Study On VOCs Adsorption And Microwave Desorption Of SiC/Na-X Composite Molecular Sieve

In order to study the applicable characteristics of molecular sieve adsorption of VOCs and microwave desorption,molecular sieves of different structures such as KA,Na-A,Ca-A,Ca-X,Na-X,Na-Y and Na-ZSM 5 are used to adsorb benzene and methanol.VOCs with different polarities such as hexane,n-hexane and microwave regeneration.Studies have shown that molecular sieve adsorption performance is better when the pore size of molecular sieve is larger and VOCs polarity is larger;X-type molecular sieve with high content of aluminum oxide tetrahedron has stronger microwave desorption;The equilibrium cation valence is low,and the Na⁺molecular sieve with a small radius has a stronger microwave absorption ability than the K⁺and Ca²⁺molecular sieves.In addition,the results show that the polarity of VOCs has little effect on microwave desorption efficiency and desorption rate.SiC/Na-X composite molecular sieves were prepared after doping with the absorbing material SiC,and the molecular sieve composites when the SiC doping amount was 0,10%,20%,30%,and 40%were investigated.The specific surface area,pore structure and adsorption isotherm of the material have shown that the specific surface area,pore size and equilibrium adsorption capacity of the prepared molecular sieve decrease with the increase of SiC doping.In this study,molecular sieves with SiC doping content of 0,10%,and 20%were used to study the microwaved esorption performance of the adsorbed VOCs.The study showed that the desorption equilibrium time of molecular sieves with SiC doping content of 0,10%,and 20%were respectively:12 min,10 min and 6 min,the order of desorption rate is:Na-X<10SiC/Na-X<20SiC/Na-X,indicating that the absorbing effect of molecular sieve increases with the increase of SiC doping.The XRD spectra of the SiC/Na-X composite molecular sieve after 5 cycles of adsorption and microwave desorption show that the structure and performance of the two molecular sieves are stable after microwave desorption.