气相三氯甲烷在三种活性炭固定床层上的吸附

Fixed-Bed Adsorption of Gaseous Trichloromethane on Three Kinds of Activated Carbons

为了研究三氯甲烷在活性炭上的吸附性能,采用固定床吸附法测定了三氯甲烷在3种商用活性炭床层上的吸附透过曲线,并对这3种活性炭的孔结构和比表面积进行表征,探讨了吸附操作条件和活性炭孔结构对活性炭床层吸附三氯甲烷性能的影响.实验结果表明:随着三氯甲烷入口浓度的降低、活性炭床层填充高度的增加以及吸附床层温度的降低,三氯甲烷在活性炭吸附床上的吸附透过时间延长;3种商用活性炭的BET比表面积和总孔容大小顺序为:SY-9>天达>SY-16;在三氯甲烷入口质量浓度为9.497g/m3、吸附温度为298.15K、吸附柱长为2.4cm、混合气体线性流速为15.28m/min时,SY-9和天达活性炭对三氯甲烷的饱和吸附量分别是SY-16活性炭的1.80和1.43倍,与3种活性炭的微孔比表面积比值接近,表明三氯甲烷在活性炭上的吸附主要发生在活性炭微孔部分.

In order to investigate the adsorption capability of trichloromethane on activated carbons,the breakthrough curves of the fixed-bed adsorption of trichloromethane on three kinds of commercial activated carbons were measured,and the pore structures and specific surface areas of the activated carbons were characterized.Moreover,the effects of operation conditions and pore structures on the adsorption capacities of trichloromethane on the commercial activated carbons were discussed.Experimental results indicate that the breakthrough time prolongs not only with the decrease in the trichloromethane inlet concentration and the adsorption temperature but also with the increase in the loading length of the fixed bed, that both the BET specific surface area and total pore volume of the activated carbons decrease in the order of SY-9 〉 Tianda 〉 SY-16, that the adsorption capacities of trichloromethane on SY-9 and Tianda activated carbons are respectively 1.80 and 1.43 times that on SY-16 activated carbon when the adsorption performs at 298.15 K with a trichloromethane inlet concentration of 9. 497 g/m^3, an adsorption column length of 2.4 cm and a line speed of carrier gas of 15.28 m/min, and that the ratio of adsorption capacities is similar to that of specific surface areas, meaning that trichloromethane is mainly adsorbed in the micropores of the activated carbons.