Please cite this article in press as: Hoseinzadeh Hesas, R., et al., Preparation of granular activated carbon from oil palm shell by microwave-induced chemical activation: Optimisation using surface response methodology. Chem. Eng. Res. Des. (2013), http://dx.doi.org/10.1016/j.cherd.2013.06.004 ARTICLE IN PRESS CHERD-1270; No. of Pages 10 chemical engineering research and design x x x ( 2 0 1 3 ) xxx–xxx Contents lists available at SciVerse ScienceDirect Chemical Engineering Research and Design j ourna l h omepage: www.elsevier.com/locate/cherd Preparation of granular activated carbon from oil palm shell by microwave-induced chemical activation: Optimisation using surface response methodology Roozbeh Hoseinzadeh Hesas a , Arash Arami-Niya a , Wan Mohd Ashri Wan Daud a,* , J.N. Sahu a,b a Department of Chemical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia b Department of Chemical Engineering, Indian Institute of Technology (IIT), Kharagpur, P.O. Kharagpur Technology, West Bengal 721302, India a b s t r a c t In this study, waste palm shell was used to produce activated carbon (AC) using microwave radiation and zinc chlo- ride as a chemical agent. The operating parameters of the preparation process were optimised by a combination of response surface methodology (RSM) and central composite design (CCD). The influence of the four major param- eters, namely, microwave power, activation time, chemical impregnation ratio and particle size, on methylene blue (MB) adsorption capacity and AC yield were investigated. Based on the analysis of variance, microwave power and microwave radiation time were identified as the most influential factors for AC yield and MB adsorption capacity, respectively. The optimum preparation conditions are a microwave power of 1200 W, an activation time of 15 min, a ZnCl 2 impregnation ratio of 1.65 (g Zn/g precursor) and a particle size of 2 mm. The prepared AC under the optimised condition had a BET surface area (S BET ) of 1253.5 m 2 /g with a total pore volume (V tot ) of 0.83 cm 3 /g, which 56% of it was contributed to the micropore volume (V mic ). © 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Keywords: Activated carbon; Agricultural waste; Microwave heating; Pore structure; Functional groups; Chemical activation 1. Introduction The discharge and effluence of dyes into the environment by some industries, including paper, leather and plastic, is a major concern of the government and the public (Métivier- Pignon et al., 2003; Ravikumar et al., 2005). Among the hazardous dyes, methylene blue (MB) is a particularly common substance in many dying industries and has strong effects on the human body, such as causing vomiting and inducing shock (Tan et al., 2008). Therefore, the treatments of such dyes are a significant issue. One of the most common methods used to treat dyes is adsorption, which is a simple approach to elimi- nate pollutants. Activated carbon (AC) has been heavily used as a solid adsorbent in many gas and liquid processes due to its highly desirable physical and chemical properties, such as its ∗ Corresponding author. Tel.: +60 3 79675297; fax: +60 3 79675319. E-mail addresses: roozbehhesas@gmail.com (R. Hoseinzadeh Hesas), arash araminiya@yahoo.com (A. Arami-Niya), ashri@um.edu.my (W.M.A. Wan Daud), jay sahu@yahoo.co.in (J.N. Sahu). Received 4 February 2013; Received in revised form 20 May 2013; Accepted 4 June 2013 controllable and highly developed porosity, large surface area, high surface reactivity and highly modifiable surface, which facilitates a broad range of surface chemistries (Abdel-Nasser, 2009; Arami-Niya et al., 2012a; Dias et al., 2007). Therefore, due to the abovementioned properties of AC and other characteris- tics, including its low acid/base reactivity and thermostability, AC is used in a variety of applications, including a catalyst or catalyst support and in purification and separation pro- cesses, especially for pollutants that are difficult to colour and the recovery or purification of chemicals (Hejazifar et al., 2011; Huang et al., 2011; Ioannidou and Zabaniotou, 2007; Stavropoulos and Zabaniotou, 2009). The adsorption capac- ity of AC is determined by its internal porosity, surface area, pore size distribution and pore volume, all of which are signif- icantly affected by the physical and chemical properties of the 0263-8762/$ – see front matter © 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cherd.2013.06.004