A staged complementary pressure swing adsorption system and method for low energy fractionation of a mixed fluid. Two beds in a four-column PSA system are selective for component A, and another two columns are selective for component B. The cycle creates an intermittent A and B product, using the purge effluent from the complementary product fed at an intermediate pressure. This intermittent product is used as purge gas for low-pressure purged elsewhere in the cycle using appropriate storage tanks. The use of an intermediate pressure in this cycle enables continuous production of purified component A and B without the use of compressors. Columns may also be configured to enable pressure to equalize between complementary columns.

In a cyclic adsorptive gas purification process, an impurity laden adsorbent is regenerated by exposing it first to an unheated gas for a pre-determined time period to desorb at least some of the impurity, followed by heating the adsorbent using a flowing stream of a heated gas to desorb the remaining impurities over another pre-determined time period, further followed by cooling of the adsorbent using a flowing stream of gas for yet another pre-determined time period to make it ready for repeating the adsorptive cycle. Introducing an unheated purge stream reduces the energy requirements for the regeneration step compared to a traditional TSA process.

This disclosure relates to the adsorption and separation of fluid components, such as oxygen, in a feed stream, such as air, using zeolite ITQ-55 as the adsorbent. A process is disclosed for adsorbing oxygen from a feed stream containing oxygen, nitrogen and argon. The process comprises passing the feed stream through a bed of an adsorbent comprising zeolite ITQ-55 to adsorb oxygen from the feed stream, carrying out an equalization step to improve recovery, thereby producing a nitrogen product stream depleted in oxygen as well as a waste stream can be collected to have enriched oxygen. The feed stream is exposed to the zeolite ITQ-55 at effective conditions for performing a rapid cycle of kinetic separation, in which oxygen exhibits greater kinetic selectivity than nitrogen and argon.