Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation

详细信息    查看全文

• 作者：Ting Wu ; Xuhui Feng ; Sameh K. Elsaidi ; Praveen K. Thallapally ; Moises A. Carreon
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2017
• 出版时间：February 15, 2017
• 年：2017
• 卷：56
• 期：6
• 页码：1682-1686
• 全文大小：344K
• ISSN：1520-5045

文摘

Herein, we demonstrate that a prototypical type of metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), in membrane form, can effectively separate Kr/Xe gas mixtures at industrially relevant compositions. The best membranes separated Kr/Xe mixtures with average Kr permeances as high as 1.5 × 10^–8 ± 0.2 mol/m² s Pa and average separation selectivities of 14.2 ± 1.9 for molar feed compositions corresponding to Kr/Xe ratio encountered typically in air. Molecular sieving, competitive adsorption, and differences in diffusivities were identified as the prevailing separation mechanisms. These membranes potentially represent a less-energy-intensive alternative to cryogenic distillation, which is the benchmark technology used to separate this challenging gas mixture. To our best knowledge, this is the first example of any metal organic membrane composition displaying separation ability for Kr/Xe gas mixtures.