Graduate Institute of Environmental Engineering, National Central University, Chungli, Taiwan.
Chemosphere. 2011 Jan;82(1):72-7. doi: 10.1016/j.chemosphere.2010.10.004. Epub 2010 Oct 30.
A laboratory-scale multi-layer system was developed for the adsorption of PCDD/Fs from gas streams at various operating conditions, including gas flow rate, operating temperature and water vapor content. Excellent PCDD/F removal efficiency (>99.99%) was achieved with the multi-layer design with bead-shaped activated carbons (BACs). The PCDD/F removal efficiency achieved with the first layer adsorption bed decreased as the gas flow rate was increased due to the decrease of the gas retention time. The PCDD/F concentrations measured at the outlet of the third layer adsorption bed were all lower than 0.1 ng I-TEQ Nm⁻³. The PCDD/Fs desorbed from BAC were mainly lowly chlorinated congeners and the PCDD/F outlet concentrations increased as the operating temperature was increased. In addition, the results of pilot-scale experiment (real flue gases of an iron ore sintering plant) indicated that as the gas flow rate was controlled at 15 slpm, the removal efficiencies of PCDD/F congeners achieved with the multi-layer reactor with BAC were better than that in higher gas flow rate condition (20 slpm). Overall, the lab-scale and pilot-scale experiments indicated that PCDD/F removal achieved by multi-layer reactor with BAC strongly depended on the flow rate of the gas stream to be treated.
开发了一种实验室规模的多层系统，用于在各种操作条件下从气流中吸附 PCDD/Fs，包括气体流速、操作温度和水蒸气含量。采用珠状活性炭（BAC）的多层设计实现了优异的 PCDD/F 去除效率（>99.99%）。由于气体保留时间的减少，第一层吸附床的 PCDD/F 去除效率随着气体流速的增加而降低。第三层吸附床出口处测量的 PCDD/F 浓度均低于 0.1 ng I-TEQ Nm⁻³。从 BAC 解吸的 PCDD/Fs 主要是低氯化同系物，随着操作温度的升高，PCDD/F 出口浓度增加。此外，中试实验（铁矿石烧结厂的实际烟道气）的结果表明，当气体流速控制在 15 slpm 时，采用 BAC 多层反应器实现的 PCDD/F 同系物去除效率优于较高气体流速条件（20 slpm）。总体而言，实验室规模和中试规模实验表明，采用 BAC 多层反应器实现的 PCDD/F 去除强烈依赖于待处理气流的流速。
