Method for production of blue ammonia

Abstract

The plant and method for producing hydrogen and / or ammonia of the present invention provides for lowering the level of contaminants such as CO, CO2 or H2O and inerts such as Ar and CH4 in the ammonia synthesis gas, thereby increasing the concentration of hydrogen in the process gas to a minimum of 99%(v / v), by having one or more hydrogen purification unit(s) downstream to the CO2 capture section and optionally upstream to the nitrogen wash unit.

Description

[0001] Title: Method for Production of Blue Ammonia

[0002] Field of Invention

[0003] The present invention provides a plant and a method for producing hydrogen and / or ammonia, providing for a high percentage of carbon capture and a process gas comprising 99% (v / v) or more of hydrogen, e.g. 99.9% (v / v) of hydrogen. Both the hydrogen and the ammonia can be considered ‘blue’ or “low carbon” by sequestering the CO2 captured in the CO2 removal step included in the invention. ‘

[0004] Background Art

[0005] Blue ammonia is a fossil fuel-based product produced with minimum emission of CO2 to the atmosphere. It is seen as a transition product between conventional fossil fuel-based ammonia and green ammonia produced from green or renewable power, water and air. The CO2 resulting from a blue ammonia production shall be stored permanently or converted into other chemicals. The main steps for producing blue ammonia are essentially the same as for producing conventional fossil fuel-based ammonia, the difference being that more of the carbon stemming from the carbon fuel is captured, providing a possibility for further processing.

[0006] The industry goal is that blue ammonia does not release any carbon dioxide when used as fertilizer or burned. Currently available technology traps nearly all CO2 generated during the conversion process making ammonia one of the first carbon free fuel options for mass use. Blue ammonia is considered an environmentally friendly product which can be used until sufficient renewable or green power is available for producing green ammonia.

[0007] In a plant for ammonia synthesis, including the synthesis of blue ammonia, the level of contaminants which may poison the sensitive ammonia synthesis catalyst and the level of inert gases present in the ammonia synthesis gas is often an issue for ammonia synthesis. In particular, an increase of inerts such as Ar or CH4 in the loop reduces the concentration of reactants H2 and N2 and increases the recycle flow. This means a larger catalyst volume in the converter and a higher power consumption for the synthesis gas compressor are required.

[0008] Therefore, there is a need in the art for sustainable solutions which reduce the level of inerts in the ammonia synthesis gas before entering the ammonia synthesis loop. One of the purposes of the final purification step upstream of the ammonia production is to remove all undesired components from the ammonia synthesis gas. This can typically be achieved by one of the following: Methanation, formally the standard concept with the disadvantage, that the methane content is not removed, but even increased, since in this process, the carbon oxides (carbon monoxide and carbon dioxide) are converted to methane;

[0009] Pressure Swing Adsorption step, which can replace the methanation, since this process produces pure hydrogen, which can be mixed with pure nitrogen; or

[0010] Liquid Nitrogen Wash, which produces an ammonia syngas for a so-called "inert free" ammonia synthesis loop, that can be operated without the withdrawal of a purge gas stream.

[0011] If there is argon in the PSA feed, the requirement of low argon content in the hydrogen product from the PSA has a big impact on obtainable PSA efficiency. This is a disadvantage since low argon in the hydrogen product is desired but also a high PSA efficiency / hydrogen recovery. Purging from the loop may therefore be needed when a PSA is used.

[0012] Summary of the Invention

[0013] The present invention refers to a plant and method for producing hydrogen and / or ammonia with a high percentage of carbon dioxide removal, preferably >99%(v / v) CO2, when compared to the standard method where optimally between about 90-93% (v / v) CO2 removal is achieved and for obtaining a process gas or hydrogen rich stream comprising at least 99%(v / v) hydrogen gas.

[0014] The plant and method for producing hydrogen and / or ammonia of the present invention provides for lowering the level of contaminants such as CO, CO2 or H2O and inerts such as Ar or CH4 in the ammonia synthesis gas, thereby increasing the concentration of hydrogen in the process gas to a minimum of 99%(v / v) in a hydrogen purification section, by including one or more PSA unit(s) downstream to the CO2 capture section , in plant for synthesis of hydrogen and / or ammonia.

[0015] In a preferred embodiment, said one or more PSA unit(s) are upstream to a nitrogen wash unit or section.

[0016] In a preferred embodiment, said hydrogen purification section comprises a PSA unit followed by a membrane.

[0017] Said hydrogen purification section recovers more than 80% of the hydrogen in the synthesis gas at a hydrogen purity above 99% (v / v), e.g. 99.9% (v / v) and provides an off-gas comprising less than 2% of the hydrogen in synthesis gas and the balance as hydrogen rich fuels.

[0018] The invention provides a solution for considerably reducing the required recycle flow of carbon comprising streams in plants where a high carbon capture is required. Besides saving recycle compressor power it also reduces the size of plant where the recycle has affect.

[0019] Definitions

[0020] Ammonia synthesis catalysts mean, within the context of the present invention, any catalysts suitable for synthesizing ammonia and also suitable for cracking ammonia. These catalysts are preferably iron (Fe) based but may also comprise other catalysts suitable for the same purpose and operating at similar conditions.

[0021] Blue Ammonia is ammonia that is created from using fossil fuel where at least 90% of the Carbon in the fossil fuel is captured to be used in other products and processes or to be stored.

[0022] Catalyst poison means a substance that reduces the effectiveness of a catalyst in a chemical reaction. In theory, because catalysts are not consumed in chemical reactions, they can be used repeatedly over an indefinite period. In practice, however, poisons, which come from the reacting substances or products of the reaction itself, accumulate on the surface of solid catalysts and cause their effectiveness to decrease. For this reason, when the effectiveness of a catalyst has reached a certain low level, steps are taken to remove the poison or replenish the active catalyst component that may have reacted with the poison. Commonly encountered poisons include carbon on the silica-alumina catalyst in the cracking of petroleum; sulfur, arsenic, or lead on metal catalysts in hydrogenation or dehydrogenation reactions; and oxygen and water on iron catalysts used in ammonia synthesis.

[0023] Contaminant means any substances or elements which are not desirable. Within the context of the present invention, contaminants comprise catalyst poisons.

[0024] Electrolysis of water means decomposition of water into oxygen and hydrogen gas due to the passage of an electric current.

[0025] Flash gas means an intermediate gas stream obtained during desorption of CO2 in a solvent based CO2 removal step.

[0026] Fuel systems comprise fuel systems for supply of fuel to the combustion side of tubular reformers and / or fired heaters and / or auxiliary boilers and / or gas turbines. These systems comprise one or more burners in which the incoming fuel streams are burned together with air at variable temperature and pressure.

[0027] Hydrogen purification unit, system or section, also known as a hydrogen purifier or hydrogen purging system, is a device or system used to remove impurities from hydrogen gas. The primary purpose of a hydrogen purification unit is to ensure that the hydrogen gas meets the required purity standards for specific applications. Impurities in hydrogen gas can negatively impact the performance and efficiency of processes that rely on hydrogen, such as fuel cells or chemical reactions.

[0028] High-pressure electrolysis (HPE) is the electrolysis of water by decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to the passing of an electric current through the water at elevated pressure, typically above 10 bar.

[0029] Make-up ammonia or Traded Ammonia comprises ammonia (NH3) and water (H2O), preferably between 0,2 to 0,5% of water content. It is usually supplied as a liquid but may also be a solution comprising different physical states. The effect of water comprised in ammonia feedstock in the ammonia decomposition process is primarily that due to poisoning the process, which usually has to take place at a high temperature. This will increase process cost for ammonia decomposition as well as cost of construction materials in the plant. According to National Bureau of Standards ammonia shall conform to the following properties: minimum purity of 99,98% (wt), maximum 0,0005% (wt) oil and maximum 0,02% (wt) moisture.

[0030] Membrane separation uses selective permeability of membranes to separate hydrogen from other gases. Hydrogen permeates through the membrane faster than other gases.

[0031] Nitrogen Wash Unit (NWU) is mainly used to produce ammonia synthesis gas. It is usually the last purification step in the ammonia production process sequence upstream of the ammonia production. A NWU typically consists of an adsorber unit where solvent traces of an upstream acid gas scrubbing process (e.g. methanol, water), traces of carbon dioxide or other compounds are completely removed in a molecular sieve bed in order to avoid freezing and subsequently blockage in the low temperature process which operates at temperatures down to 80 K (-193 °C or -315 °F).

[0032] The NWU has two main functions:

[0033] Removal of impurities or contaminants such as carbon monoxide, CO2 or H2O and inerts such as argon and methane from the hydrogen rich stream;

[0034] - Addition of the required stoichiometric amount of nitrogen to the hydrogen rich stream to achieve the correct ammonia synthesis gas ratio of hydrogen to nitrogen of 3:1 .

[0035] Off gas of a NWU is an output stream from the nitrogen wash unit and may comprise CO, Ar, and CH4, H2 and N2. This stream can be partially or totally used in the reforming section or in the fuel systems, either as fuel and / or as process gas.

[0036] Membrane Separation Units use specialized membranes that selectively allow certain gases to pass through while blocking others. These membranes can be designed to remove impurities such as carbon-containing compounds (e.g. carbon dioxide, carbon monoxide and / or methane) and other gases from the hydrogen stream. Membrane units are often compact and can be used for small-scale purification applications.

[0037] PSA means pressure swing adsorption. Pressure Swing Adsorption (PSA) Units utilize adsorption beds filled with specialized adsorbents to selectively remove impurities from hydrogen gas. The adsorbent material preferentially adsorbs impurities while allowing hydrogen to pass through. The unit typically operates by cycling between adsorption and regeneration phases, where impurities are adsorbed during the adsorption phase and then desorbed during the regeneration phase.

[0038] Shift means Water-gas shift reaction (WGSR) or Shift reaction, the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen:

[0039] CO + H2O CO2+ H2

[0040] The WGSR is an important industrial reaction that is used in the manufacture of ammonia, hydrocarbons, methanol, and hydrogen. It is also often used in conjunction with steam reforming of methane and other hydrocarbons. In the Fischer-Tropsch process, the WGSR is one of the most important reactions used to balance the H2 / CO ratio. The water gas shift reaction is a moderately exothermic reversible reaction. Therefore, with increasing temperature the reaction rate increases but the carbon dioxide production becomes less favorable. Due to its exothermic nature, high carbon monoxide percentage is thermodynamically favored at low temperatures. Despite the thermodynamic favorability at low temperatures, the reaction is faster at high temperatures.

[0041] Shift unit or section means a process step where the shift reaction is performed.

[0042] Description of the Invention

[0043] The present invention refers to a plant and method for producing ammonia with a high percentage of carbon dioxide, preferably >99% (v / v) CO2, when compared to the standard method where optimally between about 90-93% (v / v) CO2 removal is achieved and for obtaining a process gas or hydrogen rich stream comprising at least 99% (v / v) hydrogen gas.

[0044] The method of the present invention provides for lowering the level of contaminants in the ammonia synthesis gas, carbon monoxide (CO), carbon dioxide (CO2) and steam (H2O) and inerts such as argon (Ar) or methane (CH4), thereby increasing the concentration of hydrogen in the process gas to a minimum of 99%(v / v), by including one or more PSA unit(s) downstream to the CO2 capture section, optionally followed by one or more membrane(s), optionally upstream to a nitrogen wash unit or section in a plant for synthesis of hydrogen and / or ammonia.

[0045] In a preferred embodiment, the present invention refers to a plant for producing hydrogen and / or ammonia from a hydrocarbon feed, comprising: a) an optional source of oxygen; b) an optional source of nitrogen; cc) an optional desulfurization section; dd) a reforming section; ee) a shift section; ff) a CO2 removal section; g) a hydrogen purification section; h an optional nitrogen washing unit or section; f) an optional ammonia synthesis section; and ii) fuel systems, wherein the hydrogen purification section comprises at least one hydrogen purification unit located downstream to the CO2 removal section. In a preferred embodiment, the one or more hydrogen purification unit(s) are located downstream to a nitrogen washing unit .

[0046] In another preferred embodiment, the efficiency of one or more of the hydrogen purification unit(s) in the hydrogen purification section is at least 80%, i.e. recovering at least 80% of hydrogen available, with a hydrogen purity above 99% (v / v),90%, preferably above 99.9% (v / v)% or more.

[0047] In another embodiment, aa reforming section in the plant comprises a pre-reformer.

[0048] In another embodiment, the reforming section comprises an autothermal reformer.

[0049] In another embodiment, a shift section in the plant comprises a high temperature (HT) reactor or a medium temperature (MT) reactor or a low temperature (LT) reactor or any combination of at least two of them.

[0050] In another embodiment, a carbon dioxide removal section in the plant comprises one or more amine-based CO2 removal units.

[0051] In another embodiment, the carbon dioxide removal section comprises one or more hot- potassium carbonate-based CO2 removal units.

[0052] In another embodiment, the carbon dioxide removal section comprises one or more Selexol- based CO2 removal unit(s).

[0053] In another embodiment, a hydrogen purification section in the plant comprises one or more PSA unit(s). Preferably, the hydrogen purification section comprises a first PSA unit upstream to one or more PSA units or other types of hydrogen purification unit(s). Most preferably, the hydrogen purification section comprises a first PSA unit upstream to a membrane or a second PSA unit.

[0054] In another embodiment, the plant comprises at least one compressor, downstream to a PSA unit. Preferably, the hydrogen purification section comprises at least one compressor, downstream to a PSA unit.

[0055] In another embodiment, the source of oxygen and / or nitrogen stream(s) is an air separation unit (ASU), which means that an ASU (or one or more of similarly efficient alternative(s)) can be used to provide an oxygen stream to be used in the reforming section, preferably in an autothermal reforming section or unit, in a plant for producing hydrogen, hydrogen and ammonia or ammonia, and can also be used to provide a nitrogen stream to be used in an ammonia plant.

[0056] In another embodiment, one or more of said oxygen and / or nitrogen stream(s) are fully or partially imported into the plant.

[0057] In another embodiment, one or more equipment can be located between the carbon capture section and the hydrogen purification unit(s), preferably one or more PSA(s), most preferably two or more PSA and / or a membrane.

[0058] In another embodiment, one or more equipment can be located in between the hydrogen purification unit(s), preferably one or more PSA(s),most preferably two or more PSA), or membrane or a nitrogen wash unit.

[0059] In another embodiment, a nitrogen wash unit (NWU) comprises a dryer unit or section.

[0060] In another embodiment, the fuel systems comprise one or more fired heaters, electrical heaters, auxiliary boilers, and gas turbines.

[0061] In another embodiment, the fuel systems comprise one or more burners.

[0062] In a preferred embodiment, the present invention refers to a process for producing hydrogen and / or ammonia from a hydrocarbon feed comprising the steps of: a) Obtaining an oxygen stream, preferably comprising less than 3000 ppmv Ar; b) Optionally obtaining a nitrogen stream, preferably comprising less than 500 ppmv vol. Ar; c) Optionally removing sulphur and other contaminants from the hydrocarbon feed; d) Reforming said hydrocarbon feed using part or all of the oxygen stream obtained in a) for obtaining synthesis gas comprising CO, CO2, H2, H2O and CH4; e) Sending the reformed gas through a shift reaction step, reducing the CO content; f) Sending the shifted gas to a CO2 removal step where it is split into at least two streams: (i) a carbon dioxide rich stream, (ii) a carbon dioxide depleted, hydrogen containing stream and optionally (iii) a flash gas fuel stream; g) Purifying said hydrogen containing stream in a hydrogen purification section, obtaining a hydrogen rich stream (VI) comprising at least 99.0% (v / v) hydrogen and optionally using part of said hydrogen rich stream (V) as fuel; h) Optionally compressing the off-gas outlet (I) from the hydrogen purification section; i) Optionally adding part or all of the nitrogen stream obtained in b) to the hydrogen rich stream (VI) to obtain a make-up synthesis gas stream comprising N2 and H2, j) Sending part or all of said make-up synthesis gas stream through an ammonia synthesis section, where it is converted to NH3

[0063] In another embodiment, a part of the make-up synthesis gas stream is sent to the fuel systems.

[0064] In a preferred embodiment, the hydrogen purification stage comprises a pressure swing adsorption step, followed by a membrane separation step. Preferably, the off-gas from a PSA unit (I) is compressed and used as feed to a membrane. This membrane produces a hydrogen rich stream (IV), which is used as fuel and an off-gas (II) which is recycled to the reforming section as feed and / or optionally used as fuel (III). The off-gas (I) from said PSA unit may be compressed to achieve a pressure of, at least, 2 bar higher than the required pressure at the inlet of the reforming section, which will allow the off-gas from the membrane to be used as feed in the reforming section without further compression.

[0065] In another embodiment, the hydrogen purification step is a pressure swing adsorption (PSA).

[0066] In another embodiment, the off-gas stream from, at least, the first PSA unit is compressed to achieve a pressure equal to or higher than the inlet pressure to the one in the first PSA unit.

[0067] In another embodiment, wherein the hydrogen purification step comprises two or more PSA units and the off-gas stream (I) from, at least, the first PSA unit is compressed to achieve a pressure of at least 8 bar.

[0068] In another embodiment, the hydrogen rich stream (IV, V, VII) from one or more of the hydrogen purification PSA units is used as fuel, preferably the hydrogen rich stream from the membrane (IV), last PSA unit, i.e. , the unit located further downstream in the hydrogen purification section.

[0069] In another embodiment, the hydrogen rich stream (V, VI) obtained from the hydrogen purification step preferably comprises less than 10 ppmv combined of any one of CO, CO2 and / or H2O,,, as well as less than 50-100 ppmv CH4.

[0070] In another embodiment, nitrogen is added to the hydrogen rich stream (VI)..

[0071] In another embodiment, nitrogen is optionally added to the hydrogen rich stream (VI) to obtain a make-up synthesis gas stream comprising N2 and H2 in a H2 / N2 ratio preferably between 2.9 and 3.1.

[0072] In another embodiment, when the hydrogen purification section comprises more than one PSA, the off-gas stream (I) from the last PSA unit is compressed to achieve a pressure at least 2 bar higher than the inlet pressure to the reforming section.

[0073] In another embodiment, the off gas from the hydrogen purification step, preferably from the membrane separationpressure swing adsorption (PSA) step, is used in the reforming section (II) and / or in fuel systems (III)..

[0074] In another preferred embodiment, the present invention refers to a process for producing ammonia comprising the steps of: a) Optionally removing sulphur and other contaminants from a hydrocarbon feed; b) Reforming said hydrocarbon feed and obtaining synthesis gas comprising CO, CO2, H2, H2O and CH4; c) Sending said reformed gas through a shift reaction step, reducing the CO content; d) Sending the shifted gas from step c) to a CO2 removal step where it is split into at least two streams: a carbon dioxide rich stream; (1) and a carbon dioxide depleted, hydrogen containing stream (2) and optionally a flash gas fuel stream; e) Sending said hydrogen containing stream (2) through at least one hydrogen purification unit(s), where a hydrogen rich stream (5) comprising at least 99.0 % (v / v) hydrogen is produced and adding nitrogen (N2) to said hydrogen rich stream to obtain a synthesis gas stream (6) comprising N2and H2, f) Sending a part or all said synthesis gas stream (6) through an ammonia synthesis section, where it is converted to NH3 and optionally a part of the synthesis gas stream (6) is sent to the fuel systems.

[0075] In another preferred embodiment, at least one of the hydrogen purification unit(s) is a Pressure Swing Adsorption (PSA) unit.

[0076] In another embodiment, one or more of H2O, CO, CO2, Ar and CH4is removed in a tail gas streamfrom the, at least one, PSA unit.

[0077] In another embodiment, said tail gas stream (4) from a PSA unit comprises less than 10%(v / v) of H2and is recycled back into said PSA.

[0078] In another embodiment, one or more steps can occur between the CO2 removal step and the hydrogen purification step.

[0079] In another embodiment, one or more steps can occur between the sequential hydrogen purification step(s), optionally comprising a nitrogen wash step.. In another embodiment, where a nitrogen wash unit or section is present, nitrogen is added to the hydrogen rich stream (5) in a nitrogen wash unit (NWU) and one or more of CO, Ar and / or CH4 is removed in an off-gas stream (7) from the NWU.

[0080] In another embodiment, nitrogen is added to a hydrogen rich stream to obtain a synthesis gas stream (6) comprising N2 and H2 in a H2 / N2 ratio between 2.9 and 3.1.

[0081] In another embodiment, CO2 and H2O are removed from the hydrogen rich stream (5) in a dryer unit or section, upstream to the nitrogen wash step.

[0082] In another embodiment, the off-gas stream II, Illis used in the reforming section (II) and / or in fuel systems (III).

[0083] In another embodiment, where an autothermal reformer (ATR) is used to obtain syngas, the oxygen provided to said ATR comprises low content in argon (Ar), ideally less than O..3% (v / v) in Ar, most preferably less than 0.2% (v / v) Ar. This level of purity in oxygen gas can be provided when using an air separation unit (ASU) upstream to the ATR.

[0084] In another embodiment, where an autothermal reformer (ATR) is used to obtain syngas, the oxygen provided to said ATR comprises low content in argon (Ar), ideally down to 0.02% (v / v) in Ar, most preferably down to 0.01%. This level of purity in oxygen gas can be provided when using an air separation unit (ASU) upstream to the ATR.

[0085] In another embodiment, the process of the invention comprises an optional step for obtaining a nitrogen stream, comprising less than 500 ppm vol. Ar, preferably down to 100 ppm, most preferably down to 10 ppm.

[0086] In another embodiment, the vent stream or off gas (VII) from the hydrogen purification step, preferably from the pressure swing adsorption (PSA) step, which is rich in hydrogen and argon, is used in the fuel systems.

[0087] In another embodiment, at least 80%, preferably 84% of hydrogen is recovered in hydrogen-rich streams (V, VI) which comprise 99% (v / v), preferably 99.9% (v / v) or more of hydrogen.

[0088] In another embodiment, the off-gas streams II and III comprise less than 2%, preferably less than 1%, more preferably less than 0.6% of the hydrogen in the syngas to the hydrogen purification section.

Claims

Claims1. Plant for producing hydrogen and / or ammonia, comprising: a) an optional source of oxygen; b) an optional source of nitrogen; c) an optional desulfurization section; d) a reforming section; e) a shift section; f) a CO2 removal section; g) an optional nitrogen washing unit; h) an optional ammonia synthesis section; and i) fuel systems, wherein at least one hydrogen purification unit(s) is / are located downstream to said CO2 removal section and upstream to said optional nitrogen washing unit.

2. Plant according to claim 1 wherein the efficiency of said one or more hydrogen purification unit(s) is at least 80%, recovering at least 80% of hydrogen available, with a hydrogen purity above 99% (v / v) or more.

3. Plant according to any one of claims 1 or 2 wherein the reforming section comprises a prereformer.

4. Plant according to any one of claims 1 to 3 wherein the reforming section comprises an autothermal reformer.

5. Plant according to any one of claims 1 to 4 wherein the shift section comprises a high temperature (HT) reactor or a medium temperature (MT) reactor or a low temperature (LT) reactor or any combination of at least two of them.

6. Plant according to any one of claims 1 to 5 wherein the carbon dioxide removal section comprises one or more amine-based CO2 removal units.

7. Plant according to any one of claims 1 to 6 wherein the carbon dioxide removal section comprises one or more hot-potassium carbonate-based CO2 removal units.

8. Plant according to any one of claims 1 to 7 wherein the carbon dioxide removal section comprises one or more Selexol-based CO2 removal unit(s).

9. Plant according to any one of claims 1 to 8 wherein one or more of the hydrogen purification unit(s) are PSA unit(s).

10. Plant according to claim 9, wherein a a PSA unit is upstream to a membrane or to one or more PSA unit(s).

11. Plant according to any of claims 1 to 10 comprising at least one compressor, downstream to a PSA unit.

12. Plant according to any one of claims 1 to 11 wherein an air separation unit is a source of oxygen and / or nitrogen stream(s).

13. Plant according to any one of claims 1 to 11 wherein oxygen and / or nitrogen stream(s) are imported into the plant.

14. Plant according to any one of claims 1 to 13, wherein the fuel systems comprise one or more fired heaters, electrical heaters, auxiliary boilers, and gas turbines.

15. Plant according to the previous claim, wherein the fuel systems comprise one or more burners.

16. Process for producing hydrogen and / or ammonia comprising the steps of: a) Optionally obtaining an oxygen stream; b) Optionally obtaining a nitrogen stream; c) Optionally removing sulphur and other contaminants from a hydrocarbon feed; d) Reforming said hydrocarbon feed optionally using at least part of the oxygen stream from a) and obtaining synthesis gas comprising CO, CO2, H2, H2O and CH4; e) Sending said reformed gas through a shift reaction step, reducing the CO content; f) Sending the shifted gas to a CO2 removal step where it is split into at least two streams: (i) a carbon dioxide rich stream, (ii)) a carbon dioxide depleted, hydrogen containing stream and optionally (iii) a flash gas fuel stream; g) Sending said hydrogen containing stream through at least one hydrogen purification unit(s), where a hydrogen rich stream comprising at least 99.0% (v / v) hydrogen is produced andoptionally (i) adding nitrogen (N2) to said hydrogen rich stream to obtain a synthesis gas stream (6) comprising N2 and H2; and / or (ii) using part of said hydrogen rich stream as fuel; h) Optionally compressing the off-gas outlet (I) from the hydrogen purification section; i) Optionally adding part or all of the nitrogen stream obtained in b) to the hydrogen rich stream (VI) to obtain a make-up synthesis gas stream comprising N2 and H2, j) Optionally sending part or all of said make-up synthesis gas stream through an ammonia synthesis section, where it is converted to NH3 and optionally a part of the synthesis gas stream (6) is sent to the fuel systems.

17. Process according to claim 16 wherein the oxygen stream comprises less than 3000 ppmv Ar and the nitrogen stream, comprising less than 500 ppmv vol. Ar.

18. Process according to any one of claims 16 to 17, wherein at least one of the hydrogen purification steps is a Pressure Swing Adsorption (PSA).

19. Process according to any one of claims 16 to 18, wherein the off-gas stream (I) from, at least, the last PSA step is compressed to achieve a pressure at least 2 bar, equal to or higher than the inlet pressure to the reforming section.

20. Process according to any one of claims 16 to 19, wherein the hydrogen purification step comprises two or more PSA steps, the off-gas stream (I) from, at least, the first PSA unit is compressed to achieve a pressure of at least 8 bar.

21. Process according to any one of claims 16 to 20, wherein the compressed off gas from the first PSA unit is fed into a membrane.

22. Process according to any one of claims 16 to 21 wherein the off gas (III) of said membrane is used as fuel.

23. Process according to any one of claims 16 to 22 wherein the hydrogen depleted stream from said membrane (II) is recycled as feed to the reforming section.

24. Process according to any one of claims 16 to 23, wherein the hydrogen rich stream (IV) from the membrane or from the last PSA unit is used as fuel.

25. Process according to any one of claims 16 to 24 wherein the hydrogen rich stream obtained from the hydrogen purification step comprises less than 10 ppmv combined of any one of CO, CO2 and / or H2O, as well as less than 50-100 ppmv CH4.

26. Process according to any one of claims 16 to 25, wherein nitrogen is optionally added to the hydrogen rich stream to obtain a make-up synthesis (5) in a nitrogen wash unit (NWU) and one or more of CO, Ar and / or CH4 is removed in an off-gas stream comprising N2 and H2, preferably in a H2 / N2 ratio between 2.9 and 3.1.

27. Process according to any one of claims 16 to 26 wherein the vent stream or off gas (VII) from the hydrogen purification step, preferably from the pressure swing adsorption (PSA) step, which is rich in hydrogen and argon, is used in the reforming section and / or in fuel systems.

28. Process according to any one of claims 16 to 27 wherein at least 80%, preferably 84% of hydrogen is recovered in hydrogen-rich streams (V, VI) which comprise 99% (v / v) or more, preferably 99.9% of hydrogen.

29. Process according to any one of claims 16 to 28 wherein the off-gas streams II and III comprise less than 2%, preferably less than 1 %, more preferably less than 0.6% of the hydrogen in the syngas to the hydrogen purification section.

30. Process according to any one of claims 16 to 29 wherein the hydrogen purification step comprises two or more PSA steps and the hydrogen rich stream from the last PSA is used as additional hydrogen product.

31. Process according to any one of claims 16 to 30 wherein the tail gas (4) from a PSA comprises less than 10%(v / v) of H2 and is recycled back into said PSA.

32. Process according to any one of claims 16 to 31 wherein the reforming step comprises autothermal reforming and the oxygen gas used comprises up to 0,3% (v / v) of argon.

33. Process according to any one of claims 16 to 32 wherein nitrogen is added to a hydrogen rich stream to obtain a synthesis gas stream (6) comprising N2 and H2 in a H2 / N2 ratio between 2.9 and 3.1.

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