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 with an inlet for compressed gas to be dried originating from a compressor and an outlet for dried compressed gas, where this device includes a number of vessels that are filled with a regeneratable drying agent and a controllable valve system that connects the aforementioned inlet and outlet to the aforementioned vessels, where the device includes at least three vessels, where the aforementioned valve system is such that at least one vessel is always being regenerated, while the other vessels dry the compressed gas, where due to the control of the valve system the vessels are each successively regenerated in turn.

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.

Methods and systems for capture of CO.sub.2 from a hydrated gaseous stream are described. Systems can be utilized for direct air capture of CO.sub.2 and incorporate a low energy temperature-vacuum swing adsorption (TVSA) process. A TVSA process can include a multi-step CO.sub.2 capture bed regeneration process that includes depressurization of the bed, heating of the bed, venting and purging of the bed, and cooling of the bed. Multiple beds can be cycled between CO.sub.2 capture and regeneration, during which captured CO.sub.2 is recovered. Off-gas from a CO.sub.2 capture bed can be used in regenerating a parallel bed for increased efficiency.

A fuel vapor treatment system includes a plurality of adsorbent sections arranged in series and configured to adsorb fuel vapor, a tank port in fluid communication with a fuel tank, a purge port in fluid communication with an engine, an atmospheric port in fluid communication with a surrounding atmosphere, and a constriction plate disposed adjacent to an atmospheric side end of the adsorbent section of the plurality of adsorbent sections that is most proximal the atmospheric port. The constriction plate is positioned adjacent the adsorbent section without an intermediate space formed therebetween. The constriction plate has a plurality of through holes. The total cross-sectional area of the through holes in the constriction plate is smaller than a cross-sectional area of a flow passage in the atmospheric port.

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.

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 of treating a natural gas stream is provided comprising sending natural gas stream through a first adsorbent bed to remove water and heavy hydrocarbons (C8+) to produce a partially treated gas stream in which the first adsorbent bed is regenerated by a temperature swing adsorption process and then sending the partially treated gas stream through a second adsorption bed to remove carbon dioxide and lighter hydrocarbons (C7−) to produce a purified natural gas stream wherein said second adsorption bed is regenerated by a temperature pressure swing adsorption 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.

The present invention generally relates to a process for responding to feed flow variations by changing the process cycle and thereby increasing the productivity and capacity of the system significantly over constant process systems. This increases the flexibility a PSA system for customers that do not require a constant or uniform product flow rate and/or for processes and applications that experience feed streams that vary in flow, temperature, and/or composition.