Abstract:
The principle of calcium looping thermochemical energy storage is to use the reaction of calcium-based heat carrier (mainly CaO) and CO
2 to form a reversible endothermic and exothermic chemical looping cycle. Due to the low cost, wide source, high heat storage density of calcium-based raw materials, calcium looping technology is considered as a very potential thermochemical heat storage technology with good application prospects. In addition, in the process of calcium looping heat storage and release, CO
2 can be captured by carbonation reaction to form a coupling between heat storage and CO
2 capture, which decreases the energy consumption of CO
2 capture. However, calcium-based heat carrier is prone to deactivation and abrasion in the process of recycling, and most of research in calcium looping thermochemical energy storage system is still in the laboratory stage. Furthermore, its coupling with CO
2 capture aggravate the sintering deactivation of calcium based heat carrier. In this regard, a lot of basic research has been carried out , and a series of methods have been proposed to enhance the activity of calcium base carrier, reduce attrition and improve the efficiency of calcium looping heat storage. The research progress of calcium looping thermochemical energy storage and its coupling with CO
2 capture technology was reviewed. The research progress of calcium looping technology in recent years was summarized from three aspects: physicochemical properties and modification methods of calcium-based materials, design of calcium looping heat storage and CO
2 capture system, and design of calcium looping reactor, including the calcium looping heat storage assisting solar power generation, the improvement of calcium looping coupled CO
2 capture system, the characteristics and problems of direct and indirect irradiation reactors. At last, the main problems at the present stage and the research direction of this technology in the future was summarized.