Higher methane storage at low pressure and room temperature in new easily scalable large-scale production activated carbon for static and vehicular applications

The methane adsorption properties of High Surface Activated Carbon (HSAC) samples were evaluated at room temperature (298 K) and pressure up to 3.5 MPa using a new optimized volumetric apparatus f-PcT (fast Pressure-concentration- Temperature) for accurate and reliable gas adsorption measurements. A comprehensive characterization of different activated carbon samples was carried out by means of helium picnometry for the skeletal density evaluation, by the Brunauer-Emmett-Teller (BET) method for the measurement of the surface area, by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) for topography and long-range order estimation, respectively. All the adsorption data were evaluated by Langmuir/Tóth isotherm model with a very high accuracy. Comparison with data available in the literature shows a good agreement in terms of maximum methane uptake on similar materials and an enhanced performance for the reversible adsorption at very low pressure. In fact, the probed HSAC samples show both higher methane storage values for pressure up to 1.5 MPa and totally reversible methane uptake up to many cycles without any treatment in between. Furthermore, their adsorption properties are stable also after air exposure. These results represent the starting point for a real and efficient alternative method to the natural gas storage for static and/or automotive applications. © 2010 Elsevier Ltd. All rights reserved.