A process and apparatus for producing a hydrogen-enriched product and recovering CO.sub.2 from an effluent stream from a hydrogen production process unit are described. The process utilizes a CO.sub.2 recovery system integrated with a PSA system that produces at least two product streams to recover additional hydrogen and CO.sub.2 from the tail gas stream of a hydrogen PSA unit in the hydrogen production process.

A process and apparatus for producing a hydrogen-enriched product and recovering CO.sub.2 from an effluent stream from a hydrogen production unit are described. The effluent from the hydrogen production unit, which comprises a mixture of gases comprising hydrogen, carbon dioxide, water, and at least one of methane, carbon monoxide, nitrogen, and argon, is sent to a PSA system that produces at least two product streams for separation. The PSA system that produces at least two product streams separates the gas mixture into a high-pressure hydrogen stream enriched in hydrogen, optionally a second gas stream containing the majority of the impurities, and a low-pressure tail gas stream enriched in CO.sub.2 and some impurities. The CO.sub.2-rich tail gas stream is compressed and sent to a CO.sub.2 recovery unit, where a CO.sub.2-enriched stream is recovered. The CO.sub.2-depleted overhead gas stream is recycled to the PSA system that produces at least two product streams.

A three-product PSA system which produces three product streams from a feed gas mixture comprising a light key component, at least one heavy key component, and at least one intermediate key component is described. The three-product PSA system produces a high pressure product stream enriched in the light key component, a low pressure tail gas stream enriched in the at least one heavy key component, and an intermediate pressure vent gas stream enriched in the at least one intermediate key component.

A device for producing purified oxygen, has a feed (1, 1′) of a mixture of oxygen and argon, and has at least one bed (2, 2A, 2B) of oxygen adsorption material, a purge (3, 3′) for discharging the separated argon and a circuit (4, 4′) for injecting a portion of the purified oxygen produced, into the feed (1, 1′). The device has a programmable logic controller (PLC) for treating the degree of purity and/or the production flow rate that can be set by the user and a control of said purge (3, 3′) as a function of the degree of purity of the purified oxygen and/or of the production flow rate which are desired by the user.

Drying compressed air while utilizing a method for preemptive overload avoidance of moisture to a desiccant bed, including a recovery control process. The method may include a purge means, an initialization period for pre-learning to develop usage-profile log performance summary to compare against real-time data and a protocol for a normal state, a recovery state and a supplemental purge state and means to reestablish normal operations. A procedure for standby and overload alarm alerting states are also described. The purge means may be fixed rate or modulating. The system may have cycle times decrementing or incrementing stepwise in a predetermined or varying time frame to respond to on-going trending data in order to correct imbalance loading conditions by adjusting drying and regenerating cycle times, thus affording a stable delivery of quality dewpoint compressed air to the dryer output.

The invention relates to a method for managing a PSA unit having at least N adsorbers arranged in pairs, where each pair is designed to be able to be selectively isolated, a control device, and a plurality of interfaces for accessing instrumentation means of each adsorber, When a first pair is fluidically isolated, the first pair having a first and a second adsorber, the isolating of a third adsorber includes setting the control device to control N-4 adsorbers, fluidically isolating a second pair having the third and a fourth adsorber, isolating one of the first and second adsorbers and the third adsorber, configuring the interfaces so as to swap over the instrumentation means of the other of the first and second adsorbers and the instrumentation means of the fourth adsorber, placing the first and second pairs in fluidic communication, and setting the control device to control N-2 adsorbers.

A pressure swing adsorption process (PSA) comprising the following steps: feeding an input gas containing H.sub.2, CO.sub.2 and impurities through a CO.sub.2 adsorbent material in a pressure vessel under a high pressure; withdrawing a first H.sub.2-rich product gas due to adsorption of CO.sub.2 in the adsorbent material; setting the pressure to an intermediate pressure causing the adsorbent material release a second gas stream; passing a CO.sub.2-rich purge stream through the adsorbent material, obtaining a purge gas; setting the pressure to a sub-atmospheric low pressure, so that a CO.sub.2-rich product gas is released under vacuum by the adsorbent material; re-pressurizing the vessel to said high pressure; said steps being performed cyclically in a pressure vessel or in a plurality of parallel pressure vessels of a multiple vessel setup.

The present disclosure describes a system and method for maintaining oxygen purity in portable oxygen concentrators, even with asymmetric generation of oxygen enriched gas volumes from different sieve beds of the concentration system. The present system and method compensate for asymmetric oxygen enriched gas generation using asymmetric delivery of purge volumes. Purge valves are used to deliver the asymmetric purge gas volumes, enables the system to maintain oxygen purity without additional power consumption, even when a portable oxygen concentrator does not include a product tank. The present system and method are configured such that asymmetry in enriched oxygen generation can be monitored and the asymmetric purge gas compensation can be applied independently from other control mechanisms of a portable oxygen concentrator.

The current disclosure provides systems and methods for multiple beds undergoing a feed step at the same time with the same feed flow rate and multiple beds undergoing a light reflux step at the same time with the same light reflux flow rate to process a gas stream in a multi-bed, multi-unit vacuum swing adsorption (VSA) process using reasonably sized beds.

The current disclosure provides systems and methods for multiple beds undergoing a feed step at the same time with the same feed flow rate and multiple beds undergoing a light reflux step at the same time with the same light reflux flow rate to process a gas stream in a multi-bed, multi-unit vacuum swing adsorption (VSA) process using reasonably sized beds.