PTFE复合材料吸附烟气中SO2和Hg的实验研究

STUDY ON ABSORBING SULFUR DIOXIDE AND MERCURY FROM SIMULATED FLUE GAS BY PTFE COMPOSITE MATERIALS

以煤质活性炭为原料、乙醇溶液为分散剂和PTFE(聚四氟乙烯)乳液为粘结剂制备了PTFE复合材料吸附剂,采用KI浸渍负载和HNO3浸渍氧化的方法对复合材料进行了改性以提高其对烟气中SO2和Hg的吸附性能。采用固定床吸附性能评价装置对复合材料的脱硫脱汞性能进行了评价,并对不同改性方法的可能吸附机理进行了分析。结果表明:复合材料的SO2吸附寿命延长了2倍,这可能是由于PTFE的疏水性能造成的。并且复合材料经两种方法改性处理后,脱硫脱汞能力均有了较大地提高,HNO3改性复合材料脱硫效果更好,单位SO2脱除量可增加25mg/g,而KI改性复合材料具有更好的脱汞效果,单位汞吸附量增大1.6倍左右。

PTFE( polytetrafluoroethylene) composite material was prepared using coal-based activated carbon as the raw material,ethanol solution as the dispersant and PTFE emulsion as the binder. The composite material was modified by impregnation with KI and HNO3 respectively,to improve the adsorption performance of SO2 and mercury. A bench-scale fixed bed was employed to examine SO2 and mercury adsorption behaviors. Adsorption mechanisms of the composite materials were discussed. The experimental results showed that the adsorption longevity for SO2 increased by two times. This could be resulted from hydrophobic properties of PTFE. The adsorptive capacities of SO2 and mercury for both modified composite materials were greatly improved. HNO3 modified composite had a better SO2 adsorption performance,whose SO2 adsoption increased by 25 mg /g. KI modified composite showed a better mercury adsorption performance,and its mercury adsorption capacity increased by 1. 6 times.