An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.

A device for drying compressed gas, having an inlet for compressed gas to be dried and an outlet for dried compressed gas. The device includes at least two vessels, a regenerable drying agent and a controllable valve system. By controlling the valve system, the vessels are each in turn successively regenerated. The device is provided with a regeneration conduit splitting off a portion of the dried compressed gas as a regeneration gas and feeding it into the at least one vessel that is being regenerated. The regeneration conduit at least partly extends through an opening in the vessels such that the regeneration gas can be split off from the vessel that dries the compressed gas. A heater is provided in the regeneration conduit for heating the regeneration gas before the regeneration gas is fed through the drying agent into the vessel that is being regenerated.

A system for generating hydrogen includes an ammonia decomposition bed configured to introduce an ammonia gas, decompose the ammonia gas into a high-pressure first mixed gas including nitrogen and hydrogen, and discharge the high-pressure first mixed gas; an ammonia adsorption bed supplied with the high-pressure first mixed gas from the ammonia decomposition bed, and configured to adsorb ammonia of the first mixed gas, and discharge a high-pressure second mixed gas including nitrogen and hydrogen; and a nitrogen adsorption bed directly supplied with the high-pressure second mixed gas from the ammonia adsorption bed, and configured to adsorb the nitrogen, and discharge the hydrogen.

A portable pressure swing adsorption method and system for fuel gas conditioning. A fuel gas conditioning system includes a pressure swing adsorption (PSA) system fluidly coupled to a rich gas stream, the PSA system including a plurality of adsorbent beds and configured to condition the rich natural gas stream and produce therefrom a high-quality fuel gas and gaseous separated heavier hydrocarbons, a product end of the adsorbent beds fluidly coupled to a fuel gas line, wherein the high-quality fuel gas is discharged from the product end and supplied to the fuel gas line, and a feed end of the adsorbent beds configured to be fluidly coupled to the rich natural gas stream or a raw natural gas stream, wherein the produced gaseous separated heavier hydrocarbons are recirculated into the rich natural gas stream or the raw natural gas stream.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol% and 50 vol% n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol% and 50 vol% n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr BETP butane loading step.

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.

Systems and methods are provided for performing CO.sub.2 sorption and desorption using a sorbent structure with an integrated heat pump. The integrated heat pump can allow at least a portion of the heat generated during sorption to be recovered by forming steam from water. The steam raised during the sorption process can then be compressed and optionally heated to raise the temperature of the steam. The compressed and optionally heated steam can then be used as at least a portion of the steam for desorption of CO.sub.2 in the same sorbent bed or a different sorbent bed. By recovering the heat of sorption to raise steam, substantial energy savings can be achieved relative to a conventional process.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.

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.