Membranes for H2 generation from nuclear powered thermochemical cycles.
- University of California, Davis, CA
In an effort to produce hydrogen without the unwanted greenhouse gas byproducts, high-temperature thermochemical cycles driven by heat from solar energy or next-generation nuclear power plants are being explored. The process being developed is the thermochemical production of Hydrogen. The Sulfur-Iodide (SI) cycle was deemed to be one of the most promising cycles to explore. The first step of the SI cycle involves the decomposition of H{sub 2}SO{sub 4} into O{sub 2}, SO{sub 2}, and H{sub 2}O at temperatures around 850 C. In-situ removal of O{sub 2} from this reaction pushes the equilibrium towards dissociation, thus increasing the overall efficiency of the decomposition reaction. A membrane is required for this oxygen separation step that is capable of withstanding the high temperatures and corrosive conditions inherent in this process. Mixed ionic-electronic perovskites and perovskite-related structures are potential materials for oxygen separation membranes owing to their robustness, ability to form dense ceramics, capacity to stabilize oxygen nonstoichiometry, and mixed ionic/electronic conductivity. Two oxide families with promising results were studied: the double-substituted perovskite A{sub x}Sr{sub 1-x}Co{sub 1-y}B{sub y}O{sub 3-{delta}} (A=La, Y; B=Cr-Ni), in particular the family La{sub x}Sr{sub 1-x}Co{sub 1-y}Mn{sub y}O{sub 3-{delta}} (LSCM), and doped La{sub 2}Ni{sub 1-x}M{sub x}O{sub 4} (M = Cu, Zn). Materials and membranes were synthesized by solid state methods and characterized by X-ray and neutron diffraction, SEM, thermal analyses, calorimetry and conductivity. Furthermore, we were able to leverage our program with a DOE/NE sponsored H{sub 2}SO{sub 4} decomposition reactor study (at Sandia), in which our membranes were tested in the actual H{sub 2}SO{sub 4} decomposition step.
- Research Organization:
- Sandia National Laboratories
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 899362
- Report Number(s):
- SAND2006-7081
- Country of Publication:
- United States
- Language:
- English
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Oxygen nonstoichiometry and defect structure analysis of B-site mixed perovskite-type oxide (La, Sr)(Cr, M)O{sub 3-{delta}} (M=Ti, Mn and Fe)
Related Subjects
08 HYDROGEN
14 SOLAR ENERGY
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
CALORIMETRY
CAPACITY
CERAMICS
DISSOCIATION
EFFICIENCY
GREENHOUSE GASES
HYDROGEN
Hydrogen-Research.
MEMBRANES
NEUTRON DIFFRACTION
NUCLEAR POWER PLANTS
Nuclear reactors-Materials-Thermochemical properties.
OXIDES
OXYGEN
PEROVSKITE
PEROVSKITES
REMOVAL
SOLAR ENERGY
Thermochemical properties.