Steam catalysis in CaO carbonation under low steam partial pressure
Steam catalysis in CaO carbonation under low steam partial pressure
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DOI：
10.1021/ie8000265
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发表时间：
2008-05
影响因子：
4.2
通讯作者：
Shaojun Yang;Yun-han Xiao
中科院分区：
文献类型：
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作者：
Shaojun Yang;Yun-han Xiao
在直接制氢过程中，由于水蒸气的存在，CaO被广泛应用于CO2的捕集。利用加压热重仪研究了低水蒸气分压下水蒸气对CaO碳酸化性能的影响。实验结果表明，无论是否生成Ca（OH）2，水蒸气都能显著提高CaO的碳化性能。在823 K和0.5 MPa水蒸气分压下，由于CaO的水化速率很慢，水蒸气对CaO碳酸化性能的影响主要不是Ca（OH）2的生成。主要原因是CaO碳酸化过程中的水蒸气催化作用。水蒸气对CaO碳酸化性能的提高并不是因为水蒸气改善了CaO的物性，而是由于水蒸气的催化作用。CaO前体，CO2分压，水蒸气分压，温度与水蒸气添加对CaO碳酸化性能的影响进行了研究。
CaO was widely used to capture CO2 in direct hydrogen production process, where steam always existed simultaneously. The effect of steam on CaO carbonation performance under low steam partial pressure was investigated using a pressurized thermogravimetric apparatus. The experimental results revealed that steam improved CaO carbonation performance significantly no matter whether Ca(OH)2 was produced or not. At 823 K and 0.5 MPa of steam partial pressure, effect of steam on CaO carbonation performance could not be attributed mainly to production of Ca(OH)2 because the hydration rate of CaO was very slow. The main reason was steam catalysis in CaO carbonation. Enhancement of steam on CaO carbonation performance without Ca(OH)2 production could not be attributed to improvement of steam on the physical property, but to catalytic effect of steam. Effects of CaO precursors, CO2 partial pressure, steam partial pressure, and temperature with steam addition on CaO carbonation performance were also investigated.