Influence of Solvent Exchange Drying Method on Mixed Matrix Membrane for Gas Separation

The improvement of the CO2 separation efficiency from flue gases has been identified as a high-priority research area, to reduce the total energy cost of sequestration technologies in coal-fired power plant. Among the separation techniques, membrane technology, in particular mixed matrix membrane (MMM) appeared as the most attractive module due to its high separation capabilities (inorganic fillers) and economical processing materials (polymeric membrane). In this study, MMM was synthesized from cellulose acetate polymer with functionalized multi walled carbon nanotubes served as the inorganic fillers by wet phase inversion. Both vacuum drying and ethanol-hexane exchange drying methods were compared to investigate their influence on the MMM morphologies and properties. Experimental findings (FESEM, AFM and ATR-FTIR) showed that the ethanol–hexane exchange drying was an appropriate method to minimize morphology change of MMM, whereas the vacuum drying caused the greatest shrinkage to MMM structure. The CO2 permeance results supported the proposed solvent exchange mechanism where MMM with solvent exchange drying showed to have improved in their mechanical strength and better permeance of (733.90-741.67) GPU compared to the vacuum drying (18.72-18.44) GPU within pressure range of 1 to 3 bars.