Dolomite: a low cost thermochemical energy storage material
Dolomite: a low cost thermochemical energy storage material
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DOI：
10.1039/c8ta07254j
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发表时间：
2019-01-21
影响因子：
11.9
通讯作者：
Paskevicius, Mark
中科院分区：
文献类型：
--
作者：
Humphries, Terry D.;Moller, Kasper T.;Paskevicius, Mark
研究了三种来源(商业、采矿和合成)的白云石CaMG(CO3)(2)的储热性能，作为聚光式太阳能热电厂(CSP)潜在的固-气热化学储能装置。可逆的二氧化碳释放/吸收循环可以用来储存和释放大量的热能，这些热能可以在550摄氏度左右被利用。为了能够吸收二氧化碳，在白云石中加入了一种新型的熔盐共熔氯化钠：氯化镁混合物，事实证明这是有效的。奇怪的是，开采的(未精炼的)样品被证明具有最好的焙烧/碳化性能，在10个循环中的循环稳定性类似于50mol%CO2。扫描电子显微镜的形态研究表明，开采的样品中含有杂质(如石英)，这些杂质阻止了白云石及其反应产物(CaCO3和MgO)的有害团聚。在碳化过程中，开采的白云石中的高孔隙率也提供了短的气固反应路径。一种商业白云石来源含有太多的杂质，导致形成高水平的Ca2SiO4，作为钙汇，降低了二氧化碳的容量。最后，高纯度合成白云石样品表现出高水平的团聚和相分离，降低了可逆的二氧化碳容量，这归因于缺乏限制团聚的杂质。
The thermal energy storage properties of dolomite, CaMg(CO3)(2), from three sources (commercial, mined, and synthetic) are investigated as a potential solid-gas thermochemical energy store for concentrating solar thermal power (CSP) plants. The reversible carbon dioxide release/absorption cycle can be used to store and release large quantities of thermal energy that can be harnessed near 550 degrees C. To enable carbon dioxide absorption, a novel molten salt eutectic NaCl : MgCl2 mixture was added to the dolomite, which proved effective. Curiously, the mined (unrefined) sample proved to have the best calcination/carbonation properties with a stable cyclic stability of similar to 50 mol% CO2 over 10 cycles. A morphological investigation by scanning electron microscopy reveals the mined sample contains impurities (e.g. quartz) that prevent detrimental agglomeration of dolomite and its reaction products (CaCO3 and MgO). High levels of porosity in the mined dolomite also provide short gas-solid reaction pathways during carbonation. A commercial dolomite source contained too many impurities, resulting in the formation of high levels of Ca2SiO4 that acted as a Ca-sink, lowering CO2 capacity. Finally, a high purity synthetic dolomite sample displayed high levels of agglomeration and phase segregation, lowering reversible CO2 capacity, which was attributed to a lack of impurities that restrict agglomeration.