化学链燃烧中惰性组分对铁基载氧体烧结特性的影响

论文总字数：25638字

摘 要

2O₃、SiO₂、TiO₂、CaO为载体的铁基载氧体，在800℃下进行5、10、15、20组氧化还原循环。（1）为了探究不同惰性组对铁基载氧体的活性影响，对循环后样品进行了热重分析，分析表明：Fe₂O₃/Al₂O₃载氧体在循环过程中具有较高的活性，Fe₂O₃/TiO₂活性随循环周期得到强化，Fe₂O₃/SiO₂活性折中。（2）为了探不同惰性组分对铁基载氧体的晶相结构组成影响，对样品进行了XRD分析，分析表明：Fe₂O₃/Al₂O₃和Fe₂O₃/SiO₂载氧体循环中惰性组分与活性组分未发生化学反应，Fe₂O₃/TiO₂在采用机械混合法制备时二者发生化学反应生成Fe₂TiO₅，其后的循环中晶相结构由TiO₂和Fe₂TiO₅组成。（3）为了探究不同惰性组分铁基载氧体比表面积和孔容积变化的影响，对样品进行了BET分析，分析显示Fe₂O₃/Al₂O₃比表面积缓慢减小，孔径变化不大；Fe₂O₃/SiO₂和Fe₂O₃/TiO₂比表面积迅速减小，其中Fe₂O₃/TiO₂主要孔径由10nm增长到了近50nm。（4）为了探究不同惰性组铁基载氧体微观形貌的影响,对样品进行了电镜扫描，分析显示Fe₂O₃/Al₂O₃表面颗粒长大，孔径增加，Fe₂O₃/TiO₂颗粒形成团聚，Fe₂O₃/TiO₂表面晶粒粉化堆密。综合分析显示惰性组分Al2O3不与活性成分发生反应，载氧体表面不易粉化堆密，比表面积减小速率慢，保持活性能力强，是良好的惰性组分。

关键词：惰性组分、化学链燃烧、烧结、性能及表征

Abstract

The iron-based oxygen carriers with Al₂O₃, SiO₂, TiO₂ and CaO were prepared by mechanical mixing method.The oxidation-reduction cycles of 5, 10, 15 and 20 were carried out at 800 ℃.(1)In order to investigate the effect of different inert groups on the activity of iron-based oxygen carriers, the samples were analyzed by thermogravimetric analysis.And the Analysis shows that Fe₂O₃ / Al₂O₃ has a high activity during the cycle.The activity of Fe₂O₃ / TiO₂ is enhanced with the cycle period.The activity of Fe₂O₃ / SiO₂ is compromised.(2) In order to investigate the effect of different inert components on the crystal structure of iron-based oxygen carriers, the samples were analyzed by XRD, Analysis shows that the inert components and active components of Fe₂O₃ / Al₂O₃ and Fe₂O₃ / SiO₂ oxygen carrier mixed without chemical reaction.Fe₂O₃ and TiO₂ are chemically reacted to form Fe₂TiO₅.(3) In order to investigate the effect of different inert components on the specific surface area and pore volume change of iron-based oxygen carriers, the samples were analyzed by BET. The analysis showed that the specific surface area of Fe₂O₃ / Al₂O₃ decreased slowly and the pore size changed. The specific surface area of Fe₂O₃ / SiO₂ and Fe₂O₃ / TiO₂ decreases rapidly from 10nm to 50nm.(4) In order to investigate the effect of different inert components on the microstructure of

iron-based oxygen carriers during the cycle, the samples were scanned by electron microscopy. The results showed that the surface particles of Fe₂O₃ / Al₂O₃ increased, the pore size increased, Fe₂O₃ / TiO₂ The particles are agglomerated and the Fe₂O₃ / TiO₂ surface is powdered.The comprehensive analysis shows that the inert component Al₂O₃ does not react with the active component. The surface of the oxygen-carrying body is not easy to be pulverized, the specific surface area is slow to decrease, the activity is strong, and it is a good inert component.

KEY WORDS: Inert components, chemical chain combustion, performance and characterization

目 录

摘 要 I

Abstract I

第一章 绪论 1

1.1 课题背景及研究意义 1

1.1.1 中国煤燃烧CO₂减排的必要性 1

1.1.2 燃煤电站CO₂减排路线 1

1.1.3 化学链燃烧的原理 1

1.1.4 化学链燃烧技术氧载体简介 2

1.2 国内外研究现状 2

1.3 研究内容与研究目标 4

1.4 本章小结 4

第二章 实验装置与方法 6

2.1 实验系统 6

2.1.1 实验系统简介 6

2.1.2 实验操作方法 6

2.2 样本基本物化性质测量系统 7

2.2.1 样本基本物化性质测量方法 7

2.3 本章小结 8

第三章 载氧体的性能表征 10

3.1 惰性组分对氧载体性能影响 10

3.1.1 循环周期对不同惰性组分载氧体活性影响 10

3.2 载氧体的表征 14

3.2.1 X射线衍射（XRD） 15

3.2.2 BET测试 16

3.2.3 SEM测试 23

3.3 本章小结 25

第四章 结论与展望 26

致 谢 28

参考文献 29

第一章 绪论

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