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 efficient activator as compared with air and CO2. An optimal activation time of about 2 h was then determined with steam as the optimum activation agent. The porous structure of the activated carbon was characterized by nitrogen adsorption at −196 °C, and in all cases the surface areas, calculated by DR and BET methods, confirmed the production of a material with good microstructural characteristics and specific surfaces exceeding 1500 m2 g−1 for the carbon prepared by steam activation. Phenol adsorption isotherms gave the adsorption properties and the adsorption capacity of about 11.24 mg 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 fit for the experimental data. © 2000 Society of Chemical Industry