ACTIVATED CARBON FROM SUGAR-CANE BAGASSE BY CARBONIZATION IN THE PRESENCE OF INORGANIC ACIDS

Dried ground bagasse, impregnated with 50% inorganic acids and carbonized at 500-degrees-C, showed the sequence H3PO4 > H2SO4 > HCl > HNO3, with respect to the efficiency of activation. Treatment with phosphoric acid of various concentrations (30-50 wt%) was followed by carbonization at 300-500-degrees-C for 3 h. Pore structure parameters were determined from the low-temperature adsorption of nitrogen, by applying the BET and alpha(s) methods. Activated carbons obtained at low temperatures are essentially microporous with a low degree of mesoporosity. At higher temperatures products of higher surface area and total pore volume with developed mesoporosity and low microporosity are formed. An increase in the period of carbonization leads to a small decrease in both surface area and pore volume. Activated carbons with surface areas > 1000 m2 g-1 and mean pore dimensions around 2.0 nm, suitable for various purposes, are thus obtained.