Ristić Alenka, Zabukovec Logar Nataša
Department of Inorganic Chemistry and Technology, National Institute of Chemistry Slovenia, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.
School of Science, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia.
Nanomaterials (Basel). 2018 Dec 26;9(1):27. doi: 10.3390/nano9010027.
Sorption heat storage, as one of low-energy consuming technologies, is an approach to reduce CO₂ emissions. The efficiency of such technology is governed by the performance of the applied sorbents. Thus, sorbents with high water sorption capacity and regeneration temperature from 80 to 150 °C are required. Incorporation of hygroscopic salt such as calcium chloride into porous materials is a logical strategy for increasing the water sorption capacity. This work reports the study on the development of composites with PHTS (plugged hexagonal templated silicate) matrix with an average pore size of 5.7 nm and different amounts of calcium chloride (4, 10, 20 wt.%) for solar thermal energy storage. These composites were prepared by wetness incipient impregnation method. Structural properties were determined by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). CaCl₂ was confined in micro- and mesopores of the matrix. The resulting CaCl₂-PHTS materials were used for water sorption at 40 °C, showing an increase of maximal water uptake with higher amount of calcium chloride from 0.78 g/g to 2.44 g/g of the dry composite. A small reduction in water uptake was observed after 20 cycles of sorption/desorption between temperatures of 140 °C and 40 °C, indicating good cycling stability of these composites under the working conditions.
吸附式蓄热作为低能耗技术之一，是一种减少二氧化碳排放的方法。该技术的效率取决于所用吸附剂的性能。因此，需要具有高吸水能力且再生温度在80至150°C之间的吸附剂。将氯化钙等吸湿盐掺入多孔材料中是提高吸水能力的合理策略。本文报道了对以平均孔径为5.7 nm的PHTS（插层六方模板硅酸盐）为基体、含有不同量氯化钙（4%、10%、20%重量）的复合材料用于太阳能蓄热的研究。这些复合材料采用初湿浸渍法制备。通过X射线衍射（XRD）、氮物理吸附、扫描电子显微镜（SEM）和透射电子显微镜（TEM）测定其结构性能。氯化钙被限制在基体的微孔和介孔中。所得的CaCl₂-PHTS材料在40°C下用于吸水，结果表明，随着氯化钙含量的增加，干复合材料的最大吸水量从0.78 g/g增加到2.44 g/g。在140°C和40°C之间进行20次吸附/解吸循环后，吸水量略有下降，表明这些复合材料在工作条件下具有良好的循环稳定性。
