金属有机框架材料HKUST-1吸附分离CH4/N2性能研究

摘要

以均苯三甲酸为配体,与金属离子Cu2 +自组装得到稳定的金属有机框架材料(HKUST-1),并借助N2吸附-脱附、X射线粉末衍射、热重、SEM等对其结构进行表征,利用气体吸附仪测量了 CH4和 N2的吸附等温线,采用克-克(Clausius-Clapeyron)方程计算CH4的吸附热,并运用理想吸附溶液理论(IAST)来计算 HKUST-1对 CH4/N2的分离因子.结果表明:在0 ℃、101. 325 kPa和25 ℃、101. 325 kPa的条件下,HKUST-1的CH4吸附量分别为25. 1 cm3/g和15.2 cm3/g, N2吸附量分别为8. 0 cm3/g和3. 9 cm3/g,所制备的 HKUST-1对CH4具有较好的吸附效果;HKUST-1对CH4/N2的选择性分离因子为6. 8,对CH4/N2具有很好的分离效果;HKUST-1对CH4的吸附热为20 kJ/mol 左右,与分子筛类吸附剂相比吸附热较小,易于再生.%The HKUST-1 was obtained using trimesic acid self-assembly with Cu2+and character-ized by N2adsorption,X-ray powder diffraction,TGA and SEM. Adsorption values of CH4and N2were measured by gas adsorption instrument. The Clausius-Clapeyron equation was used to calculate the ad-sorption heat of CH4. The separation coefficient of CH4/N2(SCH4/N2)was calculated by Ideal Adsorbed Solution Theory(IAST). The results showed that HKUST-1 has a good adsorption effect on CH4. At conditions of 0 ℃,101. 325 kPa and 25 ℃,101. 325 kPa,the adsorption values of CH4are 25. 1 cm3/g and 1 5. 2 cm3/g,the adsorption values of N2are 8. 0 cm3/g and 3. 9 cm3/g,respectively. The selectivity factor for CH4/N2is 6. 8,and the isosteric heat of adsorption of CH4is about 20 kJ/mol. Compared with zeolite-like adsorbents,the isosteric heat was smaller,which meant a facile regeneration of adsorbents.