Zr-Based Metal–Organic Nanoporous Adsorbents of High Density for Methane Storage

A Zr–BDC metal–organic framework was synthesized by the solvothermal method using N,N‑dimethylformamide as an organic solvent at the temperature 110°С. The adsorbent thus obtained is characterized by a developed porous structure with specific BET surface SBET = 1060 m2/g, micropore volume W0 = 0.44 cm3/g, and average micropore radius х0 = 0.54 nm, which is indicative of a potentially effective adsorbent for adsorbed natural gas storage systems. The shaping parameters were determined for the Zr–BDC-based composites with polyvinyl alcohol as a binder and without the use of any binder at various compacting pressures. The influence of the shaping pressure on the packing density and structural and energy characteristics of the obtained samples was investigated. Based on the Dubinin theory of volume filling of micropores, the pressure dependences of the methane deliverable capacity both in the initial powdered and shaped Zr–BDC adsorbents at the temperatures of 243, 273, and 303 K were calculated for the pressures up to 100 bar. The deliverable volumetric methane capacity of the adsorption system based on the shaped Zr–BDC samples was measured in the specified thermodynamic conditions.