(48f) Solar Reactor Efficiency Analysis for Alternative Fuel Production Via Ferrite Based Two-Step Thermochemical Splitting of Water and CO2

Ferrite based redox reactions are considered as one of the most promising redox system for the production of solar fuels such as solar H₂, solar CO, or solar syngas via thermochemical splitting of water and CO₂. In previous investigations, various ferrites based materials such as Fe₃O₄/FeO, Ni-ferrite, Co-ferrite, Mn-ferrite, Zn-ferrite, Ni-Zn-ferrite, Ni-Mn-ferrite, and etc. were investigated for the solar thermochemical splitting of water and CO₂. These materials were derived via different synthesis approaches such as sol-gel, co-precipitation, SHS, aerosol spary analysis, solid state synthesis, combustion synthesis, and etc. Various reactor set-ups were also investigated towards the production of solar fuels via thermochemical splitting of H₂O and CO₂ using ferrites based materials such as packed bed reactors, fluidized bed reactors, aerosol reactors, cavity reactors and etc.

In this work, we performed the computational thermodynamic modeling to identify the solar to fuel conversion efficiency of the ferrite based two-step thermochemical splitting of water and CO₂. Commercially available thermodynamic softwares and databases such as HSC Chemistry and FactSage were used to perform the thermodynamic simulations. At first, the equibrium thermodynamic compositions associated with the solar thermal reduction of ferrites and splitting of water and CO₂ using the reduced ferrite materials were identified. The variation of the reaction enthalpy, entropy and Gibbs free energy for the thermal reduction and water/CO₂ splitting steps with respect to the operating conditions were also determined. Furthermore, solar reactor efficiency analysis was performed by following the second law of thermodynamics and solar absorption efficiency of the solar reactor, solar energy input to the solar reactor, radiation heat losses from the solar reactor, net energy absorbed in the solar reactor, rates of entropy produced in the solar reactor and cooling units were calculated and plotted. At the end, the solar to fuel conversion efficiency of the ferrite based thermochemical water and CO₂ splitting cycle was determined and compared with the previously investigated other metal oxide cycles. The thermodynamic simulation results will be presented in detail.