Pressure swing adsorption method with additional elution

The invention relates to a pressure swing adsorption method (PSA) for producing a gas stream enriched with a compound X from a gaseous input stream, using at least two adsorbers, each adsorber being subjected to a pressure cycle having a high pressure and a low pressure. The method includes the following consecutive steps: a) adsorption at the high pressure of the cycle with production of the gaseous stream enriched with the compound X; b) depressurisation down to the low pressure of the cycle; c) elution at the low pressure by means of an elution gas; d) repressurisation up to the high pressure. The method is characterized in that: the elution gas includes a fraction of a gaseous stream from the depressurisation of an adsorber and a fraction of the gaseous stream enriched with the compound X; the fraction of the gaseous stream enriched with the compound X can be adjusted using adjustment means; and the pressure cycle has a phase time corresponding to the duration of a pressure cycle divided by the number of