Arash Khosravi

Natural gas is one of the undeniable energy carriers in the end-user energy portfolio and will be considered in the coming decades based on energy demand forecasts due to various benefits, including less pollution than other energy carriers. On the other hand, the removal of acidic gases such as carbon dioxide (CO2) is the most important process in the natural gas processing plants, and a lot of materials and energy are used in traditional natural gas sweetening. However, gas separation through membranes as an environmentally friendly process has many advantages over conventional separation methods such as thermal distillation and adsorption. Pebax2533 polymer is suitable for CO2 separation due to its polar interactions of oxygen ether with CO2. In this thesis, the application of POSS and FS nanoparticles in the fabrication of novel Pebax2533 nanocomposite membranes for the separation of CO2 from CH4 and N2 was studied. The characterization analysis of FTIR, FESEM, AFM, TGA and DTG were manipulated to evaluate the chemical structure, morphology, topology and thermal stability of the fabricated nanocomposites and the interactions of nanoparticles on each other and on the polymer. The permeability and selectivity of pure gases CH4, CO2 and N2 were measured at different pressures of 4-10 bar. The fabricated samples had good thermal stability. CO2 permeability was increased by adding POSS nanoparticles at a pressure of 4 bar from 103.4 to 194 Barrer (87% growth). The permeability of CH4 and N2 at a pressure of 4 bar was increased from 25.4 and 6.92 Barrer to 34 and 7 Barrer, respectively, indicating an increase in selectivity. Also, the effect of plasticization is somewhat controlled by the addition of POSS nanoparticles. By adding 1 wt% of FS nanoparticles at a pressure of 4 bar, an increase in permeability and selectivity was observed. The selectivity of CO2/N2 and CO2/CH4 in 1 wt% FS is almost 2 times and 1.5 times higher than the pure state, respectively. Also, the