Thermal activation of CaO-based sorbent and self-reactivation during CO2 capture looping cycles
Thermal activation of CaO-based sorbent and self-reactivation during CO2 capture looping cycles
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DOI：
10.1021/es800152s
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发表时间：
2008-06-01
影响因子：
11.4
通讯作者：
Anthony, Edward J.
中科院分区：
文献类型：
--
作者：
Manovic, Vasilije;Anthony, Edward J.
在这项研究中，不同类型的CaO基吸收剂的热活化进行了检查。使用四种加拿大石灰石在不同温度（800-1300摄氏度）和不同持续时间（6-48小时）下进行预处理。石灰石的筛分部分，通过研磨获得的粉末，以及在管式炉中实现的多个碳酸化/煅烧循环后产生的氢氧化物进行了检查。使用两种类型的热重反应器/分析仪评价预处理的样品。最重要的结果是，热预处理可以提高吸附剂的性能。与原始相比，预处理的吸附剂在较长的CO2循环系列中显示出更好的转化率。此外，在某些情况下，吸附剂活性实际上随着循环次数增加，并且这种效果对于在1000摄氏度下预热的粉末样品尤其明显。在这些实验中，在30个循环之后，转化率随着循环次数的增加（称为自再活化）产生了对于这里检查的四种吸附剂类似于50%碳酸化的样品，并且似乎存在额外增加的可能性。用新提出的孔隙骨架模型解释了这些结果。该模型表明，除了吸附剂的多孔结构的变化，在预处理过程中产生的孔骨架的变化强烈影响随后的碳酸化/煅烧循环。
In this study, the thermal activation of different types of CaO-based sorbents was examined. Pretreatments were performed at different temperatures (800-1300 degrees C) and different durations (6-48 h) using four Canadian limestones. Sieved fractions of the limestones, powders obtained by grinding, and hydroxides produced following multiple carbonation/calcination cycles achieved in a tube furnace were examined. Pretreated samples were evaluated using two types of thermogravimetric reactors/analyzers. The most important result was that thermal pretreatment could improve sorbent performance. In comparison to the original, pretreated sorbents showed better conversions over a longer series Of CO2 cycles. Moreover, in some cases, sorbent activity actually increased with cycle number, and this effect was especially pronounced for powdered samples preheated at 1000 degrees C. In these experiments, the increase of conversion with cycle number (designated as self-reactivation) after 30 cycles produced samples that were similar to 50% carbonated for the four sorbents examined here, and there appeared to be the potential for additional increase. These results were explained with the newly proposed pore-skeleton model. This model suggests, in addition to changes in the porous structure of the sorbent,that changes in the pore-skeleton produced during pretreatment strongly influence subsequent carbonation/calcination cycles.