Preparation of activated carbon from olive mill solid residue

Abstract

A process was developed for producing high quality activated carbon from Algerian mill waste. The solid olive mill residue was carbonized at 800°C and physically activated with CO2, air or steam. An optimum activation temperature of about 850°C was determined for all the activation agents used. Steam appeared to be the most ef®cient activator as compared with air and CO2. An optimal activation time of about 2h was then determined with steam as the optimum activation agent. The porous structure of the activated carbon was characterized by nitrogen adsorption at ÿ196°C, and in all cases the surface areas, calculated by DR and BET methods, con®rmed the production of a material with good microstructural characteristics and speci®c surfaces exceeding 1500m2g ÿ1 for the carbon prepared by steam activation. Phenol adsorption isotherms gave the adsorption properties and the adsorption capacity of about 11.24mg of phenol per gram of the activated carbon produced. The kinetics of the phenol adsorption onto the porous material was evaluated by means of two models: the external resistance model and the linear model. The second model appeared to constitute a more appropriate ®t for the experimental data.