(449as) Nanocellulose Based Facilitated Transport Membranes for CO2 Separation

A new type of facilitated transport membranes, based on Microfibrillated Cellulose (MFC), have been investigated for CO₂ separation applications. In particular, the films were obtained by mixing an aqueous suspension of MFC with Lupamin (a Polyvinylamine produced by BASF), exploring different solid contents and concentrations.

The permeability of CO₂, CH₄ and N₂ was measured at 35 °C as a function of relative humidity. Water sorption experiments were also performed, allowing a better understanding of the permeability results with respect to the actual water content within the membrane. As a reference, pure MFC films have been also prepared and their gas permeability tested in the same conditions.

The overall results suggest that both MFC and MFC/PVAm films have really interesting performances for both the CO₂/CH₄ and CO₂/N₂ separations, showing very high selectivity values (higher than 400) and placing most materials well above the trade-off curve of 2008 Robesonâ??s plot.

MFC films showed higher selectivity but lower CO₂ permeability with respect to the MFC-Lupamin blends, likely because of the different level of water absorbed by the two polymeric matrixes. Indeed, pure MFC never exceeded 10 %wt water uptake, while the Polyvinylamine blends showed a clear upturn in the water sorption curve for RH larger than 60%, reaching a mass uptake higher than 50%wt at the maximum water activity inspected.