Exceptionally High Gravimetric Methane Storage In Aerogel-Derived Carbons

Storage of natural gas in highly porous materials provides a safer and more energy-efficient solution to energy-intensive compression and liquefaction options for advancing natural gas vehicular systems. Herein, we investigate the potential of highly porous aerogel-derived mesoporous carbons for storage of methane under the conditions relevant to adsorbed natural gas (ANG) tanks. Analysis of high-pressure isotherms indicated that EC-RF with a 2355 m(2)/g surface area and a 6.77 cm(3)/g total pore volume exhibited an exceptionally high gravimetric methane uptake with a deliverable capacity of 261 cm((STP))(3)/g in the pressure range of 5.8-65 bar and 25 degrees C which was 48% higher than that of the benchmark HKUST-1 material. Such behavior is attributed to its ultrahigh pore volume, large surface area, and low bulk density. In addition, our investigations demonstrated that upon desorbing the stored methane at 50 degrees C instead of 25 degrees C, both the methane deliverable capacity and the amount of methane recovered over EC-RF can be further increased to 305 cm((STP))(3)/g and 17%, respectively. Moreover, cyclic charge-discharge profiles revealed stable storage performance for this material. However, despite high gravimetric uptake, the volumetric uptake was only 89 cm((STP))(3)/cm(3), which was 50% that of HKUST-1. The results reported herein demonstrate that for aerogel-based carbons to be considered suitable as ANG adsorbents, their properties should be optimized to yield high volumetric storage capacity, balanced with their exceptionally high gravimetric uptake capacity.