ON THE PSEUDOMULTIPLICITY OF PRESSURE SWING ADSORPTION PERIODIC STATES

Pseudomultiplicity of periodic states in pressure swing adsorption (PS A) is illustrated with a simple cycle. Pseudomultiplicity in PSA is de fined by the existence of at least two different periodic states for a single PSA operating specification, such as fixed sorbent productivit y, while product purity or product recovery may vary. Non-isothermal b ehavior, number of components, isotherm nonlinearities, and cycle comp lexity are considered requirements for conventional multiplicity in PS A, defined by different periodic states depending only on the initial condition of the beds, for the same input variables. The examples pres ented here, obtained with a simple model, show that pseudomultiplicity in PSA is neither a consequence of system nonlinearities described ab ove nor the result of wave interactions due to cycle step complexity.