Experimental study on CO2 capture mechanisms using Na2ZrO3 sorbents synthesized by soft chemistry method
Experimental study on CO2 capture mechanisms using Na2ZrO3 sorbents synthesized by soft chemistry method
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DOI：
10.1016/j.cej.2016.12.103
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发表时间：
2017-04-01
影响因子：
15.1
通讯作者：
Zhao, Ming
中科院分区：
文献类型：
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作者：
Ji, Guozhao;Memon, Muhammad Zaki;Zhao, Ming
采用不同的钠前驱体和干燥方法，对软化学法制备的Na2ZrO3吸附剂的CO2捕集性能进行了研究。研究发现，Na2C2O4前驱体+加热干燥比其他前驱体-干燥组合具有更好的吸附能力（例如，在800摄氏度下，在15 vol%的N-2平衡的CO2流中，10分钟内吸收22.77 wt CO2）。在一系列碳化温度（400-800℃）下，在n -2平衡的净化流中，分别以15 vol%和50 vol%的CO2进行了进一步的研究，分别对应了燃烧后和燃烧前的CO2捕获情景。对吸附能力、稳定性和动力学的分析表明，对于CO2的捕获，钠扩散比CO2扩散更有效。烧结和随后的致密化抑制了CO2的扩散，但增强了钠的扩散，从而对吸附性能产生了积极的总体影响。因此，与其他高温固体吸附剂（如CaO）不同，Na2ZrO3在循环吸附过程中的烧结阻力不是必需的。此外，原料气中较高的CO2馏分通过促进钠扩散和CO2扩散来改善吸附动力学和稳定性。(C) 2016 Elsevier B.V.版权所有
The CO2 capture performances were demonstrated for Na2ZrO3 sorbents prepared by soft chemistry using varied sodium precursors and drying methods. It was found that Na2C2O4 precursor + heated drying' enabled superior sorption capacity (e.g. 22.77 wt CO2 uptake within 10 min at 800 degrees C in a 15 vol% CO2 stream balanced by N-2) to the other precursor-drying combinations. The as-identified strongest sorbent was further investigated at a series of carbonation temperatures (400-800 degrees C) in N-2-balanced purging streams with 15 vol% and 50 vol% CO2, corresponding post- and pre-combustion CO2 capture scenarios, respectively. The analysis of the resulting sorption capacity, stability and kinetics suggests that sodium diffusion is a more efficient driver than CO2 diffusion for the capture of CO2. Sintering and the subsequent densification inhibits CO2 diffusion but enhances sodium diffusion, which leads to a positive overall effect on the sorption performance. Hence, unlike other high-temperature solid sorbents such as CaO, sintering resistance during cyclic sorption is not a necessity for Na2ZrO3. In addition, higher CO2 fractions in the feed gas improve the sorption kinetics and stability by promoting sodium diffusion as well as CO2 diffusion. (C) 2016 Elsevier B.V. All rights reserved.