Reactivation by Steam Hydration of Sorbents for Fluidized-Bed Calcium Looping
Reactivation by Steam Hydration of Sorbents for Fluidized-Bed Calcium Looping
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DOI：
10.1021/acs.energyfuels.5b00413
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发表时间：
2015-07-01
期刊：
影响因子：
5.3
通讯作者：
Salatino, Piero
中科院分区：
文献类型：
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作者：
Coppola, Antonio;Palladino, Lucia;Salatino, Piero
本研究致力于将蒸汽水合作用作为重新激活循环钙循环系统中废石灰石基吸附剂的二氧化碳捕集潜力的工具。一种参考的高钙活性石灰石通过进行实验室规模的沸腾床钙循环工艺试验(在70%二氧化碳气氛中在940摄氏度下焙烧，在15%二氧化碳气氛中在650摄氏度下碳化)，然后在同一沸腾床中进行水蒸气水化(在250摄氏度，50%水蒸气气氛中)，进行10至60分钟的失活。在脱硫剂重新激活后的额外钙循环过程测试中，进行了在线烟气分析、淋洗出的细粉的连续捕获和粒度分布的评估。采用热重分析、扫描电子显微镜和孔隙率测定仪对废脱硫剂和水合蒸汽脱硫剂的微观结构特征进行了表征。此外，对不同材料进行了非原位冲击破碎试验。通过这种方法，可以研究水化时间对水化处理引起的物化和微观结构性质的变化、吸附剂CO2捕获能力的重新激活以及重新激活的材料的磨损/破碎倾向的影响。
The present study addresses steam hydration as a tool for reactivation of the CO2 capture potential of spent limestone-based sorbents from fluidized-bed calcium looping systems. A reference, high-calcium, reactive limestone was deactivated by carrying but lab-scale fluidized-bed calcium looping process tests (calcination at 940 degrees C in a 70% CO2 atmosphere and carbonation at 650 degrees C in a 15% CO2 atmosphere) and then steam-hydrated (at 250 degrees C in a 50% steam atmosphere) in the same fluidized bed, for times ranging from 10 to 60 min. Online flue gas analysis, continuous capture of the elutriated fines, and evaluation of particle size distribution were performed during additional calcium looping process tests after sorbent reactivation. Thermogravimetric analysis, scanning electron microscopy, and porosimetry were directed to characterize the microstructural features of the spent and steam-hydrated sorbents. Moreover, the different materials were subjected to ex situ impact fragmentation tests. In this way, it was possible to investigate the effect of the hydration time on the changes in the physicochemical and microstruttural properties induced by the hydration treatment, the reactivation of the sorbent CO2 capture capacity, and the attrition/fragmentation tendency of the reactivated materials.