活性炭纤维填充床内多组分竞争吸附  

MULTICOMPONENT COMPETITIVE ADSORPTION ONTO ACTIVATED CARBON FIBERS IN FIXED BED

作　　者：李平[1] 修国华[2] 江雷[2] 

机构地区：[1]沈阳化工学院化工系,辽宁沈阳110021 [2]中国科学院化学研究所,北京100080

出　　处：《化工学报》2001年第11期987-992,共6页CIESC Journal

摘　　要：建立了活性炭纤维填充床内多组分竞争吸附传质动力学模型 ,采用正交配置方法求解数学模型以预测突破曲线 ,从理论上探讨了竞争吸附平衡及吸附质在填充床内的轴向弥散、纤维内扩散和纤维外对流传质等因素对强、弱吸附组分突破曲线的影响。在间歇和填充床吸附器内进行了脱除水溶液中酚类化合物的实验 ,测定了活性炭纤维吸附水溶液中苯酚和氯代苯酚的吸附等温线 (间歇吸附 )以及苯酚和氯代苯酚在活性炭纤维填充床内竞争吸附时的突破曲线 ,并与模型计算值进行了比较。结果表明 ,吸附质在活性炭纤维内扩散和纤维外对流传质阻力不是填充床内吸附过程的控制步骤 ,而轴向弥散影响显著 。A mathematical model was built to describe the mass transfer processes and competitive adsorption in a fixed bed packed with activated carbon fibers (ACFs). The orthogonal collocation method was used to simulate the mathematical model in order to predict the breakthrough curves. The effects of competitive equilibrium constants, axial dispersion, intrafiber diffusion and external mass transfer resistance on the breakthrough curves were investigated for weakly-adsorbed and strongly-adsorbed components. The experiments were carried out to remove the phenolic compounds from water. With the equilibrium data and the intrafiber diffusivities obtained from separate experiments in a batch adsorber, axial dispersion coefficient was obtained by fitting the experimental data of breakthrough curves with the theoretical model. The effects of intraparticle and external mass transfer resistances can be negligible for the fixed bed packed with ACFs, and the axial dispersion is confirmed to be the main parameter the controls the adsorption kinetics. A simpler model, based solely on liquid phase mass balance and incorporating local equilibrium with axial dispersion, provides a good description of the process.

关 键 词：活性炭纤维 填充床 竞争吸附 突破曲线 酚化合物 扩散 传质 分离 吸附等温线 

分 类 号：TQ028.15[化学工程] O647.3[理学—物理化学]