Hydrogen production by partial oxidation gasification of biomass in supercritical water with fluidization bed reactor

Supercritical partial oxidation is a new technology which combines supercritical water gasification with supercritical water oxidation for high efficient hydrogen production from biomass. Supercritical partial oxidation process was analyzed theoretically, and chemical equilibrium was calculated using the thermodynamic model. It is found that the equilibrium yield of hydrogen, methane, carbon monoxide, and the molar fraction of hydrogen decrease, while the equilibrium yield of carbon dioxide increases with the increase of the oxidant equivalence ratio. Experiments on hydrogen production by partial oxidation of model compound (glucose) and real biomass (corn cob) with SCW fluidization bed were also conducted. The results show that the gasification efficiency increases sharply with the addition of oxidant which reduces the molar fraction of hydrogen. During partial oxidation gasification process of 10% glucose, the hydrogen yield reaches maximum when the oxidant (H₂O₂) equivalence ratio is 0.2 (i.e., mass fraction of 4.53%).