This paper analyses a CO₂ capture system based on calcium looping, designed for power plants that operate with very low capacity factors and large load fluctuations, including shut-down and start-up periods. This can be achieved by decoupling the operation of the carbonator and calciner reactors and connecting them to piles filled with CaO or CaCO₃. When the power plant enters into operation, calcined solids are fed into the carbonator to provide the necessary flow of CaO for capturing CO₂ and storing the carbonated solids. An oxy-CFB calciner designed to have a modest thermal capacity and operate continuously refills the CaO pile. Mass and energy balances of the entire system, combined with state-of-the-art performance criteria for reactor design, have been solved to identify suitable operating windows. An analysis of the effect of the CaO reactivity of the material stored in the piles indicates that temperatures of around 500–600 °C in the carbonator are compatible with the storage of solids at low temperature (<250 °C). This, together with the low inherent cost of the material, allows large piles of stored material. Electricity costs between 0.13–0.15 $ per kWh_e are possible for the system proposed in contrast to standard CaL systems where the cost would increase to above 0.19 $ per kWh_e when forced to operate at low capacity. The proposed concept could be integrated into existing power plants operating as back-ups in renewable energy systems in preference to other CO₂ capture technologies that are heavily penalized when forced to operate under low capacity factors.

中文翻译：

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备用电厂的钙循环CO ₂捕集系统

本文分析了一种基于钙循环的CO ₂捕集系统，该系统是为容量系数非常低且负载波动较大（包括停机和启动期）的发电厂设计的。这可以通过将碳酸化器和煅烧炉反应器的运行解耦并将其连接到填充有CaO或CaCO _3的堆中来实现。电厂投入运行后，将煅烧的固体送入碳酸化器，以提供必要的CaO流量以捕集CO ₂并储存碳酸化的固体。氧-CFB煅烧炉设计为具有适度的热容量，并且可以连续填充CaO堆。解决了整个系统的质量和能量平衡问题，并结合了用于反应堆设计的最新性能标准，从而确定了合适的运行窗口。对存储在堆中的材料的CaO反应性的影响的分析表明，碳酸化器中大约500–600°C的温度与低温（<250°C）下的固体存储兼容。这样，再加上材料固有的低成本，就可以存储大量的材料。0.13-0.15 $每千瓦时之间的电力成本_Ë是可能的对比标准CAL系统中的成本将上升到高于每千瓦时0.19 $提出的系统_e当被迫低容量运行时。提议的概念可以集成到现有的发电厂中，作为可再生能源系统中的后备设备，而不是其他被迫在低容量因素下运行的CO ₂捕集技术优先考虑的技术。