The process of the present invention provides high recovery and low capital cost giving it an economic advantage over previously known purification processes. The present process has particular applicability to the purification of synthesis gases comprising at least hydrogen (H.sub.2), carbon monoxide (CO), methane (CH.sub.4), CO.sub.2, and H.sub.2O to obtain a gas stream including at least H.sub.2, CO, and CH.sub.4, that is substantially free of H.sub.2O and CO.sub.2. The process also has applicability to the purification of natural gases inclusive of at least CH.sub.4, N.sub.2, CO.sub.2, and H.sub.2O to produce a gas stream including at least CH.sub.4 and N.sub.2, but which is substantially free of H.sub.2O and CO.sub.2.

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.

The present invention is directed to a dryer provided with an inlet for receiving a flow of compressed gas and an outlet for providing dry air, said dryer comprising: a first and a second adsorption vessel connected in parallel, a depressurization unit connectable to the inlet flow conduit of each of said first and second adsorption vessels; whereby the dryer further comprises a flow reducer connectable to the inlet flow conduit of each of the first and second adsorption vessels and whereby said control valves are adapted to be switched in a first state, and a second state.

Pressure swing adsorption process for reducing fluctuations in the flow rate of tail gas from the adsorption unit. The flow rate of the stream of blowdown gas is regulated responsive signals from a sensor measuring the pressure and/or flow rate of the tail gas comprising the blowdown gas and purge gas effluent before the tail gas is introduced into a surge vessel.

Provided are apparatus and systems for performing a swing adsorption process. In particular, the method and system involves swing adsorption processes and systems designed to lessen the temperature, pressure and product stream composition fluctuations in the adsorption step of a swing adsorption process, particularly involving preparation of the adsorption bed unit using feed stream cooling in conjunction with splitting the cooled feed stream to the adsorption bed units during adsorption steps while staggering the timing of back-to-back adsorption steps in the swing adsorption process. The process may be utilized for swing adsorption processes, such as rapid cycle TSA and/or rapid cycle PSA, which are utilized to remove one or more contaminants from a gaseous feed stream.

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.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve performing dampening for fluctuations in the streams conducted away from the adsorbent bed unit. The process may be utilized for swing adsorption processes, such as rapid cycle TSA and/or rapid cycle PSA, which are utilized to remove one or more contaminants from a gaseous feed stream.

A system and method for sulfur recovery, including hydrogenating Claus tail gas, quenching the hydrogenated gas, adsorbing water and hydrogen sulfide from the quenched gas, and regenerating adsorbent with carbon dioxide and/or nitrogen and heating the adsorbent in a regeneration temperature ramp to desorb primarily hydrogen sulfide in a first part of the temperature ramp.

An adsorption process is provided to remove oxygen from a hydrogen stream through the use of a copper material in combination with layers of adsorbent to remove water and nitrogen from a hydrogen stream. This process is particularly useful for purification of hydrogen product gas from water electrolyzers with the hydrogen product gas having greater than 99.9 mol % purity.