Hydrogen production by biomass gasification in a supercritical water fluidized bed reactor: A CFD-DEM study

•CFD-DEM study of biomass gasification in a SCW fluidized bed was conducted.•Reactions affected the fluidization mainly by the endothermic effect.•Low flow rate, high wall temperature and initial bed height favored gasification.•The results are very useful for the operation and design of SCW fluidized bed.

In this study, we used CFD-DEM model to simulate glucose gasification in a supercritical water fluidized bed reactor (SCWFBR). Simplified reaction kinetic model, including glucose decomposition, water gas shift reaction and methanation reaction, was used. Particle distributions, gas composition and reaction rate profiles were analyzed. Moreover, the influence of chemical reaction on flow behavior, and the effects of operation parameters, such as wall temperature, flow rates and initial bed height were investigated. The results show that high wall temperature, low flow rate and high initial bed height are in favor of gasification. However, lower H2 yield, gasification efficiency (GE) are found at flow rate below the minimum fluidization velocity. The simulation results show good agreement with the experimental results, demonstrating the validity of this model. The information obtained by the numerical study is useful for the operation and optimization of the gasification reactor.

Graphical abstractDownload high-res image (165KB)Download full-size image