Introduction of calcium looping and challenges

https://doi.org/10.1016/j.ccst.2021.100015

“The calcium looping process (CaLP) (Han et al., 2018; Xu et al., 2018a), which is based on the reversible carbonation/calcination cycles as shown in Eq. (1) and Figure S1, has been regarded as one of the most promising technologies to capture CO₂ from flue gases. In this CaLP system, the CO₂ from flue gas was trapped by the CaO-based sorbents at about 650 °C in a carbonator; then the carbonated product (CaCO₃) was calcined at about 900 °C in a calcination reactor, where the sorbents were regenerated, and a pure CO₂ stream was generated for geological storage (Li et al., 2019; T. Xu et al., 2021b). However, the CaO-based sorbents are industrially run in “650 °C – 900 °C” cycles, which are much higher than the Tammann point of CaCO₃ (about 529 °C); hence, the sorbent would suffer serious sintering process, and the CO₂ capture capacity of the sorbents would inevitably undergo significantly decay over the cycles. ”

“Figure S1. Schematic diagram of the calcium looping process for CO₂ capture”