钠基CO2固体吸附剂的掺杂改性研究

论文总字数：33276字

摘 要

自工业革命以来，工业生产排放的CO₂为主的温室气体已造成严重温室效应，致使地球生态环境恶化。为减少CO₂排放量，世界各地学者不断钻研CO₂捕集技术。日前，应用于燃烧后CO₂捕集的碱金属固体吸附剂技术倍受关注。其中钠基吸附剂资源储备丰富、价格低廉，应用前景十分广泛。但其存在碳酸化反应活性低、CO₂吸附效果不理想等问题，有待改善。

针对以上问题，本文进行了相应研究：(1)利用固定床试验仪研究了不掺杂MgO的钠基吸附剂受反应温度的影响，筛选出最佳反应温度为50℃，反应温度升高导致CO₂吸附量下降；（2）研究了不掺杂MgO的钠基吸附剂CO₂吸附量与反应时间的关系，筛选出合适反应时长为15min，吸附量达到最终吸附量的85%；（3）利用热重分析仪和固定床试验仪研究了不同MgO掺杂量的钠镁吸附剂的脱碳性能，发现最佳MgO掺杂量为1wt%，促进了碳酸化反应初期速率并提高了CO₂吸附量。掺杂5wt%MgO也能提高初期反应速率，但对吸附量没有提升作用。过量掺杂会导致吸附剂脱碳性能变差；（4）研究了钠镁吸附剂脱碳性能受反应温度的影响，筛选出最佳反应温度为50℃；（5）利用BET、XRD、XRF等表征手段研究了不同MgO掺杂量钠镁吸附剂的改性机理，发现1wt%MgO掺杂量下，吸附剂孔隙结构变化较小，并有中间产物促进反应的进行，从而提高吸附剂脱碳性能。过量掺杂导致Na₂CO₃团聚并导致反应不够充分完全，影响吸附剂脱碳性能。

关键词：钠基吸附剂；CO2捕集技术；掺杂改性；MgO

Abstract

With the industrial revolution, the carbon dioxide emissions from industrial production have caused serious greenhouse effect, resulting in the deterioration of the earth's ecological environment. In order to reduce CO₂ emissions, scholars around the world continue to study on CO₂ capture technology. Recently, the technology of alkali metal solid adsorbent for CO₂ capture has attracted much attention. The resources of Na-bentonite adsorbent are abundant, the price is low and the application prospect is wide. However, there are some problems such as low carbonation activity and poor adsorption effect of CO₂, which needs to be improved.

In view of the above problems, the corresponding studies were carried out in this paper : (1) Using a fixed bed tester to study the influence of reaction temperature on the sodium-based sorbent without MgO, the optimum reaction temperature was selected as 50 °C, and the increase of reaction temperature led to a decrease in CO₂ adsorption; (2) The relationship between CO₂ adsorption amount and reaction time of Na-based adsorbent not doped with MgO was selected, the suitable reaction time was selected to be 15 min, and the adsorption amount reached 85% of the final adsorption capacity; (3) In the thermogravimetric analyzer and the fixed bed tester ,the decarburization performance of different MgO doping amounts of sodium and magnesium adsorbents found that the best MgO doping amount was 1 wt%, which promoted the initial rate of carbonation and increased the amount of CO₂ adsorption. Doping 5wt% MgO can also increase the initial reaction rate, but it has no effect on the adsorption amount. Excessive doping can lead to poor decarburization performance of the adsorbent. (4) The decarburization performance of sodium and magnesium adsorbents is affected by the reaction temperature, and the optimal reaction temperature is selected to be 50°C; (5) The use of BET, XRD, XRF Such characterization methods studied the modification mechanism of different MgO-doped sodium-magnesium sorbents, and found that with a 1wt% MgO doping amount, the pore structure of the sorbent changes little, and an intermediate product promotes the reaction, thereby increasing the sorbent removal. Carbon properties. Excessive doping leads to agglomeration of Na₂CO₃ and leads to a reaction that is not sufficiently complete, affecting the decarburization performance of the adsorbent.

Key words: sodium-based adsorbent; CO₂ capture technology; doping modification; MgO

目 录

第一章 绪论 1

1.1全球变暖及温室效应 1

1.2二氧化碳捕集及封存技术介绍 3

1.3碱金属固体吸附剂的研究进展 6

1.4本文研究目标及内容 8

1.5本章小结 9

第二章 试验装置及方法 10

2.1试验样品 10

2.4表征手段 14

2.5本章小结 15

第三章 基于热重试验的钠基吸附剂脱碳性能探究 16

3.1热重仪空床试验分析 16

3.2载体空白对照组热重试验分析 17

3.3 不同反应温度对钠基吸附剂性能的影响 17

3.4不同MgO掺杂量复合吸附剂热重试验结果 18

3.5本章小结 20

第四章 基于固定床试验的钠基吸附剂脱碳性能研究 21

4.1不掺杂MgO的吸附剂脱碳性能受反应温度影响分析 21

4.2不掺MgO的吸附剂的CO₂吸附量和反应时长间关系 22

4.3不同MgO掺杂量复合吸附剂脱碳性能分析 23

4.4掺杂1wt%MgO的吸附剂脱碳性能受反应温度的影响分析 23

4.5 本章小结 24

第五章 不同吸附剂表征数据与反应微观机理分析 25

5.1载体材料的负载能力XRF测试 25

5.2 吸附剂孔隙结构分析（BET） 25

5.3吸附剂XRD分析 28

5.4掺杂改性机理分析 30

5.5本章小结 30

第六章 结论 31

致 谢 32

参考文献 33

第一章 绪论

1.1全球变暖及温室效应

1.1.1 温室气体排放现状及危害

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