CFD-DEM simulation of chemical looping hydrogen generation in a moving bed reactor

Chemical looping hydrogen generation represents a viable technology for high-purity hydrogen production and CO2 capture. Moving bed reactors are considered effective for this process, but the high cost of experiments and the complexity of the biomass gas reaction have hindered the development of hydrogen generation from biomass gas.This investigation employs Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) to simulate gas-solid phase distribution and reactions within a moving bed fuel reactor, aiming to amplify biomass gas and oxygen carrier conversion rates. Findings indicate that enhancing particle flux rate and reaction temperature substantially increases the conversion efficiency of both biomass gas and oxygen carrier. Notably, achieving complete CH4 conversion presents significant challenges in biomass gasification, with CH4 conversion dictating the requisite bed height for total biomass gas conversion. Furthermore, the gas-phase equilibrium conversion rate of Fe3O4 to FeO delineates the operational limit within the moving bed. Under full reaction conditions of biomass gas, the oxygen carrier’s maximum achievable conversion ranges between 29.2  and 31.6 % at 850 °C. These insights substantially advance the application of biomass gas in the chemical looping domain and inform future design and operational strategies for reactors.