Adsorption and compression contributions to hydrogen storage in activated anthracites

✍ Scribed by V. Fierro; W. Zhao; M.T. Izquierdo; E. Aylon; A. Celzard

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 421 KB
• Volume: 35
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.06.004

✦ Synopsis

We prepared activated carbons (ACs) that are among the best adsorbents for hydrogen storage. These ACs were prepared from anthracites and have surface areas (S BET ) as high as 2772 m 2 g À1 . Anthracites activated with KOH presented the highest adsorption capacities with a maximum of 5.3 wt.% at 77 K and 4 MPa. Non-linearity between hydrogen uptake at 77 K and pore texture was confirmed, as soon as their S BET exceeded the theoretical limiting value of (geometrical) surface area, i.e., S BET > 2630 m 2 g À1 . We separated adsorption and compression contributions to total hydrogen storage. The amount of hydrogen stored is significantly increased by adsorption only at moderate pressure: 3 MPa and 0.15 MPa at 298 and 77 K, respectively. Hydrogen adsorption on ACs at high pressure, above 30 MPa at 298 K and 8 MPa at 77 K, has not interest because more gas can be stored by simply compression in the same tank volume.