Understanding the catalytic pyrolysis conversion of metal salt-impregnated biomass into biogas and nanocatalyst-coated porous biochar

This study investigates the pyrolysis kinetics behaviour and decomposition effects of Cu/Ni nitrate impregnation on sugarcane bagasse (SCPB) through slow pyrolysis. To probe this process, coupled thermogravimetric analysis/Fourier Transform Infrared Spectroscopy (TGA/FTIR) simulated pyrolysis in a traditional procedure with a tube furnace, analyzing both biochar formation and syngas evolution. The experimental results reveal that the maximum weight loss occurs at a thermochemical conversion of ∼60 % of the biomass into char; SCPB/CuNi showed intermediate decomposition at 328 °C, 10 °C below SCPB and 5 °C above CuNi. The carbonization kinetic study of biomass was performed using a TGA at dynamic heating rates (10, 20, and 30 °C min⁻¹) in nitrogen atmosphere. The kinetic parameters were estimated using Flynn-Wall-Ozawa (FWO) and Distributed Activation Energy Model (DAEM)，i.e. Ea = 234 kJ·mol⁻¹ for SCPB, much higher than 90 kJ·mol⁻¹ for the SCPB/CuNi. Further, TGA-derived and tubular furnace-produced biochars were found to have nearly identical physicochemical properties as judged from proximate analysis, justifying TGA as a valid platform for biomass pyrolysis studies, whereas the simultaneously generated CO_x, N_xO_x, CH₄, and H₂ syngases were probed by TGA-FTIR/Py-MS. The syngases present valuable opportunities for energy recovery and chemical synthesis applications.