Application of supported ionic liquid membranes in the purification of bio-based molecules using pervaporation

The use of supported ionic liquid membranes in organophilic separation is an unexplored field. For this reason this work aim to test the separation performance of methanol and dimethyl carbonate mixtures by supported ionic liquids membranes. Immobilisation tests, pervaporation experiments with pure methanol and dimethyl carbonate at different temperatures and pervaporation experiments with different concentrations of the binary mixure were carried out. Using the results of these experiments and different solution parameters, interaction between solute and ionic liquid molecules was elucidated. [OMIm][NTf2] and [OMPyrr][NTf2] immobilised in PAN membranes provided a very selective separation of DMC. Coupling effects hindered methanol permeance. Some supported ionic liquid membranes presented sudden changes in their permeance. These changes are attributed to atmospheric water absorption and to chemical reactions in the membrane as a consequence of solute, ionic liquid and membrane interactions.