Study On Adsorption Properties Of Molecular Sieves For VOCs And Microwave Desorption

Focusing on molecular sieve adsorption of VOCs and microwave desorption,static adsorption methods were used to determine the saturated adsorption of benzene,methanol,and n-hexane on zeolite molecular sieves,such as 3A,4A,5A,and 10X.The static adsorption capacity of 10x zeolite for benzene,methanol and hexane is 96mg·g^-1,90mg·g^-1 and 75mg·g^-1.The dynamic adsorption of VOCs by 10X molecular sieves can be observed that the entire adsorption process conforms to the Langmuir adsorption equation.The desorption activation energy of three VOCs was measured by programmed heating.The desorption activation energy of 10X molecular sieve was 16.64KJ·mol^-1,17.323KJ·mol^-1 and 18.54KJ·mol^-1.Methanol is more easily desorbed from the adsorbent.In microwave desorption regeneration,the 13X zeolite with a larger silica-aluminum ratio（13X zeolite>10X zeolite>3A zeolite）had a faster desorption rate than when it desorbed methanol,benzene and n-hexane.The experimental results showed that when microwave desorption of zeolites occurred,methanol with higher dielectric constant of VOCs（methanol>benzene>n-hexane）had stronger absorption performance and higher desorption rate during microwave desorption.The XRD of the molecular sieve regenerated 10 times by microwave desorption showed that the microwave had no effect on the internal structure of the molecular sieve.Through the experimental comparison of the adsorption and regeneration performance of zeolite and activated carbon,high power microwave can make the activated carbon coking inactive;The comparison of microwave desorption and thermal desorption experiments of zeolite shows that the energy consumption（0.24kw·h）of adsorbed and saturated zeolite with the same mass through microwave desorption is far less than that of conventional thermal desorption（6.41kw·h）.Microwave desorption is more energy-efficient than traditional thermal desorption,and the complete time for microwave desorption is 12minutes,and the regeneration time required for traditional thermal desorption is 116minutes,which has been greatly shortened.