Production of membranes for the separation of CO2 from flues gas and experimental characterization of their properties

The continuous rise in carbon dioxide emissions from industrial operations and power generation is a major contributor to global climate change. Therefore, effective carbon capture technologies are essential to reduce greenhouse gas emissions and their environmental impact. Among the available gas separation methods, membrane-based technologies have gained considerable attention. Facilitated transport membranes are particularly promising because they can overcome the common trade-off between permeability and selectivity found in conventional polymeric membranes. This study investigates the development and performance of nanocellulose-based facilitated transport membranes for separating CO₂ from nitrogen, simulating post-combustion flue gas conditions. Two membranes were prepared using nano-fibrillated cellulose (NFC) and a proprietary polymer matrix (Polymer-A). The first membrane, Ms-S01, contained only NFC and Polymer-A, while the second membrane, Ms-S02, included 17% L-arginine as a FTM to improve CO₂ selectivity. The influence of key operating parameters was studied, including RH: 30–50% and 85%, T: 35–50 °C, and feed gas composition (15% and 25% CO₂ balanced with N₂). Results showed that humidity strongly activates the facilitated transport mechanism. The L-arginine membrane exhibited significantly higher CO₂ permeability and selectivity under humid conditions, reaching values near 60 barrer at 35 °C. In contrast, the membrane without L-arginine showed lower and less stable performance. Temperature increases reduced water retention, weakening the facilitated transport mechanism. Feed gas composition also affected permeability and selectivity, highlighting the importance of optimized operating conditions. Overall, incorporating L-arginine significantly improved the CO₂ separation performance of nanocellulose-based membranes, demonstrating their potential for efficient post-combustion carbon capture applications.