ARCENEGUI TROYA, JUAN JESÚS, MORENO GARCÍA, VIRGINIA, Sanchez-Jimenez, Pedro E. , Perejon, Antonio , Manuel Valverde, Jose , Perez-Maqueda, Luis A.
No
ACS Sustain. Chem. Eng.
Article
Científica
8.4
1.744
17/01/2022
000742159500001
This study explores the effect of steam addition during carbonation on the multicyclic performance of limestone under calcium looping conditions compatible with (i) CO2 capture from postcombustion gases (CCS) and with (ii) thermochemical energy storage (TCES). Steam injection has been proposed to improve the CO2 uptake capacity of CaO-based sorbents when the calcination and carbonation loops are carried out in CCS conditions: at moderate carbonation temperatures (similar to 650 degrees C) under low CO2 concentration (typically similar to 15% at atmospheric pressure). However, the recent proposal of calcium-looping as a TCES system for integration into concentrated solar power (CSP) plants has aroused interest in higher carbonation temperatures (similar to 800-850 degrees C) in pure CO2. Here, we show that steam benefits the multicyclic behavior in the milder conditions required for CCS. However, at the more aggressive conditions required in TCES, steam essentially has a neutral net effect as the CO2 uptake promoted by the reduced CO2 partial pressure but also is offset by the substantial steam-promoted mineralization in the high temperature range. Finally, we also demonstrate that the carbonation rate depends exclusively on the partial pressure of CO2, regardless of the diluting gas employed.
Concentrated solar power; CO2 capture; Thermochemical energy storage; Calcium looping; Steam