POWDERED ACTIVATED CARBONS FROM PINUS CARIBAEA SAWDUST

Abstract

Activated carbons with different porous structures have been prepared from Pinus caribaea sawdust through the use of CO₂ and steam as activating agents. The evolution of the Brunauer-Emmett-Teller (BET) surface area upon activation becomes fairly similar in both cases, and values above 1000 m²/g can be reached at high burn-off levels. Activation with steam produces a more developed porous structure, with a substantially higher contribution of mesoporosity, than does activation with CO₂. Increasing the activation temperature leads in both cases to a wide pore-size distribution. The presence of a well-developed mesoporosity makes the resulting products good candidates for adsorbents for water and waste-water treatment. For these purposes, the characteristics of these activated carbons are comparable to those used as commercial adsorbents in those fields, showing in the case of the steam-activated carbons, a somewhat higher mesopore volume than many of the commercial products while maintaining similar surface area values to them. The relative simplicity of the process makes the production of steam-activated carbons a feasible and economically valuable alternative for sawmill wastes.

Keywords:

• Sawdust waste
• Activated carbon
• Porous structure
• Surface area
• Pore size distribution

ACKNOWLEDGMENTS

The authors express their gratitude to the Universidad Internacional de Andalucia for financial support for this project, including the stay of F. Márquez in Spain.