There is described a method of using a feedstock gas reactor. Reaction of feedstock and combustion gases in the reactor produces hydrogen through pyrolysis of the feedstock gas. At least some of a mixed product stream extracted from the reactor may be recycled to the reactor to drive further pyrolysis of the feedstock gas. A portion of the recycled mixed product stream may be recirculated back to a combustion chamber of the reactor, and a portion of the recycled mixed product stream may be recirculated back to a reaction chamber of the reactor.

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.

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 present invention relates to a process for producing hydrogen and for separating carbon dioxide from synthesis gas using a physical absorption medium. The process comprises the steps where the synthesis gas and the absorption medium are cooled; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of flash stages, wherein co-absorbed carbon monoxide, hydrogen and carbon dioxide are separately removed from the laden absorption medium; hydrogen is separated from synthesis gas freed of carbon dioxide in a physical separation step, wherein hydrogen as product gas and an offgas comprising hydrogen, carbon monoxide and carbon dioxide are obtained; product gas hydrogen and carbon dioxide are discharged from the process. The invention further relates to a plant for performing the process.

A method for improving efficiency of an existing ammonia synthesis gas plant or a new ammonia synthesis gas plant by establishing a combination of secondary steam reforming using oxygen from electrolysis of water for the production of ammonia synthesis gas.

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.

Process and plant for producing hydrocarbon products from a feedstock originating from a renewable source, where a hydrogen-rich stream and on off-gas stream comprising hydrocarbons is formed. A portion of the hydrogen-rich stream is used as a recycle gas stream in a hydroprocessing stage for the production of said hydrocarbon products, and another portion may be used for hydrogen production, while the off-gas stream is treated to remove its H.sub.2S content and used as a recycle gas stream in the hydrogen producing unit, from which the hydrogen produced i.e. make-up hydrogen, is used in the hydroprocessing stage. The invention enables minimizing natural gas consumption in the hydrogen producing unit as well as steam reformer size.

A combined power generation system includes a gas turbine, a heat recovery steam generator (HRSG) generating steam using combustion gas from the gas turbine, a vaporizer vaporizing liquefied ammonia, an ammonia decomposer section decomposing ammonia with the combustion gas, a first exhaust gas line through which exhaust gas from the gas turbine is transferred to the HRSG, a steam turbine generating a rotational force with the steam from the HRSG, a decomposed gas supply line through which decomposed gases generated in the ammonia decomposer section are supplied to a combustor, and a cold heat transfer line absorbing cold heat of the liquefied ammonia and supply the cold heat to the condenser section, and a condenser section condensing the steam from the steam turbine.

A method and to a device for producing a synthesis gas, which contains carbon monoxide and hydrogen, wherein natural gas having a first carbon dioxide partial pressure (CO.sub.2 pressure) is provided and is processed inter alia by means of a pressure increase to form a natural gas input for a thermochemical conversion, in which a synthesis raw gas having a second CO.sub.2 pressure greater than the first CO.sub.2 pressure is produced, from which synthesis raw gas at least carbon dioxide is subsequently separated in order to obtain the synthesis gas and carbon dioxide, at least some of which is returned and is used in the thermochemical conversion of the natural gas input. To separate carbon dioxide, the synthesis raw gas is conducted across the one membrane on the retentate side, which membrane is permeable to carbon dioxide and is flushed on the permeate side by the provided natural gas.

Synthesis gas containing nitrogen as the majority component is processed to increase the hydrogen to carbon dioxide ratio. Nitrogen, carbon dioxide, and other contaminants are subsequently removed by a purification unit to produce a purified hydrogen gas stream. A recycle stream within the purification unit helps achieve a hydrogen purity greater than 99.9 percent, and hydrogen recovery greater than 99 percent.