| 초록 |
Biogas emits in mixed gases composed 60-65mol% CH4, 35-40mol% CO2, 0.1-0.5 mol% H2S and traces of organic impurities. The upgrading of CH4 is very important in terms of both prevention of global warming and security of renewable energy for vehicle fuels or gas grid injection. Biogas can be efficiently upgraded by removing CO2 and H2S via membrane process. The objective of this study is to develop good membrane materials with high CO2 permeability and high CO2/CH4 selectivity. We have developed novel alicyclic dianhydride-diamine (DOCDA-ODA) based copolyimides with different 20mol% of dianhydrides (6FDA, BPDA and BTDA) using m-cresol as a solvent, respectively. All synthesized copolyimides were characterized by NMR, FT-IR. The thermo mechanical properties analyzed with DSC and TGA. Then, thin dense membranes were prepared from the copolyimides to check their gas permeation properties. The copolyimide gas permeability coefficients(P) and ideal selectivities were measured with a time-lag apparatus. |
