April 10-14, 2016
Chemical looping technology has attracted significant attention due to its potential in cost-effective CO2 capture capabilities. It utilizes metal oxide as oxygen carriers to indirectly convert carbonaceous fuel such as coal, natural gas and biomass into electricity, H2, liquid fuel without the use of an air separation unit (ASU). In the case of power production, chemical looping process allows for high exergy efficiency, as the high grade heat produced from the oxidation of the oxygen carrier can be extracted for steam production, while the lower grade heat is recuperated in the oxygen carrier to perform its endothermic reduction. With the exponential growth of research and publications in this field, chemical looping has expanded to encompass both power and chemical production with in-situ gas separation. Extensive computational and experimental studies on iron-based composite material support the long-term recyclability, reactivity and physical strength of OSU’s oxygen carriers. In addition, the behavior of iron-based composite material at the micro- and nanoscale will be discussed in the context of optimal oxygen carrier candidates. Nanostructure formation mechanism and ionic diffusion play a central role in sustaining the reactivity and recyclability of Fe-Ti system. OSU’s unique moving-bed chemical looping technology takes full advantage of iron-based oxygen carriers when compared with fluidized-bed system. The synergetic effect between reactor design and oxygen carrier optimization ensures complete fuel conversion and near 100% CO2 capture. To date, more than 1000 operating hours have been achieved in 25-kWth sub-pilot scale unit with coal, biomass and syngas at the OSU Clean Energy Research Center. Near 100% conversion of both gaseous and solid fuel types to CO2 were achieved. A 250 kWth-3MWth syngas chemical looping pilot scale demonstration is currently in its testing phase at the National Carbon Capture Center. The present paper summarizes key results and development for both the syngas chemical looping and coal direct chemical looping systems.
Tong, Andrew, et al. "Iron-based syngas chemical looping process and coal-direct chemical looping process development at Ohio State University."Applied Energy 113 (2014): 1836-1845. Qin, Lang, et al. "Nanostructure formation mechanism and ion diffusion in iron–titanium composite materials with chemical looping redox reactions."Journal of Materials Chemistry A 3.21 (2015): 11302-11312.