Abstract: A gas transfer segment of a vacuum swing adsorption process cycle utilizing multiple parallel adsorbent beds which undergo cyclic process steps to separate the components of a feed gas mixture, each bed having a feed end and a product end, wherein the gas transfer segment comprises a step of withdrawing a waste gas stream from the feed end of a first bed, withdrawing a transfer gas from the product end of the first bed and introducing the transfer gas into the product end of a second bed, and withdrawing a waste gas stream from the feed end of the second bed.

Abstract: A gas transfer segment of a pressure swing adsorption process cycle utilizing multiple parallel adsorbent beds, each bed having a feed end and a product end, wherein the gas transfer segment comprises transferring gas from a bed at a higher pressure to another bed at a lower pressure followed by withdrawing a waste depressurization gas from the feed end of the bed while transferring gas from the bed at a higher pressure to another bed a lower pressure.

Abstract: System for restraining the upward motion of granular material in a vessel containing a bed of the granular material through which a fluid flows in an upward direction. The system comprises flexible porous basket within the vessel in contact with the top of the bed of granular material and in contact with the inner walls of the vessel above the bed of granular material, wherein the porous basket has openings which are smaller than the smallest particles of the granular material such that granular material does not pass through the openings. The system also includes a layer of solid bodies located within the flexible porous basket wherein the solid bodies press the flexible porous basket against the top of the bed of granular material and against the inner walls of the cylindrical vessel above the bed of granular material.

Abstract: System for restraining the upward motion of granular material in a vessel containing a bed of the granular material through which a fluid flows in an upward direction. The system comprises flexible porous basket within the vessel in contact with the top of the bed of granular material and in contact with the inner walls of the vessel above the bed of granular material, wherein the porous basket has openings which are smaller than the smallest particles of the granular material such that granular material does not pass through the openings.

Abstract: A process for pressure swing adsorption of oxygen from a gas mixture containing at least oxygen and nitrogen to recover an unadsorbed nitrogen enriched product from a plurality of parallel piped adsorbent beds undergoing adsorption, depressurization and repressurization wherein the improvement is conducting a pressure transfer from one bed to another from an intermediate point of the bed finishing adsorption to a point closer to the feed end of a bed that is repressurizing to improve productivity and recovery of nitrogen enriched gas in the process.