Butanol Separation from Humid CO₂-Containing Multicomponent Vapor Mixtures by Zeolitic Imidazolate Frameworks [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 668.5 Perfumes and cosmetics
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2017
• Mô tả vật lý: Size: p. 9467-9476 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 263215
• Chủ đề: 1. 09 biomass fuels; 2. 37 inorganic, organic, physical, and analytical chemistry; 3. Catalysis (heterogeneous); 4. Defects; 5. Membrane

Tóm tắt

 Butanol is a promising renewable fuel and feedstock. A major challenge in fermentative butanol production is to find a cost-effective butanol separation process from dilute aqueous solutions, usually an acetone-butanol-ethanol (ABE) mixture. Nanoporous zeolitic imidazolate frameworks (ZIFs) have shown potential for alcohol separation from dilute solutions. However, little is known about butanol separation from multicomponent mixtures using ZIFs, including the effects of the humid acid gas (CO<
 sub>
 2<
 /sub>
 ) used to sparge the fermenter and generate the vapor product stream. We present a study of butanol separation by ZIF-8, ZIF-90, ZIF-71 and hybrid ZIF-8?90 and ZIF-8?71 adsorbents with binary butanol/water and multicomponent ABE feeds. To obtain reliable structure?property relations for ZIF adsorbents in realistic conditions, we combine multicomponent vapor breakthrough with structural, textural, and stability characterization techniques in humid CO<
 sub>
 2<
 /sub>
  environments. In the absence of CO<
 sub>
 2<
 /sub>
 , more hydrophobic materials such as ZIF-8, ZIF-8<
 sub>
 55<
 /sub>
 -71<
 sub>
 45<
 /sub>
 , ZIF-8<
 sub>
 70<
 /sub>
 -90<
 sub>
 30<
 /sub>
 , and ZIF-71 are found to be excellent candidates with butanol/water selectivities >
 10 and butanol capacities >
 3.5 mmol/g. However, in the presence of humid CO<
 sub>
 2<
 /sub>
 , all the materials except ZIF-71 are found to degrade. The mechanistic aspects of this degradation are studied by FTIR spectroscopy and explained based upon acid gas attack of Zn?N coordinate bonds. ZIF-71 emerges as an excellent candidate owing to its acid gas stability, good butanol adsorption capacity, and selectivity. Vapor breakthrough with a model ABE solution demonstrates the high butanol selectivity of ZIF-71 relative to acetone, ethanol, and water and the recovery of a 65 mol % butanol product by desorption at 453 K. Finally, this study highlights the importance of determining structure?property relationships of MOF/ZIF materials in realistic multicomponent conditions, and the importance of acid gas stability in their applications.