Patent ID: 6171371
Filing Date: 2001-01-09
Classification: B01D,C01B,Y02P

Abstract:
A process for producing oxygen from air by transatmospheric pressure swing adsorption, using a unit having at least two adsorbers, a cycle of duration T being implemented in each adsorber, the process comprising successively and cyclically:a phase of pressurization to a high pressure of the cycle using production oxygen introduced in countercurrent and/or air introduced in cocurrent, said phase ending with a cocurrent production step in which the oxygen produced is sent to a buffer volume;a first cocurrent decompression phase;a countercurrent purge phase comprising pumping to a low pressure of the cycle; anda purge/elution phase in which gas output by another adsorber in the first cocurrent decompression phase is introduced in countercurrent and, simultaneously, countercurrent pumping is continued;wherein the buffer volume is subdivided into a buffer tank and into an auxiliary volume comprising an auxiliary pressurization tank, during an initial part of the production step, the oxygen produced is sent only into the auxiliary pressurization tank, and the gas contained in the auxiliary pressurization tank is, with regard to the adsorber, used solely during a fraction of the pressurization phase of the adsorber.