Production of H₂ from Microalgae Biomass in Supercritical Water Using a Ni/La-γAl₂O₃ Catalyst

This communication presents the catalytic gasification of microalgae (nannochloropsis oculata) biomass under supercritical water conditions using Ni/γAl₂O₃and Ni/La-γAl₂O₃ catalysts. The gasification products contain mainly hydrogen, carbon monoxide, carbon dioxide and methane. It is observed that the presence of a nickel catalyst enhances the gasification performance significantly. The desired hydrogen production is further improved by addition of La to the Ni/La-γAl₂O₃ catalyst. TPR analysis indicates that the presence of La helps to attain higher number of active nickel sites, which is mainly responsible for the higher catalytic activity. Hydrogen production could also be enhanced by retardation of methanation reaction of carbon dioxide by promoting Ni/γ-Al₂O₃ with La. The higher reaction temperature favors the hydrogen production due to the endothermic nature of the most of the involved reactions.