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High-temperature isothermal chemical cycling for solar-driven fuel production

Hao, Yong and Yang, Chih-Kai and Haile, Sossina M. (2013) High-temperature isothermal chemical cycling for solar-driven fuel production. Physical Chemistry Chemical Physics, 15 (40). pp. 17084-17092. ISSN 1463-9076. doi:10.1039/c3cp53270d.

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The possibility of producing chemical fuel (hydrogen) from the solar-thermal energy input using an isothermal cycling strategy is explored. The canonical thermochemical reactive oxide, ceria, is reduced under high temperature and inert sweep gas, and in the second step oxidized by H_2O at the same temperature. The process takes advantage of the oxygen chemical potential difference between the inert sweep gas and high-temperature steam, the latter becoming more oxidizing with increasing temperature as a result of thermolysis. The isothermal operation relieves the need to achieve high solid-state heat recovery for high system efficiency, as is required in a conventional two-temperature process. Thermodynamic analysis underscores the importance of gas-phase heat recovery in the isothermal approach and suggests that attractive efficiencies may be practically achievable on the system level. However, with ceria as the reactive oxide, the isothermal approach is not viable at temperatures much below 1400 °C irrespective of heat recovery. Experimental investigations show that an isothermal cycle performed at 1500 °C can yield fuel at a rate of ~9.2 ml g^(−1) h^(−1), while providing exceptional system simplification relative to two-temperature cycling.

Item Type:Article
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URLURL TypeDescription DOIArticle
Haile, Sossina M.0000-0002-5293-6252
Additional Information:© 2013 the Owner Societies. Received 9th June 2013; Accepted 5th August 2013; First published online 06 Aug 2013. This study is based upon work supported by the National Science Foundation under Grant No. CBET-1038307 and the US Department of Energy ARPA-e program under Grant No. DE-AR0000182 (sub-award No. A002601001). The authors would like to thank Stephen Wilke and Dr. Timothy Davenport for useful discussions.
Funding AgencyGrant Number
Department of Energy (DOE)DE-AR0000182
Issue or Number:40
Record Number:CaltechAUTHORS:20131108-084243490
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42330
Deposited By: Tony Diaz
Deposited On:08 Nov 2013 16:49
Last Modified:10 Nov 2021 16:21

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