Upgrading hydrocarbons to a methanol and hydrogen product stream

Abstract

The present invention relates to a method and system for upgrading a hydrocarbon feed gas into a methanol product stream and a hydrogen product stream. As part of the method / system, the synthesis gas stream is compressed to a pressure higher than the feed pressure of the hydrocarbon feed gas before being fed to the methanol synthesis unit. The hydrogen product stream is provided by separating a hydrogen-rich stream downstream of the methanol synthesis unit.

Description

Technical Field

[0001] The present invention relates to a method and system for upgrading a hydrocarbon feed gas into a methanol product stream and a hydrogen product stream. Background of the Invention

[0003] Worldwide, the preferred route for hydrogen production is steam methane reforming. However, with increasing concerns about climate change, there is growing interest in the CO2 emissions associated with hydrogen extraction from CH4. Therefore, through the so-called "blue hydrogen" route, research on hydrogen production associated with CO2 capture is becoming increasingly attractive.

[0004] Typically, this route involves an amine wash CO2 separation process on the produced syngas, which selectively extracts CO2 from the pressurized syngas. However, this occurs at the expense of providing a low-pressure CO2 product. This low-pressure CO2 product usually requires subsequent compression to be integrated into other uses / applications. The demand for CO2 is also low, and the best use of low-pressure CO2 is usually sequestration in natural gas reservoirs, which poses associated technical difficulties and costs.

[0005] An object of the present invention is to solve the problems associated with the prior art, particularly to fully or substantially fully utilize the carbon from blue hydrogen production. Summary of the Invention

[0006] The present invention describes a method for upgrading a hydrocarbon feed gas into a methanol product stream and a hydrogen product stream, comprising the following steps:

[0007] a) Providing a hydrocarbon feed gas to a reforming reactor,

[0008] b) Reforming the hydrocarbon feed gas in the reforming reactor to provide a first syngas stream,

[0009] b1) Optionally, feeding at least a portion of the first syngas stream from step b) to a water gas shift reactor to provide a shifted syngas stream,

[0010] c) Cooling the first syngas stream and / or the shifted syngas stream in a cooling unit to provide a second syngas stream,

[0011] d) Removing water from the second syngas stream in a dehydration unit to provide a third syngas stream,

[0012] e) Compressing the third syngas stream in a compression unit to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, to provide a fourth syngas stream,

[0013] e1) Optionally, at least a portion of the fourth synthesis gas stream from step e) is fed to a CO2 removal unit to provide a CO2-rich gas stream and a fifth synthesis gas stream.

[0014] f) At least a portion of the fourth synthesis gas stream from step e) and / or at least a portion of the fifth synthesis gas stream are fed to a methanol synthesis unit to provide a methanol-rich stream.

[0015] g) At least a portion of the methanol-rich stream from step f) is fed to a separation unit to provide a methanol product stream and a hydrogen-rich stream.

[0016] There is also provided a system for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream, the system comprising:

[0017] - A hydrocarbon feed gas, which is arranged to be fed to a reforming reactor.

[0018] - A reforming reactor, which is arranged to reform the hydrocarbon feed gas; thereby providing a first synthesis gas stream from the reforming reactor.

[0019] - Optionally, a water gas shift reactor, which is arranged to receive at least a portion of the first synthesis gas stream from the reforming reactor and provide a shifted synthesis gas stream.

[0020] - A cooling unit, which is arranged to cool the first synthesis gas stream and / or the shifted synthesis gas stream, thereby providing a second synthesis gas stream.

[0021] - A dehydration unit, which is arranged to remove water from the second synthesis gas stream, thereby providing a third synthesis gas stream.

[0022] - A compression unit, which is arranged to compress the third synthesis gas stream to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, thereby providing a fourth synthesis gas stream.

[0023] - Optionally, a CO2 removal unit, which is arranged to receive at least a portion of the fourth synthesis gas stream and provide a CO2-rich gas stream and a fifth synthesis gas stream.

[0024] - A methanol synthesis unit, which is arranged to convert at least a portion of the fourth synthesis gas stream and / or at least a portion of the fifth synthesis gas stream into a methanol-rich stream.

[0025] - A separation unit, which is arranged to provide a methanol product stream and a hydrogen-rich stream from at least a portion of the methanol-rich stream.

[0026] Accordingly, the present invention provides an alternative method / system for blue hydrogen production, in which a combination of a cryogenic CO2 separation unit and a methanol reactor is used to optimize carbon extraction from syngas. These two units (the cryogenic CO2 separation unit and the methanol reactor) are preferably operated at elevated and similar pressures, and thus can be well sequenced. In this way, the CO2 product is valorized and is also easier to handle as high-pressure CO2 or crude liquid methanol.

[0027] The synergy between the CO2 separation and the methanol reactor can also be exploited, as this combination allows the method / system of the present invention to switch between high CO2 production, low MeOH production, and high H2 production. Alternatively, production can be switched to low CO2 production, high MeOH production, and low H2 production.

[0028] Brief Description of the Drawings

[0029] Figure 1 is a schematic diagram of a system for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream.

[0030] Figure 2 is similar to Figure 1 of a system, which further includes a pre-reforming unit and a gas purification unit.

[0031] Figure 3 is similar to Figure 1 of a system, which further includes a CO2 removal unit located between a compression unit and a methanol synthesis unit.

[0032] Figure 4 and 5 are schematic diagrams of a system according to the present invention. Detailed Description

[0033] Unless otherwise specified, any given percentage of gas content is in volume %.

[0034] The modulus M of syngas is defined as

[0035] In a first aspect, a method for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream is provided.

[0036] In the first step (a) of the method, a hydrocarbon-containing feed gas is supplied to a reforming reactor. Herein, the term "hydrocarbon-containing feed" refers to a gas containing one or more hydrocarbons and possibly other components. Thus, the hydrocarbon-containing feed typically comprises hydrocarbon gases such as CH4 and optionally also usually relatively small amounts of higher hydrocarbons, as well as small amounts of other gases. Higher hydrocarbons are components having two or more carbon atoms, such as ethane and propane. Examples of "hydrocarbon-containing feed" can be natural gas, town gas, naphtha or a mixture of methane and higher hydrocarbons, biogas or LPG. Hydrocarbons can also be components having other atoms in addition to carbon and hydrogen, such as oxygen or sulfur.

[0037] The hydrocarbon-containing feed may additionally comprise one or more of the following co-reactant feeds or be mixed with one or more of the following co-reactant feeds: steam, hydrogen and possibly other components such as carbon monoxide, carbon dioxide, nitrogen and argon. Typically, the hydrocarbon-containing feed has a predetermined ratio of hydrocarbons, steam and hydrogen, and potentially carbon dioxide. In most practical applications, the hydrocarbon feed will contain steam.

[0038] On the one hand, the hydrocarbon-containing feed is biogas. Biogas is a gas mixture produced by the decomposition of organic matter under anaerobic conditions. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant materials, sewage, green waste or food waste. Biogas is mainly methane (CH4) and carbon dioxide (CO2), and may contain small amounts of hydrogen sulfide (H2S), moisture, siloxanes and possibly other components. Up to 30% or even 50% of biogas may be carbon dioxide.

[0039] The hydrocarbon-containing feed may have undergone at least steam addition (present in the form of a co-reactant feed) and optionally pretreatment (described in more detail below).

[0040] In one embodiment, the hydrocarbon-containing feed is a mixture of CH4, CO, CO2, H2 and H2O, wherein the concentration of CH4 is 5 - 50 mol%, the concentration of CO is 0.01 - 5%, the concentration of CO2 is 0.1 - 50%, the concentration of H2 is 1 - 10%, and the concentration of H2O is 30 - 70%.

[0041] The term "hydrocarbon-containing feed gas" refers to encompassing the hydrocarbon-containing feed gas as well as the purified hydrocarbon-containing feed gas and the hydrocarbon-containing feed gas with steam added and / or hydrogen added and / or the tail gas from a methanol synthesis unit added. All components of the hydrocarbon-containing feed gas are pressurized individually or jointly upstream of the reforming reactor. The pressure of the components of the hydrocarbon-containing feed gas is selected such that the pressure in the reforming reactor is between 5 and 50 bar, preferably between 20 and 40 bar.

[0042] In some cases, the hydrocarbon feed gas may be pre-reformed before being supplied to the reforming reactor. For example, when the hydrocarbon feed gas is, for example, an LPG and / or naphtha product stream or a natural gas feed, a pre-reforming unit may be arranged upstream of the reforming reactor, and the method may further include the step of pre-reforming the hydrocarbon feed together with a steam feed in the pre-reforming unit to provide a hydrocarbon feed gas.

[0043] In some cases, the hydrocarbon feed gas may contain small amounts of poisons, such as sulfur. In such cases, the hydrocarbon feed gas may be subjected to one or more purification steps, such as desulfurization. Thus, a gas purification unit may be arranged upstream of the pre-reforming unit, and the method may further include the step of purifying the crude hydrocarbon feed in the gas purification unit to provide a hydrocarbon feed gas.

[0044] In a further step (b) of the method, the hydrocarbon feed gas is reformed in a reforming reactor to provide a first synthesis gas stream. The reforming reactor may include a tubular reformer, a convective reformer, an electrically heated reformer, an autothermal reformer, a partial oxidation (POX) reformer, or a combination thereof, in particular, a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series. The operating pressure of the reforming reactor is generally between 5 and 50 bar or more preferably between 15 and 40 bar. The temperature of the gas leaving the reforming reactor is generally between 900 and 1150 °C.

[0045] A typical tubular reformer consists of a plurality of tubes containing catalyst particles placed in a furnace. The tubes are typically 10 - 13 meters long and the inner diameter is generally between 80 and 160 millimeters. Burners placed in the furnace provide the heat required for the reaction by burning fuel gas. A maximum average heat flux of 80000 - 90000 kcal / h / m 2 of the inner tube surface is not uncommon. Due to mechanical limitations, the achievable heat flux is generally limited, and thus the capacity is increased by increasing the number of tubes and the size of the furnace. More details on tubular reformer type reforming reactors can be found in the art, such as “Synthesis gas production for FT synthesis”; Chapter 4, p. 258 - 352, 2004.

[0046] Autothermal reformer (ATR)

[0047] Autothermal reformers typically include a burner, a combustion chamber, and a catalyst bed contained within a refractory-lined pressure vessel. In an ATR, a hydrocarbon feed is partially combusted with a sub-stoichiometric amount of oxygen, and subsequently the partially combusted hydrocarbon feed gas is steam reformed in a fixed bed of steam reforming catalyst. Due to the high temperature, some degree of steam reforming also occurs in the combustion chamber. The steam reforming reaction is accompanied by the water-gas shift reaction. Typically, with respect to the steam reforming and water-gas shift reactions, the gas is at or near equilibrium at the reactor outlet. More details and a complete description of the ATR can be found in the art, such as "Studies in Surface Science and Catalysis, Vol. 152," Synthesis gas production for FT synthesis"; Chapter 4, p. 258 - 352, 2004".

[0048] In cases where the reforming reactor includes an autothermal reformer, an O2-containing feed is provided to the autothermal reformer. The O2-containing feed is advantageously substantially pure O2, e.g., >90% pure, preferably >95% pure, and even more preferably >99% pure.

[0049] Typically, the outlet gas temperature from the ATR is 900 - 1100 °C. The outlet gas typically contains H2, CO, CO2, and steam. Other components such as methane, nitrogen, and argon may also often be present in small amounts. The operating pressure of the ATR reactor will be between 5 and 50 bar or more preferably between 15 and 40 bar.

[0050] Electrically heated reformer (e-SMR)

[0051] In a preferred aspect, the reforming reactor includes or consists of an electrically heated reformer. An electrically heated steam methane reformer (eSMR) is a very compact steam reforming reactor, which is an advantage, especially for small plants.

[0052] The electrically heated reformer preferably includes a pressure vessel containing a structured catalyst, where the structured catalyst includes a macroscopic structure of a conductive material. The macroscopic structure supports a ceramic coating, where the ceramic coating supports the catalytically active material. In this regard, the reforming step includes the following additional steps: providing electrical energy to the structured catalyst by an electrical conductor connected to a power source placed outside the pressure housing, allowing an electric current to flow through the macroscopic structure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500 °C.

[0053] Suitably, the electrical power supplied to the electrically heated reformer is generated by renewable energy.

[0054] The structured catalyst of the electrically heated reformer is configured for steam reforming. The reaction occurs according to the following reaction:

[0055]

[0056]

[0057]

[0058] The structured catalyst is composed of a metal structure, a ceramic phase, and an active phase. The metal structure can be FeCrAlloy, Alnico, or a similar alloy. The ceramic phase can be Al2O3, MgAl2O3, CaAl2O3, ZrO2, or a combination thereof. The catalytically active material can be Ni, Ru, Rh, Ir, or a combination thereof.

[0059] In one embodiment, the catalyst pellets are loaded on top of, around, inside, or below the structured catalyst in the reforming reactor. The catalyst material for the reaction can be Ni / Al2O3, Ni / MgAl2O3, Ni / CaAl2O3, Ru / MgAl2O3, or Rh / MgAl2O3. The catalytically active material can be Ni, Ru, Rh, Ir, or a combination thereof. This can improve the overall gas conversion rate in the electric heating reformer.

[0060] In one embodiment, the macrostructure has a plurality of parallel channels, a plurality of non-parallel channels, and / or a plurality of labyrinth channels. The channels have walls that define the channels. Several different forms and shapes of macrostructures can be used as long as the surface area of the structured catalyst exposed to the gas is as large as possible.

[0061] In one embodiment, the macrostructure is an extruded and sintered structure. Alternatively, the macrostructure is a 3D printed structure. The 3D printed structure can be provided with or without subsequent sintering. The extruded or 3D printed macrostructure, along with optional subsequent sintering, results in a uniform and coherent shaped macrostructure, which can then be coated with a ceramic coating.

[0062] Before the second sintering in an oxidizing atmosphere, a ceramic coating that may contain a catalytically active material is provided on the macrostructure to form a chemical bond between the ceramic coating and the macrostructure. Alternatively, the catalytically active material can be impregnated onto the ceramic coating after the second sintering.

[0063] As used herein, the terms "3D printing" and "3D printing" are intended to denote metal additive manufacturing processes. Such metal additive manufacturing processes encompass 3D printing processes in which materials are joined to a structure under computer control to create a three-dimensional object, where the structure will be solidified, for example by sintering, to provide a macroscopic structure. Additionally, such metal additive manufacturing processes encompass 3D printing processes that do not require subsequent sintering, such as powder bed fusion or direct energy deposition processes. Examples of such powder bed fusion or direct energy deposition processes are laser beam, electron beam, or plasma 3D printing processes.

[0064] Preferably, the catalytically active material is particles with a size of 5 nm to 250 nm. The ceramic coating can be, for example, an oxide containing Al, Zr, Mg, Ce, and / or Ca. An exemplary coating is calcium aluminate or magnesium aluminate spinel. Such a ceramic coating can contain additional elements, such as La, Y, Ti, K, or a combination thereof. Preferably, the conductor is made of a material different from the macroscopic structure. The conductor can be, for example, iron, nickel, aluminum, copper, silver, or an alloy thereof. The ceramic coating is an electrically insulating material with a thickness typically in the range of about 100 μm, for example, 10 - 500 μm.

[0065] In an optional step b1), at least a portion of the first synthesis gas stream from step b) is fed to a water gas shift reactor to provide a shifted synthesis gas stream according to the following reaction and thermodynamic constraints:

[0066]

[0067] A person skilled in the art can select a suitable water gas shift reactor and operating conditions as needed. On the one hand, the entire first synthesis gas stream from step b) is fed to the water gas shift reactor and shifted. On the other hand, only a first portion of the first synthesis gas stream from step b) is fed to the water gas shift reactor and converted, and in a subsequent step, a second portion of the first synthesis gas stream is fed to the cooling unit together with the shifted synthesis gas stream. In other aspects, additional steam is added to the first synthesis gas stream from step b) and fed to the water gas shift reactor and shifted. Using the water gas shift step allows adjusting the H2 / CO ratio in the first synthesis gas stream according to the needs of the downstream process.

[0068] In a further step (c) of the method, the first synthesis gas stream and / or the shifted synthesis gas stream are cooled in a cooling unit to provide a second synthesis gas stream. Preferably, all the synthesis gas, i.e., the first and synthesis gas streams and the shifted synthesis gas stream, are cooled in the cooling unit.

[0069] The first synthesis gas stream typically leaves the reforming reactor at a temperature between 800 °C and 1200 °C. The cooling unit reduces the temperature in the second synthesis gas stream to below the dew point of water in the gas stream, for example to between 30 °C and 50 °C. The cooling unit may comprise more than one cooling stage arranged in series, for example two cooling stages. In a further step (d) of the process, water is removed from the second synthesis gas stream in a dehydration unit. This is advantageously effected by flash separation to provide a third synthesis gas stream. Flash separation refers to a phase separation unit where a stream is split into a liquid phase and a gas phase when the stream is close to or at thermodynamic phase equilibrium at a given temperature.

[0070] In a further step (e) of the process, the third synthesis gas stream is compressed in a compression unit to a first pressure which is higher than the feed pressure of the hydrocarbon feed gas to provide a fourth synthesis gas stream. Typically, the first pressure to which the third synthesis gas stream is compressed is between 50 and 150 bar gauge, preferably between 80 and 90 bar gauge. In comparison, the feed pressure of the hydrocarbon feed gas (and the third synthesis gas stream) is typically between 20 and 50 bar gauge, preferably between 25 and 35 bar gauge. The compressor unit may comprise two or more compressors arranged in series. In the configuration of the present invention, the same compressor unit is advantageous for downstream CO2 removal and methanol synthesis, allowing these operations to be carried out without intermediate compression.

[0071] The process may optionally comprise a step (e1) of feeding at least a portion of the fourth synthesis gas stream from step (e) to a CO2 removal unit, thereby providing at least a CO2-rich gas stream and a fifth synthesis gas stream. CO2 removal refers to the process of separating CO2 from a process gas. CO2 removal can be facilitated by methods such as CO2 absorption, membranes or cryogenic separation. Generally, methods for removing CO2 at elevated pressure are advantageous.

[0072] In a specific embodiment, the CO2 removal unit is a cryogenic separation unit. Generally, cryogenic separation utilises the phase change of different substances in a gas to separate individual components (i.e. CO2) from a gas mixture by controlling the temperature, typically occurring below -50 °C. Such a cryogenic separation unit typically comprises a first cooling stage of the synthesis gas, followed by a cryogenic flash separation unit to separate the liquid condensate from the gas phase. The cooling of the first cooling stage can be provided by the resulting product from the cryogenic flash separation unit, which may be combined with other coolants. Optionally, one or more products from the CO2 removal unit can be expanded to a certain extent to produce a colder process gas for this cooling stage. The cryogenic separation of CO2 must be promoted at elevated pressure, at least above the triple point of CO2 to allow CO2 condensation. Thus, a suitable pressure range is at least 5 bar above the triple point, where an increased pressure results in an increased liquid yield.

[0073] CO2 absorption refers to the unit that removes CO2 from the process gas using processes such as chemical absorption. In chemical absorption, the gas containing CO2 passes through a solvent that reacts with CO2 and binds it in this way. Most chemical solvents are amines, which are divided into primary amines such as monoethanolamine (MEA) and diethylene glycol amine (DGA), secondary amines such as diethanolamine (DEA) and diisopropanolamine (DIPA), or tertiary amines such as triethanolamine (TEA) and methyldiethanolamine (MDEA). Ammonia and liquid alkali metal carbonates such as K2CO3 and NaCO3 can also be used.

[0074] A membrane refers to separation carried out on at least a partially solid barrier (such as a polymer), where the transport of individual gas species occurs at different rates depending on their permeability. This allows the components in the retentate of the membrane to be concentrated or diluted.

[0075] The CO2-rich stream (or the CO2-rich condensate when the CO2 removal unit is a cryogenic separation unit) is usually rich in CO2, for example, >80% pure, preferably >90% pure. If necessary, it can be expected to obtain a higher purity through distillation or other purification techniques.

[0076] In a further step (f) of the method, at least a part of the fourth synthesis gas stream and / or at least a part of the fifth synthesis gas stream (if present) is fed to the methanol synthesis unit. A methanol-rich stream is provided by the fourth and / or fifth synthesis gas stream in the methanol synthesis unit.

[0077] The term "methanol synthesis unit" is understood to mean one or more reactors configured to convert syngas into methanol. Such reactors can be, for example, boiling water reactors, adiabatic reactors, condensing methanol reactors, or gas-cooled reactors. In addition, these reactors can be many reactor shells in parallel and sequential reactor shells with intermediate heat exchange and / or product condensation. It can be understood that the methanol synthesis unit also includes equipment for recycling and pressurizing the feed to the methanol reactor, and its configuration is considered advantageous.

[0078] In a preferred aspect, a first portion of the fourth synthesis gas stream from step (e) is fed to a CO2 removal unit to provide a CO2-rich gas stream and a fifth synthesis gas stream. A second portion of the fourth synthesis gas stream is not fed to the CO2 removal unit. At least a portion of the fifth synthesis gas stream (from the CO2 removal unit) is fed to the methanol synthesis unit together with the second portion of the fourth synthesis gas stream. By adjusting the ratio of the fourth synthesis gas stream fed to the CO2 removal unit relative to the fourth synthesis gas stream fed directly to the methanol synthesis unit, the molar ratio between the methanol product stream and the hydrogen product stream can be adjusted. Generally, if the ratio of the fourth synthesis gas stream fed to the CO2 removal unit increases, the relative amount of the methanol product stream decreases compared to the hydrogen product stream. This allows the ratio between the H2 and methanol products from the plant to be changed, thus increasing the flexibility of the plant according to production requirements.

[0079] In a further step (g), at least a portion of the methanol-rich stream from step (f) is fed to a separation unit. The methanol-rich stream is separated in the separation unit to provide a methanol product stream and a hydrogen-rich stream. The separation unit is advantageously a flash separation unit. Generally, the methanol product stream will subsequently expand and any adsorbed gaseous substances in the gas will evaporate, and a second separation stage with a low-pressure flash separation unit is also advantageously carried out to provide a low-pressure methanol product stream.

[0080] The methanol product stream obtainable from the separation unit is greater than 90% methanol, preferably greater than 95% methanol. Other minor components include water and CO2, as well as potential by-products from methanol synthesis, such as acetone and ethanol. The methanol product stream can be upgraded to a higher quality methanol product stream, such as greater than 98% or greater than 99% methanol. The methanol product stream can be used to produce other useful product streams, such as gasoline, jet fuel, formaldehyde, acetic acid or ethylene. The method can also include the step of converting at least a portion of the methanol product stream into a transportation fuel. In one embodiment, the method also includes the step of upgrading the methanol product stream to fuel-grade (i.e., >80%) methanol. In one embodiment, the methanol product stream is upgraded to chemical-grade (i.e., >99%) methanol.

[0081] Upgrading the methanol product stream generally provides a tail gas stream containing alcohols, ketones and other potential by-products from methanol synthesis. This tail gas stream can be recycled and used, for example, as fuel for heating one or more units located upstream of the method / system of the present invention. A portion of this tail gas stream can alternatively form part of the hydrocarbon feed gas. The tail gas stream can also be combined with the tail gas stream from the H2 purification unit (see below).

[0082] In a further optional step (h), at least a portion of the hydrogen-rich stream from step (g) is provided to a H2 purification unit. The H2 purification unit separates the hydrogen-rich stream into a hydrogen product stream and a tail gas stream. The H2 purification unit is suitably a pressure swing adsorption (PSA) unit, a membrane unit or a cryogenic separation unit. The hydrogen product stream obtainable from the H2 purification unit has more than 95% hydrogen, preferably more than 98% hydrogen, even more preferably more than 99% hydrogen. Other minor components include nitrogen. The hydrogen product stream can be upgraded to a higher quality hydrogen product stream, for example more than 99.5% or more than 99.9% hydrogen. When using PSA, the hydrogen product can be delivered at substantially the same pressure as the hydrogen-rich stream from step (g). In such an embodiment, the process of the present invention allows for the configuration of chemical equipment that produces CO2 at elevated pressure (e.g., above 50 bara) and produces H2 at elevated pressure (e.g., more than 50 bara), while having a liquid methanol outlet. This makes it advantageous to further process each outlet as it makes transfer and integration easier.

[0083] The tail gas stream from the H2 purification unit contains a mixture of CO2, CH4, H2 and CO, as well as small amounts of N2 and methanol. This tail gas stream can be recycled and used, for example, as fuel to heat one or more units located upstream of the process / system of the present invention.

[0084] The remaining portion of the hydrogen-rich stream from step (g) that is not used for hydrogen production can advantageously be compressed and returned as a methanol loop recycle stream to the methanol synthesis unit (50) (step f). By varying the relative portions between the hydrogen-rich stream and the methanol loop recycle stream, the relative production of H2 and methanol can be varied. A relatively high proportion of the methanol loop recycle stream results in a relatively lower hydrogen production but an increased methanol production.

[0085] The process and system of the present invention allow for the adjustment of the molar ratio between the hydrogen product stream and the methanol product stream, and the process can further include the step of adjusting the molar ratio between the hydrogen product stream and the methanol product stream. For example, from a ratio in the range of 2.5 - 5 to a ratio in the range of 1 - 2.5 and vice versa. In one embodiment, the ratio between the hydrogen product stream and the methanol product stream changes from 3.5 to 2.5. In another embodiment, the ratio changes from 2.0 to 2.8. In a third embodiment, the ratio changes from 2.8 to 1.8. Conceivably, the ratio can also be changed in smaller steps, for example from 3.8 to 3.0 and vice versa. Or from 2.0 to 2.3 and vice versa.

[0086] One way to adjust this ratio is by adjusting the proportion of the fourth synthesis gas stream fed to the CO2 removal unit, as described above.

[0087] Another way to adjust this ratio is to adjust the amount of CO2 condensed in the CO2 removal unit relative to the CO2 content in the fourth syngas stream. The molar ratio between the methanol product stream and the hydrogen product stream is decreased by increasing the amount of CO2 condensed in the CO2 removal unit relative to the CO2 content in the fourth syngas. The amount of CO2 condensed in the CO2 removal unit can be increased by reducing the operating temperature in the CO2 removal unit. The relevant operating range of the CO2 removal unit in the form of a low-temperature separation unit is from about -30 °C to -80 °C.

[0088] Another way to adjust this ratio is to adjust the amount of the first syngas supplied to the water-gas shift reactor. When the relative amount of the shifted syngas stream is increased, the molar ratio between the methanol product stream and the hydrogen product stream is decreased.

[0089] On the one hand, the method of the present invention further comprises the step of providing a CO2-containing feed to the reforming reactor, which is preferably mixed with the hydrocarbon-containing feed gas. In this way, the CO2-containing feed can be adjusted so that the modulus of the first syngas stream is within a suitable range, for example, within the range of 1.5 to 2.5. In one embodiment, the CO2-containing feed is provided at least in part by the CO2 condensed in the CO2 removal unit. The CO2-containing feed can also be supplied at least in part by the tail gas from the methanol upgrading unit.

[0090] In the case where the reforming reactor comprises an autothermal reformer and a O2-containing feed is provided to the autothermal reformer, the method may further comprise the step of adjusting the O2-containing feed so that the modulus of the first syngas stream is within the range of 1.5 to 2.5. This provides an alternative - or additional - method for adjusting the modulus of the first syngas stream to the preferred range for methanol synthesis.

[0091] The method may further comprise the step of providing a H2-containing feed upstream of the methanol synthesis unit. The H2-containing feed is preferably a feed of substantially pure (i.e., >99%) H2. The H2-containing feed is preferably mixed with at least a part of the fourth syngas stream and / or at least a part of the fifth syngas stream and fed to the methanol synthesis unit. Alternatively, the H2-containing feed is fed to the hydrocarbon-containing feed gas.

[0092] Advantageously, the H2-containing feed is mixed with the third syngas stream and fed to the compression unit. This arrangement can avoid pre-compression of the H2-containing feed and provide a combined fourth syngas stream with the required modulus and the required pressure.

[0093] The H2-containing feed can also be supplied to the hydrocarbon-containing feed gas and used as the reducing gas required for the hydrocarbon-containing feed gas.

[0094] The method may further include the step of adjusting the H2-containing feed such that the modulus of the fourth and / or fifth synthesis gas streams is in the range of 1.5 to 2.5. The modulus is determined at the inlet of the methanol synthesis unit.

[0095] The molar ratio between the methanol product stream and the hydrogen product stream can also be changed by adjusting the CO2-containing feed, the O2-containing feed, and / or the H2-containing feed. Increasing the CO2-containing feed will increase the relative production of the methanol product stream with respect to the hydrogen product stream. Increasing the O2-containing feed will increase the methanol product stream with respect to the hydrogen product stream. Increasing the H2-containing feed will increase the hydrogen product stream with respect to the methanol product stream.

[0096] In a particular aspect of the method, an electrolysis unit is provided. The method further includes the step of generating the H2-containing feed and the O2-containing feed from a water feedstock in the electrolysis unit, and the method further includes the step of supplying at least a portion of the H2-containing feed to the methanol synthesis unit and / or supplying at least a portion of the O2-containing feed to the autothermal reformer. Including such an electrolysis unit allows for the easy provision of H2 and O2 while avoiding the use of fossil fuels. In a preferred embodiment, the electrolysis unit is a solid oxide electrolysis cell.

[0097] In one embodiment, the electrolysis unit is a high-temperature electrolysis unit, such as of the solid oxide electrolysis cell type, and the water feedstock for the electrolysis unit is in the form of steam generated from other processes of the method. For example, steam is generated in the methanol synthesis unit and / or the cooling unit of the first syngas.

[0098] In one aspect, the present invention provides a system for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream. All of the structural features of the method of the present invention provided above are also relevant to the system of the present invention.

[0099] Generally, the system includes:

[0100] - a hydrocarbon feed gas, which is arranged to be fed to a reforming reactor,

[0101] - a reforming reactor, which is arranged to reform the hydrocarbon feed gas; thereby providing a first synthesis gas stream from the reforming reactor,

[0102] - optionally, a water gas shift reactor, which is arranged to receive at least a portion of the first synthesis gas stream from the reforming reactor and provide a shifted synthesis gas stream,

[0103] - a cooling unit, which is arranged to cool the first synthesis gas stream and / or the shifted synthesis gas stream, thereby providing a second synthesis gas stream,

[0104] - a dehydration unit, which is arranged to remove water from the second synthesis gas stream, thereby providing a third synthesis gas stream,

[0105] - A compression unit arranged to compress the third synthesis gas stream to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, thereby providing a fourth synthesis gas stream.

[0106] - Optionally, a CO2 removal unit arranged to receive at least a portion of the fourth synthesis gas stream and provide a CO2-rich gas stream and a fifth synthesis gas stream.

[0107] - A methanol synthesis unit arranged to convert at least a portion of the fourth synthesis gas stream and / or at least a portion of the fifth synthesis gas stream into a methanol-rich stream.

[0108] - A separation unit arranged to provide a methanol product stream and a hydrogen-rich stream from at least a portion of the methanol-rich stream.

[0109] - Optionally, an H2 purification unit arranged to separate the hydrogen-rich stream into a hydrogen product stream and a tail gas stream.

[0110] All details of the units and reactors in the system of the present invention are as described above for the method of the present invention.

[0111] In one aspect of the system, a first portion of the fourth synthesis gas stream is arranged to be fed to the CO2 removal unit to provide a CO2-rich gas stream and a fifth synthesis gas stream; and at least a portion of the fifth synthesis gas stream is arranged to be fed to the methanol synthesis unit together with a second portion of the fourth synthesis gas stream. A system arranged in this way allows the composition of the synthesis gas stream to be easily adjusted at the inlet of the methanol synthesis unit.

[0112] In another aspect, the system further includes a CO2 feed arranged to be fed to the reforming reactor, preferably mixed with the hydrocarbon feed gas. The presence of this CO2 feed allows the modulus of the synthesis gas stream to be adjusted as needed.

[0113] The system may additionally include an autothermal reformer. In this case, the system also includes an O2 feed arranged to be fed to the autothermal reformer.

[0114] The system may further include an H2 feed arranged to be fed upstream of the methanol synthesis unit, preferably mixed with at least a portion of the fourth synthesis gas stream and / or at least a portion of the fifth synthesis gas stream.

[0115] Thus, the molar ratio between the methanol product stream and the hydrogen product stream can be changed by adjusting the CO2 feed, the O2 feed, and / or the H2 feed.

[0116] As described above for the method, the system according to the present invention may further include an electrolysis unit arranged to produce a H2-containing feed and an O2-containing feed from a water feedstock, and the system is further arranged to supply the H2-containing feed from the electrolysis unit to the methanol synthesis unit and / or to supply the O2-containing feed from the electrolysis unit to the autothermal reformer (when present).

[0117] The reforming reactor may include a tubular reformer, a convective reformer, an electrically heated reformer, an autothermal reformer or a combination thereof, in particular, a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series.

[0118] In particular, the reforming reactor may be an electrically heated reformer. The electrically heated reformer suitably includes a pressure shell containing a structured catalyst, wherein the structured catalyst includes a macroscopic structure of a conductive material that supports a ceramic coating, wherein the ceramic coating supports a catalytically active material; and wherein electrical conductors connected to a power source are placed outside the pressure shell and are arranged to supply electrical energy to the structured catalyst, thereby allowing an electric current to flow through the macroscopic structure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500 °C.

[0119] The H2 purification unit is suitably a pressure swing adsorption (PSA) unit, a membrane unit or a cryogenic separation unit. The separation unit is suitably a flash separation unit.

[0120] The system according to the present invention may include a pre-reforming unit located upstream of the reforming reactor and arranged to pre-reform the hydrocarbon feed gas. Similarly, the system may include a gas purification unit located upstream of the pre-reforming reactor and arranged to purify the crude hydrocarbon feed gas.

[0121] The following is a detailed description of the embodiments of the present invention depicted in the drawings. The embodiments are exemplary and their details are sufficient to clearly convey the present invention. However, the amount of detail provided is not intended to limit the expected variations of the embodiments; rather, it is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. Description of the Drawings

[0122] Figure 1It is a schematic diagram of a system for upgrading a hydrocarbon-containing feed gas 1 into a methanol product stream 61 and a hydrogen product stream 71. In the illustrated embodiment, upstream of the figure, the hydrocarbon-containing feed gas 1 is prepared with steam, hydrocarbons, and other components from the feedstock in a predetermined ratio. It is fed to a reforming reactor 10 to facilitate steam reforming to provide a first syngas stream 11. The core function of the reforming reactor is to increase the temperature of the gas, preferably to a temperature in the range of 800 - 1200 °C, such as approximately 1000 °C, while facilitating the endothermic steam reforming reaction to enable the hydrocarbon-containing feed gas to be converted into a first syngas containing at least CO and H2. In the illustrated embodiment, the system includes an electrically heated steam methane reformer (eSMR) 10, although other reforming reactors are also possible. The first syngas stream 11 is cooled in a cooling unit 20; only one heat exchanger is shown in the current embodiment, but many heat exchangers are conceivable. The cooling unit 20 cools the hot first syngas stream 11, preferably to a temperature below the dew point of the gas stream, such as between 30 and 50 °C. In Figure 1 the embodiment of, this provides a two-phase flow as the second syngas stream 21. The condensate of the second syngas stream 21 can be removed in this way in a dehydration unit 30, which is a flash separation unit in the current embodiment. In this configuration, a major portion of the water can be removed from the syngas, and typically the water content in the third syngas is less than 1%.

[0123] The third syngas stream 31 is then compressed in a compression unit 40 to a pressure higher than the feed pressure of the hydrocarbon-containing feed gas 1. The compression unit 40 provides a fourth syngas stream 41. As described above, the pressure of the fourth syngas stream is typically between 50 and 150 bar gauge, preferably between 80 and 90 bar gauge. In contrast, the feed pressure of the hydrocarbon-containing feed gas (and the third syngas stream) is typically between 20 and 40 bar gauge, preferably between 25 and 35 bar gauge.

[0124] The fourth syngas stream 41 can be further heated in a heat exchanger before being fed to a methanol synthesis unit 50 to achieve sufficient activity in this unit.

[0125] In Figure 1 the system of, the fourth syngas stream 41 is fed to a methanol synthesis unit 50. A methanol-rich stream 51 (usually with a methanol content of 20 - 30%) is output from the methanol synthesis unit.

[0126] At least a portion (and preferably all) of the methanol-rich stream 51 is fed to a separation unit 60. The separation unit 60 is arranged to provide a methanol product stream 61 and a hydrogen-rich stream 62 from at least a portion of the methanol-rich stream 51. In Figure 1 the system of, the separation unit 60 is a flash separation unit.

[0127] At least a portion of the hydrogen-rich stream 62 from the separation unit is fed to an H2 purification unit 70, which can be a pressure swing adsorption (PSA) unit, a membrane unit, or a cryogenic separation unit. In the H2 purification unit, the hydrogen-rich stream 62 is separated into a hydrogen product stream 71 and a tail gas stream 72.

[0128] Figure 2 The system shown includes Figure 1 all of the elements of, and also a gas purification unit 8, such as a desulfurization unit and a pre-reformer 9. There is also a preheating section 100 to heat the various feed gases before reforming.

[0129] The hydrocarbon feed 1A is preheated in the preheating section 100 and directed to the gas purification unit 8. The purified and preheated hydrocarbon feed 1B is sent back to the preheating section 100 from the gas purification unit 8 for further heating. In addition, steam 1C is added to the purified and preheated hydrocarbon feed 1B, and the resulting mixture is sent to the pre-reformer 9. The pre-reformed gas 1 leaves the pre-reformer 9 and is heated again in the preheating section 100, producing a hydrocarbon-containing feed gas 1, which is then fed to the eSMR 10.

[0130] Also as Figure 2 shown, at least a portion of the tail gas stream 72 from the H2 purification unit 70 is recycled as a fuel supply for heating the preheating section and / or the e-SMR 10. The portion used as fuel 81 can be mixed with air to heat the preheating section 100. The portion recycled to the hydrocarbon feed 82 can be compressed by a compressor 90 to obtain a suitable mixing pressure.

[0131] Figure 3 The system shown includes Figure 1 all of the elements of, and also a CO2 removal unit 80 in the form of a cryogenic separation unit 80' located between the compression unit 40 and the methanol synthesis unit 50. In Figure 3 this, at least a portion of the fourth synthesis gas stream 41 from the compression unit 40 is fed to the cryogenic separation unit 80'. In Figure 3 one embodiment, the cryogenic separation unit includes a cooling unit, followed by a flash separation unit, followed by a heating unit.

[0132] The output of the cryogenic separation unit is a CO2-rich stream 82 and a fifth synthesis gas stream 81. The CO2-rich stream 82 typically contains substantially pure CO2. At Figure 3 the separation point shown, the CO2 is in the liquid phase at high pressure and is suitable for integration with other parts of the process.

[0133] The fifth synthesis gas stream 81 differs mainly in terms of its CO2 content from the fourth synthesis gas stream 41. The CO2 content of the fifth synthesis gas stream 81 is typically less than 10%.

[0134] In Figure 3In the system, the methanol synthesis unit is arranged to convert at least a portion of the fourth synthesis gas stream 41 and / or at least a portion of the fifth synthesis gas stream 81 into a methanol-rich stream 51. Optionally, as Figure 3 shown by the dashed arrow in

[0135] Figure 4 A portion of the fourth synthesis gas stream 41 bypasses the low-temperature separation unit 80' and is mixed with the fifth synthesis gas stream 81. The combined fourth and fifth synthesis gas streams 41 and 81 are sent together to the methanol synthesis unit 50. This allows the composition of the (combined) synthesis gas stream fed to the methanol synthesis unit 50 to be adjusted as needed (and thus the ratio of the two product streams). Figure 3 The system shown in

[0136] Figure 5 includes all the elements of Figure 3 but includes a different embodiment of the low-temperature separation unit 80' in which the cooling and heating of the process gas is facilitated in a feed-effluent type configuration. Note that the cooling in this unit is not sufficient to reach the desired temperature, so additional cooling or cooling in combination with a supplementary stream group is required.

[0137] While the invention has been illustrated by the description of various embodiments, and while these embodiments have been described in considerable detail, the applicant does not intend to limit or in any way restrict the scope of the appended claims to these details. Additional advantages and modifications will be apparent to those skilled in the art. Accordingly, the invention in its broader aspects is not limited to the specific details, representative methods, and illustrative examples shown and described. Accordingly, departures may be made from these details without departing from the spirit or scope of the applicant's general inventive concept.

[0138] Example 1

[0139] Tables 1 and 2 show the results related to Figure 5Process data of embodiments of the present invention that are somewhat similar to the shown embodiment. A hydrocarbon feed gas (1) is provided and reformed in a reforming reactor (10) to reach a temperature of 1015 °C under almost equilibrium conditions to provide a first syngas (11). It is cooled and then shifted in a water gas shift reactor (14) to provide a shifted syngas stream (15). It is cooled to 40 °C to provide a second syngas stream (21). The increase in phases in the forced flow at this temperature and subsequent flash separation (30) can then remove the water-rich liquid condensate to provide a third syngas stream (31). It is compressed to 88 bar gauge pressure in a compression unit (40) to provide a fourth syngas stream (41). A portion of the CO2 in this stream is removed in a cryogenic separation unit (80') to provide a fifth syngas stream (81) and a CO2-rich stream (82). In the embodiment used, the cryogenic separation unit (80') includes several cooling and condensation steps to ensure proper cooling without the risk of freezing. The fifth syngas stream (81) is heated and converted to a methanol-rich stream (51) in a boiling water type methanol reactor (50). It is cooled to allow separation of methanol in liquid form by flash separation (60), in this way providing a methanol product stream (61) and a hydrogen-rich stream (62). The hydrogen-rich stream (62) is purified in a PSA to provide a hydrogen product stream (71) and a tail gas stream (72).

[0140] This embodiment of the present invention allows for the production of the following product splits: 287 Nm 3 / h of CO2 with a purity of 96% at 88 bar gauge pressure, 2109 Nm 3 / h of H2 with a purity of 99.9% at 85 bar gauge pressure, and 566 Nm 3 / h of CH3OH at 85 bar gauge pressure with a purity of 84%.

[0141] Table 1

[0142] ID of the stream 1 11 15 21 31 41 81 Temperature (°C) 403 1015 438 40 40 219 -70 Pressure (bar gage) 26.4 25.0 23.5 22.5 22.5 88.3 87.7 <![CDATA[Total flow rate (Nm 3 / h)]]> 2929 4716 4716 4716 4318 4320 4019 Composition [mol%] Carbon dioxide 1.4 2.6 10.1 10.1 11.0 11.0 5.0 Nitrogen 0.5 0.3 0.3 0.3 0.4 0.4 0.4 Methane 33.2 1.6 1.6 1.6 1.8 1.8 1.8 Hydrogen 5.5 61.9 69.5 69.5 75.9 75.9 81.4 Carbon monoxide 0.0 17.3 9.7 9.7 10.6 10.6 11.3 Water 59.4 16.2 8.7 8.7 0.3 0.3 0.0 Methanol 0.0 0.0 0.0 0.0 0.0 0.0 0.0

[0143] Table 2

[0144] ID of the stream 51 62 72 71 61 82 Temperature (°C) 250 40 40 40 40 -70 Pressure (bar gage) 86.2 85.2 0.5 84.7 85.2 87.7 <![CDATA[Total flow rate (Nm 3 / h)]]> 3047 2481 371 2109 566 287 Composition [mol%] Carbon dioxide 4.1 4.7 31.5 0.0 1.3 95.7 Nitrogen 0.5 0.6 3.8 0.1 0.0 0.0 Methane 2.4 3.0 19.7 0.0 0.1 1.2 Hydrogen 73.0 89.4 29.9 99.9 0.9 1.6 Carbon monoxide 1.5 1.9 12.4 0.0 0.0 1.3 Water 2.5 0.0 0.1 0.0 13.5 0.1 Methanol 16.0 0.4 2.6 0.0 84.1 0.0

[0145] Example 2

[0146] Tables 3 and 4 show an embodiment of the present invention similar to Example 1, but here the separation temperature in the cryogenic separation section is increased to -50 °C instead of -70 °C in Example 1. According to the method of the present invention, this allows for the production of the following product splits: 162 Nm 3 / h of CO2 with a purity of 96% at 88 bar gauge pressure, 2036 Nm 3 / h of H2 with a purity of 99.9% at 85 bar gauge pressure, and 627 Nm3 CH3OH at / h. Thus, the ratio of methanol to hydrogen is reduced from 4.4 to 4.1.

[0147] Table 3

[0148] ID of the stream 1 11 15 21 31 41 81 Temperature (°C) 403 1015 438 40 40 219 -60 Pressure (barg) 26.4 25.0 23.5 22.5 22.5 88.3 87.7 <![CDATA[Total flow rate (Nm 3 / h)]]> 2929 4716 4716 4716 4318 4320 4145 Composition [mol%] Carbon dioxide 1.4 2.6 10.1 10.1 11.0 11.0 7.8 Nitrogen 0.5 0.3 0.3 0.3 0.4 0.4 0.4 Methane 33.2 1.6 1.6 1.6 1.8 1.8 1.8 Hydrogen 5.5 61.9 69.5 69.5 75.9 75.9 79.0 Carbon monoxide 0.0 17.3 9.7 9.7 10.6 10.6 11.0 Water 59.4 16.2 8.7 8.7 0.3 0.3 0.0 Methanol 0.0 0.0 0.0 0.0 0.0 0.0 0.0

[0149] Table 4

[0150] ID of the stream 51 62 72 71 61 82 Temperature (°C) 250 40 40 40 40 -60 Pressure (barg) 86.2 85.2 0.5 84.7 85.2 87.7 <![CDATA[Total flow rate (Nm 3 / h)]]> 3124 2498 462 2036 627 162 Composition [mol%] Carbon dioxide 6.8 8.0 43.5 0.0 2.0 95.5 Nitrogen 0.5 0.6 3.0 0.1 0.0 0.0 Methane 2.4 3.0 16.3 0.0 0.1 1.1 Hydrogen 68.7 85.7 23.2 99.9 0.8 1.9 Carbon monoxide 1.8 2.2 11.8 0.0 0.0 1.3 Water 3.5 0.0 0.1 0.0 17.2 0.2 Methanol 16.3 0.4 2.0 0.0 79.9 0.0

[0151] The following numbered aspects are provided:

[0152] Aspect 1. A method for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream, comprising the following steps:

[0153] a) Supplying a hydrocarbon feed gas (1) to a reforming reactor (10),

[0154] b) Reforming the hydrocarbon feed gas (1) in the reforming reactor (10) to provide a first synthesis gas stream (11),

[0155] b1) Optionally, feeding at least a portion of the first synthesis gas stream (11) from step b) to a water gas shift reactor (14) to provide a shifted synthesis gas stream (15),

[0156] c) Cooling the first synthesis gas stream (11) and / or the shifted synthesis gas stream (15) in a cooling unit (20) to provide a second synthesis gas stream (21),

[0157] d) Removing water from the second synthesis gas stream (21) in a dehydration unit (30) to provide a third synthesis gas stream (31),

[0158] e) Compressing the third synthesis gas stream (31) in a compression unit (40) to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, to provide a fourth synthesis gas stream (41),

[0159] e1) Optionally, feeding at least a portion of the fourth synthesis gas stream (41) from step e) to a CO2 removal unit (80) to provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81),

[0160] f) Feeding at least a portion of the fourth synthesis gas stream (41) from step e) and / or at least a portion of the fifth synthesis gas stream (81) to a methanol synthesis unit (50) to provide a methanol-rich stream (51),

[0161] g) Feed at least a portion of the methanol-rich stream (51) from step f) to a separation unit (60) to provide a methanol product stream (61) and a hydrogen-rich stream (62).

[0162] Aspect 2. The method according to aspect 1, further comprising the step of adjusting the molar ratio between the hydrogen product stream and the methanol product stream.

[0163] Aspect 3. The method according to any one of the preceding aspects, the method further comprising the step of adjusting the amount of CO2 removed in the CO2 removal unit (80) relative to the CO2 content in the fourth synthesis gas stream (41).

[0164] Aspect 4. The method according to aspect 3, wherein the CO2 removal unit (80) is a cryogenic separation unit (80'), and wherein an increase in the amount of CO2 removed in the cryogenic separation unit is achieved by lowering the operating temperature in the cryogenic separation unit (80').

[0165] Aspect 5. The method according to any one of aspects 3-4, wherein a first portion of the fourth synthesis gas stream (41) from step e) is fed to the CO2 removal unit (80) to provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81); and wherein at least a portion of the fifth synthesis gas stream (81) is fed to the methanol synthesis unit (50) together with a second portion of the fourth synthesis gas stream (41) in step f).

[0166] Aspect 6. The method according to any one of the preceding aspects, wherein the hydrocarbon feed is biogas.

[0167] Aspect 7. The method according to any one of the preceding aspects, the method further comprising the step of providing a CO2-containing feed (2) to the reforming reactor (10).

[0168] Aspect 8. The method according to aspect 7, the method further comprising the step of adjusting the CO2-containing feed (2) such that the modulus of the first synthesis gas stream is in the range of 1.5 to 2.5, the modulus being defined as

[0169] Aspect 9. The method according to any one of the preceding aspects, wherein the reforming reactor (10) comprises an autothermal reformer, the method further comprising the step of providing an O2-containing feed (3) to the autothermal reformer.

[0170] Aspect 10. The method according to aspect 9, the method further comprising the step of adjusting the O2-containing feed (3) such that the modulus of the first synthesis gas stream is in the range of 1.5 to 2.5, the modulus being defined as

[0171] Aspect 11. The method according to any one of the preceding aspects, the method further comprising the step of providing a H2-containing feed (4) upstream of the methanol synthesis unit (50), the feed preferably being mixed with at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81).

[0172] Aspect 12. The method according to aspect 11, the method further comprising the step of adjusting the H2-containing feed (4) such that the modulus of the fourth and / or fifth synthesis gas stream is in the range of 1.5 to 2.5, the modulus being defined as

[0173] Aspect 13. The method according to any one of aspects 9-12, wherein an electrolysis unit is provided, and the method further comprises the step of generating a H2-containing feed (4) and an O2-containing feed (3) from a water feedstock in the electrolysis unit, the method further comprising the step of supplying the H2-containing feed (4) to the methanol synthesis unit (50) and / or supplying the O2-containing feed (3) to the autothermal reformer.

[0174] Aspect 14. The method according to any one of aspects 7-13, wherein the molar ratio between the methanol product stream and the hydrogen product stream is changed by adjusting the CO2-containing feed (2), the O2-containing feed (3) and / or the H2-containing feed (4).

[0175] Aspect 15. The method according to any one of the preceding aspects, wherein the reforming reactor (10) comprises a tubular reformer, a convective reformer, an electrically heated reformer, an autothermal reformer or a combination thereof, in particular a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series.

[0176] Aspect 16. The method according to aspect 15, wherein the reforming reactor (10) is an electrically heated reformer, which preferably comprises a pressure shell containing a structured catalyst, wherein the structured catalyst comprises a macroscopic structure of a conductive material, the macroscopic structure supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; and wherein the reforming step comprises the following additional steps: supplying electrical energy to the structured catalyst through an electrical conductor placed outside the pressure shell and connected to a power source, allowing an electric current to flow through the macroscopic structure material, thereby heating at least a portion of the structured catalyst to a temperature of at least 500 °C.

[0177] Aspect 17. The method according to aspect 16, wherein the electric power supplied to the electrically heated reformer is generated by renewable energy.

[0178] Aspect 18. The method according to any one of the preceding aspects, wherein the separation unit (60) is a flash separation unit.

[0179] Aspect 19. The method according to any one of the foregoing aspects, wherein a portion of the hydrogen-rich stream (62) from step g) is compressed and returned as a recycle stream to the methanol synthesis unit (50) in the methanol loop.

[0180] Aspect 20. The method according to any one of the foregoing aspects, further comprising step h) of providing at least a portion of the hydrogen-rich stream from step g) to an H2 purification unit to separate the hydrogen-rich stream into a hydrogen product stream and a tail gas stream.

[0181] Aspect 21. The method according to aspect 20, wherein the H2 purification unit (70) comprises a pressure swing adsorption (PSA) unit, a membrane unit or a cryogenic separation unit.

[0182] Aspect 22. A system for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream, the system comprising:

[0183] - a hydrocarbon feed gas (1) arranged to be fed to a reforming reactor (10),

[0184] - a reforming reactor (10) arranged to reform the hydrocarbon feed gas (1); thereby providing a first synthesis gas stream (11) from the reforming reactor (10),

[0185] - optionally, a water gas shift reactor (14) arranged to receive at least a portion of the first synthesis gas stream (11) from the reforming reactor and provide a shifted synthesis gas stream (15),

[0186] - a cooling unit (20) arranged to cool the first synthesis gas stream (11) and / or the shifted synthesis gas stream (15), thereby providing a second synthesis gas stream (21),

[0187] - a dehydration unit (30) arranged to remove water from the second synthesis gas stream (21), thereby providing a third synthesis gas stream (31),

[0188] - a compression unit (40) arranged to compress the third synthesis gas stream (31) to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, thereby providing a fourth synthesis gas stream (41),

[0189] - optionally, a CO2 removal unit (80) arranged to receive at least a portion of the fourth synthesis gas stream (41) and provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81),

[0190] - a methanol synthesis unit (50) arranged to convert at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81) into a methanol-rich stream (51),

[0191] - A separation unit (60) which is arranged to provide a methanol product stream (61) and a hydrogen-rich stream (62) from at least a portion of the methanol-rich stream (51).

[0192] Aspect 23. The system according to aspect 22, wherein a first portion of the fourth synthesis gas stream (41) is arranged to be fed to a CO2 removal unit (80) to provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81); and wherein at least a portion of the fifth synthesis gas stream (81) is arranged to be fed to the methanol synthesis unit (50) together with a second portion of the fourth synthesis gas stream (41).

[0193] Aspect 24. The system according to any one of aspects 22 - 23, the system further comprising a CO2-containing feed (2) which is arranged to be fed to the reforming reactor (10), preferably mixed with the hydrocarbon-containing feed gas (1).

[0194] Aspect 25. The system according to any one of aspects 22 - 24, wherein the reforming reactor (10) comprises an autothermal reformer, and the system further comprises an O2-containing feed (3) which is arranged to be fed to the autothermal reformer.

[0195] Aspect 26. The system according to any one of aspects 22 - 25, the system further comprising an H2-containing feed (4) which is arranged to be fed upstream of the methanol synthesis unit (50), preferably mixed with at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81).

[0196] Aspect 27. The system according to any one of aspects 22 - 26, the system further comprising an electrolysis unit which is arranged to generate an H2-containing feed (4) and an O2-containing feed (3) from a water feedstock, and the system is further arranged to supply the H2-containing feed (4) from the electrolysis unit to the methanol synthesis unit (50), and / or supply the O2-containing feed (3) from the electrolysis unit to the autothermal reformer.

[0197] Aspect 28. The system according to any one of aspects 22 - 27, wherein the reforming reactor (10) comprises a tubular reformer, a convection reformer, an electrically heated reformer, an autothermal reformer or a combination thereof, in particular a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series.

[0198] Aspect 29. The system according to aspect 28, wherein the reforming reactor (10) is an electrically heated reformer, which preferably comprises a pressure shell containing a structured catalyst, wherein the structured catalyst comprises a macroscopic structure of a conductive material, the macroscopic structure supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; and wherein an electrical conductor connected to a power source is placed outside the pressure shell and is arranged to supply electrical energy to the structured catalyst, thereby allowing an electric current to flow through the macroscopic structure material and thereby heating at least a portion of the structured catalyst to a temperature of at least 500 °C.

[0199] Aspect 30. The system according to any one of aspects 22-29, wherein the separation unit (60) is a flash separation unit.

[0200] Aspect 31. The system according to any one of aspects 22-30, the system further comprising an H2 purification unit (70) arranged to separate the hydrogen-rich stream (62) into a hydrogen product stream (71) and a tail gas stream (72).

[0201] Aspect 32. The system according to aspect 31, wherein the H2 purification unit (70) is a pressure swing adsorption (PSA) unit, a membrane unit or a cryogenic separation unit.

[0202] Aspect 33. The system according to any one of aspects 22-32, wherein the CO2 removal unit (80) is a cryogenic separation unit (80').

Claims

1. A method for upgrading a hydrocarbon-containing feed gas to a methanol product stream and a hydrogen product stream, comprising the following steps: a) Supplying a hydrocarbon-containing feed gas (1) to a reforming reactor (10), b) Reforming the hydrocarbon-containing feed gas (1) in the reforming reactor (10) to provide a first synthesis gas stream (11), b1) Optionally, feeding at least a portion of the first synthesis gas stream (11) from step b) to a water gas shift reactor (14) to provide a shifted synthesis gas stream (15), c) Cooling the first synthesis gas stream (11) and / or the shifted synthesis gas stream (15) in a cooling unit (20) to provide a second synthesis gas stream (21), d) Removing water from the second synthesis gas stream (21) in a dehydration unit (30) to provide a third synthesis gas stream (31), e) Compressing the third synthesis gas stream (31) in a compression unit (40) to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, to provide a fourth synthesis gas stream (41), e1) Feeding at least a portion of the fourth synthesis gas stream (41) from step e) to a CO2 removal unit (80) to provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81), f) Feeding at least a portion of the fourth synthesis gas stream (41) from step e) and / or at least a portion of the fifth synthesis gas stream (81) to a methanol synthesis unit (50) to provide a methanol-rich stream (51), g) Feeding at least a portion of the methanol-rich stream (51) from step f) to a separation unit (60) to provide a methanol product stream (61) and a hydrogen-rich stream (62), wherein the CO2 removal unit (80) and the methanol synthesis unit (50) operate at elevated and similar pressures, and wherein the CO2 removal unit (80) is a cryogenic separation unit (80'), and an increase in the amount of CO2 removed in the cryogenic separation unit is achieved by reducing the operating temperature in the cryogenic separation unit (80') to an operating range of about -30°C to -80°C, and wherein a first portion of the fourth synthesis gas stream (41) from step e) is fed to the CO2 removal unit (80) to provide the CO2-rich gas stream (82) and the fifth synthesis gas stream (81); and wherein at least a portion of the fifth synthesis gas stream (81) is fed to the methanol synthesis unit (50) together with a second portion of the fourth synthesis gas stream (41) in step f).

2. The method according to claim 1, further comprising the step of adjusting the molar ratio between the hydrogen product stream and the methanol product stream by adjusting the ratio of the fourth synthesis gas stream fed to the CO2 removal unit to the fourth synthesis gas stream fed directly to the methanol synthesis unit.

3. The method according to claim 1, the method further comprising the step of adjusting the amount of CO2 removed in the CO2 removal unit (80) by increasing the amount of CO2 condensed in the CO2 removal unit relative to the CO2 content in the fourth synthesis gas stream (41).

4. The method according to claim 3, wherein a first portion of the fourth synthesis gas stream (41) from step e) is fed to a CO2 removal unit (80) to provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81); and wherein at least a portion of the fifth synthesis gas stream (81) is fed together with a second portion of the fourth synthesis gas stream (41) to the methanol synthesis unit (50) in step f).

5. The method according to claim 1, the method further comprising the step of providing a CO2-containing feed (2) to the reforming reactor (10).

6. The method according to claim 1, wherein the reforming reactor (10) comprises an autothermal reformer, and the method further comprises the step of providing an O2-containing feed (3) to the autothermal reformer.

7. The method according to claim 1, the method further comprising the step of providing a H2-containing feed (4) upstream of the methanol synthesis unit (50), preferably mixed with at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81).

8. The method according to claim 7, wherein the molar ratio between the methanol product stream and the hydrogen product stream is changed by adjusting the CO2-containing feed (2) and the O2-containing feed (3) such that the modulus M of the first synthesis gas stream is in the range of 1.5 to 2.5, and / or by adjusting the H2-containing feed (4) such that the modulus M of the fourth and / or fifth synthesis gas stream is in the range of 1.5 to 2.5, wherein the modulus M of the synthesis gas is defined as 9. The method according to claim 1, wherein the reforming reactor (10) comprises a tubular reformer, a convective reformer, an electrically heated reformer, an autothermal reformer or a combination thereof, in particular a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series.

10. The method according to claim 1, wherein a portion of the hydrogen-rich stream (62) from step g) is compressed and returned as a methanol loop recycle stream to the methanol synthesis unit (50).

11. A system for upgrading a hydrocarbon feed gas to a methanol product stream and a hydrogen product stream, the system comprising: - a hydrocarbon feed gas (1) arranged to be fed to a reforming reactor (10), - a reforming reactor (10) arranged to reform the hydrocarbon feed gas (1); thereby providing a first synthesis gas stream (11) from the reforming reactor (10), - a water gas shift reactor (14) arranged to receive at least a portion of the first synthesis gas stream (11) from the reforming reactor and provide a shifted synthesis gas stream (15), - a cooling unit (20) arranged to cool the first synthesis gas stream (11) and / or the shifted synthesis gas stream (15), thereby providing a second synthesis gas stream (21), - a dehydration unit (30) arranged to remove water from the second synthesis gas stream (21), thereby providing a third synthesis gas stream (31), - a compression unit (40) arranged to compress the third synthesis gas stream (31) to a first pressure, the first pressure being higher than the feed pressure of the hydrocarbon feed gas, thereby providing a fourth synthesis gas stream (41), - a CO2 removal unit (80) arranged to receive at least a portion of the fourth synthesis gas stream (41) and provide a CO2-rich gas stream (82) and a fifth synthesis gas stream (81), - a methanol synthesis unit (50) arranged to convert at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81) into a methanol-rich stream (51), - A separation unit (60) which is arranged to provide a methanol product stream (61) and a hydrogen-rich stream (62) from at least a portion of the methanol-rich stream (51), wherein the CO2 removal unit (80) and the methanol synthesis unit (50) operate at elevated and similar pressures, and wherein a first portion of the fourth synthesis gas stream (41) is arranged to be fed to the CO2 removal unit (80) to provide a CO2-rich stream (82) and a fifth synthesis gas stream (81); and wherein at least a portion of the fifth synthesis gas stream (81) is arranged to be fed to the methanol synthesis unit (50) together with a second portion of the fourth synthesis gas stream (41), and wherein the system further comprises an H2 purification unit (70) which is arranged to separate the hydrogen-rich stream (62) into a hydrogen product stream (71) and a tail gas stream (72).

12. The system according to claim 11, further comprising a CO2-containing feed (2) arranged to be fed to the reforming reactor (10), preferably mixed with the hydrocarbon-containing feed gas (1).

13. The system according to claim 11, wherein the reforming reactor (10) comprises an autothermal reformer, and the system further comprises an O2-containing feed (3) arranged to be fed to the autothermal reformer.

14. The system according to claim 13, wherein the system further comprises an electrolysis unit arranged to generate an H2-containing feed and an O2-containing feed from a water feedstock, and the system is further arranged to supply the H2-containing feed from the electrolysis unit to the methanol synthesis unit and / or supply the O2-containing feed from the electrolysis unit to the autothermal reformer.

15. The system according to claim 11, further comprising an H2-containing feed (4) arranged to be fed upstream of the methanol synthesis unit (50), preferably mixed with at least a portion of the fourth synthesis gas stream (41) and / or at least a portion of the fifth synthesis gas stream (81).

16. The system according to claim 11, wherein the reforming reactor (10) comprises a tubular reformer, a convective reformer, an electrically heated reformer, an autothermal reformer or a combination thereof, in particular a combination of a tubular reformer and an autothermal reformer arranged in series, or a combination of an electrically heated reformer and an autothermal reformer arranged in series.

17. The system according to claim 11, wherein the CO2 removal unit (80) is a cryogenic separation unit (80').

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