Rationally tuning the separation performances of [M3(HCOO)6] frameworks for CH4/N2 mixtures via metal substitution

Gate opening effect of zeolitic imidazolate framework ZIF-7 for adsorption of CH4 and CO2 from N2

“…Figure 7c shows the selectivity of CH4 over N2 which reaches 10.1 at 303 K and 1500 kPa. Although there are few reported novel adsorbents with higher CO2/N2 and CO2/CH4 compared to ZIF-7, based on the author's knowledge, high equilibrium selectivity of CH4/N2 was not experimentally measured/reported in the previous literature [40][41] . As can be seen in Figure 8, ZIF-7 also shows high CH4/N2 selectivity of 9.3 and 8.5 at higher temperatures of 313 K and 323 K in the range of 1500 kPa to 2500 kPa.…”

“…, zeolites43 , metal-organic framework (MOFs)31,40,44 still couldn't fulfill the requirements of an adsorptive gas separation process. In a recent research, it was tried to tune a series of isostructural ultra-microporous MOFs compounds [M3(HCOO)6] where (M = Mg, Mn, Co and Ni)for the separation of CH4 and N2 and it was showed that [Ni3(HCOO)6] with CH4 adsorption capacity of 1.09 mmol.g -1 has the highest CH4/N2 selectivity up to 6.5 at 400 kPa and 298 K41 . In another research, Molmer et al40 measured CH4 and N2 adsorption on two microporous MOFs, Basolite ® A100 and a novel copper-based 1,2,4-triazolyl isophthalate MOF and reported the best CH4/N2 selectivity of 4-5 for the latest adsorbent at 2000 kPa and temperatures of 273-323 K. This comparison helps to conclude that open-door behaviour of ZIF-7 makes this adsorbent an excellent candidate for denitrogenation of methane-rich gas mixtures.…”

[Ni3(HCOO)6]/Poly(styrene‐b‐butadiene‐b‐styrene) Mixed‐Matrix Membranes for CH4/N2 Gas Separation

“…However, the fabricated [Ni 3 (HCOO) 6 The trend of permeability enhancement of the MMMs could be attributed to two main reasons. First, the CH 4 on the [Ni 3 (HCOO) 6 ] surface exhibited strong interaction, and the intrinsic affinity of [Ni 3 (HCOO) 6 ] to CH 4 was more favorable than N 2 , resulting in the improvement of the CH 4 permeability [33,34]. Second, possible interconnected porous structures in the MMMs were established, offering dual-mode transport pathways for both gases based on their kinetic diameters [45].…”

“…As a demonstration for [Ni 3 (HCOO) 6 ]/SBS MMMs in the application of the CH 4 /N 2 separation process, the binary gas mixtures of CH 4 6 ] shows the better adsorption capacity for CH 4 and, therefore, increases the permeability of CH 4 in the mixture [34]. Consequently, this finding indicates that the addition of [Ni 3 (HCOO) 6 ] can enhance the CH 4 permeability, which is in accordance with the measurement of pure gas.…”

Template‐based Synthesis of a Formate Metal–Organic Framework/Activated Carbon Fiber Composite for High‐performance Methane Adsorptive Separation

“…More recently, metal–organic frameworks (MOFs), three‐dimensional networks consisting of inorganic nodes linked by organic ligands, have been proposed for potential application in gas separations . Metal formate frameworks, a specific class of MOFs (Figure a), have been shown to exhibit higher selectivities than others owing to their uniform one‐dimension micropores and optimal polarizability . Overall methane sorption capacities, however, need be further enhanced for adsorptive separation …”