Adsorption properties of charcoals from wood-based materials

Wood-based materials (PB and LVL) and raw wood materials (sugi and bamboo), precarbonized at a lower temperature, were further carbonized at 500-1000 degrees C. The inner surface structure and adsorption properties of the car bonized materials were investigated when exposed to water and formaldehyde vapors. All of the carbonized materials were adsorptive to water and formal dehyde, although carbonized PB and LVL, whose inner surface area was small, were less adsorptive than carbonized sugi and bamboo. Higher carbonization temperatures generally gave larger surface area and higher adsorption, reg ardless of the origin of the charcoals. However the charcoal carbonized at 600 degrees C had the lowest adsorption. In the presence of both formaldehy de and water vapors, charcoals carbonized at the lower temperatures of 500- 700 degrees C adsorbed formaldehyde more than water with polylayer adsorpti on, whereas those carbonized at the higher temperatures of 800-1000 degrees C adsorbed water more because of their fine micropore structure. These results indicate that the adsorption properties of charcoal from wood waste could be adjusted by controlling the carbonizing temperature.