A process and apparatus for producing a hydrogen-enriched product and recovering CO.sub.2 from an effluent stream from a hydrogen production process unit are described. The process utilizes a CO.sub.2 recovery system integrated with a PSA system that produces at least two product streams to recover additional hydrogen and CO.sub.2 from the tail gas stream of a hydrogen PSA unit in the hydrogen production process.

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.

Provided herein are systems and methods for generating hydrogen and ammonia. The hydrogen is generated in an anion exchange membrane-based electrochemical stack. The hydrogen generated in the stack may be used to generate ammonia or may be used for other applications requiring hydrogen. The feedstock for the anion exchange membrane-based electrochemical stack may be saline water, such as seawater. A desalination module or a chlor-alkali stack may be used to treat the saline water prior to electrolysis in the anion exchange membrane-based electrochemical stack.

The invention provides a low-temperature hydrogen oxidation system comprising at least one hydrogen oxidation device, at least one hydrogen reaction module is disposed in the hydrogen oxidation device, at least one hydrogen reaction channel is formed in the hydrogen reaction module and is provided with at least one catalyst, the hydrogen oxidation device is provided with at least one gas inlet channel and at least one gas outlet channel to communicate with the hydrogen reaction channel, at least one cooling channel is further formed in the hydrogen oxidation device; and at least one gas humidifying device disposed at a position of the gas inlet channel.

A liquefied gas system for capturing boil-off gas and reversibly adsorbing the boil-off gas on an adsorbent for later desorption and use comprises a first vessel for storing liquefied gas; a means for delivering gas from the first vessel to a system endpoint; a second vessel for storing boil-off gas emitted from the first vessel, the second vessel containing at least one adsorbent; a means for delivering boil-off gas from the first vessel to the second vessel, whereby the boil-off gas is reversibly stored on the at least one adsorbent; and a means for delivering the stored boil-off gas from the second vessel to the system endpoint. Also disclosed is a method of capturing boil-off gas from a liquefied gas system, wherein the captured boil-off gas is captured on an adsorbent for further use in the system. In one embodiment of the system and the method, the liquefied gas is liquid hydrogen, and the captured boil-off gas is used to power a hydrogen fuel cell.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

The invention includes a gas processing system for transforming a hydrocarbon-containing inflow gas into outflow gas products, where the system includes a gas delivery subsystem, a plasma reaction chamber, and a microwave subsystem, with the gas delivery subsystem in fluid communication with the plasma reaction chamber, so that the gas delivery subsystem directs the hydrocarbon-containing inflow gas into the plasma reaction chamber, and the microwave subsystem directs microwave energy into the plasma reaction chamber to energize the hydrocarbon-containing inflow gas, thereby forming a plasma in the plasma reaction chamber, which plasma effects the transformation of a hydrocarbon in the hydrocarbon-containing inflow gas into the outflow gas products, which comprise acetylene and hydrogen. The invention also includes methods for the use of the gas processing system.

The present invention describes a process to separate ethylene products from impurities such as nitrogen, hydrogen, ethane, propane and isobutane without the need for distillation processes.

A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.

A carbon dioxide conversion system for an environment includes a first gas-liquid contactor-separator downstream of the environment; an electrochemical conversion cell downstream of the first gas-liquid contactor-separator; and a cleaned ionic liquid storage intermediate the first gas-liquid contactor-separator and the electrochemical conversion cell.