The role of temperature on slow pyrolysis of olive cake for the production of solid fuels and adsorbents

Abstract

Abstract In this work, slow pyrolysis of olive cake has been carried out under nitrogen atmosphere at different temperatures to obtain carbonaceous materials with possible applications as solid fuels and adsorbents of heavy metals from aqueous solutions. The carbonaceous materials have been completely characterized. The Gain and Loss method has been applied in order to find the best operating temperature in terms of quality of the carbonaceous material for its use as fuel. Also, a basic reaction scheme has been proposed for representing the kinetics of thermal degradation in nitrogen and air atmospheres. Good correlation of calculated and experimental data was observed for different materials. Finally, adsorption experiments were performed to test ability of carbonaceous materials as adsorbents of cadmium, chromium, copper, nickel and lead. In general, the carbonaceous solids obtained by slow pyrolysis improved the adsorption capacities of the raw material. For example, a maximum lead adsorption capacity of 102 mg/g was found for carbonaceous material obtained at 450 °C. Also, for this material, the values of maximum adsorption capacity indicated the higher preference of solid for lead ions.