CO2 Adsorption on Premodified Li/AI Hydrotalcite Impregnated with Polyethylenimine
CO2 Adsorption on Premodified Li/AI Hydrotalcite Impregnated with Polyethylenimine
复制标题
聚乙烯亚胺浸渍预改性 Li/Al 水滑石的 CO2 吸附
DOI：
10.1021/acs.iecr.8b04775
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发表时间：
2019-01-23
影响因子：
4.2
通讯作者：
Liang, Zhiwu
中科院分区：
文献类型：
--
作者：
Chen, Shu Panxiang;Sun, Xiaoyu;Liang, Zhiwu
在本研究中，Li/Al水滑石（HT）经过煅烧和羟基乙醇钾处理形成bcHT（碱性改性煅烧水滑石）。然后对这种材料进行聚乙烯亚胺 (PEI) 功能化，以创建一种具有超低能耗的新型吸附剂。采用多种方法对吸附剂进行表征，包括 N-2 吸附脱附、傅里叶变换红外光谱、X 射线衍射和扫描电子显微镜。 CO2 吸附容量受 PEI 负载量和吸附温度的影响，通过 CO2 吸附等温线和循环 CO2 吸附脱附性能进行评估。结果表明，当操作温度为323 K、PEI负载量为40%时，最佳CO2吸附容量为1.723 mmol/g。应用Freundlich模型与实验数据提供最佳相关性，相关系数达到0.997。 CO2吸附的平均等量热经计算为67.492 kJ/mol。根据Amenomiya方程计算出解吸能耗相对较低，为63.20 kJ/mol。应用四种动力学模型来分析PEI功能化bcHT的动力学，Avrami分数阶模型和DEM模型都很好地拟合了实验数据。根据Avrami分数阶模型计算得到的bcHT-PEI-40%的活化能为30.34 kJ/mol，明显低于传统胺溶液吸附CO2的活化能为30.34 kJ/mol。
In this study, Li/Al hydrotalcite (HT) was treated with calcination and potassium hydroxyl-ethanol to form bcHT (basic-modified calcined hydrotalcite). This material was then polyethylenimine (PEI)-functionalized to create a new sorbent that has ultralow energy consumption. Various methods were applied to characterize the sorbent, including N-2 adsorption desorption, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. CO2 adsorption capacity, which was affected by PEI loadings and adsorption temperatures, was assessed with the CO2 adsorption isotherms and cyclic CO2 adsorption desorption performance. Results showed that the optimal CO2 adsorption capacity of 1.723 mmol/g was reached when operating with temperature of 323 K and PEI loading of 40%. The Freundlich model was applied to provide optimal correlations with the experimental data, and the correlation coefficients reached 0.997. The average isosteric heat of CO2 adsorption was calculated to be 67.492 kJ/mol. The relatively low desorption energy consumption was calculated to be 63.20 kJ/mol with the Amenomiya equation. Four kinetic models were applied to analyze the kinetics of PEI-functionalized bcHT, and both the Avrami's fractional order model and DEM model were well fitted to the experimental data. The activation energy of the bcHT-PEI-40% was 30.34 kJ/mol calculated by the Avrami's fractional order model, which is obviously lower than the values of the CO2 adsorption with traditional amine solution.