不同钙基吸附剂捕集CO2后的硫酸化反应特性研究

钙基吸附剂进行多次CO₂捕集后,碳酸化效率会大幅衰减,此时的吸附剂能否高效脱硫利用是值得重点关注的问题。鉴于此,筛选了高性能合成钙基吸附剂和天然石灰石吸附剂,通过热重分析仪分析对比其在多循环CO₂捕集后的碳酸化和硫酸化反应性能,采用微粒模型研究其硫酸化反应动力学特征。结果发现,高性能合成钙基吸附剂的碳酸化反应速率和CO₂吸附能力明显高于石灰石吸附剂。在长达500循环的CO₂捕集试验后,高性能合成钙基吸附剂的CO₂吸附能力比石灰石高10倍以上,其SO₂吸附能力相较于石灰石提升约40%。经历多次CO₂捕集反应循环后,2种吸附剂的硫酸化能力均有提升:其中,石灰石吸附剂的提升幅度更大,硫酸化转化率从26%提升到35%,而高性能合成钙基吸附剂的硫酸化转化率则从38%提升到43%。通过微粒模型计算发现,2种吸附剂的硫酸化反应均是与SO₂浓度相关的一级反应,多循环捕集CO₂反应后,石灰石吸附剂的硫酸化反应活化能下降接近30%,而高性能合成钙基吸附剂的硫酸化反应活化能只下降了5%。研究结果说明2种不同钙基吸附剂在进行循环CO₂捕集后,脱硫能力得到了不同程度的提高,且均可以较好地应用于SO₂的脱除。

Study on sulfation reaction characteristics of different calcium-based sorbents after CO2 capture

The carbonation conversion of the calcium-based sorbent decreases significantly after multiple CO₂ capture cycles,whether the sorbent can be further used efficiently in desulfurization reaction is important issue which deserves concerns.In order to delve into this is?sue,the high performance calcium-based sorbent and natural limestone sorbent were selected,the carbonation and sulfation reaction per?formance after multiple CO₂ capture cycles were analyzed and compared by thermal gravimetric analyzer,and the sulfation kinetics charac?teristics were studied by particle model.The results showed that the rate of carbonation reaction and CO₂ adsorption capacity of the high performance calcium-based sorbents are much higher than those of limestone adsorbent.After multiple cycles of CO₂ capture test,the CO₂ adsorption capacity of high performance calcium-based sorbents is over 10 times higher than that of limestone,and its SO₂ adsorption ca?pacities was improved by 40%than that of limestone.After multiple CO₂ capture reactions,their sulfation abilities are both improved.The improvement of limestone is greater,the sulfation conversion is increased from 26%to 35%,while the sulfation conversion of high perform?ance calcium-based sorbent is increased from 38%to 43%.It is found through particle model calculation that the sulfation process of both sorbents is a first-order reaction related to the concentration of SO₂.After the multiple CO₂ capture cycles,the activation energy of sulfa?tion reaction of limestone decreases by nearly 30%,while that of high performance calcium-based sorbent only decreases by 5%.The re?sults indicate that the desulphurization capacity of two different calcium-based sorbents can be improved to different degrees after multiple CO₂ capture cycles,and both of them can be better used for SO₂ removal.