Capturing CO₂ from fossil fuel combustion is of importance for mitigation of climate warming. Among the CO₂ capture technologies, the calcium-based sorbent method is promising. However, the most prominent problem of this method at present is that the activity of the sorbent decreases as the number of cycle reactions increases. It seriously affects the industrial application of the calcium-based sorbent method in carbon capture technology. Fulvic acid (FA) is a biologically active and soluble component of humic acid. Compared with other humic acids, it contains more oxygen and heterocyclic rings. Also, the rings are connected by bridge bonds. Therefore, the ability of FA to chelate cations and its adsorption capacity is stronger than the other humic acids. Therefore, in this work, we first proposed using FA to modify CaO to improve CO₂ capture from flue gas. The effects of calcination temperature, carbonation temperature, reaction time and the amount of doped FA on the carbonation conversion rate (CCR) of CaO modified with FA (FA/CaO) were studied in the calcining/carbonizing room at atmospheric pressure. The experiment showed that the first CCR (X₁) of FA/CaO reached 0.872 under the optimal conditions, which was 31% higher than X₁ of original CaO. The 20th CCR (X₂₀) was still as high as 0.47, which was three times than X₂₀ of original CaO. In addition, the sorbent was analyzed and characterized by XRD, SEM, BET and LPSA. Due to the doped FA, the microstructure of CaO became fluffy and open, which improved the specific surface area and pore size of CaO. It indicated that the addition of FA was beneficial to the diffusion and absorption of CO₂ and delayed the appearance of sintering, which significantly enhanced the CO₂ capture performance of CaO. Using FA to modify CaO to capture CO₂ provides an idea for efficient carbon capture, and has practical application potential. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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用于钙循环的富里酸改性 CaO 吸附剂的 CO2 捕获性能

从化石燃料燃烧中捕获 CO ₂对于缓解气候变暖具有重要意义。其中CO ₂在捕获技术方面，基于钙的吸附剂方法很有前途。但该方法目前最突出的问题是吸附剂的活性随着循环反应次数的增加而降低。严重影响了钙基吸附剂法在碳捕集技术中的工业化应用。黄腐酸 (FA) 是腐植酸的一种具有生物活性的可溶性成分。与其他腐殖酸相比，它含有更多的氧和杂环。此外，环通过桥键连接。因此，FA螯合阳离子的能力和吸附能力均强于其他腐植酸。因此，在这项工作中，我们首先提出使用FA修饰CaO来改善CO ₂从烟气中捕获。在常压煅烧/碳化室中研究了煅烧温度、碳化温度、反应时间和FA掺杂量对FA改性CaO(FA/CaO)碳化转化率(CCR)的影响。实验表明，在优化条件下，FA/CaO的第一CCR( X ₁ )达到0.872，比原CaO的X _{1提高了31%。}第20次CCR（X ₂₀）依然高达0.47，是X _20的3倍原始 CaO。此外，通过XRD、SEM、BET和LPSA对吸附剂进行了分析和表征。由于FA的掺杂，CaO的微观结构变得蓬松和开放，从而提高了CaO的比表面积和孔径。表明FA的加入有利于CO ₂的扩散和吸收，延缓了烧结的出现，显着增强了CaO对CO ₂的捕集性能。利用FA修饰CaO捕集CO ₂为高效捕集碳提供了思路，具有实际应用潜力。© 2023 化学工业协会和 John Wiley & Sons, Ltd.