(545t) CaxMyOz Solid Sorbents for CO2 Capture: An in Situ X-Ray Diffraction Study

Global climate change presents a constant challenge to humankind. The release of CO₂ to the environment, the main cause of climate change, is greatly exacerbated by industrial activity. One way to mitigate this problem is post-combustion CO₂ capture using solid sorbents. Calcium oxide-based materials, an economically favorable option due to its abundance and high adsorption capacity, suffers from significant long-term surface area loss during the carbonation/regeneration cycles. A simple solution is to introduce inert second phase by mechanical mixing. This will minimize the sintering of the calcium containing particles by limiting direct contact among CaO or CaCO₃ particles. In this research, different kind of metals, such as Fe, Co, Cu, are used to synthesize single-phase calcium metal oxide in form of Ca_xM_yO_z, then this solid precursor will be decomposed to CaO and the derivatives of metal oxides by reduction under hydrogen. The former is used as sorbent for CO₂, and the latter is a support to resist sintering and facilitate heat transfer. The temperature dependent carbonation/regeneration kinetics and CO₂ capture capacity change over cycling are investigated by collecting in situ X-ray diffraction pattern. Phase quantification of the CaO-based sorbents and their conversion to CaCO₃ will be carried out by Rietveld refinement.