As the world continues to rapidly approach elevated temperature milestones due to climate change, implementation of carbon capture, utilization and storage (CCUS) is a crucial component for limiting CO2 emissions and associated global warming. However, at present the cost associated with current capture materials is hindering widespread implementation. Here, we investigate a new capture material based on an abundant and cost-effective precursor. Portlandene, a monolayer version of the three-dimensional calcium hydroxide mineral portlandite, is analyzed using density functional theory simulations and force-field molecular dynamics. We find that this single-layer phase is robust and maintains its stability even at high temperatures. The chemical activity of portlandene is seen to increase upon defect engineering its surface using vacancy sites. Defect-containing portlandene is capable of separating CO and CO2 from a syngas (CO/CO2/H2) stream, yet is inert to water vapor. This selective behavior and the associated mechanisms have been elucidated by examining the material’s electronic structure, local charge distribution and bonding orbitals. Additionally, unlike conventional CO2 capturing technologies, the regeneration process of portlandene does not require high temperature heat treatment since it can release the captured CO2 by application of a mild external electric field, making portlandene an ideal capturing material both in pre- and post-combustion processes.

Carbon capture properties of two-dimensional calcium hydroxide

2019 Spring National Meeting

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