Characteristics of activated carbons prepared from pistachio-nut shells.pdf

Journal of Colloid and Interface Science 267 (2003) 408–417 /locate/jcis Characteristics of activated carbons prepared from pistachio-nut shells by physical activation Ting Yang and Aik Chong Lua ? School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore Received 17 December 2002; accepted 17 June 2003 Abstract Activated carbons were prepared from pistachio-nut shells, which are one type of lignocellulosic material, by a two-step physical method. The effects of the preparation variables on the activated carbon pore structure were studied, followed by the optimization of these operating parameters. It was found that the activation temperature and dwell time are the important parameters that affect the characteristics of the acti- vated carbons obtained. The effects of CO2 flow rate and heating rate during activation were also studied. Under the experimental conditions used, the optimum conditions to prepare activated carbons with high surface area and pore volume were identified. The microstructure of the activated carbons prepared was examined by scanning electron microscopy while the Fourier transform infrared spectra showed the changes in the surface functional groups produced during the different preparation stages. ? 2003 Elsevier Inc. All rights reserved. Keywords: Activated carbon; Activation; Characterization; Pistachio-nut shell1. Introduction Activated carbon can be produced from a variety of car- bonaceous source materials. There are many studies in the literature relating to the preparation of activated carbons from agricultural wastes [1–6]. However, there is only lim- ited research on the preparation of activated carbons using pistachio-nut shells. Hourieh et al. [7] had carried out pre- liminary studies on the effect of zinc chloride concentra- tion on the textural properties of the activated carbons pre- pared from such shells. Detailed experimental studies such as the effects of