Hydrogen-rich syngas production from biomass pyrolysis and catalytic reforming using biochar-based catalysts

Abstract

A residual biochar-based catalyst has been studied for in-line catalytic reforming process after biomass pyrolysis. Poplar pyrolytic char and Ni/char with different Ni loading were prepared and used as catalysts for producing hydrogen-rich syngas from poplar wood. XRD, BET, SEM, and TEM analysis were used to characterize the synthesized catalysts. The results show that biochar has abundant pore structure and catalytic activity, which is in favor of bio-oil reforming. When loaded with Ni, biochar can also be used as a support, which directly reduces NiO to active Ni and protects Ni from oxidation. Ni/Char catalyst showed better catalytic activity than biochar. A series of experiments have been performed to determine the optimal operating conditions, such as catalytic temperature and water injection flow rate. The experiment results indicated that the best syngas production of 34.321 mmol per 1 g biomass can be achieved with 10 wt% Ni/Char catalyst at 650 °C. When 0.3 mL/min of water was added to the pyrolysis reactor, syngas production was significantly increased to 109.848 mmol per 1 g biomass, owing to the thorough utilization of biological carbon through reaction with water vapor. Therefore, this study points to innovative and effective approaches to make full use of biomass and biomass residues.