Chemical Kinetic Modeling of Air-Steam Gasification of Eucalyptus Wood Sawdust for H₂-Rich Syngas Production

The aim of this research paper is to develop a chemical kinetic model, based on the mechanism of surface reactions, for air-steam gasification of eucalyptus wood sawdust (CH_1.63O_1.02) and analyze the hydrogen-rich syngas production. Experiments are performed on a bubbling fluidized-bed gasifier using air-steam as a gasifying agent. For validation of the developed kinetic model, the outcome of the model is compared with that of experimental data, which shows a root-mean-square error of less than 4. Different parameters such as equivalence ratios (0 ≤ ER ≤ 0.4), particle size (100 ≤ Dp ≤ 1000 μm), gasification temperature (900 ≤ T ≤ 1200 K), pressure (1 ≤ P ≤ 20 atm), and steam-to-biomass ratio (0 ≤ SBR ≤ 2) are considered for the analysis. The one-parameter-at-a-time concept is employed to maximize the production of H₂-rich syngas. Results indicate that the maximum concentration of hydrogen is 55.04 vol % (experimental) and 51.81 vol % (predicted) at optimum conditions: ER = 0, Dp = 100 μm, T = 1100 K, P = 1 atm, and SBR = 0.75. Gasification performance parameters such as hydrogen gas yield, heating values, cold gas efficiency, etc., are evaluated.