表題番号：2025C-469
日付：2026/03/21
研究課題アミン系固体吸収材を用いた二酸化炭素直接空気回収技術における新規熱回収方法の開発
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 理工学術院 創造理工学部 | 助教 | 磯谷 浩孝 |
- 研究成果概要
- A cost- and energy-efficient direct air capture (DAC) process is essential for large-scale CO2 removal. Among mature DAC technologies, steam-assisted temperature vacuum swing adsorption (S-TVSA) is one of the most promising technologies. In this study, we proposed a novel multistage steam recovery process for CO2 DAC based on S-TVSA using amine-functionalized solid sorbents. In this process, reactor pressurization via steam and subsequent depressurization to promote water evaporation and sorbent cooling (evaporation cooling) are performed in multiple stages. Outflow gases from each evaporation-cooling stage, predominantly composed of water vapor, are spontaneously transferred to the corresponding steam-pressurization stage. This stepwise pressure-swing configuration enables a wider pressure swing range compared to the best available technology (BAT), namely the single-stage steam recovery process. As a result, greater amounts of gas and heat can be exchanged between reactor modules, reducing energy consumption. First, we developed an unsteady S-TVSA process simulation model using MATLAB software and performed a trace-based validation based on existing literature. Then, a numerical proof-of-concept was conducted using the process simulations coupled with rigorous multi-objective optimization. The results indicated that compared to the single-stage process, the multistage configuration enhances recovery of solid sensible heat through enhanced coupling with H2O evaporation during evaporation cooling. Approximately 90% of the solid sensible heat can be internally recovered, which is significantly higher than that achieved with BAT (~50%), resulting in approximately 20% lower specific energy consumption. Overall, the proposed concept establishes a thermodynamically improved, phase-change-mediated strategy for internal heat recovery between solid phases, addressing the long-standing challenge of solid sensible heat recovery in TSA processes. Beyond DAC, this approach is broadly applicable and offers significant potential for energy savings in sorbent-based separation systems. Patent applications for these achievements were completed domestically in July 2025. Aiming for future overseas rights acquisition, an application was submitted in January 2026 to the Japan Science and Technology Agency (JST)'s "Intellectual Property Utilization Support Program". Furthermore, in October 2025, an invited lecture was delivered at the Annual Meeting 2025 of The Society of Separation Process Engineers, Japan (SSPEJ), held at Nihon University in Tokyo, presenting part of these results. These results were also presented at the 91st Annual Meeting of the Society of Chemical Engineers, Japan (SCEJ), held at Kyoto University in March 2026. Additionally, submission of an academic paper detailing these results has been completed, and it is currently undergoing peer review.