Thermally Stable Complex Redox Materials for Hydrogen Generation in Themochemical Water-Splitting Process
World future energy demands must be fulfilled, at least in part, by sustainable energy resources. Energy from the sun can be harnessed for the production of hydrogen such as a new high temperature thermochemical water-splitting technology for hydrogen production, which is a promising green technology involving a cyclic operation of a low-temperature water-splitting step and a high temperature regeneration step using redox materials. Because of the cyclic nature of the process, the redox materials undergo thermal fatigue leading to decrease in surface area due to grain growth or sintering and consequently, steady hydrogen production levels are not realized. In order for this technology to be cost-competitive, hydrogen production from superheated steam generated in a solar concentrator or in a nuclear plant needs to be demonstrated in hundreds of thermochemical cycles, which poses a great challenge for the scientists and reaction engineering professionals.
A three-year program is planned to investigate hydrogen generation by a high-temperature water-splitting in multiple thermochemical cycles using thermally stabilized morphologies of redox materials. These materials will be synthesized by the sol-gel and self-propagation high temperature synthesis (SHS) methods coupled with microwave processing leading to different morphologies, for instance, the core-shell or segregated grain boundaries with YSZ (yttria-stabilized zirconia). Among redox materials, as ferrites with spinel, wustite and their combinations are known to be effective for thermochemical water-splitting, the PIs plan to synthesize these materials with thermally stable morphologies, which include MFe2O4, M1xM2yFe2O4, and M1xM2yM3zFe1-x-y-zO (where M, M1, M2, and M3 can be Ni, Zn, Sn, Mn and Li) and investigate hydrogen production in a packed-bed reactor and kinetics and transport properties in multiple thermochemical cycles with a view to achieving steady hydrogen levels. Both investigators have experience with the synthesis of ferrites and hydrogen production from the thermochemical water-splitting process. The fully instrumented reactor set-up in the investigators? laboratory is already built and tested. All necessary characterization instruments are available at SDSM&T.
The intellectual merit of this project is in the area of hydrogen generation by high temperature water-splitting in multiple thermochemical cycles using thermally stabilized novel redox materials. This knowledge will be enriched by better understanding of the microstructural stability of different morphologies of in-house synthesized redox materials under thermal fatigue and kinetics and transport processes for hydrogen generation. The experimental studies should enhance the knowledge of the physical and chemical processes involved in the thermal stabilization of redox materials? morphologies and reaction engineering aspects leading to stable hydrogen production levels in hundreds of thermochemical cycles without deterioration of complex ferrites.
Broader impacts: Both investigators have been actively involved in promoting research experience for undergraduate students by supporting students from SDSM&T and NSF-REU program. A significant effort will be on education of graduate students in both MS and PhD programs in chemical and biological engineering at SDSM&T. Results generated from the research will be disseminated via publications in peer-reviewed journals and presentations at national and international conferences. Students involved in this research program will have hands-on experience in the areas of sustainable energy, high temperature redox materials and reaction engineering aspects of hydrogen production. The investigators plan to enhance outreach activity in this area to Native Americans, middle and high school students and teachers.