Evaluation of Hydrogen Isotope Separation Property of Zeolites with 8-Membered Ring

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K06935
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: University of Toyama
• Principal Investigator: Taguchi Akira 富山大学, 学術研究部理学系, 講師 (40401799)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: ゼオライト / 吸着 / 同位体分離 / トリチウム

Outline of Final Research Achievements

The CHA type zeolite with potassium (K+) as counter cation was prepared by the hydrothermal conversion method from a mixture of H-Y zeolite (FAU) and KOH aqueous solution. X-ray diffraction studies revealed that K-CHA was successfully synthesized. Subsequently, K-CHA was ion-exchanged with Na+ or Ca2+ using aqueous solution of NaOH or Ca(OH)2, respectively.
Using H2 and D2 single- and mixed-gases, the sorption ability over K-CHA, Na-CHA and Ca-CHA as well as LTA(3A) and FAU, at 77, 201 and 250 K was investigated. The order of pore diameter was found as to FAU > Ca-CHA > (K-CHA, Na-CHA and LTA(3A)). The adsorption amounts of D2 over zeolites were larger than that of H2 at the sorption temperature studied. Higher the sorption temperature, the CHA-type zeolite with smaller crystallographic pore became superior in D2/H2 selectivity rather than LTA(3A) or FAU, suggesting the pore size dependence for hydrogen isotope separation.

Free Research Field

多孔体材料

Academic Significance and Societal Importance of the Research Achievements

重水素，トリチウムの分離は，核融合炉燃料サイクルにおけるトリチウムの分離，精製のほか，高純度水素やD2の生産による医療分野への貢献，あるいは今後大量に生産，消費される「水素社会」の水素ガスから重水素，トリチウム成分の回収などへの応用が期待できる。水素同位体分離は低温ほど有利であるが，本研究ではH2，D2の吸脱着測定から201Kにおいて，CHA型ゼオライトが水素同位体の分離に有望であることを見いだした。