Analysis of Nonisobaric Steps in Nonlinear Bicomponent Pressure Swing Adsorption Systems. Application to Air Separation

This paper presents a simulation study using a pressure swing adsorption unit performing an equilibrium-based bicomponent separation, running a traditional Skarstrom cycle. This study is also supported by experimental results obtained for oxygen separation from air in a 5A zeolite. The focus is on the influence on product purity and recovery of the pressure rising rate during pressurization, pressure lowering rate during blowdown, production pressure, and intraparticle viscous flow. A co-current equalization step is also considered. Within the range of tested conditions, it was found that the pressure rising rate during pressurization influences product purity and recovery whereas the pressure lowering rate during blowdown has almost no effect. It was concluded that higher pressurization rates decrease product purity and recovery. Intraparticle viscous flow can enhance or decrease product purity depending on the relationship between diffusional and intraparticle viscous flow contributions and an axial hea...