高级检索

CH4/N2在Zr-MOFs上的吸附分离研究

Adsorption-separation research of CH4/N2 on Zr-MOFs

  • 摘要: 以H4L为配体,与金属离子Zr4+自组装得到棒状晶体Zr基金属有机框架材料(Zr-MOFs),并借助X射线单晶衍射、N2吸附脱附、X射线粉末衍射、热重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Ideal Adsorbed Solution Theory(IAST)理论来计算CH4/N2的分离因子(SCH4/N2)。结果表明:在273 K、0.1 MPa时,晶体Zr-MOFs对CH4有较好的吸附效果,吸附量为8.2 cm3/g,对CH4/N2的选择性分离因子(S)为6.3,且具有较好的分离效果;对吸附热力学的研究表明,CH4的吸附热在20 kJ/mol左右,相对分子筛类吸附剂吸附热较小,易于吸附剂的再生。

     

    Abstract: Using ligands containing methyl and carboxylic acid H4L self-assemblyed with Zr4+, the rod-like crystals Zr-MOFs is gotten and characterized by X-ray single crystal diffraction, N2 adsorption, X-ray powder diffraction to analyze the structure. Adsorption isotherms of CH4/N2 are measured by adsorption instrument. The Clausius-Clapeyron equation is used to calculate the adsorption heat of CH4. The separation coefficient of CH4/N2 is calculated from the Ideal Adsorbed Solution Theory(IAST). The results show that Zr-MOFs has good adsorption effect on methane which is about 8.2 cm3/g at 273 K and 0.1 MPa, and the selectivity factor of CH4/N2 is 6.3 which means a better separation result. The isosteric heat of adsorption of CH4 is about 20 kJ/mol. Compared with other zeolite-like adsorbents, the isosteric heat of adsorption is lower, which means an easier regeneration.

     

/

返回文章
返回