Nanosilica supported CaO: A regenerable and mechanically hard CO2 sorbent at Ca-looping conditions
Nanosilica supported CaO: A regenerable and mechanically hard CO2 sorbent at Ca-looping conditions
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DOI：
10.1016/j.apenergy.2013.12.024
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发表时间：
2014-04
期刊：
影响因子：
11.2
通讯作者：
P. E. Sánchez-Jiménez;L. Pérez-Maqueda;J. Valverde
中科院分区：
文献类型：
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作者：
P. E. Sánchez-Jiménez;L. Pérez-Maqueda;J. Valverde
这项工作提出了一种二氧化碳吸附剂，可以用低成本和广泛可用的材料合成，方法简单，主要包括用饱和硝酸钙溶液浸渍纳米结构二氧化硅载体。在第一次浸渍阶段，使用化学计量的CaO/ sio2比用于煅烧后生成硅酸钙基质。这种硅酸钙基质通过进一步浸渍，作为沉积在其上的CaO的热稳定和机械硬的支撑。氧化钙浸渍吸附剂在钙环条件下表现出稳定的氧化钙转化率，其值取决于沉积在硅酸钙基体上的氧化钙wt%，可以通过连续再浸渍来增加。10 wt% CaO浸渍吸附剂的稳定转化率在0.6以上，而30 wt% CaO浸渍吸附剂的稳定转化率在0.3左右，远远大于天然石灰石中CaO的残余转化率（在0.07至0.08之间）。此外，对液体中预分散的样品进行了粒度分布测量，并对其进行了高能超声波处理，结果表明，与石灰石衍生的CaO相比，CaO浸渍吸附剂具有相对较高的机械强度。
This work presents a CO2sorbent that may be synthesized from low-cost and widely available materials following a simple method basically consisting of impregnation of a nanostructured silica support with a saturated solution of calcium nitrate. In a first impregnation stage, the use of a stoichiometric CaO/SiO2ratio serves to produce a calcium silicate matrix after calcination. This calcium silicate matrix acts as a thermally stable and mechanically hard support for CaO deposited on it by further impregnation. The CaO-impregnated sorbent exhibits a stable CaO conversion at Ca-looping conditions whose value depends on the CaO wt% deposited on the calcium silicate matrix, which can be increased by successive reimpregnations. A 10 wt% CaO impregnated sorbent reaches a stable conversion above 0.6 whereas the stable conversion of a 30 wt% CaO impregnated sorbent is around 0.3, which is much larger than the residual conversion of CaO derived from natural limestone (between 0.07 and 0.08). Moreover, particle size distribution measurements of samples predispersed in a liquid and subjected to high energy ultrasonic waves indicate that the CaO-impregnated sorbent has a relatively high mechanical strength as compared to limestone derived CaO.