Biochar production from waste rubber-wood-sawdust and its potential use in C sequestration: chemical and physical characterization

• Main Authors: Wan Ab. Karim Ghani, Wan Azlina, Mohd, Ayaz, Da Silva, Gabriel, Bachman, Robert T., Yap, Taufiq Yun Hin, Rashid, Umer, Al-Muhtaseb, Ala'a H.
• Format: Article
• Language: English
• Published: Elsevier 2013
• Online Access: http://psasir.upm.edu.my/id/eprint/28521/1/Biochar%20production%20from%20waste%20rubber%20wood%20sawdust%20and%20its%20potential%20use%20in%20C%20sequestration%20chemicaland%20physical%20characterization..pdf; http://psasir.upm.edu.my/id/eprint/28521/

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 analysis (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 hydrophobic 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 m2 g−1 and FTIR indicated an aromatic functional group about 866 cm−1 in most of the samples. The rate of CO2 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.