Method and device for generating ammonia synthesis gas with low release of carbon dioxide

Abstract

The invention relates to a method and a device for generating a make-up gas (15), which is free of carbon monoxide and consists largely of hydrogen and oxygen, for ammonia synthesis, wherein a hydrocarbon-containing input (2) is reacted in a reforming device (B) in order to obtain a raw synthesis gas (5) containing methane and argon, from which, with the aid of water gas conversion (G) and acid gas scrubbing (H), a hydrogen-rich fraction (8) comprising carbon monoxide, methane and argon and designated as raw hydrogen is produced, which is used for forming the make-up gas (15). The invention is characterised in that the raw hydrogen (8), with the aid of cryogenic gas decomposition (K), is separated into a hydrogen fraction (30) which is free of carbon monoxide, methane and argon and into a methane-rich, argon- and nitrogen-poor residual gas (12), which is returned and reacted in the reforming device (B) in order to obtain the raw synthesis gas (5) containing methane and argon, while at least some of the hydrogen fraction (30) which is free of carbon monoxide, methane and argon is forwarded on as the make-up gas (15) or is supplemented with nitrogen to form the make-up gas (15).

Description

[0001] Description

[0002] Method and apparatus for producing ammonia synthesis gas with low carbon dioxide release

[0003] The invention relates to a process for producing a carbon monoxide-free make-up gas for ammonia synthesis, consisting largely of hydrogen and nitrogen, wherein a hydrocarbon-containing feedstock is converted in a reforming device to obtain a synthesis crude gas containing methane and argon, from which a comprehensive fraction, referred to as crude hydrogen, is produced with the aid of water gas conversion and is used to form the make-up gas.

[0004] Furthermore, the invention relates to a device for carrying out the method according to the invention.

[0005] Ammonia is one of the world's most widely produced chemicals. It serves primarily as a raw material for the production of fertilizers, but is also increasingly gaining importance as an energy source and hydrogen storage medium. On an industrial scale, it is synthesized almost exclusively from nitrogen and hydrogen using the Haber-Bosch process. While hydrogen and nitrogen are still predominantly produced today with the formation and release of large amounts of climate-damaging carbon dioxide, there are increasing efforts to dispose of the resulting carbon dioxide through sequestration or material utilization rather than releasing it into the atmosphere.

[0006] In the Haber-Bosch process, an ammonia synthesis gas consisting primarily of hydrogen and nitrogen, in which the two substances are present in the stoichiometric ratio of 3:1 for ammonia synthesis, is fed into an ammonia synthesis reactor at a pressure between 100 and 200 bar(a) to be exothermically converted to ammonia with catalytic support in an ammonia reactor. Due to thermodynamic limitations, however, the conversion is incomplete, resulting in a gas mixture that contains significant amounts of hydrogen and nitrogen in addition to ammonia.This gas mixture leaves the ammonia reactor at a temperature between 400 and 450°C and is subsequently cooled in a series of heat exchangers to separate ammonia by condensation and to obtain a recycle gas consisting largely of hydrogen and nitrogen, containing residues of non-separated ammonia. This recycle gas is returned to the ammonia reactor in a synthesis cycle to increase the ammonia yield and is mixed with a make-up gas to form ammonia synthesis gas.

[0007] According to the state of the art, to produce a make-up gas for ammonia synthesis, a hydrocarbon-containing feedstock, such as natural gas, is desulfurized if necessary and then reformed with oxygen or oxygen-enriched air, for example, by partial oxidation or autothermal reforming, to form a synthesis raw gas consisting largely of hydrogen, carbon monoxide, and carbon dioxide. This raw gas, especially when reforming is carried out using atmospheric oxygen, also contains significant amounts of argon. The synthesis raw gas is then subjected to a water-gas conversion process to convert the carbon monoxide contained therein with water to hydrogen and carbon dioxide.In a sour gas scrubber, carbon dioxide is separated from the converted gas, yielding a carbon dioxide fraction with a purity sufficient for its sequestration or material use, as well as a hydrogen fraction known as raw hydrogen, which, in addition to hydrogen, also includes argon and residues of carbon monoxide and carbon dioxide.

[0008] To prevent carbon monoxide from entering the ammonia reactor via the make-up gas and poisoning the catalyst material used there, the raw hydrogen is treated according to the state of the art by methanation, nitrogen scrubbing or pressure swing adsorption, whereby carbon monoxide is converted or separated and a largely carbon monoxide-free hydrogen fraction is produced, from which - if necessary by adding nitrogen - the make-up gas is formed, which is referred to as carbon monoxide-free due to its low carbon monoxide content, typically below 10 ppmv.

[0009] During methanation, the carbon monoxide and carbon dioxide contained in the raw hydrogen are converted with hydrogen to water and methane, which, like argon, is inert under the conditions of ammonia synthesis. To prevent an enrichment of methane and argon in the ammonia synthesis cycle, a portion of the recycle gas is continuously removed as so-called purge gas and either discarded or fed to a purge gas separator, which recovers the hydrogen contained in the purge gas at a considerable energy expenditure. Even though methane and argon are inert substances, they have a negative impact on ammonia synthesis because they lower the partial pressures of nitrogen and hydrogen, thus impairing their conversion. Furthermore, they require larger equipment and higher drive power for the compressors used in the synthesis cycle.

[0010] In a nitrogen scrubber, the dried raw hydrogen is cooled against process streams that need to be heated and scrubbed in a column using imported high-pressure nitrogen, which is generally obtained in gaseous form from an air separator and also cooled and liquefied against process streams that need to be heated. The purified gas withdrawn from the top of this scrubber column, which consists primarily of hydrogen and nitrogen and contains only a non-critical amount of carbon monoxide, which is harmful to the ammonia synthesis catalyst, is warmed against process streams that need to be cooled and, if necessary, enriched with nitrogen to achieve the required composition for the make-up gas.After an optional intermediate expansion for the purpose of recovering co-absorbed hydrogen, the nitrogen from the bottom of the scrubbing column, laden with the components separated from the raw hydrogen, is warmed against process streams that are to be cooled and evaporated to a residual gas that, in addition to nitrogen and carbon monoxide, also includes methane and the argon contained in the raw hydrogen. To utilize methane and carbon monoxide for the production of the make-up gas, the residual gas can, in principle, be recycled before the reforming step. However, this involves considerable equipment and financial expenditure due to the avoidance of argon enrichment and the large amount of nitrogen that must be compressed. The residual gas is therefore usually combusted to form carbon dioxide, which cannot be economically separated from the flue gases generated during combustion and is therefore released into the atmosphere.

[0011] Treating the raw hydrogen by pressure swing adsorption allows the hydrogen fraction intended for the formation of the make-up gas to be obtained, largely free of carbon monoxide, with a purity of more than 99.5 vol.%, with inert substances present only in traces in ammonia synthesis. Ammonia synthesis can therefore be operated very effectively without the continuous removal of purge gas from the synthesis cycle. Since the residual gas produced during pressure swing adsorption, which consists largely of combustible substances such as carbon monoxide and methane, also includes the argon contained in the raw hydrogen, it is not recycled before the reforming step but is also burned, releasing carbon dioxide into the atmosphere.

[0012] With the methods described here, only a maximum of 95% of the carbon used in ammonia production can be separated in the form of carbon dioxide and disposed of through sequestration or recycled. Depending on legal requirements and penalties for carbon dioxide emissions, it may be necessary to achieve higher carbon capture quotas. However, given the current state of technology, this is only possible with a very complex and correspondingly expensive residual or recyclable waste treatment process.

[0013] Purge gas treatment can be achieved.

[0014] The present invention has for its object to provide a generic method and a device for carrying out the same, which make it possible to separate more than 95% of the carbon used with less effort than is possible according to the prior art.

[0015] This object is achieved according to the invention in that the raw hydrogen containing carbon monoxide, methane, nitrogen and argon is separated by means of a cryogenic gas separation into a hydrogen fraction free of carbon monoxide, methane and argon and a methane-rich, argon- and nitrogen-poor residual gas, at least a part of which is recycled and converted in the reforming device in order to obtain the synthesis raw gas containing methane and argon, while at least a part of the hydrogen fraction free of carbon monoxide, methane and argon is passed on as make-up gas or supplemented with nitrogen to form the make-up gas.

[0016] The freedom of the hydrogen fraction from carbon monoxide, methane, or argon is understood to mean that it has a carbon monoxide content of less than 10 ppm, a methane content of less than 50 ppm, or an argon content of less than 300 ppm. The methane-rich, argon- and nitrogen-poor residual gas consists of more than 50 vol.% methane, less than 3 vol.% argon, and no more than 20 vol.% nitrogen. It contains at least 70%, preferably more than 90% of the methane, less than 50%, preferably no more than 30% of the argon, and less than 5%, preferably less than 1.5%, of the nitrogen introduced into the cryogenic gas separation.

[0017] Due to the lack of, or very little, nitrogen ballast, the equipment and energy required to recycle all or at least a portion of the residual gas prior to reforming is minimal. Furthermore, due to the absence of argon, there is little or no argon enrichment, meaning that no or very little gas from the recycled residual gas stream needs to be removed as purge gas.

[0018] The raw hydrogen is fed to the cryogenic gas separation process either directly or after a processing step that includes gas drying as a feed (cryogenic feed). During cryogenic gas separation, the cryogenic feed is preferably cooled to such an extent that most of the methane it contains condenses out. The resulting two-phase mixture is separated in a separator, forming a methane-rich liquid phase and a hydrogen-rich gas phase, which contains the majority of the argon and, if present, the methane present in the cryogenic feed.

[0019] containing carbon monoxide. The methane-rich liquid phase present at the pressure of the cryogenic feed is withdrawn from the separator in a low-argon state and evaporated and warmed against the cryogenic feed to be cooled to form a methane-rich gas fraction, which forms at least a portion of the methane-rich, argon- and nitrogen-poor residual gas.

[0020] To separate argon and, if present, carbon monoxide, the hydrogen-rich gas phase obtained in the separator is scrubbed with cryogenic liquid nitrogen, producing a bottoms fraction consisting largely of liquid nitrogen, laden with absorbed argon, methane, and, if present, carbon monoxide, but also containing co-absorbed hydrogen. Nitrogen scrubbing is ideally carried out in such a way that a nitrogen-enriched gas phase consisting largely of hydrogen is obtained, in which carbon monoxide and argon are present in concentrations that allow this gas phase to be used to form the make-up gas for ammonia synthesis without a further separation or purification step. The nitrogen-enriched gas phase, consisting largely of hydrogen, is therefore passed on as make-up gas after warming against process streams to be cooled and, if necessary, after admixing with additional nitrogen.

[0021] Nitrogen scrubbing can be particularly advantageous if the raw hydrogen is treated by methanation and subsequent gas drying, resulting in a cryogenic feed with a carbon monoxide content of a few ppm. Under these conditions, the nitrogen scrubbing process can be designed to remove argon, which can be separated from the hydrogen-rich gas phase obtained in the separator much more easily than carbon monoxide and with less equipment effort.

[0022] The bottoms fraction resulting from nitrogen scrubbing, which contains the vast majority of the argon present in the raw hydrogen, but also hydrogen, methane, and possibly carbon monoxide, is preferably separated into two substreams of different sizes. The larger of these, after evaporation and warming, is discarded against process streams that are to be cooled in order to remove sufficient argon. The smaller substream, on the other hand, is advantageously converted into the methane-rich, argon- and nitrogen-poor residual gas, for which it is combined with the methane-rich liquid phase from the separator or evaporated and warmed independently.

[0023] The cryogenic liquid nitrogen required for nitrogen scrubbing is preferably produced from gaseous nitrogen, which is fed to the cryogenic gas separation unit from a nitrogen source, which may be a cryogenic air separation unit, at a pressure slightly higher than that of raw hydrogen, where it is cooled and liquefied against process streams that are to be heated.

[0024] Preferably, the hydrocarbon-containing feedstock is reformed by steam reforming, partial oxidation, autothermal reforming, or a combination of these processes to form the methane- and argon-containing synthesis gas. Furthermore, the invention relates to a device for producing a carbon monoxide-free make-up gas consisting largely of hydrogen and nitrogen for ammonia synthesis, comprising a reforming device in which a hydrocarbon-containing feedstock can be reformed to form a methane- and argon-containing synthesis gas, a water-gas conversion device, and an acid gas scrubber, with the aid of which a hydrogen-rich fraction comprising carbon monoxide, methane, and argon, referred to as raw hydrogen, can be produced from the synthesis gas, as well as a formation device in which the make-up gas can be formed from the raw hydrogen.

[0025] The stated object is achieved according to the invention in terms of the device in that the formation device comprises a cryogenic gas separator, with the aid of which the raw hydrogen can be separated into a hydrogen fraction free of carbon monoxide, methane and argon and a methane-rich, argon- and nitrogen-poor residual gas, wherein the formation device is connected to the reforming device in such a way that the residual gas can be recycled and converted by reforming in order to obtain the synthesis raw gas containing methane and argon, and wherein at least a part of the hydrogen fraction free of carbon monoxide, methane and argon can be withdrawn from the formation device, optionally after admixture of nitrogen as make-up gas.

[0026] Preferably, the formation facility comprises a gas dryer located upstream of the cryogenic gas separation unit, which can be used to separate water and any residual carbon dioxide from the raw hydrogen or from the treated raw hydrogen to produce a dry gas stream as a feed (cryogenic feed) for the cryogenic gas separation unit. The gas dryer can be a temperature or pressure swing adsorber, for example, that adsorbs water and any residual carbon dioxide from the supplied gas stream. However, the use of other gas dryers should not be excluded.

[0027] Particularly preferably, a methanizer for processing the raw hydrogen is arranged in the formation facility upstream of the gas dryer, in which the carbon monoxide and carbon dioxide contained in the raw hydrogen can be reacted with hydrogen to form methane and water.In further developing the device according to the invention, it is proposed that the cryogenic gas separator comprises, in addition to lines for guiding the process streams, at least one heat exchanger in which the cryogenic feed can be cooled and partially condensed against process streams to be heated, a separator for separating the two-phase mixture of substances formed during the partial condensation into a methane-rich liquid phase and a hydrogen-rich gas phase, and a scrubbing column to which the hydrogen-rich gas phase obtainable in the separator can be fed for scrubbing with liquid nitrogen in order to obtain a bottoms fraction containing nitrogen, argon and methane and the hydrogen fraction free of carbon monoxide, methane and argon.

[0028] It is expedient for the scrubbing column to be connected to the heat exchanger in such a way that at least a portion of the hydrogen-rich gas phase can be warmed up in the heat exchanger, with the portion of the hydrogen-rich gas phase being supplemented with nitrogen to form the make-up gas before and / or during and / or after the warming up.

[0029] Preferably, the separator is connected to the reforming device via the heat exchanger in such a way that the methane-rich liquid phase, after evaporation and heating in the heat exchanger, can be returned to the reforming device as the methane-rich, argon- and nitrogen-poor residual gas or as part of the methane-rich, argon- and nitrogen-poor residual gas.

[0030] Furthermore, the scrubbing column can be connected to the reforming device via the heat exchanger in such a way that a part of the nitrogen, argon and methane-containing bottom fraction can be returned to the reforming device after evaporation and heating in the heat exchanger, either alone or as part of the methane-rich, argon and nitrogen-poor residual gas.

[0031] In addition, the washing column can be connected to a heat exchanger with a

[0032] The burner may be connected in such a way that at least a portion of the hydrogen-rich gas phase obtainable in the scrubbing column can be fed to the burner as fuel. The reforming device may comprise a steam reformer, a POX reactor, an autothermal reformer, or a combination of two or more such devices.

[0033] In the following, the invention will be explained in more detail with reference to two embodiments shown schematically in Figures 1 and 2.

[0034] Figure 1 shows a preferred variant of a device according to the invention for generating a make-up gas for ammonia synthesis.

[0035] Figure 2 shows a cryogenic gas separation which can be used particularly advantageously in the production of the make-up gas according to the invention.

[0036] In Figure 1, a hydrocarbon-containing feed 1, which is for example natural gas, is fed to a desulfurization device A in order to obtain a desulfurized hydrocarbon-containing feed 2, which is converted in the reforming device B using oxygen s, which is obtained from air 4 in an air separator F, for example by partial oxidation or autothermal reforming, into a synthesis raw gas 5 containing hydrogen, carbon monoxide, carbon dioxide and argon. To increase the hydrogen content, the synthesis raw gas 5 is subjected to a water gas conversion G, in which carbon monoxide reacts with water to form hydrogen and carbon dioxide, and a low-carbon monoxide gas fraction 6 is produced, from which the majority of the carbon dioxide is removed in a sour gas scrubber H.The separated carbon dioxide 7 is fed for sequestration or material use, while the remaining gas fraction 8, which is rich in hydrogen and comprises carbon monoxide, methane, and argon and is referred to as raw hydrogen, is passed on to the educational facility M, where the cryogenic feed 10 is produced from it using a drying process L, preferably carried out by adsorptive means. Optionally, the raw hydrogen 8 can be subjected to methanation J, in which carbon monoxide and carbon dioxide are converted with hydrogen to methane, producing a largely carbon monoxide-free gas mixture 9, from which the cryogenic feed 10 is produced by drying L. In the cryogenic gas separator K, which is also part of the educational facility M, a purge gas 11 containing nitrogen, argon, and methane, a methane-rich, argon- and nitrogen-poor residual gas 12, and a hydrogen fraction free of carbon monoxide, methane, and argon are separated from the cryogenic feed 10.A smaller portion 13 of the hydrogen fraction can be used as fuel gas 13, while a larger portion is supplemented with nitrogen supplied via line 14 to form make-up gas 15. The methane-rich, argon- and nitrogen-poor residual gas 12 is recirculated via compressor P upstream of the reformer B, while the purge gas 11—possibly after use as purge gas in the drying process L—is discharged as fuel gas 16 to prevent the accumulation of argon in the reformer circuit.

[0037] The hydrogen-rich cryogenic feed 10, which contains methane, nitrogen, argon, and possibly carbon monoxide, is fed to the cryogenic gas separator K of Figure 2, located in the cold box C. There it is cooled in the heat exchangers E1 and E2 to such an extent that the methane it contains condenses almost completely. The two-phase mixture 20 formed during cooling is separated in the separator D into a methane-rich liquid phase 21 and a hydrogen-rich gas phase 22, which contains the majority of the argon and possibly carbon monoxide present in the cryogenic feed 10. The hydrogen-rich gas phase 22 is fed to the lower section of the scrubbing column W via line 23, where it is initially separated in a controlled manner into two partial streams 24 and 25 via the control valve a. In order to control the temperature profile of the wash column W, the smaller partial stream 24 is heated in the heat exchanger E2 and then recombined with the larger partial stream 25.By controlling the temperature profile, it is possible to cool the cryogenic insert 10 very deeply and to maximize the condensation of the methane without falling below the dew point of the nitrogen used to purge the cold box C (not shown).

[0038] Via line 26, a portion of the nitrogen 14, which is obtained in gaseous form, for example, at increased pressure from a cryogenic air separator, is introduced into the cold box C, where cooling in the heat exchangers E1 and E2 produces the liquid nitrogen stream 27, the majority of which is expanded via valve b as scrubbing nitrogen 28 to the top of the scrubbing column W. The hydrogen-rich gas phase 23 is passed upwards in the scrubbing column W and is brought into intensive contact with the scrubbing nitrogen 28, whereby argon and any carbon monoxide contained therein, as well as methane residues and a large portion of the nitrogen present in the cryogenic feed 10 are scrubbed out and pass into the bottoms fraction, which is withdrawn via line 29.The overhead stream 30 of the scrubbing column W is a gas mixture consisting predominantly of hydrogen and nitrogen, free of carbon monoxide, methane, and argon. Although it meets the purity requirements for the make-up gas for ammonia synthesis, its nitrogen content is still too low. Therefore, after a first warming step in heat exchanger E2, pre-cooled nitrogen 31 is added to the overhead stream 30 via valve c. After a second warming step in heat exchanger E1, a further amount of nitrogen 32 is added via valve d to obtain the make-up gas 15 with the required hydrogen / nitrogen ratio. A portion of the overhead stream 30 is branched off upstream of the admixture point of the pre-cooled nitrogen 31 and, after warming in heat exchanger E1, is fed as carbon-free fuel gas 13, for example, to a steam reformer used in the reforming device B or to a fired preheating furnace.

[0039] The methane-rich liquid phase 21 present at the pressure of the cryogenic feed 10 is withdrawn from the separator D largely free of argon and combined via the valve e with a first portion 33 of the bottom fraction 29 supplied via the valve f to form the material stream 34, which, after evaporation and heating in the heat exchangers E2 and E1, forms the methane-rich, argon- and nitrogen-poor residual gas 12, which is returned before the reforming R. In order to prevent argon enrichment in the reformer circuit, a second portion 35 of the bottom fraction 29 is withdrawn from the wash column W via the valve g in a controlled manner and, after evaporation and heating in the heat exchangers E2 and E1, is discharged from the process as purge gas 11.

[0040] To compensate for cooling losses, liquid nitrogen 36 is introduced into the cold box C, which is supplemented by a portion 37 of the liquefied nitrogen 27 supplied via the valve h to form the nitrogen stream 38, which, after evaporation and heating in the heat exchangers E2 and E1, is disposed of via line 39 or fed for further use.

Claims

A method for producing a carbon monoxide-free make-up gas (15) consisting largely of hydrogen and nitrogen for ammonia synthesis, wherein a hydrocarbon-containing feedstock (2) is converted in a reforming device (B) to obtain a synthesis raw gas (5) containing methane and argon, from which, with the aid of water gas conversion (G) and acid gas scrubbing (H), a hydrogen-rich fraction (8) comprising carbon monoxide, methane and argon, referred to as raw hydrogen, is produced, which is used to form the make-up gas (15), characterized in that the raw hydrogen (8) is separated by means of a cryogenic gas separation (K) into a hydrogen fraction (30) free of carbon monoxide, methane and argon and a methane-rich, argon- and nitrogen-poor residual gas (12), which is recycled and converted in the reforming device (B) to produce the synthesis raw gas containing methane and argon (5) to receive,while at least a portion of the hydrogen fraction (30) free of carbon monoxide, methane, and argon is passed on as make-up gas (15) or supplemented with nitrogen to form the make-up gas (15). Method according to claim 1, characterized in that a feed (cryogenic feed) (10) for cryogenic gas separation (K) is obtained from the raw hydrogen (8) by drying (L). Method according to claim 1, characterized in that a feed (cryogenic feed) (10) for cryogenic gas separation (K) is obtained from the raw hydrogen (8) by methanation (J) and subsequent drying (L). Method according to one of claims 2 or 3, characterized in that a two-phase mixture of substances (20) is formed from the cryogenic insert (10) in the cryogenic gas separation (K) by cooling, which mixture is separated in a separator (D) into a methane-rich liquid phase (21) and a hydrogen-rich gas phase (22),wherein the methane-rich liquid phase (21) after evaporation and heating against process streams to be cooled forms at least a part of the methane-rich, argon- and nitrogen-poor residual gas (12) and the hydrogen-rich gas phase (22) is subjected to a scrubbing with liquid nitrogen (28) in a scrubbing column (W), in which a nitrogen, argon and, The methane-containing bottom fraction (29) and the hydrogen fraction (30) free of carbon monoxide, methane and argon are obtained.

5. Process according to claim 4, characterized in that at least a part (35) of the bottom fraction (29) obtained in the washing column (W) and consisting largely of nitrogen, argon and methane is discarded after evaporation and heating against process streams to be cooled.

6. Process according to claim 4, characterized in that the bottom fraction (29) obtained in the washing column (W) and consisting largely of nitrogen, argon and methane is divided into a first (35) and a second fraction (33), of which the first (35) is discarded after evaporation and heating against process streams to be cooled and the second (33) is combined with the methane-rich liquid phase (21) obtained in the separator (D).

7. Process according to one of claims 4 to 6, characterized in that the hydrogen-rich gas phase (22) obtained in the separator (D) is warmed upstream of the washing column (W) against process streams to be cooled.

8. Process according to one of claims 4 to 7, characterized in that nitrogen (31, 32) is admixed to at least a part of the hydrogen fraction (30) free of carbon monoxide, methane and argon obtained in the wash column (W) before and / or during and / or after its heating against process streams to be cooled in order to obtain the make-up gas (15).

9. Process according to one of claims 1 to 8, characterized in that a part (13) of the hydrogen fraction (30) obtained in the washing column (W) and free of carbon monoxide, methane and argon is burned in order to provide heat for the reforming device.

10. Process according to one of claims 1 to 6, characterized in that the hydrocarbon-containing feed (2) is reformed by steam reforming, partial oxidation, autothermal reforming or a combination of these processes to form the synthesis crude gas (5) containing methane and argon. 11 . Device for producing a carbon monoxide-free make-up gas (15) consisting largely of hydrogen and nitrogen for ammonia synthesis, with a reforming device (B) in which a hydrocarbon-containing feedstock (2) can be converted to obtain a synthesis raw gas (5) containing methane and argon, a water-gas conversion (G) and a sour gas scrubber (H), with the aid of which a hydrogen-rich fraction (8) comprising carbon monoxide, methane and argon, referred to as raw hydrogen, can be produced from the synthesis raw gas (5), and a formation device (M) in which the make-up gas (15) can be formed from the raw hydrogen (8), characterized in that the formation device (M) comprises a cryogenic gas separator (K), with the aid of which the raw hydrogen (8) can be separated into a hydrogen fraction free of carbon monoxide, methane and argon and a methane-rich, argon- and nitrogen-poor residual gas (12), wherein the formation device (M) is connected to the reforming device (B) in such a way that the residual gas (12) can be recycled and converted by reforming,to obtain the synthesis raw gas (5) containing methane and argon, and wherein at least a portion of the hydrogen fraction free of carbon monoxide, methane, and argon can be withdrawn from the formation device (M), optionally after admixing nitrogen (14) as a make-up gas (15). Device according to claim 11, characterized in that the formation device (M) comprises a gas dryer (L) arranged upstream of the cryogenic gas separator (K), with which gas dryer water and optionally carbon dioxide can be separated from the raw hydrogen (8) or from treated raw hydrogen (9) and an insert (cryogenic insert) (10) for the cryogenic gas separator (K) can be obtained. Device according to claim 12, characterized in that the formation device (M) comprises a methanizer (J) arranged upstream of the gas dryer, in which the raw hydrogen (8) can be treated by methanation. Device according to one of claims 11 to 13, characterized in thatthat the cryogenic gas separator (K) comprises, in addition to lines for guiding the process streams, at least one heat exchanger (E1, E2) in which the cryogenic insert (10) can be cooled and partially condensed against process streams to be heated, a separator (D) for separating the two-phase mixture (20) formed during the partial condensation into a methane-rich liquid phase (21) and a hydrogen-rich gas phase (22), as well as a washing column (W), which, the hydrogen-rich gas phase (22) obtainable in the separator (D) can be fed to the scrubbing with liquid nitrogen (28) in order to obtain a bottom fraction (29) containing nitrogen, argon and methane and the hydrogen fraction (30) free of carbon monoxide, methane and argon.

15. Device according to claim 14, characterized in that the separator (D) is connected to the reforming device (B) via the heat exchanger(s) (E1, E2) in such a way that the methane-rich liquid phase (21) after evaporation and heating in the heat exchanger(s) (E1, E2) can be returned to the reforming device (B) as part of the methane-rich, argon- and nitrogen-poor residual gas (12).

16. Device according to one of claims 14 or 15, characterized in that the washing column (W) is connected to the reforming device (B) via the heat exchanger or exchangers (E1, E2) in such a way that a part (33) of the nitrogen, argon and methane-containing bottom fraction (29) can be recycled to the reforming device (B) as part of the methane-rich, argon- and nitrogen-poor residual gas (12) after evaporation and heating in the heat exchanger or heat exchangers (E1, E2).

17. Device according to one of claims 14 to 16, characterized in that the washing column (W) is connected to the heat exchanger or the heat exchangers (E1, E2) in such a way that at least a part of the hydrogen fraction (30) free of carbon monoxide, methane and argon can be heated in the heat exchanger or the heat exchangers (E1, E2), it being supplemented with nitrogen (31, 32) to form the make-up gas (15) before and / or during and / or after the heating.

18. Device according to one of claims 14 to 17, characterized in that the washing column (W) is connected to a burner via the heat exchanger(s) (E1, E2) in such a way that at least a part (13) of the hydrogen fraction (30) obtainable in the washing column (W) and free from carbon monoxide, methane and argon can be fed to the burner as fuel.

19. Device according to one of claims 11 to 18, characterized in that the reforming device (B) comprises a steam reformer and / or a POX reactor and / or an autothermal reformer.

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