Compared to common organic solvents, ionic liquids have almost no vapor pressure and a high thermal stability up to 450 °C. In combination with (especially ceramic) membranes as support structure liquid membranes are possible which are safe from drying out. Different geometries and membrane materials as well as the huge number of ionic liquids have the potential for a broad range of applications. One goal is the development of supported ionic liquid membranes (SILM) to be applied for the separation of carbon dioxide from other gases.