High-temperature sorption of CO2 via calcium looping (CaO(s) + CO2(g) → CaCO3(s)) has applications in post-combustion carbon capture, sorption-enhanced hydrogen production and solar thermal energy storage. However, the fast deactivation of Ca-based sorbents, owing to sintering, is the major current drawback of this technology. We, for the first time, exploit temperature-induced phase transitions to resist sintering of sorbent materials. The significant volume expansion of Ca2SiO4 spacer particles resists sintering and regenerates the surface area, resulting in unparalleled long-term reactivity for multi-cycle sorption of CO2 using Cabased sorbents. The results are validated by a range of analytical techniques,demonstrating unambiguously the potential and operating mechanism of the new materials. Sintering is a common issue in materials science that limits the development of many high-temperature solid looping systems including post-combustion carbon capture, sorption-enhanced steam reforming and water–gas shiftreactions for hydrogen production, supported metallic catalysts, oxygen carrying materials for chemical looping, etc. The findings about the potential of polymorphic spacers are thus of general implication in these wider areas of energy materials research.

Novel strategy to reduce sintering, based on polymorphic materials, and application to carbon capture and storage

249th National Meeting (2015)

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