Ion-Exchanged SAPO-34 membranes for Krypton-Xenon Separation: Control of Permeation Properties and Fabrication of Hollow Fiber Membranes

Journal Article · 29 January 2018 · ACS Applied Materials and Interfaces

DOI: https://doi.org/10.1021/acsami.7b18244 · OSTI ID:1418424

Kwon, Yeon Hye ^[1]; Min, Byunghyun ^[1]; Yang, Shaowei ^[1]; Koh, Dong -Yeun ^[1]; Bhave, Ramesh R. ^[2]; Nair, Sankar ^[1]

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1. Georgia Inst. of Technology, Atlanta, GA (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Separation of radioisotope ⁸⁵Kr from ¹³⁶Xe is of importance in used nuclear fuel reprocessing. Membrane separation based on zeolite molecular sieves such as chabazite SAPO- 34 is an attractive alternative to energy-intensive cryogenic distillation. We report the synthesis of SAPO-34 membranes with considerably enhanced performance, via thickness reduction based upon control of a steam-assisted vapor-solid conversion technique followed by ion exchange with alkali metal cations. The reduction of membrane thickness leads to a large increase in Kr permeance from 7.5 gas permeation units (GPU) to 26.3 GPU with ideal Kr/Xe selectivities > 20 at 298 K. Cation-exchanged membranes show large (>50%) increases in selectivity at ambient or slight sub-ambient conditions. The adsorption, diffusion, and permeation characteristics of ionexchanged SAPO-34 materials and membranes are investigated in detail, with potassium exchanged SAPO-34 membranes showing particularly attractive performance. Lastly, we then demonstrate the fabrication of selective SAPO-34 membranes on α-alumina hollow fibers.

• Research Organization: Georgia Institute of Technology, Atlanta, GA (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: NE0008298
• OSTI ID: 1418424
• Journal Information: ACS Applied Materials and Interfaces, Vol. 10, Issue 7; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English