KOH改性活性炭及其对微量乙烷的吸附性能

KOH modified activated carbon and its adsorption performance to trace ethane

采用KOH改性椰壳活性炭(AC)作为吸附剂,调变KOH和AC的质量比(KOH/AC,以下简称碱碳比)和活化温度制备一系列改性吸附剂,通过动态吸附法评价其脱除微量乙烷的性能,并与AC进行对比研究。评价结果表明,最佳制备条件为:KOH和吸附剂的最佳碱碳比为0. 5,最佳活化温度为800℃。在该条件下制备的KOH改性AC吸附剂的乙烷穿透吸附量达到482. 1μg/g,高于AC的169. 6μg/g。表征结果显示,与AC相比,KOH改性AC表面的氧含量更高,并增加了吸附剂的微孔数量,微孔比率从75. 3%增加到了83. 9%,并有适量的介孔,该结构有利于对乙烷的吸附。

A series of modified adsorbents are prepared by using KOH to modify coconut shell activated carbon( AC),while adjusting the ratio of KOH/AC and activation temperature.The performance of the modified adsorbents is evaluated through removing trace ethane by dynamic adsorption method and is compared with that of common AC. The evaluation results show that the optimum preparation conditions are that the optimum ratio of KOH/AC is 0. 5 and the optimum activation temperature is 800℃. The modified adsorbent that is prepared under these optimal conditions can reach an ethane breakthrough adsorption amount of 482. 1 μg·g-1,which is higher than the 169. 6 μg·g-1 for AC. The characterization results show that compared with AC,the KOH-modified AC adsorbent contains higher oxygen content in its surface,increases the number of micropores,and has an appropriate amount of mesopores.The micropore volume ratio increases to 83. 9% from 75. 3% of AC.Such a structure is good to the adsorption of ethane.