ゼオライト系ハイブリッド膜による炭素回収：材料開発から産業実装まで

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

🔬研究者:膜材料設計と実プロセス条件評価を統合する研究手法の指針が得られる。

🏢実務担当者:セメント・鉄鋼・化学など自社排出源への膜分離導入の実現性評価に活用できる。

🏛政策担当者:CCUS産業化支援策や脱炭素技術ロードマップの設計に示唆を与える。

Rising atmospheric CO₂ concentrations are a major driver of climate change. Carbon capture is therefore considered essential for achieving net-zero emissions, particularly for hard-to-abate industries such as cement, steel, and chemicals. Although conventional CO₂ separation technologies such as amine absorption and cryogenic distillation are effective, their high energy demand and operational costs motivate the development of alternative approaches. Membrane technology offers several advantages, including low energy consumption, a compact footprint, modularity, and no waste stream. However, improvements in membrane performance and scalability remain necessary for large-scale implementation. The origin of this thesis lies in previous research highlighting the potential of mixed-matrix membranes (MMMs) based on CHA-type zeolite for CO₂/N₂ and CO₂/CH₄ separations. Consequently, upscaling these membranes became of interest, yet it posed multiple challenges. As a result, this thesis investigated the development and industrial translation of zeolite-based mixed-matrix membranes (MMMs) to thin-film nanocomposite (TFN) membranes for CO₂ separation. The objective was to establish both a fundamental understanding, practical guidelines, and preparation for upscaling for carbon capture. First, a systematic protocol was developed for preparing highly loaded (50 wt%) zeolite-based MMMs using SSZ-13, a CHA-type zeolite. Several glassy polymers with different glass transition temperatures were evaluated to determine whether a lower glass transition temperature, associated with lower polymer rigidity, could reduce the need for intensive thermal annealing commonly used to mitigate membrane defects. The results revealed that the effect of thermal treatment is strongly dependent on the polymer. While thermal annealing improved the separation performance of Matrimid- and polysulfone-based MMMs, it was detrimental to cellulose acetate-based systems. Contrary to the common assumption that zeolite transport dominates at high filler loadings, the polymer matrix remained a significant contributor to membrane performance. These findings highlight the importance of polymer-specific optimization strategies in MMM development. The influence of zeolite topology and Si/Al ratio was subsequently investigated under both ideal and industrially relevant conditions. SSZ-13 (CHA-type, 8-MR) with lower and higher Si/Al ratio and NaY (FAU-type, 12-MR) zeolites were selected as fillers. Whereas CHA-type zeolites combine strong diffusivity selectivity and selective CO₂ solubility, FAU-type zeolites primarily depend on solubility selectivity within their larger pore structure. Exposure to H₂S, SO₂, and H₂O significantly altered membrane performance, with water vapor causing the greatest losses. Membrane susceptibility to impurities was governed by both impurity adsorption strength and the dominant transport mechanism. These results demonstrate that membrane materials should be evaluated under realistic process conditions from an early stage of development. To facilitate industrial translation, a lab-scale kiss-coating setup was developed for preparing thin-film composite (TFC) membranes. Kiss-coating proved to be a simple, versatile, and material-efficient technique that is more compatible with future roll-to-roll manufacturing. Systematic investigation of coating parameters revealed strong dependencies on polymer concentration, withdrawal speed, and solvent properties. Film formation exhibited clear transitions between evaporation-controlled and entrainment-controlled coating regimes, providing practical guidelines for the reproducible preparation of defect-free thin selective layers. Finally, insights obtained from MMM optimization and kiss-coating were integrated into the preparation of high-loading SSZ-13-based TFN membranes. A substantial portion of the separation performance achieved in free-standing MMMs could be translated to the thin-film configuration, although imperfections persisted. Nevertheless, the TFNs achieved attractive combinations of permeance and selectivity, highlighting the potential of zeolite-based nanocomposite membranes for next-generation carbon capture applications. Overall, this thesis demonstrates that successful membrane development for carbon capture requires an integrated approach combining material design, process optimization, and realistic performance evaluation. By addressing challenges related to MMM preparation, impurity resistance, scalable coating technology, and thin-film nanocomposite preparation, this work helps bridge the gap between lab-scale membrane research and industrial carbon capture implementation. Together, these findings support the continued development of membrane technology for a low-carbon future.

• openalex https://lirias.kuleuven.be/handle/20.500.12942/795852first seen 2026-11-10 04:41:50 · last seen 2026-11-14 04:44:10