分子筛吸附VOCs与微波脱附性能研究

Study on adsorption properties of zeolites for VOCs and microwave desorption

为筛选适于吸附VOCs与微波脱附的分子筛,并研究其孔径、铝氧四面体、平衡阳离子等性能的影响因素,采用7种吸附剂(K-A,Na-A,Ca-A,Ca-X,Na-X,Na-Y和Na-ZSM5沸石分子筛)和3种VOCs吸附质(苯、甲醇、正己烷)进行了实验研究,利用BET,XRD表征方法对分子筛的孔径、比表面积、孔容和晶胞参数等进行了测试。结果表明:分子筛孔径较大、VOCs极性较大时,吸附量较高;采用不同铝氧四面体结构含量(Na-X,Na-Y,Na-A和Na-ZSM5)及不同平衡阳离子(K-A,Na-A,Ca-A和Ca-X,Na-X)分子筛进行微波脱附时,铝氧四面体结构含量高的分子筛更适用于微波脱附,平衡阳离子为Na^+的分子筛吸波能力强于K^+和Ca^2+;经5次循环静态吸附、微波脱附,分子筛微波脱附的结构性能稳定。研究成果可为分子筛吸附VOCs与微波脱附新方法的工业化应用提供重要参考。

In order to screen zeolites suitable for adsorption of VOCs and microwave desorption,and to study the performance influencing factors such as pore size,aluminum-oxygen tetrahedron,balanced cations,seven kinds of adsorbents(K-A,Na-A,Ca-A,Ca-X,Na-X,Na-Y and Na-ZSM5 zeolites)and three kinds of VOCs adsorbent(benzene,methanol,n-hexane)were experimentally studied,and the pore size,specific surface area,pore volume and cell parameters of the zeolite were tested by BET and XRD characterization methods.The results show that the adsorption capacity is higher when the pore size of the zeolite is larger and the polarity of the VOCs is larger;when different aluminum-oxygen tetrahedral structure content(Na-X,Na-Y,Na-A and Na-ZSM5)and different balanced cations(K-A,Na-A,Ca-A and Ca-X,Na-X)zeolites microwave desorption are used,the zeolites with a high content of aluminum-oxygen tetrahedron structure is more suitable for microwave desorption,and the zeolites with a balanced cation of Na^+ is stronger than with K^+ and Ca^2+,after 5 cycles of static adsorption and microwave desorption,the zeolites microwave desorption has stable structure and performance.The research results can provide important reference for the industrial application of the new method of zeolites adsorption of VOCs and microwave desorption.