LAUSR

The structural changes of biochar prepared from sweet sorghum bagasse during fast pyrolysis of 200 to 700 °C in a novel V-shaped down-tube reaction device was investigated by ultimate analysis, bomb calorimeter, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and N2/CO2 adsorption methods. The results showed that the pyrolysis temperature had an important effect on the composition and physicochemical properties of sweet sorghum bagasse biochar. With the increase of pyrolysis temperature, the yield of biochar and the polar functional groups decreased, but the higher heating values and mineral salts increased. However, the surface area, pore volume, and adsorption (N2, CO2) increased first and then decreased. The biochar obtained at 500 °C had the most developed pore structures. The experimental results shed light on the high-quality utilization of sweet sorghum bagasse obtained from advanced solid-state fermentation.