CHEMICALLY ACTIVATED CARBONS FROM SUGAR-CANE BAGASSE FRACTIONS

Chemically activated carbons were prepared from the rind and pith frac tions of a sugar cane separator. Similar samples were made from sugar cane bagasse and bagacillo. Phosphoric acid, sulphuric acid, zinc chlo ride and calcium chloride were the chemical activating agents. Reactan ts were pyrolised at 500 degrees C in an inert nitrogen atmosphere. Yi elds of activated carbon and the recovery of the chemicals for recycli ng were determined. Decolourisation tests were performed on a sugar sy rup. Phosphoric acid activation had the best ICUMSA colour removals fo r all sugar cane bagasse fractions and the highest yield of activated carbon per unit biomass feed. However the low pH of 1.8 of the decolou rised syrup will negate potential use of phosphoric acid activated car bon in the sugar industry, using the present method. The high colour r emovals are in part due to the leaching of the adsorbed acid. The syru p was clarified by a phosphitation process during pH correction to 7.0 , as required by the ICUMSA colour method. Similar effects were notice d for the zinc chloride carbons. Activated carbons prepared from zinc chloride and calcium chloride both yield promising results.