Enhanced oxygen exchange capacity in nano-structured vanadia–ceria multi-phase oxygen carriers for solar thermal fuel production

2019 ◽  
Vol 7 (48) ◽  
pp. 27347-27360 ◽  
Author(s):  
Asim Riaz ◽  
Muhammad Umair Ali ◽  
Wojciech Lipiński ◽  
Adrian Lowe

Developing an efficient redox material is a fundamental and crucial step in sustainable hydrocarbon fuel production via solar energy-driven thermochemical redox cycles.

2018 ◽  
Vol 6 (14) ◽  
pp. 5807-5816 ◽  
Author(s):  
R. Jacot ◽  
J. Madhusudhan Naik ◽  
R. Moré ◽  
R. Michalsky ◽  
A. Steinfeld ◽  
...  

This work reports an improved and stable oxygen exchange capacity (OEC) of optimized doped ceria Ce1−xMxO2−δ (M = Zr, Hf, Nb) materials for two-step thermochemical CO2 splitting over 50 consecutive redox cycles (7 days).


Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Asim Riaz ◽  
Muhammad Umair Ali ◽  
T. Gabriel Enge ◽  
Takuya Tsuzuki ◽  
Adrian Lowe ◽  
...  

The effects of V and Ce concentrations (each varying in the 0–100% range) in vanadia–ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO2 and H2O splitting coupled to methane partial oxidation reactions. The oxidation of prepared oxygen carriers is performed by separate and sequential CO2 and H2O splitting reactions. Structural and chemical analyses of the mixed-metal oxides revealed important information about the Ce and V interactions affecting their crystal phases and redox characteristics. Pure CeO2 and pure V2O5 are found to offer the lowest and highest oxygen exchange capacities and syngas production performance, respectively. The mixed-oxide systems provide a balanced performance: their oxygen exchange capacity is up to 5 times higher than that of pure CeO2 while decreasing the extent of methane cracking. The addition of 25% V to CeO2 results in an optimum mixture of CeO2 and CeVO4 for enhanced CO2 and H2O splitting. At higher V concentrations, cyclic carbide formation and oxidation result in a syngas yield higher than that for pure CeO2.


2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 23095-23104
Author(s):  
Asim Riaz ◽  
Wojciech Lipiński ◽  
Adrian Lowe

Cerium doping into the V2O5 lattice forms a reversible V2O3/VO redox pair after sequential methane partial oxidation and CO2/H2O splitting reactions and produces syngas (H2, CO) with fast rates and high oxygen exchange capacity.


Author(s):  
Stephanie Drozek ◽  
Christopher Damm ◽  
Ryan Enot ◽  
Andrew Hjortland ◽  
Brandon Jackson ◽  
...  

The purpose of this paper is to describe the implementation of a laboratory-scale solar thermal system for the Renewable Energy Systems Laboratory at the Milwaukee School of Engineering (MSOE). The system development began as a student senior design project where students designed and fabricated a laboratory-scale solar thermal system to complement an existing commercial solar energy system on campus. The solar thermal system is designed specifically for educating engineers. This laboratory equipment, including a solar light simulator, allows for variation of operating parameters to investigate their impact on system performance. The equipment will be utilized in two courses: Applied Thermodynamics, and Renewable Energy Utilization. During the solar thermal laboratories performed in these courses, students conduct experiments based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) 93-2010 standard for testing and performance characterization of solar thermal systems. Their measurements are then used to quantify energy output, efficiency and losses of the system and subsystem components.


Author(s):  
E. Ogbonnaya ◽  
L. Weiss

Increasing focus on alternative energy sources has produced significant progress across a wide variety of research areas. One particular area of interest has been solar energy. This has been true on both large and small-scale applications. Research in this paper presents investigations into a small-scale solar thermal collector. This approach is divergent from traditional micro solar photovoltaic devices, relying on transforming incoming solar energy to heat for use by devices like thermoelectrics. The Solar Thermal Collector (STC) is constructed using a copper collector plate with electroplated tin-nickel selective coating atop the collector surface. Further, a unique top piece is added to trap thermal energy and reduce convective, conductive, and radiative losses to the surrounding environment. Results show a capture efficiency of 92% for a collector plate alone when exposed to a 1000 W/m2 simulated solar source. The addition of the top “glazing” piece improves capture efficiency to 97%. Future work will integrate these unique devices with thermoelectric generators for electric power production. This will yield a fully autonomous system, capable of powering small sensors or other devices in remote locations or supplementing existing devices with renewable energy.


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