Membrane Gas Separation

Membrane-based gas separation (GS) systems are widely accepted today and in some cases, these systems are used as an operating unit for generation, separation and purification of gases in gas, chemical, petroleum and allied industries. There are many field applications, membrane materials and module solutions that are available worldwide for various fields of interest. However, the growth of large-scale industrial applications is still far from all the real potentialities that the membrane GS offers. Combining the investigations of new materials with improved properties, a key role for the widespread use of this technology is represented by the development of a new knowledge for better utilization of unit operations that are already available on the market in integrated membrane systems and combining various membrane operations in the same industrial process. On this hurdle, the membrane engineering plays a crucial role. This chapter describes the main aspects related to membrane GS. After a brief introduction to the main transport mechanisms that are involved in the gas permeation and main variables that are usually used for describing it, the chapter provides an overview of the membrane materials and membrane modules now available at the market level or are under study at laboratory scale. Afterward, a description of the main GS processes involving membranes is presented together with a comparison with traditional technologies currently in use.