[Zurück]

G. Gravogl, F. Birkelbach, D. Müller, Ch. Lengauer, P. Weinberger, R. Miletich:
"Pressure Dependence of the Low Temperature Carbonation Kinetics of Calcium Oxide for Potential Thermochemical Energy Storage Purposes and Sustainable CO₂ Fixation";
Advanced Sustainable Systems, 2100022 (2021), S. 1 - 11.

The pressure effect on the carbonation behavior of CaO as model compound is studied under mild hydrothermal conditions, as relevant to sustainable geological CO₂ sequestration and for potential utilization in thermochemical energy storage. Reaction yields are determined experimentally by means of in situ powder X-ray diffraction using CaO powder samples in a controlled reaction with CO₂ under gas pressures between 1.0 and 5.0 MPa and at temperatures between 298 and 373 K. The results show a two-step conversion of CaO to CaCO₃, involving Ca(OH)₂ as a reactive intermediate, with differing influences of the microstructures on the individual reaction sub-steps. A kinetic evaluation of the experimental data delivers a high rate-enhancing effect of temperature on the hydration reaction, whereas the CaCO₃ formation is strongly dependent on the available CO₂ gas pressure. With this systematic investigation the optimal
pressure and temperature conditions for this reaction system can be determined delivering a contribution to a sustainable climate and energy management.

thermochemical energy storage materials; pressure dependence; calcium oxide

http://dx.doi.org/10.1002/adsu.202100022

https://publik.tuwien.ac.at/files/publik_296127.pdf