Monolithic bamboo-based activated carbons for dynamic adsorption of toluene

Monolithic activated carbon (MAC) tubes were prepared from shrubby bamboo. They could be stacked to form honeycomb-like structures with tubular channels, which were then used as alternative adsorbent beds for large-flow-rate emissions of volatile organic compounds (VOCs). The activation agents phosphoric acid, zinc chloride, steam, and carbon dioxide were used to prepare the MAC samples. The MAC samples were characterized by N-2 adsorption measurements at -196 A degrees C, scanning electron microscopy, Fourier transform spectroscopy, energy dispersive X-ray spectroscopy, and thermogravimetric analysis. The samples had microcellular structures that resemble the cellular tissue of the precursor bamboo. In comparison with commercial honeycomb activated carbon (HAC) prepared by extruding powder carbon and additives, the MAC samples had superior mechanical strength, were much more stable under wet conditions, and had much higher carbon content. The dynamic toluene adsorption on MAC and HAC was also studied. Well-developed micropores in MAC seemed to have a crucial role in toluene adsorption. Under the experimental conditions, the optimized MAC samples had high dynamic toluene adsorption capacity (up to 350 mg/g). The results suggest that MAC materials have potential use as adsorbents in the control of VOCs emission.