Processes and apparatuses for recovering a high purity carbon dioxide stream. A first separation zone that may include a cryogenic fractionation column provides the high-purity CO.sub.2 stream. A vapor stream from the cryogenic fractionation column is passed to a second separation zone to separate the CO.sub.2 from the other components. The second separation zone may include a pressure swing adsorption unit or a solvent separation unit. The second separation zone provides a hydrogen enriched gas stream that may be used in a gas turbine. The second stream from the second separation zone includes carbon dioxide and, after a pressure increase in a compressor, may be recycled to the first separation zone.

A plant including a reverse water gas shift (RWGS) section including a first feed including hydrogen to the RWGS section, and a second feed including carbon dioxide to the RWGS section, or a combined feed comprising hydrogen and carbon dioxide to the e-RWGS section, a water removal section downstream the RWGS section, a compressor downstream the water removal section, and a cryogenic CO2 separation section downstream the compressor, wherein the plant has means for recycling at least a portion of a CO2 rich condensate to the RWGS section or to a feed to the RWGS section, and wherein the RWGS section is an electrically heated RWGS (e-RWGS) section.

The invention relates to a method and also a device for producing a gas product, wherein a first gas stream is combined with a second gas stream and the first gas stream that is present at a lower output pressure than the second gas stream is fed to a mechanical compressor in order to be compressed to the preset pressure of the gas product. It is characteristic in this case that the pressure of the first gas stream is elevated using a gas jet compressor arranged upstream of the mechanical compressor, to which gas jet compressor at least a part of the second gas stream is fed as pumping medium.

Methods which utilize low-grade heat produced in the hydrogen production process to reduce the energy required by the compressor to compress the PSA tail gas stream. The low-grade heat is used to produce a low-pressure steam stream. The low pressure steam stream is introduced to a steam turbine to generate power. The power produced by the turbine reduces the amount of power required to operate the tail gas compressor, thus reducing the overall power requirement for the process.

Integrated steam cracking processes and hydrogen production processes are described. The steam cracker off gas stream and the synthesis gas stream are sent to the separation zone of the hydrogen production process and separated into a hydrogen stream, a carbon dioxide stream, and a second off gas stream in a separation zone. The second off gas stream comprises methane from the synthesis gas and methane from the steam cracker off gas stream, as well as carbon monoxide from the synthesis gas stream. All or a portion of the hydrogen product stream is sent to the steam cracking zone as fuel for the steam cracker reactor. The remainder (if any) of the hydrogen product stream can be recovered. The second off gas stream is sent to the hydrogen production zone as feed for the synthesis gas reactor. The carbon dioxide can be recovered.

A process for preparing hydrogen by a catalytic conversion of sour natural gas, including feeding sour natural gas and one or more H2S recycled streams, optionally mixed with fresh CO2, to a reformer reactor packed with a catalyst activated in-situ by sulfidation. An apparatus for carrying out the process, to convert sour natural gas to sweet natural gas, hydrogen and carbon disulfide, and catalysts that can be used in the process, are also disclosed.

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 method for producing hydrogen from biomass. For this purpose, the biomass is fed into a fluidized bed reactor, in which the biomass is converted into a flow of products. Solid particles are separated in at least one cyclone. Further solid particles and hydrocarbons are separated in a venturi scrubber. A flow of products is generated in the biodiesel scrubbing, which is fed into a water scrubbing and then to a cooling unit for separation. A flow of products is generated in the high-purification of gas, which is fed into a water gas conversion and CO.sub.2 removal. A flow of products is generated in the gas separation.

A gas-liquid separation apparatus includes a tank and a flow reducing component. An inlet is formed in a middle of the tank. A hydrogen outlet is formed in a top of the tank. A processing chamber connected to the inlet. The flow reducing component is formed in the processing chamber and maintained above the inlet. The flow reducing component forms a flow reducing space and a flow partition chamber in a part of the processing chamber above the inlet, a gas-liquid initial separation space in the processing chamber and below the flow reducing component, at least one connection hole and a connection channel. The flow partition chamber is connected to the flow reducing space through the at least one connection hole. The gas-liquid initial separation space is connected to the flow partition chamber through the connection channel. The flow reducing space is arranged to be connected to the hydrogen outlet.

A plant and process for producing a hydrogen rich gas are provided, said process including the steps of: steam reforming a hydrocarbon feed into a synthesis gas; shifting the synthesis gas and conducting the shifted gas to a hydrogen purification unit, subjecting CO.sub.2-rich off-gas from the hydrogen purification unit to a carbon dioxide removal in a low temperature CO.sub.2-removal section and recycling CO.sub.2-depleted off-gas rich in hydrogen to the process. A drying unit upstream the CO.sub.2-removal section is provided, under the addition of regeneration gas produced in the plant and process.