Evolution of Pyrolysis Characteristics and Gas Components of Biochar Prepared by Either Mixing or Layering Rice Husk with Inert Aluminum Oxide

Abstract

A comparison of pyrolysis characteristics and gas product evolution of biochar with different packing arrangements was investigated. Pyrolysis properties and released gas products of rice husk char were obtained by particles in two different modes of packing. The results of the combustion characteristics of rice husk/char showed that the maximum pyrolysis rate of the rice husk decreased and the pyrolysis curve shifted to higher temperatures when the biomass was covered by Al₂O₃. The volatilization analysis of char from the covered biomass had a larger characteristic index and a lower activation energy. The 2D Fourier transform infrared (FTIR) results showed that layering hindered gaseous products from being released during rice husk pyrolysis, and there was no obvious release peak of C=O-containing organic matter. The 3D FTIR results showed that gaseous product absorption peak of solid product char pyrolysis gradually decreased while the rice husk conversion rate increased. The amount of H₂O, CO₂, CO, CH₄, and C=O-containing organic components released during combustion of pyrolyzed char when blended with Al₂O₃ decreased gradually. However, the pyrolysis gaseous product release was increased by the layering procedure.