Development of efficient carbon dioxide capture with acoustic waves by a thermoacoustic engine

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03874
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Toyohashi University of Technology
• Principal Investigator: YOKOYAMA HIROSHI 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (60581428)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 二酸化炭素分離回収 / 物理吸着 / ゼオライト / 音響共鳴 / 音響加振 / 流体制御

Outline of Final Research Achievements

The effects of acoustic excitation on CO2 physisorption were investigated using a monolith coated with zeolite. The monolith was placed in a flow duct, where acoustic resonance occurred due to acoustic excitation by speakers. The adsorption was promoted by acoustic excitation, and the promotion was intensified when the monolith was placed at the anti-node of the velocity fluctuations. The high velocity profiles downstream of the monolith occurred periodically under acoustic excitation. Moreover, the effects of acoustic excitation on the CO2 concentration field in a planar jet comprising a CO2 + N2 gas mixture were investigated using a background-oriented Schlieren method. The CO2 concentration around the jet exit was indicated to become periodically larger compared with the baseline case without sound. This indicates the possibility of enhanced CO2 concentration in the monolith with acoustic excitation, which can contribute to promotion of CO2 adsorption.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

工場や発電所ではCO2排出量の削減が求められており, 排出ガス中のCO2を吸着し回収する手法が着目されている．吸着方法の一つにファンデルワールス力を利用した物理吸着があるが，実用化のためには吸着速度や回収率の改善が必要と考えられる．
本研究により音響加振を用いた制御がCO2物理吸着を促進可能であることが示された．さらに，吸着促進に適切な音響加振条件が明らかになり，今後CO2分離回収技術の確立に貢献する研究成果を得たと考えられ, 社会的意義は大きい．また，研究の中で得られたBOS法を用いた濃度場分析技術は種々の濃度場の分析に活用可能であり学術的意義も大きい．