钙循环热化学储能及其耦合CO_(2)捕集技术研究进展

Recent advances on calcium looping thermochemical energy storage and its coupling for CO_(2)capture

钙循环热化学储能的基本原理是采用钙基热载体(以CaO为主)与CO_(2)的化学链循环可逆反应进行循环的储热与放热过程。由于钙基原料的成本低廉、来源广泛、储放热密度高,钙循环技术被认为是一种十分有潜力的热化学储能技术,具有良好的应用前景。此外,在钙循环储放热过程中,可利用碳酸化反应捕集CO_(2),形成储能与CO_(2)捕集耦合以降低碳捕集的能量需求。但钙基热载体在循环利用过程中易失活和磨损,且钙循环热化学储能系统大部分研究仍处于实验室阶段,而与碳捕集耦合会加剧钙基热载体的烧结失活。对此,国内外开展了大量基础研究,提出了一系列增强钙基载体活性,减少磨损,提高钙循环储热效率的方法。综述了钙循环热化学储能及其耦合CO_(2)捕集技术的研究进展,从钙基热载体的物化特性与改性方法、钙循环储能和CO_(2)捕集系统的流程设计、反应器设计3方面归纳了近年来钙循环储热技术的研究进展,包含钙循环储能辅助太阳能发电、钙循环热化学储能耦合CO_(2)捕集系统的改进方法,以及直接与间接辐照煅烧储热反应器的开发研究现状。最后总结了现阶段存在的主要问题,并提出该技术未来研究方向。

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.