VOCs气体在活性炭上的二元吸附过程研究

采用穿透曲线法研究了4种VOCs在活性炭上的的二元吸附过程。研究表明:对于甲苯-苯、甲苯-丙酮、甲苯-乙酸乙酯、苯-丙酮、丙酮-乙酸乙酯二元吸附体系,吸附过程存在置换作用,即随着高沸点组分在床层内吸附量的逐渐增加,相对挥发性大的低沸点组分重新汽化而脱附,出现高沸点组分置换低沸点组分的现象,表现为被置换组分的穿透曲线上出现峰值。之后随着高沸点组分吸附趋于饱和,置换作用停止,低沸点组分吸附也趋于平衡。但对于沸点相近的苯-乙酸乙酯二元体系,吸附过程没有明显的置换现象。吸附量的计算结果表明,有机物在二元体系中的吸附量较同等条件时的单组分吸附量均有不同程度的降低,其中被置换组分降低程度较大,但总吸附量可近似按照浓度为二元组分总浓度低沸点组分的平衡吸附量的近似法计算,平均误差为7.9%。

Binary Adsorption of Gaseous VOCs on Activated Carbon

Laboratory experiments were described regarding binary adsorption of gaseous volatile organic compounds(VOCs) on activated carbon.The adsorption process was studied by a method of breakthrough curve with respect to VOCs such as toluene-benzene,toluene-acetone,toluene-ethyl acetate,benzene-acetone and acetone-ethyl acetate,which indicated that displacement phenomena took place during the process until adsorption of compounds of high boiling-point saturated and thereafter the adsorption of low boiling-point compounds approached the saturation as well.However,it was found that few displacement effects appeared in the case of benzene-ethyl acetate due to their very close boiling points.Finally,method of calculation of adsorption amount was discussed on the basis of experimental data analysis.