Industrial Crops and Products 44 (2013) 18–24 Contents lists available at SciVerse ScienceDirect Industrial Crops and Products journa l h o me pag e: www.elsevier.com/locate/indcrop Biochar production from waste rubber-wood-sawdust and its potential use in C sequestration: Chemical and physical characterization Wan Azlina Wan Abdul Karim Ghani a,b,∗ , Ayaz Mohd a,c , Gabriel da Silva b , Robert T. Bachmann d , Yun H. Taufiq-Yap e , Umer Rashid f , Ala’a H. Al-Muhtaseb g,∗∗ a Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia b Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia c Sur College of Applied Sciences, P.O. Box 484 Postal Code- 411, Sur - Oman d Malaysian Institute of Chemical and Bioengineering Technology (MICET), Universiti Kuala Lumpur, Lot 1988, TabohNaning 78000 Alor Gajah, Malaysia e Centre of Excellence for Catalysis Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia f Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia g Petroleum and Chemical Engineering Department, Faculty of Engineering, Sultan Qaboos University, P.O. Box 33, Oman a r t i c l e i n f o Article history: Received 6 August 2012 Received in revised form 13 October 2012 Accepted 15 October 2012 Keywords: Biochar Rubber-wood-sawdust Pyrolysis Characterization C sequestration a b s t r a c t Biochars have received increasing attention because of their potential environmental applications such as soil amending and atmospheric C sequestration. In this study, biochar was produced from waste rubber-wood-sawdust. The produced biochars were characterized by Brunauer–Emmett–Teller (BET) gas porosimetry, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric anal- ysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Pyrolysis temperature was shown to have a strong influence on both thermal and chemical characteristic of biochar samples. The experimental data shows that the biochar samples can absorb around 5% water by mass (hydrophilic) at lower temperatures (<550 ◦ C), and that lignin is not converted into a hydrophobic polycyclic aromatic hydrocarbon (PAH) matrix. At higher temperatures (>650 ◦ C), biochar samples were thermally stable and became hydropho- bic due to the presence of aromatic compounds. Carbon content (over 85%) increased with increasing temperature, and showed an inverse effect to the elemental ratios of H/C and O/C. The very low H/C and O/C ratios obtained for the biochar indicated that carbon in this material is predominantly unsaturated. BET results showed that the sawdust derived biochars have surface areas between 10 and 200 m 2 g -1 and FTIR indicated an aromatic functional group about 866 cm -1 in most of the samples. The rate of CO 2 adsorption on sawdust derived biochar generally increased with increasing temperature from 450 to 650 ◦ C but then decreased with increase in the production temperature. Derived biochar represents a potential alternative adsorbent for C sequestration. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Climate change is now a global issue due to unprecedented high levels of greenhouse gases (GHGs) in the atmosphere. Burning of fossil fuels is one of the main anthropogenic activities that con- tribute to increasing levels of carbon dioxide in the atmosphere and is cited as a major contributing factor for global warming (IPCC, 2002). Since 2000, anthropogenic carbon dioxide (CO 2 ) emissions have risen by more than 3% annually, putting earth’s ecosystems ∗ Corresponding author at: Department of Chemical and Environmental Engineer- ing, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. ∗∗ Corresponding author. E-mail addresses: wanaz@eng.upm.edu.my (W.A.W.A.K. Ghani), muhtaseb@squ.edu.om (A.H. Al-Muhtaseb). on a trajectory toward rapid climate change that is both dangerous and irreversible. Lignocellulosic biomass such as wood wastes, waste paper, saw- dust, grass, and the biomass-derived char (biochar), is non-food based biomass and is therefore viewed as a promising feedstock for renewable and alternative fuels (Li et al., 2011; Cardona et al., 2010). Lignocellulosic biomass is considered as a carbon-neutral resource that does not increase the total atmospheric CO 2 in its life cycle, since the plants absorb CO 2 released from biomass fuels in their growing processes. It also has the advantages of high volatile matter content, low ash, sulfur and nitrogen contents, and there- fore has low pollution to the environment when burned (Feng-Ke et al., 2008). The annual biomass resources from crop and wood waste, which can be used for fuel, are about 350 million tons of standard coal. Thermochemical processes such as gasification, pyrolysis, hydrothermal liquefaction/carbonization are generally used for the 0926-6690/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.indcrop.2012.10.017