Synthesis Ge-ZSM-5 Membrane And Study On Pervatoration Performance

Zeolite membrane which is a kind of inorganic membrane materials,has excellent performance and some advantages,such as,its pore diameter can be altered and it has potential wide application value in the fields of catalysis,separation,photoelectricity and so on.Including Ge-ZSM-5 molecular sieve film because excellent hydrophobicity,and been concerned.This paper adopted first situ hydrothermal synthesis and many times in situ hydrothermal synthesis method to prepare hydrophilic and hydrophobic Ge-ZSM-5 zeolite membrane.The prepared Ge-ZSM-5 membranes were characterized by X-ray diffraction,SEM,EDX and contact angle.Then,we studied the separation function of Ge-ZSM-5 zeolite membrane on the a-alumina carrier in the system of ethanol/water.acetic acid/water separation.Hydrophilic Ge-ZSM-5 zeolite membrane was successfully prepared by first-situ hydrothermal synthesis in which the Si/Ge is 25,100,200 of hydrophilic.When Si/Ge is 100 membrane was applied to the pervaporation of concentrated ethanol(10 wt.%?98 wt.%)and acetic acid(30 wt.%?98 wt.%),the separation factor were ?,flux were 2.4 kg/m2·h and 0.57 kg/m2·h.The hydrophilic of the Si/Ge = 100 film was strongest.The prepared hydrophilic Ge-ZSM-5 membrane has high acid-tolerance properties,only water molecules passed through the membrane after 25 h.Total pervaporation fluxes of Si/Ge =25 and Si/Ge = 100 Ge-ZSM-5 membranes which prepared by Second-situ hydrothermal synthesis increased with the temperature rised from 30 to 90 ?decreased later in the system of 5 wt.%acetic acid aqueous feed solution,but the separation factor was increased in the whole pervaporation process.Selectivity through the Si/Ge = 25 Ge-ZSM-5 membrane increased to 1.8 when the two synthesis duration was 24 h and 18 h,and the flux was 1.4 kg/m2·h.Total pervaporation fluxes of Si/Ge = 25 and Si/Ge = 100 Ge-ZSM-5 membranes which prepared by third-situ hydrothermal synthesis increased with the temperature rised from 30 ? to 90 ?decreased later in the system of 5 wt.%acetic acid aqueous feed solution,the separation factor was increased in the whole pervaporation process.Selectivity through the Si/Ge = 25 Ge-ZSM-5 membrane increased to 2 when the three synthesis duration was 24 h and 18 h,and the flux was 1.1 kg/m2·h.The Si/Ge = 25 Ge-ZSM-5 membrane which three synthesis duration were 24 h,18 h,12 h as the acetic acid feed concentration increasedfrom 0.33 wt.%to 5 wt.%,and the separation selectivity decreased to one-halfits initial value from 3.4 to 1.82.