摘要: |
为了减少温室效应,应采取有效措施减少温室气体CO2的排放。氨基改性吸附剂是捕获烟道气中CO2的重要吸附材料。建立了描述氨基改性MCM-41吸附剂在低CO2压力下吸附等温线的平衡模型,并计算了吸附热力学参数。该模型基于Dual-site Langmuir模型,同时假设CO2吸附具有两种独立的吸附机理,分别是氨基基团的化学吸附和吸附剂表面的物理吸附,提出了一种基于未改性介孔材料吸附容量和比表面积计算改性材料的物理吸附量方法。结果 表明,该模型能较好地拟合吸附等温线,计算得到的物理化学吸附热分别为-25.4 kJ/mol和-41.9 kJ/mol,总吸附热为-67.3 kJ/mol,与实验数据一致,且氨基改性MCM-41-TEPA饱和吸附容量可达到7.79 mmol/g。 |
关键词: 氨基改性 MCM-41 低CO2分压 吸附CO2 热力学 |
DOI:10.3969/j.issn.1007-3426.2015.05.001 |
分类号:TE645 |
基金项目:国家自然科学基金资助项目“流化床内B类颗粒介尺度流动特征及其对煤气化过程影响”(91434120);中央高校基本研究基金“传质强化的脱硫除尘一体化装置的开发和优化”(2014ZD06);“111”计划“煤的清洁转化与高效利用创新引智基地”(B12034)。 |
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Thermodynamic study on amine-modified adsorbent of CO2 adsorption at low CO2 partial pressures |
Liu Zhilin, Teng Yang, Zhang Kai
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(Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation, North China Electric Power University, Beijing 102206, China)
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Abstract: |
To reduce the greenhouse effect, effective measures should be taken to reduce the emissions of CO2. Amine-modified adsorbents are considered as important adsorbent materials to capture CO2. In this paper, a balance model was established to describe the adsorption isotherms of amine modified MCM-41 under low CO2 partial pressure and the thermodynamic parameters was calculated. The model was based on Dual-site Langmuir model and assumed that there were two independent adsorption mechanisms:chemical adsorption on amine groups and physical adsorption via surface area. In order to distinguish the physical adsorption and chemical adsorption of amine modified adsorbents, a new method based on adsorption of non-modified adsorbents and surface area was proposed. The results showed that the model could fit well with the measured adsorption isotherms. The calculated physical and chemical adsorption heats are -25.4 kJ/mol and -41.9 kJ/mol respectively, the total adsorption heats is -67.3 kJ/mol, which were in accordance with the experimental data. The saturation adsorption capacity of MCM-41-TEPA could reach 7.79 mmol/g. |
Key words: amine-modified MCM-41 low CO2 partial pressure CO2 adsorption thermodynamic |