Activated Carbons Prepared from Pine Wastes for the Uptake of Organic Compounds from Aqueous Solution

Abstract

The feasibility of preparing chemically-activated carbons from a char obtained by the gasification of pine wastes has been studied. The optimised conditions for producing activated carbons with well-developed porosity were investigated and the influence of activating agent (KOH)/char ratio, temperature and duration of the pyrolysis process established. Additionally, for comparative purposes, two different designs for the stainless-steel basket in which the sample to be activated was inserted were tested in selected cases to determine the quality of the activated carbons produced. The results obtained showed that micropore development depended strongly on the KOH/char ratio, which was the most important variable under the conditions studied. The activated carbon with the largest adsorption capacity produced had a well-developed porosity, providing a total micropore volume of 0.678 cm3/g and an apparent surface area (as estimated by the DR method) of 1908 m2/g. The activated carbons prepared exhibited high benzene adsorption rates that increased with increasing micropore volume. The initial adsorption coefficient (γ) appeared to correlate strongly with the micropore volume deduced from nitrogen adsorption data.