Carbon dioxide and methane capture in metal-organic framework MIL-101 (Cr) at high pressure

Due to the presence of high CO2 amounts in the natural gas stream, a variety of efforts have been employed in the search for more efficient materials for the separation of gaseous mixtures such as CO2/CH4. In this article, a metal-organic framework (MIL-101) was synthesized and characterized, which showed a wide surface area (2924.8 m2 g-1 per BET) and a high volume of pores (1.32 cm3 g-1 per DFT). This structure was used to study the adsorption capacity of CO2 and CH4 within systems pressurized up to 100 bar -where a high adsorption capacity of CO2 was evidenced under 45 degrees C. Moreover, it was possible to distinguish between the high selectivity of this structure for CO2 molecules and its low capture of CH4 molecules. Also, the high stability of MIL-101 was noted after 6 cycles of adsorption and desorption of CO2 under 50 bar and 45 degrees C, thereby maintaining its adsorption capacity and crystallinity. Finally, isotherms of CO2 adsorption were successfully adjusted with the use of the Toth model.