Production of hydrogen from a hydrogen-rich feed by pressure swing adsorption comprises recycling compressed effluents from adsorbers in regeneration phase to adsorbers in absorption phase

摘要

Production of hydrogen from a hydrogen-rich feed by pressure swing adsorption, in which the depressurization phase includes a cocurrent subphase, comprises passing the effluents from adsorbers in cocurrent depressurization phase to adsorbers in purge phase and recycling compressed effluents from adsorbers in regeneration (depressurization, purge, repressurization) phase to adsorbers in absorption phase. Independent claims are also included for: (1) production of hydrogen from a hydrogen-rich feed by pressure swing adsorption, in which the depressurization phase includes a cocurrent subphase, comprising partially equilibrating the pressures between adsorbers at the start of cocurrent depressurization phase and adsorbers in repressurization phase until the adsorbers at the start of cocurrent depressurization phase have a partial equilibration pressure strictly less than the adsorption pressure, and passing the effluents from adsorbers in cocurrent depressurization phase in which the pressure is below the partial equilibration pressure to adsorbers in purge phase, and recycling compressed effluents from adsorbers in regeneration phase to adsorbers in absorption phase; (2) a unit for production of hydrogen from a hydrogen-rich feed by pressure swing adsorption, in which the depressurization phase includes a cocurrent subphase, comprising one or more absorbers connected to a fuel gas network; a recycle line for effluents from absorbers in regeneration phase; a compressor in the recycle line; and a branch line for passing fuel gas from the network to the recycle line.