Method for regulating a unit for separating a gas stream

A method for regulating a unit for separating a gas stream, having P adsorbers, where P≥2, each following a PSA-type adsorption cycle with a phase time shift, the unit having a control device allowing the unit to provide a required flow rate and to operate selectively according to a nominal cycle or according to a reduced cycle, the nominal cycle involving, successively, at least a first step and a second step, the reduced cycle following the same succession of steps as the nominal cycle, with insertion of an intermediate step between the first step and the second step, the intermediate step being different from a dead time and being different from an extension of the first step or an extension of the second step, the method comprising:

• operating the unit according to the nominal cycle when the required flow rate is equal to a nominal flow rate or when the required flow rate is higher than the nominal flow rate,
• 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.