A sorption drying system for dehumidification of a moist gas stream, includes a mass of absorbing material, a moist gas stream arranged to flow through at least a part of the absorbent mass, and a heated stream of regeneration gas arranged to flow through at least a part of the absorbent mass. The sorption drying system further includes structure for deflecting a part of the dehumidified gas stream after flowing through the absorbent mass, a cooler for cooling the deflected dehumidified gas stream, and structure for returning the cooled deflected dehumidified gas stream to the moist gas stream at the inlet into the absorbent mass. At least a part of the cooled deflected dehumidified gas stream is arranged to flow through the absorbent mass in a channel separated from the moist gas stream.

A method of purifying a gas composed of a product gas and one or more impurity gases including combining a feed stream with a second stream thereby forming a combined feed stream, introducing the combined feed stream into a pressure swing adsorption device, thereby producing a high purity product gas stream and an off-gas stream, and introducing the off-gas stream into a membrane separation device, thereby producing a gas stream lean in product gas and a permeate stream.

A method of obtaining helium from a process gas. The process gas is at a pressure less than 15 bar to a first membrane separation stage having a first membrane more readily permeable for helium than for at least one other component in the process gas. A first retentate stream is fed to a second membrane separation stage having a second membrane more readily permeable for helium than for at least one other component in the process gas. Helium is separated from a first helium-containing permeate stream using a pressure swing adsorption to obtain a helium-containing product stream. A second helium-containing permeate stream is recycled to the first membrane separation stage. A purge gas from the pressure swing adsorption is also recycled to the first membrane separation stage.

A rapid cycle pressure swing adsorption (RCPSA) air purification process, apparatus, and device for the removal of at least one of water, carbon dioxide, nitrous oxide, and one or more hydrocarbons from a feed air stream prior to cryogenic air separation.

Several embodiments of the present technology are directed to the removal of one or more air pollutants using cooling and/or calcium-containing particles. In some embodiments, a method for removing air pollutants comprises flowing a gas stream having calcium-containing particles and one or more of mercury or hydrochloric acid molecules, and cooling the gas stream, thereby causing at least a portion of the calcium-containing particles to adsorb to the mercury and/or hydrochloric acid molecules in the gas stream. The method can further comprise, after cooling the gas stream, filtering the gas stream to remove at least a portion of the calcium-containing particles having adsorbed mercury and hydrochloric acid.

Embodiments of the invention are directed to methods, processes, and systems for safely and reliably purifying hydrogen from a gas mixture containing hydrogen and oxygen.

Biogas containing H.sub.2S and CO.sub.2 is upgraded by removing H.sub.2S using PTSA and CO.sub.2 using two stages of gas separation membranes. The first stage permeate may optionally be used a regeneration gas stream. The second stage permeate may optionally be used a cool down gas stream. The PTSA unit includes two or more adsorbent beds each selective for water, VOCs, and H.sub.2S over CO.sub.2 and for H.sub.2S over methane.

A method for producing biomethane by purifying biogas from non-hazardous waste storage facilities involves compressing the initial gas flow, introducing the gas flow to be purified into at least one adsorber loaded with adsorbents capable of reversibly adsorbing the VOCs, and subjecting the VOC-depleted gas flow to at least one membrane separation step in order to partially separate the CO.sub.2 and O.sub.2 from the gas flow. The method also involves introducing the retentate from the membrane separation step into at least one adsorber loaded with adsorbents capable of reversibly adsorbing the major portion of the remaining CO.sub.2, subjecting the CO.sub.2-depleted gas flow exiting the adsorber loaded with adsorbents capable of reversibly adsorbing the major portion of the remaining CO.sub.2 to a cryogenic separation step in a distillation column in order to separate the O.sub.2 and N.sub.2 from the gas flow, and recovering the CH.sub.4-rich flow from the cryogenic separation step.

A smart multi-modal vehicular air filtration management system including a first filter element and a second filter element disposed in a fresh air housing, wherein the fresh air housing has an inlet and an outlet. Additionally, a third filter element is provided which is disposed in a cabin housing, the cabin housing having one or more inlet. A fluid channel arranged between the fresh air and cabin housing. Finally, a diverter is included which is disposed near an outlet of the fresh air housing, wherein the diverter is configured to cause air to flow through the fresh air housing selectively through one or both of the first filter element and the second filter element.

A hydrogen gas dryer or system for drying or removing water from hydrogen gas for use in hydrogen-cooled generators includes a drying tower or column comprising a housing, a heater, a desiccant, and a controller. The system is configurable and operable for regeneration of the saturated column, with activation of the heater to cause water retained in the saturated desiccant to turn into steam such as steam and exit on its own via the vent. A supply of generally dry hydrogen is used to purge the remaining vaporized water from the isolated substantially dry regenerated desiccant.