Structural evolution in synthetic, Ca-based sorbents for carbon capture
Structural evolution in synthetic, Ca-based sorbents for carbon capture
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DOI：
10.1016/j.ces.2015.09.016
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发表时间：
2016-01
影响因子：
4.7
通讯作者：
Wen Liu;Belén González;Matthew T. Dunstan;D. S. Sultan;A. Pavan;C. Ling;C. Grey;J. S. Dennis
中科院分区：
文献类型：
--
作者：
Wen Liu;Belén González;Matthew T. Dunstan;D. S. Sultan;A. Pavan;C. Ling;C. Grey;J. S. Dennis
CaO 基材料在高温（例如 >600 °C）下的碳化是捕获二氧化碳等排放物的一种有前途的方法。碳质燃料的燃烧。所得的 CaCO3 可以通过在平衡分压超过 CO2 局部分压（例如 950 °C）的温度下煅烧来再生。涉及钙质材料的碳酸化和煅烧重复循环的过程称为钙循环。 CaO基吸附剂在多次循环中接受和排斥CO2的能力受到许多因素的影响，例如化学成分、表面形态和孔隙结构，所有这些因素通常随着循环而变化。本文研究了控制由 CaO 与惰性载体 Ca12Al14O33 和 MgO 混合组成的一系列合成吸附剂微观结构演变的潜在机制。这些吸附剂经历了煅烧和碳酸化循环，并使用各种原位技术进行了表征。研究发现，煅烧过程中的表面裂纹程度和碳化过程中的烧结程度之间的平衡是循环过程中吸收量变化的原因，导致负载型 CaO 的吸收量增加，而未负载型 CaO 的吸收量减少。
The carbonation of CaO-based materials at high temperatures (e.g. >600 °C) is a promising method of capturing CO2emitted from,e.g. the combustion of carbonaceous fuels. The resulting CaCO3can be regenerated by calcination at a temperature at which the equilibrium partial pressure exceeds that of the local partial pressure of CO2(e.g. 950 °C). A process involving repeated cycles of carbonation and calcination of a calcareous material is called calcium looping. The capacity of a CaO-based sorbent to accept and reject CO2over many cycles is governed by a number of factors, such as chemical composition, surface morphology and pore structure, all of which often evolve with cycling. The present paper investigates the underlying mechanisms controlling the evolution of the micro-structures of a series of synthetic sorbents consisting of CaO mixed with the inert supports Ca12Al14O33and MgO. These sorbents were subjected to cycles of calcination and carbonation and were characterised using a variety ofin situandex situtechniques. It was found that the balance between the degree of surface cracking during calcination and the extent of sintering during carbonation was responsible for changes in uptake during cycling, giving an increase in uptake for the supported CaO and a decrease for the unsupported CaO.