The principal aim of this project is preparation, characterization and testing of advanced separation polymeric membranes with enhanced performance containing anchored ionic liquids in a suitable non-porous polymeric membrane using (i) Van der Waals forces in coated (composite) porous asymmetric polymeric membrane or (ii) a covalent bond or (iii) high ionic liquid content cross-linked polymer gels. Preparation of such novel separation membranes is targeted for an efficient methane separation from biogas. It will also be developed a model enabling prediction the transport and separation characteristics of these membranes intended for separation of gas mixtures.