化学表征分析发现:采用冷冻干燥法制备的材料其主要的活性物质C=O含量明显上升,孔径得以提高,并且钾元素也分布更加均匀,更有利于改性电石渣脱除SO_(2)/NO.

To further enhance the utilization of carbide slag resources,this study prepared modified carbide slag using potassium bicarbonate(KHCO_(3)) impregnation combined with freeze-drying.The resulting modified carbide slag can be employed for simultaneous desulfurization and denitrification of flue gas.Comparative to modified carbide slag prepared through conventional drying,the freeze-dried modified carbide slag demonstrates higher efficiency in removing SO_(2) and NO.The removal rate of sulfur dioxide(SO_(2)) remains at 100% within the initial 90 minutes of the reaction,with an additional effective time of 15 minutes.The removal efficiency of nitrogen monoxide(NO) increases by 15%,with an additional effective time of 35 minutes,and the reaction activation energy decreases by 5.69 kJ·mol^(-1).The SO_(2) and NO adsorption capacities of the modified carbide slag increase by 1.18 and 2.05 times,respectively.Physical and chemical characterization analysis reveals that the material prepared by freeze-drying shows a significant increase in the content of active substance C=O,an improvement in pore size,and a more uniform distribution of potassium elements,which is more conducive to the removal of SO_(2) and NO by modified carbide slag.