A continuous desulfurization process and process system are described for removal of reduced sulfur species at gas stream concentrations in a range of from about 5 to about 5000 ppmv, using fixed beds containing regenerable sorbents, and for regeneration of such regenerable sorbents. The desulfurization removes the reduced sulfur species of hydrogen sulfide, carbonyl sulfide, carbon disulfide, and/or thiols and disulfides with four or less carbon atoms, to ppbv concentrations. In specific disclosed implementations, regenerable metal oxide-based sorbents are integrated along with a functional and effective process to control the regeneration reaction and process while maintaining a stable dynamic sulfur capacity. A membrane-based process and system is described for producing regeneration and purge gas for the desulfurization.

Methods, systems, and apparatus are provided for modulating fluid flow in a cyclical swing adsorption system that includes multiple adsorption bed vessels that are in fluid communication. When opening a valve to transition an adsorption bed vessel into a blowdown stage or a re-pressurization stage of a cyclical swing adsorption process, the valve is partially lifted from a closed position prior to being fully lifted. The valve includes a flow restriction aid positioned to restrict flow through the valve when the valve is in the partially lifted position.

A gas treatment device treats, at atmospheric pressure, the gases pumped by at least one rough pumping device. The gas treatment device includes a treatment chamber and at least one discharge pipe to connect a discharge of the at least one rough pumping device to an inlet of the treatment chamber. The gas treatment device further includes at least one auxiliary pumping device to lower the pressure in the at least one discharge pipe, situated less than 1 meter from the inlet of the treatment chamber, such as less than 50 cm.

A method and exhaust gas treatment system for treating an ammonia-containing exhaust gas, for example a livestock house exhaust gas. The exhaust gas treatment system comprises a plurality of sorbent beds comprising a copper-doped small-pore zeolite, a valve system configured to establish independently for each sorbent bed fluid communication in a first or second configuration, wherein in the first configuration a flow of ammonia-containing exhaust gas contacts the sorbent bed at a temperature of less than 50° C. for storing the ammonia; and in the second configuration a flow of heated gas maintains the sorbent bed at a temperature of at least 300° C. for releasing and treating the ammonia in situ.

A portable pressure swing adsorption system and method for fuel gas conditioning. A fuel gas conditioning system includes a pressure swing adsorption (PSA) system fluidly coupled to a compressed rich gas stream, the PSA system including a plurality of adsorbent beds and configured to condition the compressed 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, and a feed end of the adsorbent beds configured to be fluidly coupled to the compressed rich natural gas stream or a raw natural gas stream, wherein the produced gaseous separated heavier hydrocarbons are desorbed at at least 50 psia and recirculated into the rich natural gas stream or the raw natural gas stream without post-desorption compression.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

An environment control system utilizes oxygen and humidity control devices that are coupled with an enclosure to independently control the oxygen concentration and the humidity level within the enclosure. An oxygen depletion device may be an oxygen depletion electrolyzer cell that reacts with oxygen within the cell and produces water through electrochemical reactions. A desiccating device may be g, a dehumidification electrolyzer cell, a desiccator, a membrane desiccator or a condenser. A controller may control the amount of voltage and/or current provided to the oxygen depletion electrolyzer cell and therefore the rate of oxygen reduction and may control the amount of voltage and/or current provided to the dehumidification electrolyzer cell and therefore the rate of humidity reduction. The oxygen level may be determined by the measurement of voltage and a limiting current of the oxygen depletion electrolyzer cell. The enclosure may be a food or artifact enclosure.

A natural gas adsorptive separation system and method is described. A method of separating natural gas includes directing a natural gas mixture through an activated carbon adsorption tower until the adsorption tower is saturated, collecting methane from the output of the adsorption tower, heating the saturated carbon adsorption tower with adsorbate using a heater and/or a vacuum pump in a closed loop circuit with the carbon adsorption tower until the input to the vacuum pump is within a specified temperature of the output of the heater, lowering the pressure in the heated activated carbon adsorption tower using the vacuum pump to desorb at least one hydrocarbon compound of the plurality of different hydrocarbon compounds, compressing and cooling the desorbed hydrocarbon compound, separating the cooled and compressed hydrocarbon compound into gas and liquid in a fluid separator, and collecting the liquid from the fluid separator.

A vapor fuel processing includes a canister for absorbing vapor fuel, a purge pipe, a purge control valve, a pump, a pressure sensor, and a determination unit. The pump may be provided on the purge pipe upstream of the purge control valve. The pressure sensor may be provided between the purge control valve and the pump. The determination unit may determine a state of a purge path by comparing a first detected value of the pressure sensor detected when the pump is driven with the purge control valve in a cutoff state with a first reference value and then comparing a second detected value of the pressure sensor detected when the pump is driven with the purge control valve in the communicated state with a second reference value.

A system for gas adsorbate capture has an adsorption reactor(s) configured for receiving an adsorbate gas flow. A egeneration reactor(s) is configured for receiving a regenerative fluid flow. A plurality of individual sorbent cells are in a generally continuous cycle between the adsorption reactor and the regeneration reactor. A group of the individual sorbent cells may form an adsorption moving bed in the adsorption reactor to capture the adsorbate from the gas flow.