Abstract The calcium looping (CaL) process is a promising thermochemical energy storage option for concentrated solar power systems due to its great advantages of high energy density and low material cost. However, CaO-based sorbents often suffer from continuous degradation in their reversibility due to the formation of a passivation layer and evolution of a sintering effect. In this work, we focused on the effects of CaCl2 as an additive to CaO sorbents with the aim to enhance reversibility by addressing the mass-transfer issue. A variety of CaO-based sorbents with CaCl2 were synthesized, characterized, and examined their reaction patterns during cyclic carbonation-calcination. The experimental results show that the addition of CaCl2 enhances the rate of the carbonation reaction, based on enhanced reactant diffusion. The CaCl2 causes reduction of surface area; however, the addition of MgO effectively delays sintering. Therefore, CaO-based sorbents with CaCl2 and MgO achieved high reversibility with enhanced durability.

中文翻译：

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CaCl2 对 CaO 基复合材料的循环碳酸化-煅烧动力学的影响，可能应用于太阳能热化学储能

摘要 钙循环（CaL）工艺具有能量密度高和材料成本低的巨大优势，是聚光太阳能系统的一种很有前途的热化学储能选择。然而，由于钝化层的形成和烧结效应的演变，CaO 基吸附剂的可逆性通常会持续退化。在这项工作中，我们专注于 CaCl2 作为 CaO 吸附剂的添加剂的影响，旨在通过解决传质问题来提高可逆性。合成、表征并检查了循环碳酸化-煅烧过程中的各种 CaO 基吸附剂和 CaCl2。实验结果表明，基于增强的反应物扩散，CaCl2 的添加提高了碳酸化反应的速率。CaCl2 导致表面积减少；然而，添加 MgO 有效地延迟了烧结。因此，具有 CaCl2 和 MgO 的 CaO 基吸附剂实现了高可逆性和增强的耐用性。