Synthesis and Characterization of SAPO-34/6FDA-Durene Mixed Matrix Membrane for CO2 Capture

Membrane separation has become a promising technology in CO2 removal from natural gas sweetening recently. In the present research, a series of SAPO-34/6FDA-durene mixed matrix membranes (MMMs) were developed to remove the CO2 from CH4. The MMMs were fabricated by incorporating different compositions of SAPO-34 fillers into 6FDA-durene polymer matrix. SAPO-34 fillers modified with (3-Aminopropyl)-triethoxysilane (APTES) were synthesized and incorporated into 6FDA-durene polymer matrix in order to study their effects on the membrane defects, as well as their effects on the performances of the resulting MMMs towards the gas separation. The resulting SAPO-34 and silane-modified SAPO-34 were characterized by using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), whereas all the fabricated MMMs were characterized by using Energy Dispersive X-ray (EDX) and SEM. The performances of the membranes in CO2/CH4 separation were tested by using CO2 membrane cell filter test rig (CO2MCEF). The morphology of the silane-modified MMMs showed the improvement on the compatibility between the polymeric and inorganic phases. EDX results showed that the inorganic SAPO-34 particles were evenly distributed in the polymer matrix and no phase separation was found. However, all MMMs showed lower separation performance compared to pure 6FDA-durene membrane mainly due to large inorganic particles size, moisture contact, poor interfacial adhesion and polymer matrix rigidification.