Microporous activated carbon prepared from coconut shells using chemical activation with zinc chloride

Microporous activated carbon samples were prepared from coconut shells (low-cost lignocellulose waste), using chemical activation with zinc chloride followed by physical activation. Textural characterization was performed using nitrogen adsorption at 77 K. The sample that presented the best characterization results was then evaluated for methane adsorption at pressures between 0.1 MPa and 7 MPa and temperatures in the range 283-333 K. At 298 K and 40 bar, a capacity of ca. 122 mg of methane/g of carbon (80 v/v) was observed, just short of the target established in Brazil for ANG in remote sites transportation (100 v/v). These results suggest that activated carbons prepared from coconut shells, using chemical activation followed by physical activation, may be further developed as potential adsorbents for natural gas storage applications. (c) 2006 Elsevier Inc. All rights reserved.