Development of solute separation system from ionic liquid using supercritical carbon dioxide

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05547
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34020:Analytical chemistry-related
• Research Institution: Ibaraki University
• Principal Investigator: Ohashi Akira 茨城大学, 理工学研究科(理学野), 教授 (50344833)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 溶媒抽出 / 分離化学 / イオン液体 / 超臨界二酸化炭素 / 溶媒和 / 分配定数

Outline of Final Research Achievements

In this study, supercritical carbon dioxide (SC-CO2)/ionic liquid (IL) extraction was investigated from the viewpoint of CO2 density. It was found that CO2 dissolution into IL had no effect on partition behavior. The dissolution states of solutes in the SC-CO2 phase estimated from CO2 solvation showed almost the same behavior in water and IL. In addition, IL-specific behavior was also observed, suggesting the possibility of solute-IL association formation. From the three-dimensional plot, we investigated the distribution behavior also thermodynamically. These fundamental studies on SC-CO2/IL partitioning behavior are expected to be applied to improve efficiency and selectivity in SC-CO2/IL extraction of metallic elements in the future.

Free Research Field

分析化学

Academic Significance and Societal Importance of the Research Achievements

イオン液体から溶質を回収する媒体として超臨界二酸化炭素(SC-CO2)に注目した．SC-CO2を抽出媒体として用いることができれば，環境調和型のイオン液体からの溶質回収法として非常に有用な方法となると考えられる．本研究では，まず基礎的検討としてSC-CO2の温度や圧力を変化させ，CO2密度変化が溶質のSC-CO2/イオン液体間分配挙動に及ぼす影響を詳細に検討した．また，溶質やイオン液体の種類によって生じる分配挙動の変化を明らかにした．得られた結果は金属元素のSC-CO2/IL抽出における効率性及び選択性の向上への利用が期待される．