Syngas Production from Corn Stover via Pyrolysis and Steam Gasification in a Fixed-Bed Reactor: Effects of Temperature, Steam-to-Carbon Ratio, and Catalyst Loading

The growing demand for sustainable energy has intensified interest in converting abundant agricultural residues into renewable fuels. Among these feedstocks, corn stover represents a promising biomass for thermochemical conversion due to its high volatile matter content and widespread availability. This study investigates syngas production and product distribution from corn stover via pyrolysis and steam gasification in an atmospheric fixed-bed tubular furnace at temperatures of 650–850 °C. Furthermore, the effects of steam-to-carbon (S/C) ratio and nickel aluminate (NiAl2O4) catalyst loading at 650 °C were also investigated to determine their influence on product distribution and syngas composition. Increasing temperature significantly enhanced gas production in both processes, while steam gasification consistently produced higher gas yields than pyrolysis. At an S/C ratio of 3, the gas yield increased from 37% to 58.6%, with a 55.1% increase in H2 production after 60 min compared with the pyrolysis baseline. Furthermore, incorporation of NiAl2O4 improved the H2 yield and H2/CO molar ratio while suppressing CO2 and CH4 formation, indicating enhanced catalytic reforming and secondary cracking of pyrolysis vapors. These findings demonstrate that optimizing steam addition and nickel aluminate catalyst loading effectively promotes hydrogen-rich syngas from corn stover and provides valuable insight for the development of efficient biomass-to-fuel conversion technologies.