Abstract
Japanese rice husk was converted into an adsorbent for the removal of two types of aldehyde vapors. The rice husks carbonized at 250-800°C in N2 for 1h were exposed to vapors containing 1.0 vol. ppm formaldehyde or 100 vol. ppm acetaldehyde (both N2 carrier) in 5 L-gas sampling bags. Maximum adsorption rates of formaldehyde and acetaldehyde were observed for rice husks carbonized at 800 and 600°C, respectively. The adsorption rates of the aldehydes on the carbonized rice husks were higher than or comparable to those of the commercial granular coconut-shell activated carbon (GCSAC), whereas the specific surface area and the total pore volume of the carbonized rice husks were much lower than that of the GCSAC. The surface basic property of the rice husks carbonized at high temperatures was attributed to the intrinsic inorganic matters of K and Ca, which enhanced an uptake of the aldehydes on their surfaces.
