Abstract:

Solar water splitting is a promising process for the storage and conversion of sunlight power into clean-burning hydrogen gas, this paper presents a CFD analysis of hydrogen production via a proposed packed bed thermochemical receiver/reactor system. The idea of this study is the use of packed bed of spherical ceramic particles coated with active redox ferrite materials. The first step is an endothermic reaction, nickel ferrite (NiFe2O4) dissociate thermally into nickel oxide (NiO), ferrous oxide (FeO) and oxygen at 1473 K, this reaction take place under 2 KW concentrated solar energy. The second is the hydrolysis step at 1073 K to form hydrogen and NiFe2O4, the latter is recycled to the first step for a new production cycle. The CFD code solves the momentum, energy and species transport equations. The temperature fields of the reactor solid & the fluid phases were attained using the local thermal non-equilibrium model (LTNE). The LTNE model sources terms were computed through the user-defined functions to couple the energy equations of the fluid phase and solid phase. The complete model was used to analyse numerically the reaction through the packed bed in order to predict the thermal behavior under different conditions (inlet velocity, packing arrangement and solar concentrated flux).

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