Preparation Of Novel Gas Separation Membranes And Study On CO₂Separation

In recent years, researches on organic-inorganic nanocomposites have attracted greatinterest since they frequently exhibit unexpected properties synergistically derived fromtwo components, which combine the advantages of the inorganic materials and theorganic polymer. As our special coal-based energy consumption structure, China’scarbon dioxide emissions remain high. It has a major impact on the warming of theclimate.By using polyamic acid of polyimide prepolymer as a precursor, and TiO2, ZSM-5and Y zeolite molecular as dopants, composite gas separation hybrid membranes weresynthesized at certain procedures and the temperature was raised to350℃thermalimidization in1h by dip-coating on a porous support and further treated at roomtemperature. The structures of the hybrid membranes were characterized by TG, XRD,FTIR and SEM. The results showed that the introductions of the three kinds of dopantsall had a promoting effect on the improvement of hybrid membrane thermal stability. Thetwo types of zeolite crystal were not destroyed and exhibited completed structures. Theprepared membranes surfaces were smooth, and the particles scattered on the surfaces ofmembranes had the relatively uniform distributrion, the hybrid membranes and thesupports had a good combination and compatibility.In order to study the gas separation performance of the hybrid membranes, gaspermeability test methods were employed. The results indicated that when the contentamount of Y zeolite in PI/Yhybrid membrane was20wt%, N2can not be penetrated, andCO2can be separated completely, and the CO2permeation coefficient was1.76×10-10mol·m-2·s-1·Pa-1. When the content amount of ZSM-5zeolite in PI/ZSM-5hybridmembrane was15wt%, the gas separation factor of the hybrid membrane for CO2/N2wasup to24.10, and the CO2permeation coefficient was5.06×10-9mol·m-2·s-1·Pa-1. When thecontent amount of TiO2in PI/TiO2hybrid membrane was7wt%, the gas separation factorforCO2/N2wasupto22.29,andtheCO2permeationcoefficient was3.79×10-9mol·m-2·s-1·Pa-1.