The invention concerns an optimization method for a pressure swing adsorption process for separating CO.sub.2 from a feed gas by adapting the ratio of rinse steam to purge steam at a fixed amount of total steam.

The present invention relates to a temperature enhanced pressure swing adsorption (TEPSA) process for removing at least two components including a less strongly adsorbed component and a more strongly adsorbed component from a gas mixture, said process comprising using one single heater and at least two adsorber vessels, in each of which repeated cycles comprising an adsorption phase and subsequent regeneration phases.

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.

The invention relates to a method for regulating a unit for separating a gas stream, having P adsorbers, where P2, each following a PSA-type adsorption cycle with a phase time shift, the method involving the steps of operating the unit according to the nominal cycle when the required flow rate is equal to a nominal flow rate or optionally when the required flow rate is higher than the nominal flow rate, and operating the unit according to the reduced cycle when the required flow rate is lower than or equal to a predetermined flow rate, the predetermined flow rate being lower than the nominal flow rate.