Intensified direct air capture of CO2 by integrating a tailor-made water-lean absorbent with high-gravity technology

[Geoengineering News]

https://www.sciencedirect.com/science/article/abs/pii/S2213343726009462

Authors: Zexiang Gao, Kerui Li, Wangxin Jian, Hao Qin, Youzhi Liu, Weizhou Jiao

26 February 2026

https://doi.org/10.1016/j.jece.2026.121972

Highlights

●New water-lean absorbent (MEA:EG:H2O) is tailor-made for direct air capture of CO2.

●Regeneration energy consumption is markedly lower than the conventional absorbent.

●High-gravity technology is adopted to dramatically intensify the absorption process.

●Experiments and DFT reveal synergistic molecular interactions to promote absorption.

Abstract

The acceleration of global industrialization has sharply increased CO2 emissions, highlighting the urgent need for efficient and energy-saving carbon capture technology. Direct air capture (DAC) has emerged as a pivotal negative-emission strategy for advancing decarbonization within the chemical industry. However, conventional DAC absorption processes are hindered by high solvent regeneration energy, low mass-transfer efficiency, and large equipment size. To address these challenges, an innovative DAC strategy that integrates high-gravity technology with a tailor-made water-lean absorbent is proposed. The absorbent, composed of ethanolamine (MEA), ethylene glycol (EG), and water, exhibits high CO2 absorption capacity and reduces regeneration energy consumption compared with aqueous MEA solutions. A rotating packed bed (RPB) is employed to intensify the DAC process, and the effects of high-gravity factor and liquid flow rate are systematically investigated. The results demonstrate that high-gravity operation significantly enhances CO2 absorption, with the CO2 uptake reaching approximately four times that of conventional absorption conditions. The CO2 capture mechanism is elucidated using FT-IR, 13C NMR, and reduced density gradient analysis, which reveal that MEA chemically reacts with CO2, while additional vdW interactions occur among CO2, MEA, and EG. Overall, the integration of a high-performance water-lean absorbent with high-gravity technology substantially improves CO2 capture efficiency while reducing energy consumption, offering a promising and scalable pathway for the practical deployment of DAC.

Source: ScienceDirect