Simultaneous extraction of C3H8 and C2H6 from ternary C3H8/C2H6/CH4 mixtures in an ultra-microporous metal-organic framework

The efficient purification of methane from other light hydrocarbons is of prime importance in natural gas pu-rification. However, the exploitation of stable adsorbents with both high selectivity and high adsorption capacity remains a challenge. Herein, an ultra-microporous Co-based metal-organic framework (Co-MOF) with abundant selective binding sites decorating the pore wall was applied for the highly efficient separation of ternary C3H8/ C2H6/CH4 mixtures. The Co-MOF shows remarkable C3H8 and C2H6 adsorption capacities with uptakes of 59.4 cm3/g and 58.6 cm3/g, respectively, while only adsorbing a low amount of CH4 with an uptake of 16.6 cm3/g at 298 K and 100 kPa. The ideal adsorbed solution theory selectivities for C2H6/CH4 (v/v = 50/50) and C3H8/CH4 (v/v = 50/50) reach 26.0 and 290.0 at 298 K, respectively, surpassing most of the state-of-the-art MOF materials. The molecular simulation reveals that the excellent adsorption and separation performance of Co-MOF derives from its suitable pore size and functional pore surfaces. Furthermore, the breakthrough experiments reveal that the Co-MOF exhibits excellent separation performance of C3H8 and C2H6 from natural gas. Notably, the dynamic separation performance of Co-MOF can be well-maintained after five cycles, demonstrating its excellent cycling stability. The high stability and excellent separation performance make Co-MOF a promising adsorbent for natural gas purification.

Automated summary

A Co-based metal-organic framework (Co-MOF) with abundant selective binding sites demonstrates high efficiency in separating C3H8 and C2H6 from natural gas. It exhibits remarkable adsorption capacities for C3H8 and C2H6 while adsorbing only a low amount of CH4. The Co-MOF shows excellent cycling stability and has the potential to be a promising adsorbent for natural gas purification.