Calcium looping for CO2 capture and thermochemical heat storage, a potential technology for carbon neutrality: A review

CO₂ emissions have posed numerous global challenges, leading to an increasing consensus on the need for carbon neutrality in future development. CO₂ capture and energy storage technologies represent a critical step in the carbon neutrality journey. Calcium looping (CaL), a promising technology for both CO₂ capture and energy storage, holds significant potential in future carbon neutral technology strategies. In this paper, a comprehensive review of the application of CaL in CO₂ capture and thermochemical heat storage (TCHS) is offered to inform further advancements in this field. Firstly, a brief overview and analysis of the fundamental technical routes and principles underlying of CaL for CO₂ capture and TCHS are provided. Then, the research progress in the development of CaL-integrated systems for CO₂ capture and TCHS is subsequently reviewed, with the existing limitations and outlining future prospects for further development highlighted. Additionally, a comprehensive summary of the proposed improvements in the performance of calcium-based materials is presented, focusing on enhancing carbonation reactivity in the multiple cycles and improving sunlight absorption performance of calcium-based materials. Finally, based on the current status of CaL development, insights and perspectives on potential avenues for further technological advancement are offered. Solar-driven CaL is a promising avenue for future CaL development, calling for greater research efforts on optimizing relevant equipment and enhancing calcium-based materials for sunlight-driven CaL systems. In addition, the CO₂ in-situ conversion in the calcination stage of CaL is also a great potential direction for technological evolution.