Method for the preparation of ammonia synthesis gas by a combination of ATR or secondary reforming process using oxygen from an air separation unit and electrolysis of water for the production of ammonia synthesis gas.

A hydrogen production system including a steam reformer unit, a steam addition line arranged to add steam upstream the steam reformer unit, a hydrogen membrane unit comprising a hydrogen permeable membrane and being arranged to allow at least a part of a reformed stream and a hydrocarbon feed stream to pass on different sides of a hydrogen permeable membrane, so that hydrogen passes from the reformed stream into the hydrocarbon feed stream, thereby forming said hydrogen enriched hydrocarbon stream, and a separation unit downstream the first side of the hydrogen membrane unit, where the separation unit is arranged to separating the reformed stream exiting the first side of the hydrogen membrane unit into a hydrogen product gas and an off-gas.

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

A plant and process for producing a hydrogen rich gas and improved carbon capture are provided, said process comprising the steps of: reforming a hydrocarbon feed by optional prereforming, autothermal reforming (ATR), yet no primary reforming, thereby obtaining a synthesis gas; shifting said synthesis gas in a shift section including a high temperature shift step; removal of CO.sub.2 upstream hydrogen purification unit, thereby producing a hydrogen rich stream and an off-gas stream, and where at least part of the off-gas stream is recycled to the process, thus to the ATR and optional prereforming, and/or to the shift section.

The device (100) for hybrid production of synthetic dihydrogen and/or synthetic methane comprises: an inlet (105) for a synthesis gas stream preferably comprising at least CO and H.sub.2, a catalytic conversion reactor (110), the following alternative configurations: a first configuration in which the operating conditions of the reactor promote a Sabatier reaction, so as to produce an outlet gas comprising mainly methane, or a second configuration in which the operating conditions of the reactor promote a water gas shift reaction, so as to produce an outlet gas comprising mainly dihydrogen; an outlet (115) for synthetic dihydrogen and/or synthetic methane and a control system (120) comprising a means (121) for selecting a configuration for operating the reactor and a control means (122) according to the selected configuration, the reactor being configured to operate according to a command.

A process for producing a gas stream comprising carbon monoxide comprising the steps of (a) feeding a gas mixture comprising carbon dioxide and hydrogen to a burner and combusting it with a sub-stoichiometric amount of an oxygen gas stream to form a combusted gas mixture comprising carbon monoxide, carbon dioxide, hydrogen and steam, (b) passing the combusted gas mixture through a bed of reverse water-gas shift catalyst to form a crude product gas mixture containing carbon monoxide, steam, hydrogen and carbon dioxide, (c) cooling the crude product gas mixture to below the dew point and recovering a condensate to form a dewatered product gas, (d) removing carbon dioxide from the dewatered product gas in a carbon dioxide removal unit to form the gas stream comprising carbon monoxide, and (e) combining carbon dioxide recovered by the carbon dioxide removal unit with the gas mixture comprising hydrogen and carbon dioxide.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.

A hydrogen feed stream comprising one or more impurities selected from the group consisting of nitrogen, argon, methane, carbon monoxide, carbon dioxide, oxygen, and water, is contacted with liquid hydrogen in a cryogenic wash column (CWC) process that produces pure hydrogen with high overall recovery. The waste liquid stream leaving the CWC may be used to improve the performance of upstream hydrogen processing steps.

A hydrogen feed stream comprising oxygen and one or more impurities selected from the group consisting of nitrogen, argon, methane, carbon monoxide, carbon dioxide, and water, is purified using a cryogenic temperature swing adsorption (CTSA) process with high overall recovery of hydrogen. The CTSA is regenerated using an inert gas to prevent an explosive mixture of hydrogen and oxygen from occurring.

A process for steam reforming a hydrocarbon feedstock containing one or more nitrogen compounds, including passing a mixture of the hydrocarbon feedstock and steam through a catalyst bed of one or more nickel steam reforming catalysts disposed within a plurality of externally heated tubes in a tubular steam reformer, each tube having an inlet to which the mixture of hydrocarbon and steam is fed, an outlet from which a reformed gas containing hydrogen, carbon monoxide, carbon dioxide, steam, ammonia and methane is recovered. The steam reforming catalyst at least at the outlet of the tubes comprises nickel dispersed over a porous metal oxide surface present as a coating on a non-porous metal or ceramic structure. The nickel content of the metal oxide coating is in the range of 5 to 50% by weight and the thickness of the coating is in the range of 5 to 150 micrometres.