Activated carbons from bamboo scaffolding using acid activation

A series of activated carbons were prepared from bamboo by chemical activation with HCl, HNO3 and H2SO4. Unlike phosphoric acid, these three acids are not commonly used as an activating agent for lignocellulosic materials. The effect of operating variables such as activation temperature, impregnation ratio (the mass ratio between bamboo/acid) and holding time were investigated. The resultant carbons were evaluated for the yield, surface area, pore size distribution, pH, elemental composition and ash. At an impregnation ratio (the mass ratio between bamboo/acid) of 1, activated carbon with BET surface area and micropore volume as high as 553 m2/g and 0.239 cc/g was obtained at 1173 K using H2SO4 as an activating agent. Lower impregnation ratio and shorter holding time were favourable to the yield and surface area while increasing impregnation ratio enhanced mesoporosity of the carbons. This can be attributed to the transformation of micro- to mesopores in the presence of higher ‘basic’ element contents such as nitrogen and sulphur.

The amount of nitrogen adsorbed by activated carbons from acid-impregnated bamboo (Xp = 1, activation time = 2 h) are in the following order: H2SO4 > HCl > HNO3. This can be attributed to the nature of reactions between different acids and the major components of bamboo.Figure optionsDownload as PowerPoint slide