不同性能掺炭纤维脱除燃煤烟气中Hg^0的试验研究

通过固定床实验系统的烟气脱除零价汞实验,研究了活性炭纤维协同滤袋用聚酰亚胺、芳纶1313、聚苯硫醚、玻璃纤维、芳砜纶以及聚四氟乙烯等常用纤维,对烟气中零价汞的脱除效果。研究了改性前不同性能掺炭纤维,以及用质量分数分别为5%、10%、15%的溴化钾、碘化钾溶液改性后的活性炭纤维(activated carbon fiber,ACF)和聚苯硫醚(polyphenylene sulfide,PPS)形成的掺炭纤维,对模拟燃煤烟气中零价汞(Hg0)的吸附性能。结果表明:在汞蒸气入口浓度为30μg/m3,吸附温度为160℃时,不同性能掺炭纤维脱Hg0率在39%～71%范围之间变化,区别较大。经过溴化钾和碘化钾改性后的ACF+PPS掺炭纤维对Hg0的吸附效率分别能达到80%、90%以上,未改性ACF+PPS掺炭纤维的吸附效率最高也只有70%左右;相同质量分数时,碘化钾溶液改性后的ACF+PPS掺炭纤维对Hg0的吸附效果要优于溴化钾溶液改性后的ACF+PPS掺炭纤维,并且碘化钾溶液浓度越大,改性后的ACF+PPS掺炭纤维对Hg0的吸附效果越好,当用质量分数为15%的碘化钾溶液改性后的ACF+PPS掺炭纤维吸附Hg0一定时间后,对Hg0的脱除率可以达到98%以上,因此,经过改性后的掺炭纤维能保持较高的烟气脱Hg0率。

速差射流引射型喷吹管喷嘴出口流场特性分析

速差射流引流型脉冲喷吹清灰这种新的清灰方法,可以引射更多的清洁气体到喷吹系统中,提高了清灰效率,由于其喷吹气流平顺,均匀地喷吹滤袋,避免了滤袋极易被吹坏,延长了滤袋的使用寿命。采用二维稳态单方程湍流模型对脉冲袋式除尘器速差射流引流型脉冲喷吹气流流场进行了数值模拟。结果表明,速差射流引流型脉冲喷吹管在气流流态方面具有很好的效果,可用于袋式除尘器脉冲反吹系统的优化设计。

活性炭对染料废水的脱色研究

采用一种高比表面积活性炭吸附处理活性蓝溶液模拟废水。测定了所用的活性炭以及活性蓝染料的物理和化学参数,考察了pH、盐离子浓度对活性炭吸附活性蓝染料的影响。结果表明：在pH〈4时活性炭对染料的去除率最高,pH〉8时最低,在pH=4－8之间的去除率大致相等。中性条件下,增大溶液的离子强度能增加染料去除率,而碱性条件下相反。高初始浓度的染料体系中,增大盐离子强度能增加染料去除率,低初始浓度的染料体系中相反。

Structural Performance and Characterization of Polyimide Doped Activated Carbon Fibers for Mercury Adsorption

Structure characteristics about activated carbon fibers (ACF) and polyimide (P84) doped ACF modified by HNO3 solution were studied to apply in mercury removal in coal-fired flue gases. The P84, which was always used in the non-woven fabric for bag filter, was intermingled with polyacrylonitrile-based ACF (PAN-ACF) in the weight ratio of 1∶1 in order to make the doped ACF with P84 (doped-ACF-P84). Then the doped-ACF-P84 fibers were modified by HNO3 solution. The structure and morphology of doped-ACF-P84 were characterized and compared with those of ACF and doped-ACF-P84 modified by HNO3solution. The results show that the modified doped-ACF-P84 fibers have almost the same pore structure and specific surface area comparing with the original one. However, contrasted with the original PAN-ACF, the doped-ACF-P84 fibers modified by HNO3 solution have more oxygen-containing groups used for mercury removal. In particular, they have more lactone and carboxyl groups.