A shrinking core model for steam hydration of CaO-based sorbents cycled for CO2 capture
A shrinking core model for steam hydration of CaO-based sorbents cycled for CO2 capture
复制标题
DOI：
10.1016/j.cej.2016.01.086
复制
发表时间：
2016-05
影响因子：
15.1
通讯作者：
J. Blamey;Mingru Zhao;V. Manović;E. Anthony;D. Dugwell;P. Fennell
中科院分区：
文献类型：
--
作者：
J. Blamey;Mingru Zhao;V. Manović;E. Anthony;D. Dugwell;P. Fennell
钙循环是一种新兴的CO2捕集技术。它是基于CaO吸附剂的可逆碳酸化，其在循环时变得不那么反应。提高非反应性吸附剂的反应性的一种方法是通过煅烧（CaO）形式的水合。在此，吸附剂在小型流化床反应器内进行碳酸化和煅烧的重复循环。循环次数为0（即，一次煅烧）、2、6和13已经被研究以产生不同程度失活的吸附剂。随后，使用473、573和673 K的水合温度，在热重分析仪内对所产生的吸附剂进行蒸汽水合测试。在水合之前循环较少的吸附剂迅速水合。然而，更多的循环吸附剂表现出的行为，其中的水合转化倾向于一个渐近值，这是可能与孔堵塞。在较高的水化温度下，这一渐近值往往较低;然而，最大水化速率被发现随着水化温度的增加而增加。一个收缩的核心模型已经开发和应用到数据。它适合的数据，没有表现出广泛的孔隙堵塞的实验，但适合的数据，表现出孔隙堵塞的实验。
Calcium looping is a developing CO2capture technology. It is based on the reversible carbonation of CaO sorbent, which becomes less reactive upon cycling. One method of increasing the reactivity of unreactive sorbent is by hydration in the calcined (CaO) form. Here, sorbent has been subjected to repeated cycles of carbonation and calcination within a small fluidised bed reactor. Cycle numbers of 0 (i.e., one calcination), 2, 6 and 13 have been studied to generate sorbents that have been deactivated to different extents. Subsequently, the sorbent generated was subjected to steam hydration tests within a thermogravimetric analyser, using hydration temperatures of 473, 573 and 673 K. Sorbents that had been cycled less prior to hydration hydrated rapidly. However, the more cycled sorbents exhibited behaviour where the hydration conversion tended towards an asymptotic value, which is likely to be associated with pore blockage. This asymptotic value tended to be lower at higher hydration temperatures; however, the maximum rate of hydration was found to increase with increasing hydration temperature. A shrinking core model has been developed and applied to the data. It fits data from experiments that did not exhibit extensive pore blockage well, but fits data from experiments that exhibited pore blockage less well.