Optimal Porosity Distribution of Non-Uniform Macroporous Ceria in Solar Thermochemical Water Splitting
- Type: Conference Presentation
- Conference Type: AIChE Annual Meeting
- Presentation Date: November 17, 2020
- Duration: 16 minutes
- Skill Level: Intermediate
- PDHs: 0.30
We developed a multi-scale and multi-physics modeling framework for the complete solar-driven two-step redox cycle process, including reduction and oxidation reactions. Based on the volume-averaged conservation equations of mass, momentum, and energy, this model incorporated morphology related effective properties of the porous ceria, coupled the heat and mass transfer interactions, and non-equilibrium local heterogeneous chemistry between solid and fluid phase. The effective transport properties of the porous media were determined by direct pore-level simulations and Monte Carlo ray tracing utilizing the digital 3D micro-structures obtained by X-ray computed tomography.
The porosity distribution was optimized for enhanced reaction rate and fuel yield, considering different operational conditions (temperature, mass flow rate and species concentration). The optimization objectives were to maximize the conversion efficiency and rate of solar energy into chemical energy, considering their constraints given by the conservation equations.
The results indicated that, under certain operation conditions, volumetric radiation absorption could be increased and species concentration could be smoothened and made more uniform within the non-uniform porous reactor. The advancements in the reaction rate and fuel yield for the optimized non-uniform porosity distribution are quantified.
The optimized non-uniform porosity distribution function of the ceria provides a practical opportunity in additive manufacturing, material engineering, and scalable manufacturing.
|AIChE Member Credits||0.5|
|AIChE Graduate Student Members||Free|
|AIChE Undergraduate Student Members||Free|