ABSTRACT
Various types of membranes exist nowadays, many of which are applied in separation processes. The membranes can consist of porous inorganic materials (silica, alumina, carbon), mixed solid oxides, metals, polymers, and liquid systems. The first three types listed are favorable for operation at elevated temperatures because of their thermal stability in separation systems or membrane reactors and also because of their chemical stability in organic solvents or liquids with high or low pH values.
