Production and characterisation of activated carbon from wood components in powder: Cellulose, lignin, xylan

The aim of this work was to characterise the activated carbon produced from wood and its basic components: cellulose, lignin and xylan (hemicelluloses). Two ways of activation were tested: simple pyrolysis under N-2 and thermal treatment of the material impregnated with KOH (KOH-activation). Concerning the pyrolysis, simultaneous measurements of DTA-TGA allowed to compare the heat of reaction and the decomposition rate of the 3 wood components. Moreover it was shown that only the char from cellulose has a significant BET-surface area of pores. The KOH-activated carbons from wood and wood components were characterised by their BET surface area, their spectra in temperature programmed desorption (TPD) up to 1173 K and by their capacity to adsorb pollutant compounds in aqueous phase such as phenol and methylene blue. It was shown that the theoretical models of Langmuir and Freundlich satisfactorily fit to the adsorption isotherms of these pollutants, moreover most of the parameters of these theoretical models rank as the BET-surface area of pores. (c) 2005 Elsevier B.V. All rights reserved.