Pressure Dependence of the Low Temperature Carbonation Kinetics of Calcium Oxide for Potential Thermochemical Energy Storage Purposes and Sustainable CO₂ Fixation

Abstract

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.

Particle Size-Dependent Degradation Kinetics of Garnet-Type Li6.5La3Zr1.5Ta0.5O12 Solid Electrolyte Powders in Ambient Air

“…Thus, the rate-limiting step of the overall reaction mechanism is the diffusion process of H 2 O and CO 2 . This is typical for two-step consecutive reactions and has been investigated for calcium oxide in detail , as well as for other compounds, such as calcium silicate . For LLZO, such detailed kinetic studies of both hydration and carbonation have not been reported before.…”

“…There are various complex mathematical models considering material properties, e.g., porosity, molar flux, diffusivity of gas educts, and changes of particle size during the reaction. Details including the required assumptions can be found in elsewhere. − …”

Integrated low carbon H2 conversion with in situ carbon mineralization from aqueous biomass oxygenate precursors by tuning reactive multiphase chemical interactions

“…Carbonate Formation Mg 2+ + CO 3 2− → MgCO 3(s) Ca 2+ + CO 3 2− → CaCO 3(s) Despite the simplicity of the stoichiometric reactions describing the formation of Ca- or Mg-carbonates, complex chemo-morphological interactions result in non-monotonic kinetics of carbonate nucleation and growth. For example, the kinetics of carbon mineralization are strongly influenced by the pH and composition of the aqueous phase, 51 partial pressure of CO 2 , 52 and temperature. 34 pH conditions greater than 8 favor (bi)carbonate formation which aid in solid carbonate formation while more acidic pH conditions favor the dissolution of Ca- or Mg-oxides and hydroxides.…”

Geo-mechanical and geo-morphology characterisation of the cap rocks in the Niger Delta for potential carbon capture and storage

“…Hangx et al [ 23 ], found that the integrity of the caprock is dependent on the stress-strain changes that are exposed to the rock. According to Aminu et al [ 26 ], and Gravogl et al [ 35 ], the viable candidate technology for carbon dioxide subsurface storage should provide a minimum residence length of 1000 years and a leakage rate of less than 0.1 % annually. Injection and storage of carbon dioxide may drastically influence the geo-mechanical and geochemical characteristics of caprocks.…”