Abstract:

A novel process combined cyclic CO₂ capture with hydration/dehydration for energy storage was proposed based on calcium looping of CaO. The effects of calcination and carbonation conditions during CO₂ capture on the heat storage performance of CaO were studied on a dual fix-bed reactor. In addition, the mutual effects of cyclic CO₂ capture and hydration/dehydration processes were investigated. The results show that the CaO after multiple CO₂ capture cycles possesses high heat storage capacity. After 10 cycles of CO₂ capture, the hydration conversion of CaO was 0.66mol/mol. The heat storage performance of CaO from CO₂ capture cycles under mild calcination condition was higher than that under severe calcination condition. The presence of steam in the carbonation atmosphere had no apparent effect on the heat storage performance of CaO from CO₂ capture cycles. The CO₂ capture and the hydration/dehydration processes can promote with each other. This process simultaneously achieves CO₂ capture and energy storage, and thus is quite promising for the industrial application.

Key words: CaO/Ca(OH)₂ heat storage, carbon dioxide capture, calcium looping, fixed-bed, limestone, solar energy

摘要：

提出了基于CaO的钙循环捕集CO₂与CaO/Ca(OH)₂体系热化学储热耦合新工艺，在双固定床反应器上，研究了循环捕集CO₂中煅烧条件和碳酸化条件对CaO储热性能的影响，探究CaO循环捕集CO₂过程和循环水合/脱水储热过程的相互作用。研究表明，多次循环碳酸化/煅烧捕集CO₂后CaO仍具有较高储热性能，10次循环捕集CO₂后再经10次储热循环，CaO水合转化率可达0.66mol/mol。与苛刻煅烧条件相比，温和煅烧条件下经历多次循环捕集CO₂后CaO的储热性能更高。在碳酸化气氛中加入水蒸气对经历多次循环捕集CO₂后CaO储热性能的影响不大。钙循环捕集CO₂过程和水合/脱水循环储热过程能够相互促进。该工艺有望同时实现CO₂捕集和储热，具有一定的应用前景。

关键词: CaO/Ca(OH)₂储热, 二氧化碳捕集, 钙循环, 固定床, 石灰石, 太阳能