Process and plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas

Abstract

A process for producing hydrogen is provided by: (a) producing a crude synthesis gas stream in reformer tubes disposed within a reformer furnace (104, 204) that are internally heated by at least one burner (106, 206) that includes a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210); (b) cooling the crude synthesis gas stream; (c) generating a hydrogen product stream and a PSA off-gas stream from the cooled synthesis gas stream; (d) splitting the PSA off-gas stream into first and second partial PSA off-gas streams; (e) separating carbon dioxide from the first partial PSA off-gas stream; and (f) introducing the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to the first fuel gas supply (108, 208) and the second partial PSA off-gas stream as a second fuel gas stream to the second fuel gas supply (110, 210).

Description

[Technical Field]

[0001] The present disclosure relates generally to reforming processes, and more particularly to a process and plant for the continuous production of hydrogen by steam reforming of a hydrocarbon-containing feed gas regardless of the operating mode of a carbon dioxide capture device. The present disclosure also relates to a method for the retrofitting of a hydrogen production plant. [Background technology]

[0002] Today, hydrogen is seen by many as the most promising energy vector of the future, which should be able to reduce atmospheric carbon dioxide emissions. However, large-scale hydrogen production still leads to substantial carbon dioxide emissions. As a result, solutions to produce low-carbon hydrogen are being developed and deployed in industry, among which capturing carbon dioxide from the process is the most discussed.

[0003] Existing operation of hydrogen plants equipped with a pre-combustion carbon dioxide capture unit, i.e., an amine scrubbing unit upstream of a pressure swing adsorption (PSA) unit, can be challenging due to the need to ensure continuous hydrogen production even when the carbon dioxide capture unit is not operating (e.g., due to tripping). One of the main challenges in this regard is the handling of the PSA tail gas in two scenarios: with and without the carbon dioxide capture unit. For example, when the carbon dioxide capture unit is operating, the PSA tail gas will have a lower flow rate, be essentially carbon dioxide-free, and have a high lower heating value (LHV). Conversely, when the carbon dioxide capture unit is not operating, the PSA tail gas will have a higher flow rate, a high carbon dioxide content, and a lower LHV due to the inert content. Combustion of two very different streams (PSA tail gas) in the same burner (i.e., steam methane reforming (SMR) fuel side) is problematic due to different fuel properties (Ubbe number), resulting in significantly increased nitrogen oxide (NOx) emissions and affecting plant reliability. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, there is a need to address the aforementioned technical shortcomings in existing known techniques for producing hydrogen. [Means for solving the problem]

[0005] The present disclosure seeks to provide an improved approach for continuously producing low-carbon hydrogen. Combusting different streams of pressure swing adsorption (PSA) tail gas as a result of different operating modes of a carbon dioxide capture device is problematic due to different fuel properties and a significant increase in nitrogen oxide (NOx) emissions, which also affects plant reliability. The objective of the present disclosure is to provide a solution that at least partially overcomes the problems faced in the prior art and to provide a process and plant for continuously producing hydrogen regardless of the operating mode of the carbon dioxide capture device, such as full-load operation, part-load operation, or when the carbon dioxide capture device is shut down. The process and plant use a burner system including at least two fuel gas supplies, i.e., a first fuel gas supply and a second fuel gas supply, on the same burner to cover a wide fuel range while minimizing nitrogen oxide (NOx) emissions and ensuring continuous hydrogen production. The objective of the present disclosure is achieved by the solutions provided in the accompanying independent claims. Advantageous implementations of the present disclosure are further defined in the accompanying dependent claims.

[0006] According to a first aspect, the present disclosure provides a process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following steps: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing the feed gas stream into a reforming stage and reacting the feed gas stream in the reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of the reforming furnace being heated by burning at least two fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners including a first fuel gas supply and a second fuel gas supply on the same burner, the first fuel gas being introduced into the first fuel gas supply and the second fuel gas being introduced into the second fuel gas supply, the flow rates of the first fuel gas stream and the second fuel gas stream being adjustable; (c) discharging a crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device, cooling the crude syngas stream in the first cooling device by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device; (d) optionally, introducing at least a portion of the cooled raw syngas stream into a CO shift plant comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device, cooling the shifted syngas stream in the second cooling device by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device; (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, wherein the PSA off-gas stream comprises hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (h) introducing the first partial PSA off-gas stream into a carbon dioxide capture device; separating carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; and discharging the first carbon dioxide-depleted partial PSA off-gas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (i) introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0007] According to a second aspect, the present disclosure provides a process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following steps: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing the feed gas stream into a reforming stage and reacting the feed gas stream in the reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of the reforming furnace being heated by burning at least two fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners including a first fuel gas supply and a second fuel gas supply on the same burner, the first fuel gas being introduced into the first fuel gas supply and the second fuel gas being introduced into the second fuel gas supply, the flow rates of the first fuel gas stream and the second fuel gas stream being adjustable; (c) discharging a crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device, cooling the crude syngas stream in the first cooling device by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device; (d) optionally, introducing at least a portion of the cooled raw syngas stream into a CO shift plant comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device, cooling the shifted syngas stream in the second cooling device by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device; (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a carbon dioxide capture device, separating carbon dioxide from the cooled raw syngas stream or from the cooled shifted syngas under carbon dioxide separation conditions, and discharge a carbon dioxide-depleted syngas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (g) introducing the carbon dioxide-depleted synthesis gas stream into a hydrogen concentration device, operating on the principles of pressure swing adsorption (PSA), and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (i) introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0008] The process for producing hydrogen according to the present disclosure is advantageous in that it ensures continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating. The process uses at least two fuel gas supplies, i.e., a first fuel gas supply and a second fuel gas supply, on the same burner to accommodate different streams of PSA tail gas or PSA off-gas while minimizing NOx emissions and ensuring continuous production of hydrogen. When this process is implemented, switching between the first fuel gas supply and the second fuel gas supply is performed automatically without affecting hydrogen production. Furthermore, this process increases the overall reliability of the hydrogen production plant and extends the life of the burner system.

[0009] According to a third aspect, the present disclosure provides a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device; and means for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) a carbon dioxide capture device designed to permit separation of carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; means for introducing the first partial PSA off-gas stream into the carbon dioxide capture device; and means for exhausting the first carbon dioxide-depleted partial PSA off-gas stream and the carbon dioxide-enriched off-gas stream from the carbon dioxide capture device. (i) means for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0010] According to a fourth aspect, the present disclosure provides a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a carbon dioxide capture device designed to permit separation of carbon dioxide from the cooled shifted syngas stream under carbon dioxide separation conditions; means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the carbon dioxide capture device; and means for exhausting a carbon dioxide-depleted syngas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device. (g) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide depleted synthesis gas stream into the hydrogen concentration device; and means for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) means for introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0011] The hydrogen production plant according to the present disclosure is advantageous in that it ensures continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating. The plant uses at least two fuel gas supplies, i.e., a first fuel gas supply and a second fuel gas supply, on the same burner to accommodate different PSA tail gas or PSA off-gas flows resulting from different operating modes of the carbon dioxide capture device, such as full-load operation, part-load operation, and when the carbon dioxide capture device is shut down. Thus, the plant ensures continuous hydrogen production, minimizes NOx emissions, and extends the life of the burner system. When the plant is operating, switching between the first and second fuel gas supplies is performed automatically without affecting hydrogen production.

[0012] According to a fifth aspect, the present disclosure provides a method for the retrofitting of a hydrogen production plant, the hydrogen production plant comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device; and means for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) providing a carbon dioxide capture device designed to permit separation of carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; providing means for introducing the first partial PSA off-gas stream into the carbon dioxide capture device; and providing means for exhausting the first carbon dioxide-depleted partial PSA off-gas stream and the carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (i) providing means for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and providing means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0013] According to a sixth aspect, the present disclosure provides a method for the retrofitting of a hydrogen production plant, the hydrogen production plant comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide-depleted synthesis gas stream into the hydrogen concentration device; and means for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing a carbon dioxide capture device designed to permit separation of carbon dioxide from the cooled shifted syngas stream under carbon dioxide separation conditions; providing means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the carbon dioxide capture device; and providing means for exhausting the carbon dioxide-depleted syngas stream and the carbon dioxide off-gas stream from the carbon dioxide capture device; (h) providing means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) providing means for introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and providing means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0014] The method for retrofitting a hydrogen production plant according to the present disclosure is advantageous in that it allows for the conversion of an existing hydrogen production plant to continuously produce low-carbon hydrogen even when the carbon dioxide capture device is not operating.

[0015] Embodiments of the present disclosure eliminate the aforementioned drawbacks of existing known approaches by using a burner system with at least two fuel gas supplies to accommodate different streams of PSA off-gas, thereby enabling continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating and also minimizing NOx emissions.

[0016] Additional aspects, advantages, features, and objects of the present disclosure will become apparent from the following drawings and detailed description of exemplary embodiments taken in conjunction with the appended claims. It will be understood that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure, as defined by the appended claims.

[0017] The foregoing summary and the following detailed description of exemplary embodiments will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the disclosure, example structures of the disclosure are shown in the drawings. However, the disclosure is not limited to the particular methods and instrumentalities disclosed herein. Moreover, those skilled in the art will appreciate that the drawings are not to scale. Wherever possible, like elements have been designated with like numerals. Embodiments of the present disclosure will now be described, by way of example only, with reference to the following drawings, in which: [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a block diagram of a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, with a carbon dioxide capture device downstream of a hydrogen concentration device according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram of a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, with a carbon dioxide capture device upstream of a hydrogen concentration device according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following detailed description illustrates embodiments of the present disclosure and how they may be practiced. While several modes of carrying out the present disclosure have been disclosed, those skilled in the art will recognize that other embodiments for carrying out or practicing the present disclosure are possible.

[0020] As used herein, several terms are defined below: Wobbe Index (IW)=HHV / √(SG), where: HHV is the higher heating value. SG is the specific gravity of a gas defined at standard conditions STD (0°C and 1 atmosphere). Furthermore, SG: It can be expressed as follows: SG = density of gas (at standard conditions) / density of air (at standard conditions) = molar mass of gas / molar mass of air. √(SgG) is the square root of the specific gravity of the gas.

[0021] The term "feed gas stream" should be understood to mean the feedstock or raw material used to produce the synthesis gas product.

[0022] Steam reforming is the most common process used to produce synthesis gas products. The reaction is represented by this equilibrium:

number

[0023] Steam reforming conditions and carbon monoxide (CO) shift conversion conditions are known to those skilled in the art from the prior art. These are physicochemical conditions under which measurable, preferably industrially relevant, conversion of hydrocarbons to synthesis gas products is achieved. For example, in the context of steam reforming, important parameters include adjusting a suitable steam reforming inlet temperature, typically around 1000°C, and adding steam to the hydrocarbon-containing input gas, thus adjusting the steam-to-carbon ratio (S / C ratio). Typical values ​​for the S / C ratio are 1.5 to 3.5 mol / mol. Typical steam reforming inlet temperatures are up to 700°C, typically in the range of 550°C to 650°C. Necessary adjustments of these conditions to respective operating requirements will be made by those skilled in the art based on routine experimentation. Any specific reaction conditions disclosed herein may serve as a guideline, but they should not be considered limiting with respect to the scope of the present invention.

[0024] Pressure is reported in absolute pressure units, abbreviated as bara, or gauge pressure units, abbreviated as barg, if any, unless otherwise specified in a particular individual context.

[0025] A fluid connection between two areas of an apparatus or plant according to the invention should be understood to mean any type of connection that allows a fluid, for example a gas stream, to flow from one of the two areas to the other, disregarding any intervening areas or components. In particular, a direct fluid connection is understood to mean any type of connection that allows a fluid, for example a gas stream, to flow directly from one of the two areas to the other, without any further intervening areas or components, except for pure transport operations and the means required therefor, such as pipelines, valves, pumps, compressors, reservoirs. An example would be a pipeline directly connecting one of the two areas to the other.

[0026] Means should be understood to mean something that allows or helps to achieve a goal. In particular, means for performing a particular process step should be understood to mean any physical item that would be considered by a person skilled in the art to enable this process step to be performed. For example, a person skilled in the art would consider that means for introducing or discharging a material flow includes any transport and conveying equipment, i.e., for example, pipelines, pumps, compressors, valves, that said person, based on his or her knowledge, would consider necessary or advisable for the performance of this process step.

[0027] For the purposes of this description, steam should be understood to be synonymous with water vapor, unless the opposite is indicated in a particular case. In contrast, the term "water" refers to water in the liquid state of matter, unless otherwise stated in a particular case.

[0028] In the context of the present disclosure, carbon dioxide separation conditions refer to the specific conditions of a selected physical or chemical carbon dioxide separation process known to those skilled in the art. A physical or chemical carbon dioxide separation process is understood to be a process that allows the separation of a fluid mixture, e.g., a gas mixture, into its components or the separation of undesired components from this mixture by applying suitable physicochemical conditions, for example, by a phase transition such as condensation, or by using a suitable adsorbent. When a sorption process is used, it can be based on adsorption, i.e., the binding of one or more substances to be separated to the surface or interface of a solid adsorbent, or absorption, i.e., the incorporation of one or more substances to be separated into the volume of a liquid or solid adsorbent. The one or more substances separated and bound by sorption are called adsorbates or absorbents. The binding forces acting in this process can be physical or chemical in nature. Thus, weaker non-specific binding forces, such as van der Waals forces, usually act in physical sorption, while stronger, more specific binding forces act in chemical sorption, in which the adsorbate and / or absorbent are chemically altered.

[0029] As synonyms for the term absorbent, the terms solvent or cleaning agent in the case of liquid absorbents are used in the context of this disclosure.

[0030] A specific physical absorption process is a cryogenic methanol gas scrub using methanol as the absorbent or scrubbing agent, the temperature of which is cooled by a cryogenic generation process to below ambient temperature, preferably below 0° C., and most preferably below −30° C. This process is known to those skilled in the art as the Rectisol process.

[0031] In contrast, amine washing, which is known per se and frequently used for the absorption of carbon dioxide, is based on chemical absorption (chemisorption) and achieves high purity even at relatively low pressures in the absorption column, and the selectivity is usually higher than in physical absorption processes.

[0032] In amine washing, a slightly alkaline aqueous solution of an amine, often an ethanolamine derivative, is used in an absorption unit (absorption section), usually designed as a wash column. Absorption occurs at low temperatures, e.g., 40°C, and slightly elevated pressures, e.g., 8 bar. Fresh or regenerated absorbent is fed to the top of the column, and the gas stream to be separated is introduced into the lower section of the scrubbing column. In this process, carbon dioxide is reversibly chemically absorbed. The carbon dioxide-depleted gas leaves the column at the top, and the packed scrubbing agent is discharged at the bottom of the column and fed to the desorption section, which is often also designed as a separation column. In the desorption column (regeneration section), a reaction reverses the chemical equilibrium at high temperature and low pressure, releasing the absorbed carbon dioxide as a gas. It can then be discharged at the head of the desorption column for further use or disposal. The regenerated absorbent is returned to the absorption section.

[0033] A commonly used absorbent in amine scrubbing is methyldiethanolamine (MDEA), which is primarily used in aqueous solutions. Additionally, activators, such as piperazine, are often added to accelerate carbon dioxide absorption, as described in the paper "The Activator Mechanism of Piperazine in Aqueous Methyldiethanolamine Solutions" by J. Ying et al., Energy Procedia 114 (2017), pp. 2078-2087. In this case, these mixtures are called activated MDEA solutions (aMDEA).

[0034] Optional or optionally means that the described event or circumstance may or may not occur. The description includes cases where the event or circumstance occurs and cases where it does not occur.

[0035] "Providing" in the claims is defined to mean furnishing, supplying, making available, or preparing something. A step may be performed by any actor unless the claim contains explicit language to the contrary.

[0036] According to a first aspect, the present disclosure provides a process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following steps: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing the feed gas stream into a reforming stage and reacting the feed gas stream in the reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of the reforming furnace being heated by at least one burner, preferably a plurality of burners, by burning at least two fuel gases with oxygen and / or air, the at least one burner or plurality of burners including a first fuel gas supply and a second fuel gas supply on the same burner, the first fuel gas being introduced into the first fuel gas supply and the second fuel gas being introduced into the second fuel gas supply, the flow rates of the first fuel gas stream and the second fuel gas stream being adjustable; (c) discharging a crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device, cooling the crude syngas stream in the first cooling device by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device; (d) optionally, introducing at least a portion of the cooled raw syngas stream into a CO shift plant comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device, cooling the shifted syngas stream in the second cooling device by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device; (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, wherein the PSA off-gas stream comprises hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (h) introducing the first partial PSA off-gas stream into a carbon dioxide capture device; separating carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; and discharging the first carbon dioxide-depleted partial PSA off-gas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (i) introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0037] According to a second aspect, the present disclosure provides a process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following steps: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing the feed gas stream into a reforming stage and reacting the feed gas stream in the reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of the reforming furnace being heated by at least one burner, preferably a plurality of burners, by burning at least two fuel gases with oxygen and / or air, the at least one burner or plurality of burners including a first fuel gas supply and a second fuel gas supply on the same burner, the first fuel gas being introduced into the first fuel gas supply and the second fuel gas being introduced into the second fuel gas supply, the flow rates of the first fuel gas stream and the second fuel gas stream being adjustable; (c) discharging a crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device, cooling the crude syngas stream in the first cooling device by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device; (d) optionally, introducing at least a portion of the cooled raw syngas stream into a CO shift plant comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device, cooling the shifted syngas stream in the second cooling device by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device; (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a carbon dioxide capture device, separating carbon dioxide from the cooled raw syngas stream or from the cooled shifted syngas under carbon dioxide separation conditions, and discharge a carbon dioxide-depleted syngas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (g) introducing the carbon dioxide-depleted synthesis gas stream into a hydrogen concentration device, operating on the principles of pressure swing adsorption (PSA), and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (i) introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0038] The process for producing hydrogen according to the present disclosure is advantageous in that it ensures continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating. The process uses at least two fuel gas supplies, i.e., a first fuel gas supply and a second fuel gas supply, on the same burner to accommodate different streams of PSA tail gas or PSA off-gas while minimizing NOx emissions and ensuring continuous production of hydrogen. When this process is implemented, switching between the first fuel gas supply and the second fuel gas supply is performed automatically without affecting hydrogen production. Furthermore, this process increases the overall reliability of the hydrogen production plant and extends the life of the burner system.

[0039] Optionally, the carbon dioxide capture device is an amine scrubbing unit. Optionally, the first fuel gas supply is a small burner header that is only used when the carbon dioxide capture device is in operation. The first fuel gas supply may be connected to a staged burner tip and the second fuel gas supply may be connected to a primary burner tip.

[0040] Optionally, the carbon dioxide capture device may be completely or partially bypassed.

[0041] In one example, the first fuel gas supply is always operating at its maximum, while the second fuel gas supply begins to accept flow once the carbon dioxide capture device is partially bypassed.

[0042] Optionally, the first fuel gas supply of the at least one burner or burners is configured to allow operation with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value, and the second fuel gas supply of the at least one burner or burners is configured to allow operation with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value.

[0043] Optionally, the first fuel gas supply of the at least one burner is configured to enable operation of the at least one burner or burners with a fuel gas having a first Wobbe Index (IW1), and the second fuel gas supply of the at least one burner is configured to enable operation of the at least one burner or burners with a fuel gas having a second Wobbe Index (IW2), wherein the ratio r between the two Wobbe Indexes (r=IW1 / IW2) is greater than 1.8, preferably between 3 and 7, more preferably between 4.5 and 5.5.

[0044] Optionally, when the process is carried out with the carbon dioxide capture device in full load operation, the entire first fuel gas stream is introduced into the first fuel gas supply, while only a portion of the second fuel gas stream, corresponding to a fraction of the total flow rate less than one or zero, is introduced into the second fuel gas supply, thus increasing the overall reliability of the hydrogen plant and the life of the burners.

[0045] Optionally, when the process is carried out with the carbon dioxide capture device operating at part load or when the carbon dioxide capture device is turned off, the entire second fuel gas stream is introduced into the second fuel gas supply, while only a portion of the first fuel gas stream, corresponding to a fraction of its total flow rate or zero, is introduced into the first fuel gas supply, thus minimizing burner tip pressure drop and increasing fuel throughput while allowing nominal heat release.

[0046] If the carbon dioxide capture device is upstream of the hydrogen concentrator, both the first and second fuel gas supplies may receive the same PSA off-gas stream composition. In such a scenario, the process may enable an automatic flow control system to divert a desired flow rate to each fuel gas supply.

[0047] Optionally, the flow division between the first fuel gas supply and the second fuel gas supply is controlled to allow as much fuel to the first fuel gas supply as can be tolerated due to pressure drop limitations or opening and closing the connection to the second fuel gas supply via an automatic on or off valve, in which case the PSA off-gas flow distribution is determined by the overall restriction of the burner tip of the second fuel gas supply relative to the first fuel gas supply.

[0048] Optionally, a third fuel gas containing hydrocarbons is additionally supplied to at least one burner or burners and combusted with oxygen and / or air, which allows for better stability of burner operation, for example during transient operations such as plant startup or shutdown, and at the same time allows for an increase in the energy input generated by the burners.

[0049] Optionally, a third fuel gas is supplied to at least one or more burners via a first fuel gas supply and / or a second fuel gas supply and / or a third fuel gas supply, preferably arranged on the same at least one burner or burners, thereby allowing greater flexibility for introducing the third fuel gas, thereby avoiding or spontaneously creating thermal gradients in the reformer.

[0050] Optionally, the first fuel gas supply is used as a common fuel gas supply for all fuel gases, while the second fuel gas supply is used to operate with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value.

[0051] Optionally, the exhaust gas from the plant is at least partially recycled, for example to the reformer, thereby improving the operability of the plant and burner system with a flexible carbon dioxide capture scenario.

[0052] According to a third aspect, the present disclosure provides a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device; and means for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) a carbon dioxide capture device designed to permit separation of carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; means for introducing the first partial PSA off-gas stream into the carbon dioxide capture device; and means for exhausting the first carbon dioxide-depleted partial PSA off-gas stream and the carbon dioxide-enriched off-gas stream from the carbon dioxide capture device. (i) means for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0053] According to a fourth aspect, the present disclosure provides a plant for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage containing a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed in a reforming furnace, the interior of which is heated by at least one burner, preferably a plurality of burners, by burning at least two different fuel gases with oxygen and / or air, the at least one burner or burners including a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a carbon dioxide capture device designed to permit separation of carbon dioxide from the cooled shifted syngas stream under carbon dioxide separation conditions; means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the carbon dioxide capture device; and means for exhausting a carbon dioxide-depleted syngas stream and a carbon dioxide off-gas stream from the carbon dioxide capture device. (g) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide depleted synthesis gas stream into the hydrogen concentration device; and means for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) means for introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0054] The hydrogen production plant according to the present disclosure is advantageous in that it ensures continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating. The plant uses at least two fuel gas supplies, i.e., a first fuel gas supply and a second fuel gas supply, on the same burner to accommodate different PSA tail gas or PSA off-gas flows resulting from different operating modes of the carbon dioxide capture device, such as full-load operation, part-load operation, and when the carbon dioxide capture device is shut down. Thus, the plant ensures continuous production of hydrogen, minimizes NOx emissions, and extends the life of the burner system. When the plant is operating, switching between the first and second fuel gas supplies is performed via an automatic flow control system without affecting hydrogen production.

[0055] Optionally, the carbon dioxide capture device is an amine scrubbing unit.

[0056] Optionally, the first fuel gas supply is the only small burner header used when the carbon dioxide capture device is in operation. The first fuel gas supply may be connected to the staged burner tip and the second fuel gas supply is connected to the primary burner tip.

[0057] Optionally, the carbon dioxide capture device is fluidly connected to a bypass line that allows the carbon dioxide capture device to be completely or partially bypassed.

[0058] The first fuel gas supply is always operating at its maximum capacity, while the second fuel gas supply begins to accept flow once the carbon dioxide capture device is partially bypassed.

[0059] Optionally, the first fuel gas supply of the at least one burner or burners is configured to enable operation of the one or more burners with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value, and the second fuel gas supply of the at least one burner or burners is configured to enable operation of the one or more burners with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value.

[0060] Optionally, a first fuel gas supply of the at least one burner or burners is configured to enable operation of the one or more burners with a fuel gas having a first Wobbe Index (IW1), and a second fuel gas supply of the at least one burner or burners is configured to enable operation of the one or more burners with a fuel gas having a second Wobbe Index (IW2), and means are included to enable the ratio r between the two Wobbe Indexes (r=IW1 / IW2) to be set to greater than 1.8, preferably between 3 and 7, more preferably between 4.5 and 5.5.

[0061] Optionally, means are included to additionally supply a third fuel gas containing hydrocarbons to the at least one burner or burners and enable it to be combusted with oxygen and / or air.

[0062] Optionally, means are included for allowing a third fuel gas to be supplied to at least one burner via a first fuel gas supply or a second fuel gas supply or a third fuel gas supply, preferably arranged on the same at least one burner or on the same plurality of burners.

[0063] According to a fifth aspect, the present disclosure provides a method for the retrofitting of a hydrogen production plant, the hydrogen production plant comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device; and means for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) providing a carbon dioxide capture device designed to permit separation of carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; providing means for introducing the first partial PSA off-gas stream into the carbon dioxide capture device; and providing means for exhausting the first carbon dioxide-depleted partial PSA off-gas stream and the carbon dioxide-enriched off-gas stream from the carbon dioxide capture device; (i) providing means for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and providing means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0064] According to a sixth aspect, the present disclosure provides a method for the retrofitting of a hydrogen production plant, the hydrogen production plant comprising the following assemblies and components in fluid communication with each other: (a) means for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace, the interior of which is heated by burning at least two different fuel gases with oxygen and / or air by at least one burner, preferably by a plurality of burners, the at least one burner or burners comprising a first fuel gas supply and a second fuel gas supply on the same burner, means for introducing the first fuel gas stream into the first fuel gas supply, means for introducing the second fuel gas stream into the second fuel gas supply, and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing the feed gas stream into the reforming stage; means for discharging a crude synthesis gas stream from the reforming stage; (c) a first cooling device designed to allow cooling of the crude syngas stream in the first cooling device in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device, and means for discharging the cooled crude syngas stream from the first cooling device; (d) optionally, a CO shift plant including at least one CO shift stage, means for introducing at least a portion of the cooled raw syngas stream into the CO shift plant, and means for discharging a shifted syngas stream from the CO shift plant that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, a second cooling device designed to allow the shifted syngas stream in the second cooling device to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted syngas stream into the second cooling device, and means for discharging the cooled shifted syngas stream from the second cooling device; (f) a hydrogen concentration device operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide-depleted synthesis gas stream into the hydrogen concentration device; and means for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device, the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing a carbon dioxide capture device designed to permit separation of carbon dioxide from the cooled shifted syngas stream under carbon dioxide separation conditions; providing means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the carbon dioxide capture device; and providing means for exhausting the carbon dioxide-depleted syngas stream and the carbon dioxide off-gas stream from the carbon dioxide capture device; (h) providing means for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be in the range of 0 to 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) providing means for introducing at least a portion of the first partial PSA off-gas stream as a first fuel gas stream to a first fuel gas supply of at least one burner or burners in the reformer, and providing means for introducing at least a portion of the second partial PSA off-gas stream as a second fuel gas stream to a second fuel gas supply of at least one burner or burners in the reformer.

[0065] The method for retrofitting a hydrogen production plant according to the present disclosure is advantageous in that it allows an existing hydrogen production plant to continuously produce low-carbon hydrogen even when the carbon dioxide capture device is not operating.

[0066] Table 1 below shows two operating scenarios for the carbon dioxide capture device, including full operation and shutdown for hydrogen production.

[0067] Embodiments of the present disclosure substantially eliminate or at least partially address the aforementioned technical shortcomings in existing technologies for hydrogen production by using a burner system with at least two fuel gas supplies to accommodate different streams of PSA off-gas, thereby enabling continuous production of low-carbon hydrogen even when the carbon dioxide capture device is not operating, and by minimizing NOx emissions.

[0068] [Table 1]

[0069] Detailed Description of the Drawings 1 is a block diagram of a plant 100 for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, in which a carbon dioxide capture device 126 is disposed downstream of a hydrogen concentrating device 118 according to one embodiment of the present disclosure. The plant 100 comprises a feed gas providing means 102, a reformer furnace 104 including a plurality of reforming tubes packed with a solid particulate reforming catalyst, a first cooling device 112, an optional carbon monoxide (CO) shift plant 114, an optional second cooling device 116, a hydrogen concentrating device 118, a splitting means 124, a range setting means (not shown in FIG. 1 ), and the carbon dioxide capture device 126. The feed gas providing means 102 provides a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha. The feed gas stream is introduced into the reforming stage via an introducing means. In the reforming stage, the feed gas stream is introduced into a plurality of reforming tubes by an introduction means (not shown in FIG. 1 ) and reacted in the plurality of reforming tubes under steam reforming conditions to produce a raw syngas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons. The raw syngas stream is discharged from the reforming stage by an exhaust means. The plurality of reforming tubes are disposed within a reformer furnace 104, the interior of which is heated by at least one burner 106, preferably by multiple burners, by burning at least two different fuel gases with oxygen and / or air. The at least one burner 106 or multiple burners includes a first fuel gas supply 108 and a second fuel gas supply 110 on the same burner 106. The burner 106 or burners further include means for introducing a first fuel gas stream to the first fuel gas supply 108, means for introducing a second fuel gas stream to the second fuel gas supply 110, and means for adjusting the flow rates of the first and second fuel gas streams (not shown). The crude syngas stream is discharged from the reforming stage via a discharge means. The crude syngas stream is introduced by the introduction means into a first cooling device 112. The first cooling device 112 is designed to allow cooling of the crude syngas stream in the first cooling device 112 in indirect heat exchange with at least one coolant stream. The cooled crude syngas stream is discharged from the first cooling device 112 by a discharge means.At least a portion of the cooled raw syngas stream is introduced into a CO shift plant 114 via an introduction means. The CO shift plant 114 is designed to shift carbon monoxide (CO) in the cooled raw syngas stream to carbon dioxide and hydrogen as useful components. A shifted syngas stream, enriched in carbon dioxide and hydrogen and depleted in CO relative to the raw syngas stream, is discharged from the CO shift plant 114 via an outlet means. The shifted syngas stream is introduced into a second cooling device 116 via an introduction means. The second cooling device 116 is designed to allow cooling of the shifted syngas stream in the second cooling device 116 in indirect heat exchange with at least one coolant stream. The cooled shifted syngas stream is discharged from the second cooling device 116 via an outlet means. The cooled raw syngas stream from the first cooling device 112 and / or the cooled shifted syngas stream from the optional CO shift plant 114 and second cooling device 116 are introduced into a hydrogen concentration device 118 by an introduction means. The hydrogen concentration device 118 operates on the principle of pressure swing adsorption (PSA) to recover and purify hydrogen. A hydrogen product stream is discharged from the hydrogen concentration device 118 by an outlet means 120. A PSA off-gas stream is discharged from the hydrogen concentration device 118 by an outlet means 122. The PSA off-gas stream comprises hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons. The splitting means 124 is designed to split the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream. The range setting means is designed to set the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream between 0 and 100 mole percent of the PSA off-gas stream, and to set the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream. The first partial PSA off-gas stream is introduced into the carbon dioxide capture device 126 by the introducing means. The carbon dioxide capture device 126 is designed to enable separation of carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions. The first carbon dioxide-depleted partial PSA off-gas stream is discharged from the carbon dioxide capture device 126 by means 128.A carbon dioxide-enriched off-gas stream is discharged from the carbon dioxide capture device 126 by means 130. At least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as a first fuel gas stream is introduced by introducing means 132 to a first fuel gas supply 108 of at least one burner 106 or burners in the reformer 104. At least a portion of the second partial PSA off-gas stream as a second fuel gas stream is introduced by introducing means 134 to a second fuel gas supply 110 of at least one burner 106 or burners in the reformer 104. The carbon dioxide capture device 126 is fluidly connected to bypass lines 136 and 138 that allow the carbon dioxide capture device 126 to be completely or partially bypassed.

[0070] The first fuel gas supply 108 is configured to enable operation of the burner 106 or burners with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value. The second fuel gas supply 110 is configured to enable operation of the burner 106 or burners with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value. The first fuel gas supply 108 is configured to enable operation of the burner 106 or burners with a fuel gas having a first Wobbe index (IW1). The second fuel gas supply 110 is configured to enable operation of the burner 106 or burners with a fuel gas having a second Wobbe index (IW2), and includes means for enabling the ratio r between the two Wobbe indexes (r=IW1 / IW2) to be set to greater than 1.8, preferably between 3 and 7, and more preferably between 4.5 and 5.5. The burner 106 or burners further comprise means for allowing a third fuel gas containing hydrocarbons to be additionally supplied to the at least one burner 106 or burners via the first fuel gas supply 108, or the second fuel gas supply 110, or the third fuel gas supply 140, preferably located on the same at least one burner 106 or burners, and combusted with oxygen and / or air.

[0071] 2 is a block diagram of a plant 200 for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, in which a carbon dioxide capture device 218 is disposed upstream of a hydrogen concentrating device 224 according to one embodiment of the present disclosure. The plant 200 includes a feed gas providing means 202, a reformer furnace 204 including a plurality of reforming tubes packed with a solid particulate reforming catalyst, a first cooling device 212, an optional carbon monoxide (CO) shift plant 214, an optional second cooling device 216, a carbon dioxide capture device 218, a hydrogen concentrating device 224, a splitting means 230, and a range setting means (not shown in FIG. 2 ). The feed gas providing means 202 provides a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha. The feed gas stream is introduced into the reforming stage via an introducing means. In the reforming stage, the feed gas stream is introduced into the reforming tubes by an introduction means and reacted in the reforming tubes under steam reforming conditions to produce a raw syngas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons. The raw syngas stream is discharged from the reforming stage by an exhaust means. The reforming tubes are disposed within a reformer furnace 204, the interior of which is heated by at least one burner 206, preferably multiple burners, by burning at least two different fuel gases with oxygen and / or air. The burner 206 or multiple burners includes a first fuel gas supply 208 and a second fuel gas supply 210 on the same burner 206. The burner 206 or burners further include means for introducing a first fuel gas stream to a first fuel gas supply 208, means for introducing a second fuel gas stream to a second fuel gas supply 210, and means for adjusting the flow rates of the first and second fuel gas streams (not shown). The crude syngas stream is discharged from the reforming stage via a discharge means. The crude syngas stream is introduced by the introduction means into a first cooling device 212. The first cooling device 212 is designed to allow cooling of the crude syngas stream in the first cooling device 212 in indirect heat exchange with at least one coolant stream. The cooled crude syngas stream is discharged from the first cooling device 212 by a discharge means.At least a portion of the cooled raw syngas stream is introduced into a CO shift plant 214 via an introduction means. The CO shift plant 214 is designed to shift carbon monoxide (CO) in the cooled raw syngas stream to carbon dioxide and hydrogen as useful components. A shifted syngas stream, enriched in carbon dioxide and hydrogen and depleted in CO relative to the raw syngas stream, is discharged from the CO shift plant 214 via an outlet means. The shifted syngas stream is introduced into a second cooling device 216 via an introduction means. The second cooling device 216 is designed to allow cooling of the shifted syngas stream in the second cooling device 216 in indirect heat exchange with at least one coolant stream. The cooled shifted syngas stream is discharged from the second cooling device 216 via an outlet means. The cooled raw syngas stream from the first cooling device 212 and / or the cooled shifted syngas stream from the optional CO shift plant 214 and second cooling device 216 are introduced into a carbon dioxide capture device 218 via an inlet means. The carbon dioxide capture device 218 is designed to separate carbon dioxide from the cooled shifted syngas stream under carbon dioxide separation conditions. A carbon dioxide-depleted syngas stream is discharged from the carbon dioxide capture device 218 via an outlet means 220. A carbon dioxide off-gas stream is discharged from the carbon dioxide capture device 218 via an outlet means 222. The carbon dioxide-depleted syngas stream is introduced into a hydrogen concentrating device 224 via an inlet means. The hydrogen concentrating device 224 operates on the principle of pressure swing adsorption (PSA) to recover and purify hydrogen. A hydrogen product stream is discharged from the hydrogen concentrating device 224 via an outlet means 226. A PSA off-gas stream is discharged from the hydrogen concentrating device 224 via an outlet means 228. The PSA off-gas stream comprises hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons. The splitting means 230 is designed to split the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream.The range setting means is designed to set the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream between 0 and 100 mole % of the PSA off-gas stream, and to set the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream. At least a portion of the first partial PSA off-gas stream as a first fuel gas stream is introduced by introducing means 232 to a first fuel gas supply 208 of at least one burner 206 or burners in the reformer furnace 204.

[0072] At least a portion of the second partial PSA off-gas stream as a second fuel gas stream is introduced by introducing means 234 to a second fuel gas supply 210 of at least one burner 206 or burners in the reformer 204. The carbon dioxide capture device 218 is fluidly connected to bypass lines 236, 238, 240 that allow the carbon dioxide capture device 218 to be completely or partially bypassed.

[0073] The first fuel gas supply 208 is configured to enable operation of the burner 206 or burners with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value. The second fuel gas supply 210 is configured to enable operation of the burner 206 or burners with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value. The first fuel gas supply 208 is configured to enable operation of the burner 206 or burners with a fuel gas having a first Wobbe index (IW1). The second fuel gas supply 210 is configured to enable operation of the burner 206 or burners with a fuel gas having a second Wobbe index (IW2), and includes means for enabling the ratio r between the two Wobbe indexes (r=IW1 / IW2) to be set to greater than 1.8, preferably between 3 and 7, and more preferably between 4.5 and 5.5. The burner 206 or burners further include means for allowing a third fuel gas containing hydrocarbons to be additionally supplied to the at least one burner 206 or burners via the first fuel gas supply 208, or the second fuel gas supply 210, or the third fuel gas supply 242, preferably located on the same at least one burner 206 or burners, and combusted with oxygen and / or air. [Explanation of symbols]

[0074] 100, 200 plants or hydrogen production plants 102, 202 supply gas providing means 104, 204 Reformer 106, 206 burners 108, 208 First fuel gas supply unit 110, 210 Second fuel gas supply unit 112, 212 first cooling device 114, 214 CO shift plant 116, 216 Second cooling device 118, 224 Hydrogen concentration device 120, 226 Hydrogen discharge means 122, 228 PSA off-gas discharge means 124, 230 Division means 126, 218 Carbon dioxide capture devices 128 First carbon dioxide depleted portion PSA off-gas stream discharge means 130 Carbon dioxide enriched off-gas stream discharge means 132 first carbon dioxide depleted partial PSA off-gas stream introduction means 134, 234 second partial PSA off-gas flow introduction means 136, 138, 236, 238, 240 Bypass lines 140, 242 No. 3 fuel gas supply unit 220 Carbon dioxide depleted synthesis gas stream discharge means 222 Carbon dioxide off-gas stream extraction means 232 first partial PSA off-gas flow introduction means

Claims

1. 1. A process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the steps of: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing said feed gas stream into a reforming stage and reacting said feed gas stream in said reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, said reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably a plurality of burners, to heat at least two fuel gases to oxygen and and / or air, the at least one burner (106, 206) or burners including a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), a first fuel gas being introduced into the first fuel gas supply (108, 208) and a second fuel gas being introduced into the second fuel gas supply (110, 210), and flow rates of the first fuel gas stream and the second fuel gas stream are adjustable; (c) discharging the crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device (112, 212), cooling the crude syngas stream in the first cooling device (112, 212) by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally introducing at least a portion of the cooled raw syngas stream into a CO shift plant (114, 214) comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant (114, 214) under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device (116, 216), cooling the shifted syngas stream in the second cooling device (116, 216) by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device (116, 216); (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a hydrogen concentration device (118, 224) operating on the principle of pressure swing adsorption (PSA); and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (h) introducing the first partial PSA off-gas stream into a carbon dioxide capture device (126, 218); separating carbon dioxide from the first partial PSA off-gas stream under carbon dioxide separation conditions; and discharging a first carbon dioxide-depleted partial PSA off-gas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device (126, 218); (i) introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or burners in the reformer (104, 204), and introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or burners in the reformer (104, 204).

2. 1. A process for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the steps of: (a) providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) introducing said feed gas stream into a reforming stage and reacting said feed gas stream in said reforming stage under steam reforming conditions in a plurality of reforming tubes filled with a solid particulate reforming catalyst to produce a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, said reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably a plurality of burners, to heat at least two fuel gases to oxygen and and / or air, the at least one burner (106, 206) or burners including a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), a first fuel gas being introduced into the first fuel gas supply (108, 208) and a second fuel gas being introduced into the second fuel gas supply (110, 210), and flow rates of the first fuel gas stream and the second fuel gas stream are adjustable; (c) discharging the crude syngas stream from the reforming stage, introducing the crude syngas stream into a first cooling device (112, 212), cooling the crude syngas stream in the first cooling device (112, 212) by indirect heat exchange with at least one coolant stream, and discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally introducing at least a portion of the cooled raw syngas stream into a CO shift plant (114, 214) comprising at least one CO shift stage, converting the cooled raw syngas stream introduced into the CO shift plant (114, 214) under CO shift conditions into a shifted syngas stream, and discharging the shifted syngas stream enriched in hydrogen and carbon dioxide and depleted in carbon monoxide relative to the raw syngas stream; (e) optionally, introducing the shifted syngas stream into a second cooling device (116, 216), cooling the shifted syngas stream in the second cooling device (116, 216) by indirect heat exchange with a second coolant stream, and discharging the cooled shifted syngas stream from the second cooling device (116, 216); (f) introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into a carbon dioxide capture device (126, 218), separating carbon dioxide from the cooled raw syngas stream or the cooled shifted syngas stream under carbon dioxide separation conditions, and discharge a carbon dioxide-depleted syngas stream and a carbon dioxide-enriched off-gas stream from the carbon dioxide capture device (126, 218); (g) introducing the carbon dioxide-depleted synthesis gas stream into a hydrogen concentration device (118, 224) operating under the principles of pressure swing adsorption (PSA), and discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, wherein the first partial PSA off-gas stream and the second partial PSA off-gas stream are both in the range of 0 to 100 mole % of the PSA off-gas stream, and the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream equals the PSA off-gas stream; (i) introducing at least a portion of the first partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or burners in the reformer (104, 204), and introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or burners in the reformer (104, 204).

3. 3. The process of claim 1 or 2, wherein the carbon dioxide capture device (126, 218) can be completely or partially bypassed.

4. the first fuel gas supply (108, 208) of the at least one burner (106, 206) or the plurality of burners is configured to enable operation with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value; 4. The process of claim 1, wherein the second fuel gas supply (110, 210) of the at least one burner (106, 206) or of the plurality of burners is configured to allow operation with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value.

5. the first fuel gas supply (108, 208) of the at least one burner (106, 206) is configured to enable operation of the at least one burner or burners with a fuel gas having a first Wobbe Index (IW1); And in that the second fuel gas supply (110, 210) of the at least one burner (106, 206) is configured to enable operation of the at least one burner or burners using a fuel gas having a second Wobbe Index (IW2); 5. The process according to claim 1, wherein the ratio r between the two Wobbe indices (r=IW1 / IW2) is greater than 1.8, preferably between 3 and 7, more preferably between 4.5 and 5.

5.

6. 6. The process of claim 1, wherein when the process is carried out with the carbon dioxide capture device (126, 218) in full load operation, the entire first fuel gas stream is introduced into the first fuel gas supply (108, 208), while only a portion of the second fuel gas stream is introduced into the second fuel gas supply (110, 210), corresponding to a fraction of that total flow rate less than one or zero.

7. 6. The process of claim 1, wherein when the process is carried out with the carbon dioxide capture device (126, 218) operating at part load or with the carbon dioxide capture device (126, 218) turned off, the entire second fuel gas stream is introduced into the second fuel gas supply (110, 210), while only a portion of the first fuel gas stream is introduced into the first fuel gas supply (108, 208), corresponding to a fraction of the total flow rate less than one or zero.

8. 8. The process according to any one of claims 1 to 7, characterized in that a third fuel gas containing hydrocarbons is additionally supplied to the at least one burner (106, 206) or burners and combusted with oxygen and / or air.

9. 9. The process according to claim 8, characterized in that the third fuel gas is supplied to the at least one burner (106, 206) or to the plurality of burners via the first fuel gas supply (108, 208) and / or the second fuel gas supply (110, 210) and / or a third fuel gas supply (140, 242), preferably arranged in the same at least one burner (106, 206) or in the same plurality of burners.

10. A plant (100, 200) for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means (102, 202) for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst for producing a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably by a plurality of burners, by combustion of at least two different fuel gases with oxygen and / or air; at least one burner (106, 206) or burners comprising a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), means for introducing a first fuel gas stream into the first fuel gas supply (108, 208), means for introducing a second fuel gas stream into the second fuel gas supply (110, 210), and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing said feed gas stream into said reforming stage; means for discharging a crude synthesis gas stream from said reforming stage; (c) a first cooling device (112, 212) designed to allow cooling of the crude syngas stream in the first cooling device (112, 212) in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device (112, 212), and means for discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally, a CO shift plant (114, 214) including at least one CO shift stage, means for introducing at least a portion of said cooled raw syngas stream into said CO shift plant (114, 214), and means for discharging a shifted syngas stream from said CO shift plant (114, 214) that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to said raw syngas stream; (e) optionally, a second cooling device (116, 216) designed to allow the shifted synthesis gas stream in the second cooling device (116, 216) to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted synthesis gas stream into the second cooling device (116, 216), and means for discharging the cooled shifted synthesis gas stream from the second cooling device (116, 216); (f) a hydrogen concentration device (118, 224) operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device (118, 224); and means (120, 122) for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (g) means (124, 230) for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream between 0 and 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) a carbon dioxide capture device (126, 218) designed to permit separation of carbon dioxide from said first partial PSA off-gas stream under carbon dioxide separation conditions; means for introducing said first partial PSA off-gas stream into said carbon dioxide capture device (126, 218); and means (128, 130) for exhausting a first carbon dioxide-depleted partial PSA off-gas stream and a carbon dioxide-enriched off-gas stream from said carbon dioxide capture device (126, 218). (i) a plant (100, 200) comprising: means (132) for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or burners in the reformer (104, 204); and means (134, 234) for introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or burners in the reformer (104, 204).

11. A plant (100, 200) for producing hydrogen by steam reforming of a hydrocarbon-containing feed gas, comprising the following assemblies and components in fluid communication with each other: (a) means (102, 202) for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst for producing a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably by a plurality of burners, by combustion of at least two different fuel gases with oxygen and / or air; at least one burner (106, 206) or burners comprising a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), means for introducing a first fuel gas stream into the first fuel gas supply (108, 208), means for introducing a second fuel gas stream into the second fuel gas supply (110, 210), and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing said feed gas stream into said reforming stage; means for discharging a crude synthesis gas stream from said reforming stage; (c) a first cooling device (112, 212) designed to allow cooling of the crude syngas stream in the first cooling device (112, 212) in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device (112, 212), and means for discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally, a CO shift plant (114, 214) including at least one CO shift stage, means for introducing at least a portion of said cooled raw syngas stream into said CO shift plant (114, 214), and means for discharging a shifted syngas stream from said CO shift plant (114, 214) that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to said raw syngas stream; (e) optionally, a second cooling device (116, 216) designed to allow the shifted synthesis gas stream in the second cooling device (116, 216) to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted synthesis gas stream into the second cooling device (116, 216), and means for discharging the cooled shifted synthesis gas stream from the second cooling device (116, 216); (f) a carbon dioxide capture device (126, 218) designed to permit separation of carbon dioxide from said cooled shifted syngas stream under carbon dioxide separation conditions; means for introducing said cooled raw syngas stream from step (c) or said cooled shifted syngas stream from optional steps (d) and (e) into said carbon dioxide capture device (126, 218); and means (220, 222) for exhausting a carbon dioxide-depleted syngas stream and a carbon dioxide off-gas stream from said carbon dioxide capture device (126, 218). (g) a hydrogen concentration device (118, 224) operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide-depleted synthesis gas stream into the hydrogen concentration device (118, 224); and means (226, 228) for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; (h) means (124, 230) for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and means for setting the ranges of both the first partial PSA off-gas stream and the second partial PSA off-gas stream between 0 and 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) a plant (100, 200) comprising: means (232) for introducing at least a portion of the first partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or burners in the reformer (104, 204); and means (134, 234) for introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or burners in the reformer (104, 204).

12. 12. The plant (100, 200) of claim 10 or 11, characterized in that the carbon dioxide capture device (126, 218) is fluidly connected to a bypass line (136, 138, 236, 238, 240) that allows for complete or partial bypass of the carbon dioxide capture device (126, 218).

13. the first fuel gas supply (108, 208) of the at least one burner (106, 206) or of the plurality of burners is configured to enable operation of the one burner (106, 206) or of the plurality of burners with a fuel gas having a low flow rate, a low carbon dioxide concentration, and a high lower heating value; 13. The plant (100, 200) according to any one of claims 10 to 12, characterized in that the second fuel gas supply (110, 210) of the at least one burner (106, 206) or of the plurality of burners is configured to enable operation of the one burner (106, 206) or of the plurality of burners with a fuel gas having a high flow rate, a high carbon dioxide concentration, and a low lower heating value.

14. the first fuel gas supply (108, 208) of the at least one burner (106, 206) or of the plurality of burners is configured to enable operation of the one burner (106, 206) or of the plurality of burners with a fuel gas having a first Wobbe Index (IW1); And in that the second fuel gas supply (110, 210) of the at least one burner (106, 206) or of the plurality of burners is configured to enable operation of the one burner (106, 206) or of the plurality of burners with a fuel gas having a second Wobbe Index (IW2); 13. The plant (100, 200) according to any one of claims 10 to 12, characterized in that it comprises means that enable the ratio r between the two Wobbe indices (r=IW1 / IW2) to be set to greater than 1.8, preferably between 3 and 7, more preferably between 4.5 and 5.

5.

15. 15. The plant (100, 200) according to any one of claims 10 to 14, characterized in that it comprises means for allowing a third fuel gas containing hydrocarbons to be additionally supplied to the at least one burner (106, 206) or to the burners and combusted with oxygen and / or air.

16. 16. The plant (100, 200) according to claim 15, characterized in that it comprises means, preferably arranged on the same at least one burner (106, 206) or on the same burners (106, 206), for enabling the third fuel gas to be supplied to the at least one burner (106, 206) via the first fuel gas supply (108, 208), or the second fuel gas supply (110, 210), or a third fuel gas supply (140, 242).

17. A method for retrofitting a hydrogen production plant (100, 200), comprising: Said hydrogen production plant (100, 200) comprises the following assemblies and components in fluid communication with each other: (a) means (102, 202) for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst for producing a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably by a plurality of burners, by combustion of at least two different fuel gases with oxygen and / or air; at least one burner (106, 206) or burners comprising a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), means for introducing a first fuel gas stream into the first fuel gas supply (108, 208), means for introducing a second fuel gas stream into the second fuel gas supply (110, 210), and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing said feed gas stream into said reforming stage; means for discharging a crude synthesis gas stream from said reforming stage; (c) a first cooling device (112, 212) designed to allow cooling of the crude syngas stream in the first cooling device (112, 212) in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device (112, 212), and means for discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally, a CO shift plant (114, 214) including at least one CO shift stage, means for introducing at least a portion of said cooled raw syngas stream into said CO shift plant (114, 214), and means for discharging a shifted syngas stream from said CO shift plant (114, 214) that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to said raw syngas stream; (e) optionally, a second cooling device (116, 216) designed to allow the shifted synthesis gas stream in the second cooling device (116, 216) to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted synthesis gas stream into the second cooling device (116, 216), and means for discharging the cooled shifted synthesis gas stream from the second cooling device (116, 216); (f) a hydrogen concentration device (118, 224) operating on the principle of pressure swing adsorption (PSA); means for introducing the cooled raw syngas stream from step (c) or the cooled shifted syngas stream from optional steps (d) and (e) into the hydrogen concentration device (118, 224); and means (120, 122) for discharging a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing means (124, 230) for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the range of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be between 0 and 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (h) providing a carbon dioxide capture device (126, 218) designed to permit separation of carbon dioxide from said first partial PSA off-gas stream under carbon dioxide separation conditions; providing means for introducing said first partial PSA off-gas stream into said carbon dioxide capture device (126, 218); and providing means for exhausting a first carbon dioxide-depleted partial PSA off-gas stream and a carbon dioxide-enriched off-gas stream from said carbon dioxide capture device (126, 218); (i) providing means (132) for introducing at least a portion of the first carbon dioxide-depleted partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or plurality of burners in the reformer (104, 204); and providing means (134, 234) for introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or plurality of burners in the reformer (104, 204).

18. A method for retrofitting a hydrogen production plant (100, 200), comprising: Said hydrogen production plant (100, 200) comprises the following assemblies and components in fluid communication with each other: (a) means (102, 202) for providing a feed gas stream containing gaseous or vaporized hydrocarbons, preferably natural gas or naphtha; (b) a reforming stage comprising a plurality of reforming tubes packed with a solid particulate reforming catalyst for producing a raw synthesis gas stream containing hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons, the reforming tubes being disposed within a reforming furnace (104, 204), the interior of which is heated by at least one burner (106, 206), preferably by a plurality of burners, by combustion of at least two different fuel gases with oxygen and / or air; at least one burner (106, 206) or burners comprising a first fuel gas supply (108, 208) and a second fuel gas supply (110, 210) on the same burner (106, 206), means for introducing a first fuel gas stream into the first fuel gas supply (108, 208), means for introducing a second fuel gas stream into the second fuel gas supply (110, 210), and means for adjusting the flow rates of the first fuel gas stream and the second fuel gas stream; means for introducing said feed gas stream into said reforming stage; means for discharging a crude synthesis gas stream from said reforming stage; (c) a first cooling device (112, 212) designed to allow cooling of the crude syngas stream in the first cooling device (112, 212) in indirect heat exchange with at least one coolant stream, means for introducing the crude syngas stream into the first cooling device (112, 212), and means for discharging the cooled crude syngas stream from the first cooling device (112, 212); (d) optionally, a CO shift plant (114, 214) comprising at least one CO shift stage, means for introducing at least a portion of said cooled raw syngas stream into said CO shift plant (114, 214), and means for discharging a shifted syngas stream from said CO shift plant (114, 214) that is rich in hydrogen and carbon dioxide and depleted in carbon monoxide relative to said raw syngas stream; (e) optionally, a second cooling device (116, 216) designed to allow the shifted synthesis gas stream in the second cooling device (116, 216) to be cooled by indirect heat exchange with at least one coolant stream, means for introducing the shifted synthesis gas stream into the second cooling device (116, 216), and means for discharging the cooled shifted synthesis gas stream from the second cooling device (116, 216); (f) a hydrogen concentration device (118, 224) operating on the principle of pressure swing adsorption (PSA); means for introducing the carbon dioxide-depleted synthesis gas stream into the hydrogen concentration device (118, 224); and means (226, 228) for exhausting a hydrogen product stream and a PSA off-gas stream from the hydrogen concentration device (118, 224), the PSA off-gas stream comprising hydrogen, carbon monoxide, carbon dioxide, and unreacted hydrocarbons; The method for refurbishment comprises the following steps: (g) providing a carbon dioxide capture device (126, 218) designed to permit separation of carbon dioxide from said cooled shifted syngas stream under carbon dioxide separation conditions; providing means for introducing said cooled raw syngas stream from step (c) or said cooled shifted syngas stream from optional steps (d) and (e) into said carbon dioxide capture device (126, 218); and providing means (220, 222) for exhausting a carbon dioxide-depleted syngas stream and a carbon dioxide off-gas stream from said carbon dioxide capture device (126, 218); (h) providing means (124, 230) for dividing the PSA off-gas stream into a first partial PSA off-gas stream and a second partial PSA off-gas stream, and providing means for setting the range of both the first partial PSA off-gas stream and the second partial PSA off-gas stream to be between 0 and 100 mole % of the PSA off-gas stream, and setting the sum of the first partial PSA off-gas stream and the second partial PSA off-gas stream to be equal to the PSA off-gas stream; (i) providing means (232) for introducing at least a portion of the first partial PSA off-gas stream as the first fuel gas stream to the first fuel gas supply (108, 208) of the at least one burner (106, 206) or plurality of burners in the reformer (104, 204); and providing means (134, 234) for introducing at least a portion of the second partial PSA off-gas stream as the second fuel gas stream to the second fuel gas supply (110, 210) of the at least one burner (106, 206) or plurality of burners in the reformer (104, 204).

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