Highly microporous carbons from olive tree pruning: Optimization of chemical activation conditions

Abstract

The growing environmental problems and the depletion of fossil fuels have driven the research towards the development of renewable energy sources and the technologies that make use of them. In this context appears the demand of renewable, abundant and low-cost precursors as an alternative to traditional fossil sources. Activated carbons are materials with a great variety of applications which can be obtained from lignocellulosic wastes. This work evaluates the valorization of olive tree pruning (OTP) through the production of highly microporous carbons with KOH. A statistical optimization study was performed and the effect of the impregnation ratio, temperature and activation time on the developed surface area was studied. The optimum activation conditions for maximum porous development were: impregnation ratio of 6.38, 788.5 °C and 145 min. Under these conditions 3514 m 2 /g of surface area was generated, exceeding the values found in the bibliography. The sample obtained under optimal conditions was further characterized with SEM and FTIR and pH pzc . From its characteristics it was concluded that activated carbons generated from olive tree pruning residues using KOH are suitable for applications such as adsorption, EDLC electrodes and gas storage, among others.