改性活性炭吸附净化低浓度磷化氢

Adsorption Purification of Low-Concentration PH_3 by Modified Activated Carbon

采用活性炭载体浸渍醋酸铜,并经热分解制备CuO为主要吸附成分的改性活性炭吸附剂,净化磷化工尾气中的低浓度PH3。研究并讨论了吸附剂制备时的焙烧温度和吸附过程中的氧含量对改性炭净化效率的影响。实验结果表明：300℃为最佳焙烧温度;2%（vol）为最佳氧含量。经扫描电镜（SEM）、比表面分析（N2-BET）和X射线光电子能谱（XPS）分析,结果表明：经醋酸铜改性,能显著提高活性炭对PH3的吸附能力;孔径为2~20的微孔对PH3的吸附起主导作用;经CuO催化生成的活性氧原子使PH3氧化为多种形式的磷氧化物,CuO因转变为Cu3P2或Cu3（PO4）2而失去活性。

In order to purify the tail gases of phosphorus chemical industry by removing the low-concentration PH3 in it, the modified activated carbon （MAC） adsorbent with CuO as its main adsorbing component was prepared by pyrolyzing the active carbon impregnated with copper acetate. The effects of pyrolysis temperature during the adsorbent preparation and the oxygen content during the adsorption process on the purification efficiency of the MAC were studied and discussed. It was found from the experiment results that 300℃ is the optimum pyrolysis temperature, and 2%（vol） is the optimum oxygen content for the PH3 adsorption process. The analysis results of scanning electron microscopy （SEM）, specific surface area analysis （N2-BET） and X-ray photoelectron spectroscopy （XPS） indicate that, after the modification with copper acetate, the PH3 adsorbing capability of the activated carbon is significantly increased. The micropores with radius of 2-20 A in MAC play the predominant role for the PH3 adsorption, and the active oxygen atoms produced by the catalysis of the CuO oxidize the PH3 into various phosphorus oxides. At the same time the CuO losses its activity because of its turning into Cu3P2 or Cu3（PO4）2.