The present disclosure provides systems and methods for hydrogen production as well as apparatuses useful in such systems and methods. Hydrogen is produced by steam reforming of a hydrocarbon in a gas heated reformer that is heated using one or more streams comprising combustion products of a fuel in an oxidant, preferably in the presence of a carbon dioxide circulating stream.

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.

The present disclosure provides systems and methods for hydrogen production as well as apparatuses useful in such systems and methods. Hydrogen is produced by steam reforming of a hydrocarbon in a gas heated reformer that is heated using one or more streams comprising combustion products of a fuel in an oxidant, preferably in the presence of a carbon dioxide circulating stream.

The invention is an improved method of making an improved carbon molecular sieve (CMS) membrane in which a precursor polymer (e.g., polyimide) is pyrolyzed at a pyrolysis temperature to form a CMS membrane that is cooled to ambient temperature (about 40° C. or 30° C. to about 20° C.). The CMS membrane is then reheated to a reheating temperature less than the pyrolysis temperature to form the improved CMS membrane. The improved CMS membranes have shown an improved combination of selectivity and permeance as well as stability for separating hydrogen from gas molecules (e.g., methane, ethane, propane, ethylene, propylene, butane, carbon dioxide, nitrogen, butylene, and combinations thereof).

A catalyst used for dehydrogenation of an organic hydrogen-storage material to generate hydrogen, a support for the catalyst, and a preparation process thereof are presented. A hydrogen-storage alloy and a preparation process thereof are provided. A process for providing high-purity hydrogen, a high-efficiently distributed process for producing high-purity and high-pressure hydrogen, a system for providing high-purity and high-pressure hydrogen, a mobile hydrogen supply system, and a distributed hydrogen supply apparatus are also described.

Steam reforming processes can include treatment of syngas by water gas shift, water separation, and hydrogen separation by pressure swing adsorption (PSA). Additionally, CO.sub.2 can be scrubbed from the syngas prior to the PSA. PSA tail gas, including CH.sub.4, CO, and H.sub.2, can be recompressed and recycled to the PSA for further hydrogen separation and to the steam reformer feed to convert eventually all carbon in the feedstock into CO.sub.2 for the scrubber to separate. Fuel requirements can be fulfilled by part of the hydrogen product to eliminate stack CO.sub.2 emissions. The hydrogen used as fuel is heated and turbo-expanded to provide power before being combusted as fuel. A nitrogen purge may be added.

Processes and systems for recovering hydrogen may include feeding a gas stream, comprising hydrogen and additional gases, to a pressure swing adsorption (PSA) system and feeding a membrane permeate stream comprising hydrogen to the PSA system. In the PSA system, a portion of the hydrogen may be separated from the additional gases to recover a hydrogen product stream and a PSA tail gas stream comprising unseparated hydrogen and the additional gases. The PSA tail gas stream may be fed to a membrane separation unit for separating hydrogen from the additional gases and to recover (i) the membrane permeate stream comprising hydrogen fed to the PSA system and (ii) a membrane tail gas stream comprising the additional gases. Embodiments herein may additionally include a refrigeration system for partially condensing one or both of the feed gas stream and the PSA tail gas stream, enhancing the efficiency of the membrane separation unit.

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.

The present invention relates to processes for the preparation of biofuel from biomass by fast hydropyrolysis or fast pyrolysis, using hydrogen generated by sorption enhanced steam reforming. The present invention also relates to fixed bed tandem catalytic-upgrading processes, and reactors and hydrodeoxygenation (HDO) catalysts useful in those processes.

A structure in which a plurality of particles each containing a hydrogen absorption metal element are arranged in a fixed member such that the plurality of particles are apart from each other. An entire surface of each of the plurality of particles is surrounded by the fixed member. The fixed member contains at least one of an oxide and a nitride.