CO2 capture over amine-functionalized MCM-22, MCM-36 and ITQ-2
CO2 capture over amine-functionalized MCM-22, MCM-36 and ITQ-2
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DOI：
10.1016/j.fuel.2012.03.034
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发表时间：
2012-07
期刊：
影响因子：
7.4
通讯作者：
Seung-Tae Yang;Jiyoung Kim;Jun Kim;W. Ahn
中科院分区：
文献类型：
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作者：
Seung-Tae Yang;Jiyoung Kim;Jun Kim;W. Ahn
合成了MCM-22及其相关结构MCM-36和ITQ-2，以及铁取代的MCM-22(Fe-MCM-22)。用元素分析(EA)测定了接枝胺的量，用X射线衍射仪、扫描电子显微镜和比表面积测定了沸石样品的相应性能。得到了273、298和303K时沸石对CO2的吸附等温线，并用Clausius-Clapeyron方程估算了相应的吸附热。298K时吸附CO2的大小顺序为：MCM-22(2.09)>；NH2-ITQ-2(1.73)>；ITQ-2(1.64)>；NH2-MCM-22(1.52)>；MCM-36(1.32)>；NH2-MCM-36(1.20)>；Fe-MCM-22(1.20 mmol/g)。对于无胺接枝的沸石，铝含量是决定吸附容量的主要因素。由于Fe-MCM-22的比表面积较小，导致其对CO2的吸附较低。胺在沸石上的接枝通常会提高CO2/N2的选择性，增加CO2的吸附热，但降低了CO2的捕集能力。在固定床穿透曲线分析中，NH_2-ITQ-2表现出极高的CO_2/N_2选择性(10.8)和最佳的分离能力(0.88 mmol/g)。在流动体系中用热重分析法考察了样品对CO2的循环吸附-脱附性能，发现样品表现出稳定的循环运行。
MCM-22 and its related structures MCM-36 and ITQ-2, as well as Fe-substituted MCM-22 (Fe-MCM-22), were synthesized and evaluated collectively as a CO2capturing agent with or without post-synthesis amine (NH2)-functionalization. The amount of the grafted amine was measured by elemental analysis (EA), and the corresponding properties of the zeolite samples were examined by XRD, SEM, and BET surface area measurement. CO2adsorption isotherms of the zeolites were obtained at 273, 298, and 303K, and the corresponding heats of adsorption were estimated by the Clausius–Clapeyron equation. CO2adsorption capacity varied in the sequence of MCM-22 (2.09)>NH2-ITQ-2 (1.73)>ITQ-2 (1.64)>NH2-MCM-22 (1.52)>MCM-36 (1.32)>NH2-MCM-36 (1.20)>Fe-MCM-22 (1.20mmol/g) at 298K. For the zeolites without amine-grafting, aluminum content was the governing factor determining the adsorption capacity. Fe-MCM-22 resulted in low CO2adsorption due to its low surface area. Amine-grafting on zeolites in general resulted in an enhancement in CO2/N2selectivity and increased heats of CO2adsorption at the expense of reduction in CO2capture capacity. NH2-ITQ-2 showed exceptionally high CO2/N2selectivity (10.8) accompanied by the best separation capacity (0.88mmol/g) among the samples in the fixed bed breakthrough curve analyses. Cyclic CO2adsorption–desorption performance of the samples were examined by TGA in a flow system, and were found to exhibit stable cyclic runs.