Journal ArticleDOI
Solar Thermal Reduction of ZnO Using CH4:ZnO and C:ZnO Molar Ratios Less Than 1
TLDR
In this article, the solar thermal reduction of ZnO, using solar process heat and CH 4 or C as reducing agent, is investigated for CH 4 :ZnO or C:ZnOs molar ratios ranging from 0 (thermal decomposition at above about 2000°C) to 1 (stoichiometric reduction at above approximately 1000°C).Abstract:
The solar thermal reduction of ZnO, using solar process heat and CH 4 or C as reducing agent, is investigated for CH 4 :ZnO or C:ZnO molar ratios ranging from 0 (thermal decomposition at above about 2000°C) to 1 (stoichiometric reduction at above about 1000°C). At 1400°C, in thermodynamic equilibrium ZnO can be completely reduced using a CH 4 :ZnO molar ratio of 0.3 and produces one fuel (Zn-metal) rather than two for the stoichiometric case (Zn and syngas). The maximal reactor thermal efficiency without heat recovery from the offgas, defined as the ratio of the heating-value of the zinc produced to the total thermal energy input, is 55%. CO 2 -emissions are reduced by a factor of 10-15 compared to fossil-fuel-based zinc-production technologies. For a closed materials cycle, in which power is extracted from the solar zinc using a fuel cell and the ZnO formed is recycled to the solar reactor, the total exergy efficiency, defined as the work output of the fuel cell to the thermal energy input, varies between 30 to 40% when based on the absorbed solar power in the reactor. These efficiency values are very encouraging, especially since the solar ZnO/Zn cycle allows-in contrast to other regenerative power plants-to store and transport solar energy.read more
Citations
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Journal ArticleDOI
A review of solar thermochemical processes
Deepak Yadav,Rangan Banerjee +1 more
TL;DR: In this article, a review of the development in the field of solar thermochemical processing by considering experimental demonstrations, reactor technology development, thermodynamic, economic and life cycle analyses is presented.
Journal ArticleDOI
Likely near-term solar-thermal water splitting technologies
TL;DR: In this paper, a two-and three-step thermochemical cycle to split water using solar-thermal processing is described. But the problem of high-temperature separation of H2 from O2 at these temperatures is not addressed.
Journal ArticleDOI
A 300kW Solar Chemical Pilot Plant for the Carbothermic Production of Zinc
Christian Wieckert,U. Frommherz,Stefan Kräupl,Emmanuel Guillot,Gabriel Olalde,Michael Epstein,S. Santén,T. Osinga,Aldo Steinfeld +8 more
TL;DR: In this paper, a 300kW solar chemical pilot plant for the production of zinc by carbothermic reduction of ZnO was experimentally demonstrated in a beam-down solar tower concentrating facility of Cassegrain optical configuration.
Journal ArticleDOI
Pilot-scale solar reactor operation and characterization for fuel production via the Zn/ZnO thermochemical cycle
TL;DR: In this article, a solar reactor pilot plant for thermal reduction of ZnO as part of a two-step water and CO 2 splitting cycle has been demonstrated at the 100kW th scale in a 1MW solar furnace.
Journal ArticleDOI
Experimental Investigation of the Solar Carbothermic Reduction of ZnO Using a Two-cavity Solar Reactor
TL;DR: In this article, a 5 kW solar chemical reactor prototype with two cavities in series, with the inner one functioning as the solar absorber and the outer one as the reaction chamber, is presented.
References
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Journal ArticleDOI
A solar chemical reactor for co-production of zinc and synthesis gas
TL;DR: In this paper, a novel solar chemical reactor was designed to perform the combined ZnO-reduction and CH4-reforming processes, consisting of a gas-particle vortex flow confined to a solar cavity-receiver that is exposed to concentrated solar irradiation.
Journal ArticleDOI
Solarthermal Processing: A Review
TL;DR: Research on solarthermal processing and the need for alternative energy sources have reached the point where efforts to develop some industrial processes and expand research to suggest others are at least desirable, if not imperative as discussed by the authors.
Journal ArticleDOI
The production of Zn from ZnO in a high- temperature solar decomposition quench process—I. The scientific framework for the process
Robert Palumbo,Jacques Lédé,Olivier Boutin,E.E. Ricart,Aldo Steinfeld,Stephan Möller,Anke Weidenkaff,Edward A. Fletcher,Jeffrey M. Bielicki +8 more
TL;DR: In this article, the authors present a theoretical and experimental study of a solar decomposition process for producing Zn and O 2 from ZnO(s) in a solar furnace.
Journal ArticleDOI
The production of zinc by thermal dissociation of zinc oxide - Solar chemical reactor design
TL;DR: In this article, the authors describe the design, fabrication, and preliminary test of a solar chemical reactor for conducting the thermal dissociation of ZnO into zinc and oxygen at above 2000 K.