Synthesis of Carbonous Nano Adsorbents and Their Application in Methane Gas Storage

In this research, adsorbed natural gas methods have been studied. The adsorbents used in this thesis are carbon-based nano-sorbents (activated carbon, pure and functionalized carbon nanotubes, and porous graphene) which were synthesized by the chemical vapor deposition method. The accuracy of synthesized results was examined using scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and Brunauer–Emmett–Teller analyses. The adsorption capacity of adsorbents for methane gas adsorption at three temperatures of 28, 45, and 60 ° C was calculated and matched with three isotherm equations of Langmuir, Freundlich, and Temkin. The R of the Langmuir isotherm for pure and functional nanotube adsorbents were 0.9963 and 0.9997, respectively, and for activated carbon was 0.9995, which is the closest isothermal equation for these adsorbents, while for the graphene adsorbent the closest prediction is Temkin isotherm with calculated R of 0.9986. It can be concluded that with increasing temperature, the amount of adsorbed gas decreases, and with increasing pressure, the amount of adsorbed gas increases. Therefore, the maximum adsorption for all adsorbents occurred at a temperature of 28°C and a pressure of 40 bar. Among the used adsorbents, porous graphene showed the best performance at a temperature of 28°C, and a pressure of 40 bar, which according to its high specific surface area, Brunauer–Emmett–Teller analysis (1200 m2/g), and significant pore size, such an outcome was predictable.