Modification of magnesium and calcium hydroxides with salts: An efficient way to advanced materials for storage of middle-temperature heat
Modification of magnesium and calcium hydroxides with salts: An efficient way to advanced materials for storage of middle-temperature heat
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DOI：
10.1016/j.energy.2015.04.004
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发表时间：
2015-06-01
期刊：
影响因子：
9
通讯作者：
Aristov, Yuri
中科院分区：
文献类型：
--
作者：
Shkatulov, Alexandr;Aristov, Yuri
热化学储热可以极大地提高众多工业过程和装置的效率，特别是基于可再生能源和/或多联产系统的工业过程和装置。纯氢氧化镁和氢氧化钙是储存中温热量（250-500 摄氏度）的便利材料，但两者都存在动力学障碍。在这项工作中，我们研究了各种盐的掺杂效应，以影响这些氢氧化物的脱水动力学。在选定类别的盐（即碱金属的氯化物、硝酸盐、硫酸盐和乙酸盐）中的筛选显示了a）改善脱水动力学和b）管理脱水温度的有价值的可能性。脱水温度的变化取决于盐的性质和含量。硝酸盐和乙酸盐对两种氢氧化物的脱水速率有强烈影响。 LiNO3 和 XOOCCH3 (X = Li、Na、K) 使 Mg(OH)(2) 的脱水温度降低了 50-80 K。对于掺杂 KNO3 的 Ca(OH)(2) (约 40 K)，效果类似，但较弱。事实证明，用盐进行改性是获得用于中温蓄热的新型先进氢氧化物基材料的一种有前景的方法，该材料具有增强且可控的脱水反应性。 (C) 2015 Elsevier Ltd. 保留所有权利。
Thermochemical heat storage can greatly contribute to higher efficiency of numerous industrial processes and units, especially based on renewable energy sources and/or polygeneration systems. Pure magnesium and calcium hydroxides are convenient materials for storage of middle temperature heat (250-500 degrees C), however, both suffer from kinetic impediments. In this work, we studied the doping effect of various salts in order to affect the dehydration dynamics of these hydroxides. The screening among the selected classes Of salts, namely, chlorides, nitrates, sulphates and acetates of alkaline metals, showed a valuable possibility to a) improve the dehydration dynamics, and b) manage the dehydration temperature. Variation of the dehydration temperature was shown to depend on the salt nature and content. A strong effect of nitrates and acetates on the dehydration rate of both hydroxides was revealed. LiNO3 and XOOCCH3 (X = Li, Na, K) diminished the dehydration temperature of Mg(OH)(2) by 50-80 K. Alike, though weaker, effect was found for Ca(OH)(2) doped with KNO3 (c.a. 40 K). The modification with salts is proven to be a promising way to get new advanced hydroxide-based materials for middle temperature heat storage with enhanced and controllable dehydration reactivity. (C) 2015 Elsevier Ltd. All rights reserved.