Physicochemical Properties of Biochar Prepared from Guinea Corn Straw as a Function of Different Pyrolysis Temperatures
Abubakar I*, Saeed MD and Ayuba AM
ABSTRACT
The present study examined the effect of pyrolysis temperature on the physicochemical properties of biochar produced from guinea corn straws at different temperatures (300-600℃). However, the produced biochars were designated as BCG-300, BCG-400, BCG-500 and BCG-600, respectively. The produced biochar’s were characterized by different analytical techniques. These include; the proximate and elemental analyses, morphological, crystallographic, functional groups and specific surface area analyses were investigated using elemental analyzer, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller (BET), respectively. The results indicated that. increasing pyrolysis temperature increased the content of fixed carbon (C), the C content, the total content of K, Ca, and Fe, as well as the cation exchange capacity (CEC), pH, and EC. While the yield, the content of volatile matter O and H, and the ratios of O/C and H/C decreased. Additionally, at higher pyrolysis temperature, the BET surface area and pore volume increased with increased in temperature, typically due to the increase of the micropore surface area and micropore volume. Furthermore, the data of Fourier transformation infrared showed that at higher pyrolysis temperature, the biochar aromaticity increased and decreased in polarity. Similarly, the crystalline mineral components increased with pyrolysis temperatures due to the cellulose loss, as indicated by X-ray diffraction analysis and scanning electron microscope images. Hence, pyrolysis temperature has a strong effect on biochar properties, and therefore biochars can be produced by changing pyrolysis temperature in order to meet their applications, such as carbon sequestration, greenhouse gas mitigation and as an adsorbent for organic and inorganic contaminants when applied to the environment etc.
