Tuning Crystal Structure for Enhancement of CO2 Selectivity in Clathrate Hydrates

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05594
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34030:Green sustainable chemistry and environmental chemistry-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Jin Yusuke 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 研究グループ長 (30462857)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ゲストホスト相互作用 / ガス分離 / 二酸化炭素

Outline of Final Research Achievements

In order to enhance the selectivity of carbon dioxide (CO2) separation using structure H clathrate hydrates (sH hydrates), we successfully discovered five novel help molecules that can form sH hydrates. Through crystallographic structure analysis using powder X-ray diffraction (PXRD) measurements, we elucidated the relationship between the shape of the help molecules and the crystal structure (size) of the sH hydrates. These findings provided insights into the variation of the lattice parameter along the c-axis of the crystal structure in relation to the length of the help molecules.
By comparing the crystals of structure H hydrates generated from 12 LMGS compounds, including the previously reported help molecules, we achieved an improvement in the carbon dioxide selectivity of the sH hydrates by utilizing help molecules that result in larger crystal sizes.

Free Research Field

分子分光学、結晶学

Academic Significance and Societal Importance of the Research Achievements

ハイドレートは水によって形成される包接化合物で環境負荷が少なく、温度や圧力でゲスト分子の包接と放出をのコントロールできるため環境低負荷な二酸化炭素分離材としての期待が大きい。本研究を通じて明らかとなったヘルプ分子の形状と結晶構造の関係性は、ハイドレートがどのようにゲスト分子を包接するかというハイドレートのゲスト分子の選択性の解明の一助となるだけでなく、我が国の排出二酸化炭素削減に向けて、高効率な二酸化炭素分離材の開発に向けての貢献が期待できる。