Biomass catalytic gasification in a fluidized-bed to produce hydrogen rich gas

The characteristics of hydrogen yield from biomass are investigated using dolomite in the fluidized-bed gasifier and nickel-based catalysts in the outlet of fixed bed reactor. Some calcined dolomite is placed initially in the gasifier with an amount of 120 g/(kg·h^-1) biomass. To replace the eroded and elutriated dolomite, calcined dolomite (0.3-0.45 mm) is continuously fed and its feeding rate is determined by preliminary test. The influence of the operating conditions in the catalytic reactor on the production of gases, especially H₂ is studied over the temperature range of 650-850°C, for weight hourly space velocity (WHSV) in the range of 2.68-10.72 h^-1. In the gaseous product, the average content of H₂ exceeds over 50 vol%; C₂ content is lowered to below 1 vol% and nearly half of CH₄ is converted after the catalytic reactor. Over the ranges of experimental conditions examined, the highest gas yield reaches 3.31 Nm₃/kg biomass, wet basis; the maximum hydrogen yield gets to 130.28 g H₂/kg biomass, wet basis. This system shows a good performance over a lifetime test of 350 minutes.