炭素回収向けLDH材料研究がパイロットプラント段階へ進展（From Nanosheets to Pilot Plants: Oxford-Shanghai Partnership Advances LDH Materials for Carbon Capture）

2026-08-13 上海交通大学（SJTU）

Figure 1. Opening LDH nanosheets for elevated-temperature CO₂ capture. Aqueous miscible organic solvent treatment separates stacked LDH layers and creates open, flower-like particles. Potassium modification then introduces additional active sites, producing higher CO₂ working capacities than conventional commercial potassium-modified LDHs at 400 °C.

＜関連情報＞

• https://global.sjtu.edu.cn/en/news-events/news/3379
• https://www.sciencedirect.com/science/article/abs/pii/S1385894724082731
• https://www.sciencedirect.com/science/article/abs/pii/S2095495624003607

層状複水酸化物のその場アミングラフト化によるCO2直接空気捕集用吸着剤性能の向上 Enhancing adsorbent performance for direct air capture of CO2 by in-situ amine-grafting of layered double hydroxides

Bingyao Ge, Chunping Chen, Yifei Xu, Samuel Roberts, Man Zhang, Qingyang Shao, Dermot O’Hare, Xuancan Zhu
Chemical Engineering Journal  Available online: 16 October 2024
DOI:https://doi.org/10.1016/j.cej.2024.156782

Highlight

• New in-situ amine grafting method based layered double hydroxide nanosheets for direct air capture.
• Doubles CO₂ adsorption capacity compared with traditional two-step grafting method.
• Maintains CO₂ capture capacity 0.85 mmol g⁻¹ at 70 °C desorption temperature without moisture.
• NMR confirms amine grafting matches traditional method’s chemical modification.
• In-situ adsorbent enables rapid adsorption and desorption with high stability and low cost in DAC conditions.

Abstract

The development of efficient and cost-effective CO₂ adsorbents is crucial for carbon capture from ultradilute conditions. Amine-grafted mesoporous materials prepared by silane chemical reactions are well-known CO₂ adsorbents with high thermal stabilities, but their capacities for direct air capture (DAC) are usually restricted by low amine loadings and CO₂ capture capacity. Herein, we present an in-situ amine grafting method that enables high amine loadings by in-situ grafting initial ultrathin LDHs nanosheets in an organic solvent. For in-situ triamine grafted Mg₂Al-CO₃ LDH (IN-TRI-LDH) amine loading is boosted to 5.91mmol N g⁻¹ and ultimately achieving a remarkable adsorption capacity of 0.98 mmol g⁻¹ at 25°C and 400 ppm CO₂, nearly double that of the amine-LDHs grafted through a conventional two-step process. A further 22 % enhancement of the CO₂ capacity is observed under 20 RH%. In addition, IN-TRI-LDH maintains a working capacity of 0.85 mmol g⁻¹ at a low desorption temperature of 70 °C. A 50 adsorption–desorption cyclic test under simulated humid DAC conditions shows minimal performance degradation. Such a sufficient working capacity and low desorption temperature reduces the thermal energy consumption to 2.27 GJ t⁻¹ at a desorption temperature of 40 °C.

CO2の直接空気捕捉のためのポリエチレンイミン官能化Mg-Al混合金属酸化物モノリスの3Dプリント 3D printing of poly(ethyleneimine)-functionalized Mg-Al mixed metal oxide monoliths for direct air capture of CO2

Qingyang Shao, Zhuozhen Gan, Bingyao Ge, Xuyi Liu, Chunping Chen, Dermot O’Hare, Xuancan Zhu
Journal of Energy Chemistry  Available online: 18 May 2024
DOI:https://doi.org/10.1016/j.jechem.2024.05.015

Abstract

Direct air capture (DAC) of CO₂ plays an indispensable role in achieving carbon-neutral goals as one of the key negative emission technologies. Since large air flows are required to capture the ultradilute CO₂ from the air, lab-synthesized adsorbents in powder form may cause unacceptable gas pressure drops and poor heat and mass transfer efficiencies. A structured adsorbent is essential for the implementation of gas-solid contactors for cost- and energy-efficient DAC systems. In this study, efficient adsorbent poly(ethyleneimine) (PEI)-functionalized Mg-Al-CO₃ layered double hydroxide (LDH)-derived mixed metal oxides (MMOs) are three-dimensional (3D) printed into monoliths for the first time with more than 90% adsorbent loadings. The printing process has been optimized by initially printing the LDH powder into monoliths followed by calcination into MMO monoliths. This structure exhibits a 32.7% higher specific surface area and a 46.1% higher pore volume, as compared to the direct printing of the MMO powder into a monolith. After impregnation of PEI, the monolith demonstrates a large adsorption capacity (1.82 mmol/g) and fast kinetics (0.7 mmol/g/h) using a CO₂ feed gas at 400 ppm at 25 °C, one of the highest values among the shaped DAC adsorbents. Smearing of the amino-polymers during the post-printing process affects the diffusion of CO₂, resulting in slower adsorption kinetics of pre-impregnation monoliths compared to post-impregnation monoliths. The optimal PEI/MeOH ratio for the post-impregnation solution prevents pores clogging that would affect both adsorption capacity and kinetics.