Thermochemical heat storage through CaO-Mayenite/CaCO3 system: Thermal performances comparison for two synthesis methods

Spadoni, A.; Sau, Salvatore; Corsaro, Natale; Lanchi, M.; Tizzoni, Anna Chiara; Veca, Elisabetta; Falconieri, M.; Seta, L. Della; Mauro, Anna De Girolamo Del; Turchetti, Luca; Mansi, Emiliana; Liberatore, Raffaele

doi:10.1016/j.est.2023.108386

Cited by 2 publications

(1 citation statement)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mixed solid powders were added to 11 mL of isopropyl alcohol (99.5%, Sigma-Aldrich) and 83 mL of deionized water and homogenized at 70 °C for 1 h. The solvent was then evaporated at 150 °C for 1 h, and the resulting sample was transferred to a kiln for calcination. The calcination procedure was as follows: (i) from 50 to 150 °C at a heating rate of 5 °C/min and dwell at 150 °C for 1 h; (ii) from 150 to 500 °C at a heating rate for 5 °C/min and dwell for 1 h; and (iii) from 500 to 1000 °C at a heating rate of 5 °C/min and dwell for 1 h. The recipe for mayenite synthesis was taken from the previous work by Li et al, but the calcination temperature was selected according to the findings previously published by some of the same authors of the present work . In the second step, a sample of 0.5 g of synthetic mayenite thus obtained was mixed with 1.5 g of CaO in 4.4 mL of isopropyl alcohol and 33.2 mL of deionized water.…”

Section: Methodsmentioning

confidence: 99%

Calcium Looping for Thermochemical Storage: Assessment of Intrinsic Reaction Rate and Estimate of Kinetic/Transport Parameters for Synthetic CaO/Mayenite Particles from TGA Data

Lo Conte,

Murmura,

Fratini

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Mayenite-supported CaO represents an affordable and safetycompliant candidate material for thermochemical storage processes. We here analyze the thermogravimetric analysis (TGA) performance of synthetic CaO/mayenite micrometric powder under carbonatation/calcination looping and develop a model to interpret and analyze the experimental results. In the experimental campaign, calcination is run at 900 °C, while the carbonatation temperature is varied between 600 and 800 °C. For the carbonatation reaction, a generalized shrinking core model assuming a thermodynamically consistent first-order kinetic and a conversion-dependent diffusivity of CO 2 inside the porous CaCO 3 layer is validated through TGA carbonatation tests conducted with CO 2 /N 2 mixtures at different compositions. Interestingly, the kinetic constant of this reaction is found to be relatively insensitive to the temperature in the interval considered. In contrast, diffusion-limited regimes are never found for the calcination reaction so that this phase of the cycle can be predicted based on a single kinetic constant of the heterogeneous reaction. This constant is found to follow the typical Arrhenius-type dependence on temperature. Sizably different kinetic and transport parameters are obtained in the first carbonation performed on virgin CaO/mayenite particles with respect to those associated with subsequent cycles. When different parameters are afforded for the first and following cycles, the shrinking core model proposed closely predicts the TGA data over five CaO/CaCO 3 cycles. The results found constitute an essential preliminary piece of information for designing equipment geometry and operating conditions of industrial-scale reactors. In this respect, knowledge of the parameters defining the intrinsic reaction rates and diffusive transport is essential in defining the optimal conversion of the material associated with minimal looping time.

show abstract

Section: Methodsmentioning

confidence: 99%