Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting

Christopher Muhich, Brian D. Ehrhart, Ibraheam Al-Shankiti, Alan W. Weimer

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Hydrogen productivity exceeding 350 micromoles H2/g total redox material has been demonstrated for near-isothermal processing using the "hercynite cycle" for oxidation with steam carried out at 1350°C following 1500°C reduction. This temperature difference driving the redox is quite narrow compared to standard 500oC temperature swing (T-swing) redox processing. Such processing substantially reduces the difficult solid/solid heat recuperation required for standard Tswing systems and the thermal stresses associated with heating/cooling active materials during redox cycling. Focused ion beam (FIB) milling followed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) after 200 redox cycles shows that the ferrite/alumina is well-dispersed, indicating a robust active redox material. Efficiency analysis identifies isothermal processing with perfect steam/steam heat exchange as the highest theoretically possible efficiency. Since isothermal processing at the highest reduction temperatures is unlikely due to simultaneous redox (producing both H2 and O2 together), near-isothermal processing provides for the best scenario to achieve the highest solar-thermal process efficiency possible.

Original languageEnglish (US)
Title of host publicationOptics for Solar Energy, OSE 2014
PublisherOptical Society of America (OSA)
ISBN (Print)9781557527561
StatePublished - Jan 1 2014
Externally publishedYes
EventOptics for Solar Energy, OSE 2014 - Canberra, Australia
Duration: Dec 2 2014Dec 5 2014

Other

OtherOptics for Solar Energy, OSE 2014
CountryAustralia
CityCanberra
Period12/2/1412/5/14

Fingerprint

water splitting
Aluminum Oxide
Ferrite
ferrites
Alumina
aluminum oxides
cycles
Water
Steam
Processing
steam
heat
Focused ion beams
thermal stresses
Hot Temperature
Oxidation-Reduction
productivity
Thermal stress
Temperature
Hydrogen

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment

Cite this

Muhich, C., Ehrhart, B. D., Al-Shankiti, I., & Weimer, A. W. (2014). Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting. In Optics for Solar Energy, OSE 2014 Optical Society of America (OSA).

Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting. / Muhich, Christopher; Ehrhart, Brian D.; Al-Shankiti, Ibraheam; Weimer, Alan W.

Optics for Solar Energy, OSE 2014. Optical Society of America (OSA), 2014.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Muhich, C, Ehrhart, BD, Al-Shankiti, I & Weimer, AW 2014, Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting. in Optics for Solar Energy, OSE 2014. Optical Society of America (OSA), Optics for Solar Energy, OSE 2014, Canberra, Australia, 12/2/14.
Muhich C, Ehrhart BD, Al-Shankiti I, Weimer AW. Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting. In Optics for Solar Energy, OSE 2014. Optical Society of America (OSA). 2014
Muhich, Christopher ; Ehrhart, Brian D. ; Al-Shankiti, Ibraheam ; Weimer, Alan W. / Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting. Optics for Solar Energy, OSE 2014. Optical Society of America (OSA), 2014.
@inproceedings{18dd6151c25547ce9b34386d5029ca4e,
title = "Near-isothermal ferrite/alumina ({"}hercynite cycle{"}) twostep Red/Ox cycle for solar-thermal water splitting",
abstract = "Hydrogen productivity exceeding 350 micromoles H2/g total redox material has been demonstrated for near-isothermal processing using the {"}hercynite cycle{"} for oxidation with steam carried out at 1350°C following 1500°C reduction. This temperature difference driving the redox is quite narrow compared to standard 500oC temperature swing (T-swing) redox processing. Such processing substantially reduces the difficult solid/solid heat recuperation required for standard Tswing systems and the thermal stresses associated with heating/cooling active materials during redox cycling. Focused ion beam (FIB) milling followed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) after 200 redox cycles shows that the ferrite/alumina is well-dispersed, indicating a robust active redox material. Efficiency analysis identifies isothermal processing with perfect steam/steam heat exchange as the highest theoretically possible efficiency. Since isothermal processing at the highest reduction temperatures is unlikely due to simultaneous redox (producing both H2 and O2 together), near-isothermal processing provides for the best scenario to achieve the highest solar-thermal process efficiency possible.",
author = "Christopher Muhich and Ehrhart, {Brian D.} and Ibraheam Al-Shankiti and Weimer, {Alan W.}",
year = "2014",
month = "1",
day = "1",
language = "English (US)",
isbn = "9781557527561",
booktitle = "Optics for Solar Energy, OSE 2014",
publisher = "Optical Society of America (OSA)",

}

TY - GEN

T1 - Near-isothermal ferrite/alumina ("hercynite cycle") twostep Red/Ox cycle for solar-thermal water splitting

AU - Muhich, Christopher

AU - Ehrhart, Brian D.

AU - Al-Shankiti, Ibraheam

AU - Weimer, Alan W.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Hydrogen productivity exceeding 350 micromoles H2/g total redox material has been demonstrated for near-isothermal processing using the "hercynite cycle" for oxidation with steam carried out at 1350°C following 1500°C reduction. This temperature difference driving the redox is quite narrow compared to standard 500oC temperature swing (T-swing) redox processing. Such processing substantially reduces the difficult solid/solid heat recuperation required for standard Tswing systems and the thermal stresses associated with heating/cooling active materials during redox cycling. Focused ion beam (FIB) milling followed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) after 200 redox cycles shows that the ferrite/alumina is well-dispersed, indicating a robust active redox material. Efficiency analysis identifies isothermal processing with perfect steam/steam heat exchange as the highest theoretically possible efficiency. Since isothermal processing at the highest reduction temperatures is unlikely due to simultaneous redox (producing both H2 and O2 together), near-isothermal processing provides for the best scenario to achieve the highest solar-thermal process efficiency possible.

AB - Hydrogen productivity exceeding 350 micromoles H2/g total redox material has been demonstrated for near-isothermal processing using the "hercynite cycle" for oxidation with steam carried out at 1350°C following 1500°C reduction. This temperature difference driving the redox is quite narrow compared to standard 500oC temperature swing (T-swing) redox processing. Such processing substantially reduces the difficult solid/solid heat recuperation required for standard Tswing systems and the thermal stresses associated with heating/cooling active materials during redox cycling. Focused ion beam (FIB) milling followed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) after 200 redox cycles shows that the ferrite/alumina is well-dispersed, indicating a robust active redox material. Efficiency analysis identifies isothermal processing with perfect steam/steam heat exchange as the highest theoretically possible efficiency. Since isothermal processing at the highest reduction temperatures is unlikely due to simultaneous redox (producing both H2 and O2 together), near-isothermal processing provides for the best scenario to achieve the highest solar-thermal process efficiency possible.

UR - http://www.scopus.com/inward/record.url?scp=84928978364&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84928978364&partnerID=8YFLogxK

M3 - Conference contribution

SN - 9781557527561

BT - Optics for Solar Energy, OSE 2014

PB - Optical Society of America (OSA)

ER -