Multi-scale, multi physics modeling of thermo-chemical iron/iron oxide cycle for fuel production

Present dissertation focuses on multi-scale, multi-physics modeling of thermochemical iron/iron oxide cycle for hydrogen production. Matlab/Fortran based numerical models are developed to study the thermochemical hydrogen production using iron/iron oxide looping process from the perspective of a system level, a reactor level and finally down to the reactive material itself. For the system scale study, a model is created to develop four different layouts of the overall hydrogen production plant based on the operating temperature ranges. An efficiency based comparison is also performed between a hydrogen production plant using the iron/iron oxide looping cycle and a hydrogen production plant using the conventional process involving a water gas shift reaction and a pressure swing adsorber. For the reactor scale study, an open system, quasi-steady state thermodynamic model is developed and is used to predict the optimum operating conditions for hydrogen production. The validation of the thermodynamic model with the experimental results is carried out for the hydrogen production step and the iron oxide reduction step. A collision based Monte Carlo ray tracing model is developed and coupled to the lattice Boltzmann conduction model to optimize the geometry of the windowless horizontal cavity reactor. Finally, for the reactive material scale analysis, a participating medium Monte Carlo ray tracing code is created for the continuum model involving heat and mass transfer coupled with chemical kinetics to investigate the effect of various parameters (such as operating temperature, input steam flow rate, steam concentration) on hydrogen production.