連続ボールミリング下でのCO2回収に向けたMgOの(反応)活性向上

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:メカノケミカル活性化がMgOのCO2吸着速度と容量を大幅に改善することを示し、固体吸着材設計の新たな方向性を提供する。

🏢実務担当者:排出集約型産業において、既存のアミン吸収法に代わる省エネルギー型CO2回収技術の可能性を示すが、実装にはスケールアップ検証が必要。

🏛政策担当者:CCUS技術の実用化に向けた研究開発支援の根拠となり、産業脱炭素化ロードマップにおける固体吸着材の位置づけを強化する。

Abstract Carbon capture and storage from point emission sources is a crucial technology able to mitigate the progress of climate change by slowing down the emission of greenhouse gases. Current technologies, such as amine scrubbing and calcium looping, face challenges including high energy consumption and limited efficiency under humid conditions. Magnesium oxide (MgO) is a promising CO2 sorbent due to its lower decarboxylation enthalpy compared to calcium oxide, but its practical use is hindered by slow CO2 uptake kinetics and the formation of a passivating carbonate layer that inhibits further CO2 diffusion. While synthetic methods have improved MgO surface area, scalability remains an issue. This study addresses the kinetic limitations of MgO by investigating how continuous ball milling can reduce the performance hindrance from the passivating-carbonate layer on MgO and enhance CO2 uptake under industrially relevant conditions. Here we show that continuous ball milling of MgO under a CO2 atmosphere significantly increases its CO2 uptake capacity. Unlike conventional approaches that rely on presynthesized high-surface-area MgO, our results demonstrate that ball milling during the sorption step does not only increase the specific surface area of MgO but also actively enhances its CO2 capture performance, with a 6-fold increase in adsorption capacity compared to static exposure. The addition of water further boosts performance, doubling uptake under simulated flue gas conditions (10% CO2, 40 °C), likely due to the formation of bicarbonates and hydroxycarbonates. The performance stability of MgO under continuous milling and moisture conditions was evaluated in several sorption-regeneration cycles, showing consistent CO2 uptake over ten cycles with an average sorption capacity of 17.4 wt %. Structural analyses reveal that carbonation proceeds via magnesium hydroxycarbonate species, which fully decompose upon regeneration, preserving sorbent stability over ten cycles. This study underscores the practical relevance of mechanochemical activation for enhancing the capture capacity of MgO, offering a promising approach for industrial point-source CO2 capture applications.

• openalex https://doi.org/10.1021/acs.chemmater.6c01597first seen 2026-10-10 05:10:32