Pressure swing adsorption method with additional elution

A pressure swing adsorption process for producing a gas stream enriched in a compound X from a feed gas stream, the process comprising at least 2 adsorbers, each adsorber being subjected to a pressure cycle having a high pressure and a low pressure, the process comprising the following successive steps:

• a) adsorption at the high pressure with production of the gas stream enriched in compound X;
• b) depressurization to the low pressure;
• c) elution at the low pressure by means of an elution gas;
• d) repressurization to the high pressure
• wherein:
• the elution gas comprises a fraction of a gas stream resulting from the depressurization of an adsorber and a fraction of the gas stream enriched in compound X,
• the fraction of the gas stream enriched in compound X is adjustable via an adjustment means, and
• the pressure cycle has a phase time corresponding to the duration of a pressure cycle divided by the number of adsorbers and the fraction of the gas stream enriched in compound X is determined as a function of the phase time.

A pressure swing adsorption process for producing a gas stream enriched in a compound X from a feed gas stream, the process comprising at least 2 adsorbers, each adsorber being subjected to a pressure cycle having a high pressure and a low pressure and comprising the following successive steps:

• a) adsorption at the high pressure with production of the gas stream enriched in compound X;
• b) depressurization to the low pressure;
• c) elution at the low pressure by means of an elution gas;
• d) repressurization to the high pressure
• wherein:
• the elution gas comprises a fraction of a gas stream resulting from the depressurization of an adsorber and a fraction of the gas stream enriched in compound X,
• the fraction of the gas stream enriched in compound X is adjustable via an adjustment means, and
• the pressure cycle has a phase time corresponding to the duration of the pressure cycle divided by the number of adsorbers and the fraction of the gas stream enriched in compound X is selected so that the phase time corresponds to the nominal phase time ±5%, the nominal phase time corresponding to the phase time of the PSA under design conditions.