Technical Gas Permeation Processes

Both microporous membranes (of ceramic material or metal) and pore‐free membranes (usually polymers, but also metal and glass) are used in industrial gas separations. The only process of industrial significance utilizing microporous partitions is the enrichment of uranium; pore‐free membranes are mainly used in practice. Among the separations using polymeric membranes, the following processes are considered: (1.) purification of refinery hydrogen; (2.) enrichment of a CO/H 2 synthesis gas in CO; and (3.) isolation of helium from natural gas. Metallic membranes are employed in the following processes: (1.) purification of hydrogen with the aid of a Pd/Ag membrane and (2.) separation of H 2 from a CO/H 2 mixture. In conclusion, problems yet to be solved and recognizable development trends are considered.