分子筛负载型吸附剂对典型VOCs的吸附行为特性

Adsorption characteristics of typical VOCs on Cu-Mn-Ce/ZSM adsorbent fixed-bed

以浸渍法制备的分子筛负载铜锰铈(Cu-Mn-Ce/ZSM)为吸附剂,以甲苯、乙酸乙酯和丙酮作为挥发性有机物(VOCs)的典型代表,考察了单组分和混合组分VOCs在吸附剂固定床上的吸附行为。研究表明,Cu-Mn-Ce/ZSM吸附单组分VOCs时,甲苯的吸附穿透时间与饱和吸附量分别为110 min和32.47 mg/g,乙酸乙酯为150 min和52.29 mg/g,丙酮为210 min和86.40 mg/g,可见Cu-Mn-Ce/ZSM对单组分VOCs的吸附能力大小为:丙酮>乙酸乙酯>甲苯。Cu-Mn-Ce/ZSM吸附混合组分VOCs时,在甲苯与乙酸乙酯的穿透曲线上出现了明显的"驼峰",吸附穿透过程中存在共吸附和竞争吸附行为,甲苯的吸附穿透时间与饱和吸附量降至50 min、10.42 mg/g,乙酸乙酯为95 min、15.12 mg/g,丙酮为105 min、44.37 mg/g。通过Yoon-Nelson模型对单组分VOCs吸附穿透曲线的拟合,表明吸附模型参数可以准确地预测吸附质在固定床上的穿透行为。速率参数k'值计算表明,不同VOCs在固定床上的吸附速率大小为丙酮<乙酸乙酯<甲苯。

The adsorption performances of single and mixed volatile organic compounds（ VOCs）,including toluene,ethyl acetate,and acetone,were investigated using a fixed-bed filled with Cu-Mn-Ce / ZSM adsorbent prepared by the impregnation method. When a single VOC was used as the adsorbate,the breakthrough time and saturated adsorption amount,respectively were 110 min and 32. 47 mg / g for toluene,150 min and 52. 29 mg / g for ethyl acetate,and 210 min and 86. 40 mg / g for acetone. The results indicate that the adsorption properties of VOCs on Cu-Mn-Ce / ZSM are in the order of acetone 〉ethyl acetate〉 toluene. When mixed VOCs were tested for adsorption,there were clear humps in the breakthrough curves for toluene and ethyl acetate,indicating obvious co-adsorption and competitive adsorption. The breakthrough time and saturated adsorption amount,respectively decreased to 50 min and 10. 42 mg / g for toluene,95 min and 15. 12 mg / g for ethyl acetate,and 105 min and 44. 37 mg / g for acetone. The Yoon-Nelson model was used to fit the breakthrough curve for single VOCs,and the obtained model parameters were useful for predicting the breakthrough process on the fixed-bed. Moreover,the rate parameter k＇ indicated that the adsorption rates were in the order of acetone〈 ethyl acetate〈 toluene.