2025 AIChE Annual Meeting

(586n) Engaging University of Tennessee Undergraduates in Research on the Manganese Oxide/Manganese Sulfate H2O Splitting Cycle for Solar Hydrogen Production

Authors

Rahul Bhosale - Presenter, Qatar University
Amya Arnold, University of Tennessee
Monica Ball, University of Tennessee
Katie Collins, University of Tennessee
Katelyn Hamilton, University of Tennessee
Nolan Heath, University of Tennessee
Jessica Hobbs, University of Tennessee
Cael Howell, University of Tennessee
Wesley Johnson, University of Tennessee
Caleb Kouvarakis, University of Tennessee
Vitaliy Kyslytsya, University of Tennessee
Caleb Latham, University of Tennessee
Gavin Prater, University of Tennessee
Maria Sanchez, University of Tennessee
Reese Self, University of Tennessee
Acelynn Sellers, University of Tennessee
Matt Serven, University of Tennessee
Several thermochemical cycles were examined to produce H2 through a water-splitting reaction, including the sulfur-iodine cycle, mixed ferrite cycle, tin/tin oxide cycle, iron oxide cycle, zinc/zinc oxide cycle, and hybrid sulfur cycle. Compared to other thermochemical cycles, the sulfur-iodine cycle and its hybrid sulfur cycle variant are more attractive since they require lower operating temperatures.

The sulfur-iodine and hybrid sulfur cycles involve the energy-intensive breakdown of SO3 into SO2 and O2, which requires high temperatures and catalytic conditions due to its endothermic nature. Various metal-based catalysts have been studied, but sulfation poisoning is a significant issue that reduces efficiency. Transition metal catalysts often form stable sulfates at high temperatures, while noble metal catalysts on metal oxides have been more effective. However, their limited availability and high-cost pose challenges for practical use.

Using metal oxides as catalysts instead of noble metals provides an effective way to generate H2 at lower temperatures through a "metal oxide – metal sulfate" water-splitting cycle powered by concentrated solar energy. This process involves two steps: first, the oxidation of metal oxide by SO2 and H2O produces metal sulfate MSO4 and H2. The second, endothermic step uses solar heat to reduce MSO4 back to MO, SO2, and O2, allowing for continual recycling in the process.

In this innovative study, a team of chemical engineering undergraduate researchers from the University of Tennessee at Chattanooga embarks on an exciting journey to develop a cutting-edge thermodynamic model for the manganese oxide/manganese sulfate water-splitting cycle. Through meticulous computational thermodynamic analysis, they delve into the intricate dynamics of the process, evaluating a variety of parameters, including diverse temperature ranges and the molar flow rates of inert sweep gases. The students also explore the integration of sophisticated components such as gas separators, heat exchangers, heaters, coolers, and fuel cells, all with the aim of optimizing solar-to-fuel energy conversion efficiency. This comprehensive investigation advances our understanding of thermodynamic processes as well as sustainable energy solutions.