Nguyen Minh Hoang, Zbair Mohamed, Dutournié Patrick, Limousy Lionel, Bennici Simona
Université de Haute-Alsace, CNRS, IS2M UMR 7361, F-68100 Mulhouse, France.
Université de Strasbourg, F-67000 Strasbourg, France.
Molecules. 2023 Jul 13;28(14):5381. doi: 10.3390/molecules28145381.
Heat storage technologies are essential for increasing the use of solar energy in the household sector. Their development can be achieved by designing new storage materials; one way is to impregnate a porous matrix with hygroscopic salts. In this article, the possibility of using biochar-based composite sorbents to develop promising new heat storage materials for efficient thermal storage is explored. Biochar-based composites with defined salt loadings (5, 10, 15, and 20%) were produced by impregnating MgSO into a biochar matrix derived from corn cobs. The new materials demonstrated a high water sorption capacity of 0.24 g/g (20MgCC). After six successive charging-discharging cycles (dehydration/dehydration cycles), only a negligible variation of the heat released and the water uptake was measured, confirming the absence of deactivation of 20MgCC upon cycling. The new 20MgCC composite showed an energy storage density of 635 J/g (Tads = 30 °C and RH = 60%), higher than that of other composites containing a similar amount of hydrate salt. The macroporous nature of this biochar increases the available surface for salt deposition. During the hydration step, the water molecules effectively diffuse through a homogeneous layer of salt, as described by the intra-particle model applied in this work. The new efficient biochar-based composites open a low-carbon path for the production of sustainable thermal energy storage materials and applications.
蓄热技术对于增加太阳能在家庭领域的应用至关重要。它们的发展可以通过设计新型蓄热材料来实现；一种方法是用吸湿盐浸渍多孔基质。在本文中，探索了使用基于生物炭的复合吸附剂来开发用于高效蓄热的新型有前景蓄热材料的可能性。通过将硫酸镁浸渍到源自玉米芯的生物炭基质中，制备了具有确定盐负载量（5%、10%、15%和20%）的基于生物炭的复合材料。新材料表现出0.24 g/g（20MgCC）的高吸水能力。经过六个连续的充放电循环（脱水/脱水循环）后，所测量的释放热量和吸水量仅有可忽略不计的变化，证实了20MgCC在循环时没有失活。新型20MgCC复合材料显示出635 J/g的储能密度（Tads = 30°C且RH = 60%），高于含有相似量水合盐的其他复合材料。这种生物炭的大孔性质增加了盐沉积的可用表面积。在水合步骤中，水分子如本文应用的颗粒内模型所述，有效地扩散通过均匀的盐层。新型高效的基于生物炭的复合材料为生产可持续的蓄热材料和应用开辟了一条低碳途径。
