(446i) Porous Carbons for Adsorbed Natural Gas (ANG) Revisited: Methane Adsorption in Low and Ultra-High Pressure

Adsorptive storage of natural gas or methane has gained a lot of attention as an efficient method for on-board storage for vehicular applications. Traditionally, activated carbon-based materials were investigated for adsorptive storage of methane at elevated pressure. With time, several adsorbents were developed and examined for adsorptive methane storage. In order to further examine the adsorptive storage of methane in carbon-based adsorbents, in this work, methane adsorption was performed in low and ultra-high pressure (400 bar) in different carbon-based adsorbents. Adsorption amount of methane was directly related to BET surface area of the carbons along heat of adsorption methane in the range of 38 to 21 kJ/mol. Although the gravimetric uptake was lower than DOE target, highest volumetric methane uptake was above 500 V/V at ~400 bar or ~200 V/V at 35 bar (293 K) that exceeded the DOE volumetric target for methane storage and higher than that of most of the MOFs and COFs. Comparing the overall uptake in both gravimetric and volumetric form, compressibility, stability and cost, it can be claimed that carbons are the still the most optimum adsorbents for ANG applications.