PSA or VSA unit having jointly-controlled production output and production pressure

Abstract

The invention relates to a process for controlling a PSA, especially VSA, plant for separating a gas stream, in particular a gas stream containing nitrogen and at least one less polar gaseous component, especially oxygen and/or hydrogen. The PSA plant operates in a production cycle and has one or more adsorbers, each production cycle comprising at least one feed step of feed duration (TA), which comprises introducing the gas stream to be separated into an adsorber; at least one production step, which comprises recovering a stream of gas produced at a prefixed production pressure (PP) and with a prefixed nominal production output (DN); and at least one pumping step of pumping duration (TP); which comprises extracting a gas stream from at least one adsorber. According to this control process, the total feed duration (TA) and the total pumping duration (TP) are jointly adjusted in order to maintain, downstream of the PSA plant, a constant production pressure (PP) and to minimize the energy consumption whether the actual production output (DR) is less than or equal to a nominal production output (DN).

Dependencies are inferred from the claim text.