1. General aspects

Unlike most other separation technologies (distillation, absorption, most adsorption processes), gas permeation separation is a kinetic process. This process is based on differences in the permeation velocities of the constituents of a gas mixture across a membrane. The separation performance of gas permeation technology depends on :

• permselectivities – defined by the nature of the gases and the material used;

• available driving forces (usually partial pressure differences) ;

• the arrangement of the different flows within the membrane modules.