471163 Hercynite Reduction and ITM Membrane Oxygen Removal System for Solar Thermal Water Splitting

Thursday, November 17, 2016: 10:30 AM
Powell (Hilton San Francisco Union Square)
Ibraheam Al-Shankiti1, Yahya Al-Salik2, Hicham Idriss2 and Alan W. Weimer3, (1)Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO, (2)Sabic, Thuwal, Saudi Arabia, (3)Chemical & Biological Engineering, University of Colorado at Boulder, Boulder, CO

Solar Thermochemical Water Splitting Processing (STWS) is a promising technology for producing renewable H2[1]. A metal oxide, such as hercynite (FeAl2O4), is first reduced with high temperature concentrated sunlight to produce O2[2]. Then, the reduced material is exposed to steam to re-oxidize it and produce H2. Low O2 partial pressure is required to drive the reduction reaction. An intriguing potentially highly efficient process is the recycle of inert sweep gas at near atmospheric pressure using a high temperature O2 ionic transport membrane (ITM)[3], since the recycled gas is already at the required high temperature. In this work, we present preliminary experimental results for hercynite reduction using a TGA and separately the removal of O2 from 1% O2/inert down to ppm levels using a laboratory high temperature ITM. The impact of separation energy requirements is evaluated for the overall solar to H2 cycle.

1. Muhich, C.L., et al., A review and perspective of efficient hydrogen generation via solar thermal water splitting. WIREs Energy Environ 2016, 5:p. 261–287. doi: 10.1002/wene.174

2. Muhich, C.L., et al., Predicting the solar thermochemical water splitting ability and reaction mechanism of metal oxides: a case study of the hercynite family of water splitting cycles. Energy & Environmental Science, 2015. 8(12): p. 3687-3699.

3. Ehrhart, B.D., et al., System efficiency for two-step metal oxide solar thermochemical hydrogen production – Part 3: Various methods for achieving low oxygen partial pressures in the reduction reaction. Int. J Hydrogen Energy (online) http://dx.doi.org/10.1016/j.ijhydene.2016.07.106.

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See more of this Session: Solar Thermochemical Fuels II
See more of this Group/Topical: 2016 International Congress on Energy