【摘要】 通过超声波辅助溶液浸渍的方法,将K₂S₂O₈、Ca（ClO）₂、（NH₄）₄Ce（SO₄）₄及K₂Cr₂O₇等氧化剂分别浸渍在钙基吸收剂表面,形成具有氧化性的活性位点,即氧化位点,改善钙基吸收剂脱除NO_x的效果。通过正交实验,在不同超声波功率、浸渍时间和浸渍温度下,按照一定掺杂比例,利用氧化剂对钙基吸收剂进行化学调质。将改性后钙基吸收剂在固定床反应器上进行了同时脱硫脱硝实验,选择污染物的平均脱除率作为评价指标。正交实验结果表明:以Ca（ClO）₂作为氧化剂进行超声波浸渍改性效果最好,最优改性工艺参数为氧化剂掺杂比例20%（质量分数,下同）、超声波功率100%、浸渍时间1.5 h、浸渍温度70℃。同时,基于晶相结构（XRD）分析和扫描电镜（SEM）显微形貌观测,可知超声波辅助氧化改性的方法能有效改善钙基吸收剂表面形貌,表面上形成了氧化位点,该氧化位点不仅能够增大吸收剂与SO₂和NO_x的接触,还能促进NO氧化为NO₂,进一步提高SO₂和NO_x的脱除率。更多还原

【Abstract】 In this work, the oxidants such as K₂S₂O₈, Ca（ClO）₂,（NH₄）₄Ce（SO₄）₄ and K₂Cr₂O₇ were impregnated on the surface of calcium-based absorbent by ultrasonic-assisted solution impregnation method, and the active sites with oxidation were formed to improve the effect of cal-cium-based absorbent on NO_x removal. Through orthogonal experiment, under different ultrasonic power, impregnation time and impregnation temperature, the calcium-based absorbent was chemically modified by oxidant according to a certain doping ratio. The simultaneous desulfurization and denitrification experiments of modified calcium-based absorbent were carried out in a fixed bed reactor, and the average removal rate of pollutants was selected as the evaluation index. The orthogonal experiment results showed that Ca（ClO）₂ was the best oxidant for ultrasonic impregnation modification. The optimal modification process parameters were as follows: the oxidant doping ratio of 20%, the ultrasonic power of 100%, the impregnation time of 1.5 h, and the impregnation temperature of 70 ℃. At the same time, based on the crystal structure（XRD） analysis and scanning electron microscopy（SEM）, it can be seen that the ultrasonic-assisted oxidation modification method can effectively improve the surface morphology of calcium-based absorbent, and the oxidation sites are formed on the surface. On the one hand, it can increase the contact between the absorbent and SO₂ and NO_x, on the other hand, it can promote the oxidation of NO to NO₂, and further improve the removal rate of both.更多还原