Development of alternative CFC separation or recovery technology using gas separation membrane

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H03641
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 64030:Environmental materials and recycle technology-related
• Research Institution: Nagaoka University of Technology
• Principal Investigator: Himeno Shuji 長岡技術科学大学, 工学研究科, 准教授 (60334695)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ゼオライト膜

Outline of Final Research Achievements

Difluoromethane (HFC32, R32), the most widely used CFC substitute, has a high global warming potential, and there is concern that it will be emitted in large quantities in the future.In particular, R32 is difficult to separate from air (N2 and O2) because its molecular size is extremely close to that of nitrogen (N2) and oxygen (O2) molecules.
In this study, we used a zeolite membrane that has pore sizes close to those of gas molecules, and can separate small molecules with high precision. Experiments were conducted to separate R-32 from air (nitrogen and oxygen mixed gas) using the Al-containing ZSM-58 membrane with a high separation coefficient.The concentration of R-32 in the permeate gas was significantly reduced.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

代替フロンR32の消費量は今後途上国で膨大に消費され、大量廃棄される事が懸念されている。日本においてもフロンの回収率は38％と低迷しており、R32の簡便かつ高精度な回収・再生技術により温暖化抑制を図る必要がある。本研究でZSM-58膜を用いてR32とN2の分離の可能性を示す結果を得た。さらに膜の性能が向上すればこれまで分離困難と考えられていた代替フロンを高純度に回収でき、他の分離系にも応用可能な再利用技術の開発に繋がる革新的な技術になる。