Abstract
Chemical looping hydrogen production is of interest because of its ability to simultaneously produce hydrogen and capture CO2 at the same time.Achieving an energy balance is crucial in chemical-looping hydrogen production systems.Decreasing the external heat duty can effectively reduce carbon capture and energy conversion efficiency.In this study,two auto-thermal chemical looping H2 generation systems are proposed.An adiabatic counter current moving bed chemical looping H2 generation system using CH4 as fuel and Fe2O3 and Al203(inert carriers)as oxygen carriers(OC)is proposed to analyse the energy balance and exergy balance of the systems.A parametric analysis was conducted to investigate the influence of the reaction ratio and temperature on the product outcomes,leading to the determination of optimal operating conditions.Subsequently,the impact of hydrogen production efficiency and reduction reactor outlet stream ratio and inert component proportion in the oxygen carrier on the system's thermal balance was analysed under these optimal conditions,culminating in the identification of key parameters for the two auto-thermal systems.Energy balance and exergy balance analyses were employed to compare the energy efficiency and irreversible losses of the autothermal and reference systems.The results demonstrated that the autothermal system enhanced the energy efficiency by 2.5％and the CO2 capture rate by 11％(percentage points)compared with the reference system.
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