WO2025257322A1

WO2025257322A1 - Process and plant for producing low carbon intensity methanol and/or transportation range fuel

Info

Publication number: WO2025257322A1
Application number: PCT/EP2025/066408
Authority: WO
Inventors: Manish Agrawal; Troels Juel FRIIS-CHRISTENSEN; Per Juul Dahl; Pudi ABHIMANYU
Original assignee: Haldor Topsoe AS
Current assignee: Topsoe AS
Priority date: 2024-06-12
Filing date: 2025-06-12
Publication date: 2025-12-18
Anticipated expiration: 2026-12-12

Abstract

Plant and process for converting a gaseous hydrocarbon feed to methanol, optionally to a transportation range fuel such as any of a gasoline product, a jet fuel product, and a diesel product; the plant including a synthesis gas section, a methanol synthesis section, optionally and a transportation range fuel synthesis section. The plant also includes diverting and supplying a purge gas from the methanol synthesis section to a water gas shift (WGS) section, CO₂-removal section, and a first hydrogen purification section. In an embodiment, the first hydrogen purification section provides a first H₂-rich gas, a second H₂-rich gas, and a first hydrogen purification section off-gas. One or more fired heaters are suitably arranged to receive at least a portion of the second H₂-rich gas.

Description

Title: Process and plant for producing low carbon intensity methanol and/or transportation range fuel

FIELD OF THE INVENTION

The invention relates to the field of methanol production from a gaseous hydrocarbon feed such as natural gas, more specifically the production of low carbon intensity methanol. The invention pertains also to the field of hydrocarbon fuel production utilizing the methanol as raw material, more specifically the production of low carbon intensity transportation range fuel products such as gasoline, jet fuel, and diesel.

BACKGROUND

Methanol is an important chemical feedstock used in a variety of industries including plastics, adhesives, and solvents. Methanol is becoming a highly relevant chemical as it can be utilized as energy carrier, more specifically as hydrogen carrier and thus suitably used as green methanol for transportation where methanol can be produced by renewable sources or where any associated carbon dioxide being produced is captured, stored and/or sequestered. Methanol may be further converted to gasoline, jet fuel and diesel, thus providing transportation range hydrocarbon fuels. The production of transportation range hydrocarbon fuels such as gasoline, jet fuel, and diesel is a critical aspect of the energy sector. In connection with e.g. gasoline production, one common method involves reforming natural gas (NG) by autothermal reforming (ATR), obtaining a synthesis gas (syngas) which is conditioned into a methanol synthesis gas. This syngas is then converted to methanol and subsequently to a raw gasoline product. This raw hydrocarbon product is then upgraded and processed into a final gasoline product. However, traditional methods often result in significant CO2 emissions, leading to an overall increase in the carbon intensity (Cl) associated with the production of the methanol and optionally a gasoline, diesel or jet fuel product. This is primarily due to the firing i.e. burning of NG and/or waste off-gases in fired heater(s) of the plant, which results in the emission of flue gases and thereby significant CO2 emissions.

Related prior art is found in e.g. US 20160168476 and applicant’s WO 2022248434, WO 2023187147, WO 2023247316 and WO 2023247315. For instance, WO 2022248434 Fig. 5 discloses a system for producing methanol, in which purge gas from the methanol synthesis section is directed to water gas shift and CCh-removal, thereby producing a CCh-depleted gas which is directed to a hydrogen recovery section (G), this being a pressure swing adsorption (PSA) unit or a membrane unit. A first and second hydrogen-rich streams 14, 16 are produced, as so are a first and a second offgas streams 15, 17. The second hydrogen-rich stream 16 and the second off-gas stream 17 are directed to a fuel system (H). Inert reduction occurs via sending the offgas 17 from the HRU (G) to the fuel system (H) which leads to loss of carbon when employed along with associated higher 002-emissions (thereby higher Cl) from the fuel system, due to a significant carbon content e.g. CH4 and CO, in the off-gas.

SUMMARY

One of the challenges that are typically faced in connection with methanol production is how to produce the methanol with the lowest possible Cl. Another challenge typically faced in connection with methanol production is how to get rid of the inert components, these being at least one of nitrogen (N2) and argon (Ar), and which enter into the plant via feed streams such as the gaseous hydrocarbon feed stream or an oxygen (O2) stream to an ATR in the synthesis gas section of the plant. The inert components accumulate at least in the methanol synthesis section, as well as in other parts of the plant, for instance also in a water gas shift section and/or hydrogen purification section, thereby requiring higher capital and operating expenses (CAPEX and OPEX), as bigger processing units are needed to process the associated gas streams.

It would be desirable to be able to provide a significant decrease in the carbon intensity (Cl) associated with the production of methanol and optional downstream production of transportation range fuels.

It would be desirable to be able to provide a more efficient removal of inert components in the plant.

Accordingly, in a first general embodiment of a first aspect of the invention there is provided a plant 100 for converting a gaseous hydrocarbon feed 1 such as natural gas to methanol; wherein the plant comprises: - a synthesis gas section 8, 10, 12 arranged to receive the gaseous hydrocarbon feed 1 and provide a synthesis gas 13, 15;

- a methanol synthesis section 14 arranged to receive at least a portion 13 of the synthesis gas and provide: a raw methanol product 17, a first purge gas 33, and a first set 31’ of one or more waste off-gas streams;

- a water gas shift (WGS) section 20 arranged to receive at least a portion of said first purge gas 33 and provide a shifted gas;

- a CC>2-removal section 22 arranged to receive said shifted gas and provide: a CO2- rich gas 37 and a CCh-depleted shifted gas 39;

- a first hydrogen purification section 24’ arranged to receive said CCh-depleted shifted gas 39 and provide: a first H2-rich gas 41’ and a first hydrogen purification section offgas 9; wherein said first hydrogen purification section 24’ is further arranged to provide a second H2-rich gas 41” with a lower content of H2 and a higher content of an inert component than the first H2-rich gas 41’, the inert component being at least one of nitrogen (N2) and argon (Ar); wherein the plant comprises:

- one or more fired heaters arranged to receive at least a portion of the second H2-rich gas 41”;

- a conduit arranged to supply at least a portion of the first H2-rich gas 41’ to the methanol synthesis section 14.

In an embodiment, the one or more fired heaters arranged to receive the entire portion of the second H2-rich gas 41”.

In an embodiment, the conduit is arranged to supply the entire portion of the first H2- rich gas 41’ to the methanol synthesis section 14.

The invention provides the associated benefit of unique integration of proven sections, namely the synthesis gas section for producing methanol synthesis gas from a gaseous hydrocarbon feed, the methanol synthesis section for producing raw methanol product or a methanol product, the raw methanol or methanol product now having a significantly lower carbon intensity (Cl). A blue methanol plant is thereby provided, in which the term “blue methanol” is understood as methanol produced limiting the emission of CO2. Optionally, as it will become apparent from one or more of below embodiments, a transportation range fuel synthesis section for producing transportation range fuel from the methanol, is also provided; the transportation range fuel product, such as gasoline, or jet fuel, or diesel, now also having a significantly lower carbon intensity (Cl). A blue gasoline or blue jet fuel plant is thereby provided, in which the term “blue gasoline” or “blue jet fuel” is understood as the production of any of these transportation fuels limiting the emission of CO2. As also explained further below, the invention enables reducing the Cl while at the same time avoiding the build-up of inerts in the methanol synthesis section.

For the purposes of the present application:

The term “present invention” or simply “invention” may be used interchangeably with the terms “present application” or simply “application”, respectively.

The term “first aspect of the invention” means the plant (process plant) of the invention. The term “second aspect of the invention” means the process of the invention.

The term “plant/process” means plant and/or process. In general, when referring to the plant there is implicit reference to the process as well.

The term “and/or” means in connection with a given embodiment any of three options. The term “and/or” may be used interchangeably with the term “at least one of” the three options.

The term “comprising” includes “comprising only” i.e. “consisting of”.

The term “suitably” means “optionally”, i.e. an optional embodiment.

The term “synthesis gas” may be used interchangeably with the term “syngas”.

The terms “water gas shift (WGS)” and “shift” or “shifting” may be used interchangeably.

The term “at least a portion” of a certain item means a portion thereof or the entire portion. For instance, “at least a portion of a given stream” means “a portion of the stream or the entire stream”.

The use of the article “a” or “an” means at least one. It is also used interchangeably with the term “one or more”.

The term “section” may be used interchangeably with the term “unit” and means a physical section comprising one or more units.

The term “conduit” means a process line, such as a pipe, carrying a given process stream. For instance, in connection with the appended figures, process stream 9 is a first hydrogen purification section off-gas; the associated conduit may also be denoted by ref. numeral 9.

The term “arrange” may be used interchangeably with “configure”. For instance, “a synthesis gas section arranged to receive the gaseous hydrocarbon feed” is understood “a synthesis gas section configured to receive the gaseous hydrocarbon feed”.

Unless otherwise stated, percentages of a given stream or a given compound in a stream are in vol. basis i.e. vol.%.

Other definitions are provided in connection with one or more of above or below embodiments.

In an embodiment, the supply of at least a portion of the first H2-rich gas 4T to the methanol synthesis section 14 is arranged in combination with the at least a portion 13 of the synthesis gas.

The high purity (high H2 content) of this gas stream makes it suitable for adjusting the H2 content in the synthesis gas, thereby the proper module “M” to the methanol synthesis section. As it will also become apparent from one or more of below embodiments, the module “M” is preferably about 2 in the synthesis gas, in which M=(H2- CO2)/(CC>2+CO) in molar or vol. basis.

In an embodiment, the purge gas comprises 60-80% H2, 2-6% CO and 2-6% CO2.

As recited, said first hydrogen purification section 24’ is further arranged to provide a second H2-rich gas 41” with a lower content of H2 and a higher content of an inert component than the first H2-rich gas 4T, the inert component being at least one of nitrogen (N2) and argon (Ar).

In connection with any of the above or below embodiments, there is the associated benefit of the major fuel gas source, namely at least 90%, for instance up to 99%, for the firing in fired heater(s) being the hydrogen in the first and/or second H2-rich gas recovered from the purge gas in the methanol synthesis section, preferably the at least a portion of the second H2-rich gas, thereby enabling significantly lower CCh-emissions (accordingly lower Cl) than prior art plant/process layouts, in which natural gas which is mainly methane and/or waste off-gases comprising light hydrocarbons including methane, are the major fuel gas source to the fired heater(s). There is high energy and carbon efficiency, as the requirement for e.g. natural gas for the firing in fired heater(s) is minimized, and most of the carbon in the gaseous hydrocarbon feed, such as natural gas, goes into the methanol, or the downstream transportation range fuel product, as well as into CO2 withdrawn in said CCh-removal section, which is then suitably sequestrated.

Hence, suitably there is carbon capture and storage (CCS), or carbon capture and utilization (CCU), of said CCh-rich gas.

The term “carbon capture and storage (CCS)” means a process in which the pure stream of carbon dioxide, i.e. said CCh-rich gas, is separated, treated and transported to a storage location. Suitably, water is removed to provide a dry CCh-rich gas which is then transported to the storage location. The term “carbon capture and utilization (CCU)” means that the CCh-rich gas is used for producing high-value chemicals, such as a component of synthesis gas for the production of methanol i.e. as a methanol synthesis gas.

In an embodiment, the first hydrogen purification section 24’ is arranged to provide only three outlets, the first outlet being the first H2-rich gas 4T, the second outlet being the first hydrogen purification section off-gas 9, and the third outlet being the second H2- rich gas 41” or a gas stream 41 C forming part of the second H2-rich gas 41”.

Preferably, the first hydrogen purification section 24’ is a pressure swing adsorption unit (PSA unit).

The provision of such an arrangement enables, as for instance shown in connection with particular reference to the first hydrogen purification unit 24’A of appended Fig. 5, apart from the outlet off-gas 9, the provision of a separate (another) gas stream 41 C as a separate outlet of the first hydrogen purification unit 24’A, preferably a PSA unit, in which the separate gas stream 41 C carries the inerts, This gas stream 41 C is thus referred to as inert-containing gas. From the first hydrogen purification unit 24’A, another outlet is provided, this being raw H2-rich gas 41 of which at least a portion 41 D is split and optionally combined with the inert-containing gas 41 C to a combined H2-rich and inert containing gas stream 41 E. The separate inert-containing gas stream 41 C and/or the combined gas stream 41 E may be sent to fired heater(s) as the second H2-rich gas 41”.

For a methanol production plant with no production of transportation range fuel, such as gasoline production, the second PSA (24’B) is not needed.

In another embodiment, any of the gas streams 41 C, 41 E may be combined with the off-gas outlet of second hydrogen purification unit 24’B to form the second H2-rich gas 41”.

In an embodiment,

- the first H2-rich gas 4T comprises at least 95 vol.% H2, such as at least 99 vol.% H2, and the inert content of the first H2-rich gas 4T in terms of N2 and Ar is: less than 0.10 vol. % N2 and less than 0.6 vol.% Ar; and/or

- the second H2-rich gas 41” comprises at least 80 vol.% H2, such as up to 97 or 96 vol.% H2, and the inert content of the second H2-rich gas 41” in terms of N2 and Ar is: 0.5 vol.% N2 or higher, such as 0.6-10 vol.% N2, and 0.6 vol. % Ar or higher, such as 0.6-1.0 vol.% Ar.

Hence, the inerts are removed and carried with the second H2-rich gas to fired heater(s). This is a simpler, more carbon-efficient and CCh-friendly way of removing the inerts than for instance withdrawing inerts with an off-gas which is rich in carbon containing compounds such as CH4. The term “carbon efficient” means herein that there is lower loss of carbon to the atmosphere, optionally to CO2 removed in the CCh-removal section.

It is understood that for the purposes of the present application, the term “inert component” or “inert” or “inert(s)” refer to at least one of N2 and Ar. The inert(s) may also comprise CH4.

For the purposes of the present application, the inert(s) may also comprise at least one of CO and CO2, herein also referred to as CO_X where “x” is 1 or 2. CO_X may be detrimental for downstream catalysts in the production of transportation range fuel product. These may also be referred to as “impurities”.

In an embodiment, the one or more fired heaters are arranged so that:

- there is no supply thereto of said first hydrogen purification section off-gas 9; and/or

- there is no supply thereto of a second hydrogen purification section off-gas.

So, off-gas comprising significant amounts of hydrocarbons, e.g. CH4, and which is typically supplied to the burners of fired heater(s), are advantageously utilized elsewhere in the plant/process as a carbon source, while cleaner hydrogen-rich gas streams are the ones utilized in the fired heater(s), thereby significantly reducing the CO2 emitted in the fired heater flue gas. The loss of carbon is reduced while at the same time the Cl of the plant is significantly reduced.

A trim fuel gas, such as natural gas, may be supplied to the fired heater(s) as a makeup fuel gas. Accordingly, the one or more fired heaters are arranged so that there is a supply thereto of a make-up fuel gas, preferably natural gas, for instance a portion natural gas used as the gaseous hydrocarbon feed.

In an embodiment, the methanol synthesis section 14 is arranged as a methanol synthesis loop; the methanol synthesis loop comprising: a methanol reactor arranged to receive the at least a portion 13 of the synthesis gas and provide a raw methanol effluent stream; a first separator arranged to receive the raw methanol effluent stream and provide: an overhead recycle gas, and a bottom stream as said raw methanol product 17; a recycle compressor arranged to supply the overhead recycle gas to the methanol reactor; a conduit arranged to divert a portion of the overhead recycle gas as said first purge gas 33.

The first hydrogen purification section, such as a pressure swing adsorption unit (PSA unit) produces, in an embodiment, and as exemplified in appended Fig. 1 and 3, two different quality H2-rich gases: the first H2-rich gas having high H2 purity, such as 95 vol.% H2 or higher, and minimal amount of the inert component, and the other i.e. the second H2-rich gas, having lower hydrogen concentration, such as less than 95 vol.% H2, but higher content of inert components. The higher purity H2-product, i.e. the first H2-rich gas, is advantageously recycled to the methanol synthesis section, as it will also become apparent from a below embodiment, to meet module requirement, i.e. module “M” of about 2 in the synthesis gas, in which M=(H2-CO2)/(CC>2+CO) in molar or vol. basis. Since this stream is very low in inert components, the build-up of inert components, herein also referred to as “inerts”, in the methanol synthesis section, for instance in the overhead recycle gas of the methanol synthesis loop recycle, and/or in different sections of the plant is reduced. A portion of any of the first and second H2-rich gas, preferably the first H2-rich gas, having the higher H2-purity i.e. higher ^-concentration, is suitably also routed to, for instance, the upgrading section of optional downstream gasoline synthesis section or optional downstream jet fuel synthesis section in connection with the production of transportation range fuels. Preferably, the second H2- rich gas, having most, if not all, of the inerts, is sent as fuel to fired heater(s)s. This allows effectively purging out of the inerts via the fired heater(s) flue gases.

As recited, the plant comprises:

- one or more fired heaters arranged to receive at least a portion of the second H2-rich gas 41”.

It is understood that in connection with this embodiment, the first hydrogen purification section is further arranged to provide said second H2-rich gas 41” with a lower content of H2 and a higher content of an inert component than the first H2-rich gas 4T.

By removing the inerts, the efficiency of the methanol synthesis is improved. The inerts provide a dilution effect which reduces the partial pressure of the reactive species in the methanol synthesis gas, namely H2, CO2, CO. The lower partial pressure may result in lower reaction rates in the methanol synthesis reactor (methanol reactor). Further, to compensate for the dilution, the recycle compressor of the methanol synthesis section e.g. methanol synthesis loop, has to recirculate more gas thus increasing the recycle compressor power consumption. As the inerts are not consumed in the methanol synthesis, over time they accumulate in the methanol synthesis loop, thereby further diluting the reactive species. The presence of inerts conveys also the problem of higher volumetric flow rates through the methanol reactor, resulting in larger units i.e. the methanol reactor and associated units such as heat exchangers; as well as potentially also affecting the purification of methanol downstream, by a high concentration of inerts reducing the efficiency of methanol condensation and thereby potentially resulting in less methanol recovery.

In an embodiment,

- the first hydrogen purification section 24’ is arranged to provide a single H2-rich gas as said first H2-rich gas 4T along with said first hydrogen purification section off-gas 9; and the plant comprises:

- one or more fired heaters arranged to receive: at least a portion of said first H2-rich gas 4T.

For instance, where there is a second hydrogen purification section, as exemplified in appended Fig. 2, the first H2-rich gas from the first hydrogen purification section, having a high inert content, is sent to the fired heater(s).

The invention enables therefore that all the inert containing hydrogen gas is supplied to fired heater(s). Hence, where the first hydrogen purification section provides a single H2-rich gas as said first H2-rich gas, i.e. this first hydrogen purification section produces only the first H2-rich gas along with the hydrogen purification off-gas, the first H2-rich gas comprises the inerts. Where the first hydrogen purification section provides, i.e. produces, not only a first H2-rich gas but also a second H2-rich gas, along with the hydrogen purification off-gas, the major part of the inerts are now carried in the second H2-rich gas, which is then supplied to fired heater(s). The first H2-rich gas, having lower inert content and higher hydrogen content than the second H2-rich gas, is advantageously supplied to e.g. methanol synthesis section, as explained earlier.

It is understood that the term “one or more fired heaters” is used interchangeably with the term “fired heater(s)”.

As recited above, one of the major challenges that are typically faced in connection with design and operation of plants for methanol production is how to get rid of the inerts entering the plant via the gaseous hydrocarbon feed, e.g. natural gas, or via an oxygen (O2) stream or oxygen-rich stream to e.g. the ATR in the synthesis gas section, or due to recycle of off-gas streams. The present invention makes the removal more efficient and enables taking advantage of inter alia the off-gas streams, as for instance, not only one but at least two H2-rich gas streams are withdrawn from the first hydrogen purification section, apart from the first purification section off-gas, the latter having a lower hydrogen content and higher content of lower hydrocarbons such as methane (CH4) than any of the first and second H2-rich gases. The first hydrogen purification section off-gas is also withdrawn at lower pressure, e.g. 1-10 bar or 3-10 bar, thus requiring the provision of an off-gas compressor that can bring the pressure up to e.g. the pressure required in the synthesis gas section.

Hence, again, the first hydrogen purification section, in an embodiment, simultaneously produces, apart from off-gas, two different qualities of H2 product streams: one high purity H2 product i.e. the first H2-rich gas and another H2-rich gas with lower purity, i.e. the second H2-rich gas. The first H2-rich gas contains minimum amounts of any of the inerts. The provision of the second H2-rich gas enables transferring the maximum possible amount inerts to this stream, while at the same time minimizing the amount of carbon containing molecules therein, e.g. CO, CO2 and CH4. This second H2-rich gas is utilized as the major fuel gas source in fired heater(s) thereby minimizing CO2 emission in the flue gases from the fired heater(s), while effectively purging out the inerts, as explained earlier. The off-gas, i.e. first hydrogen purification section off-gas, comprising most of the carbon containing molecules and minimum content of inerts, is suitably routed to synthesis gas section, in particular to the reforming unit therein, more particularly to pre-reformed hydrocarbon feed to an ATR unit, as it will also become apparent from a below embodiment.

In an embodiment,

-- the first hydrogen purification section 24’ comprises at least two hydrogen purification units 24’A, 24’B arranged in series;

- the first 24’A hydrogen purification unit is arranged to receive said CCh-depleted shifted gas 39 and provide: a raw H2-rich gas 41 and a first hydrogen purification unit off-gas as said first hydrogen purification section off-gas 9;

- the second 24’B hydrogen purification unit is arranged to receive at least a portion 41 A of said raw H2-rich gas 41 and provide: said first H2-rich gas 4T and a second hydrogen purification unit off-gas as said second H2-rich gas 41”. In an embodiment, the first hydrogen purification section 24’ further comprises: a conduit arranged to divert and supply a portion 41 B of said raw H2-rich gas 41 to said second hydrogen purification unit off-gas and provide said second H2-rich gas 41”.

An example of this embodiment is shown in Fig. 3.

It is understood that in connection with this embodiment, the second hydrogen purification section is further arranged to provide said second H2-rich gas 41” with a lower content of H2 and a higher content of an inert component than the first H2-rich gas 4T.

In an embodiment,

- the first hydrogen purification section (24’) further provides: a separate inert-containing gas (41 C) having a higher inert content than the raw H2-rich gas (41); and wherein: a conduit is arranged to supply the inert-containing gas (41 C) to said second hydrogen purification unit off-gas and provide said second H2-rich gas (41”); and/or a conduit is arranged to divert and supply a portion (41 D) of said raw H2-rich gas (41) to said inertcontaining gas (41 C) into a combined raw H2-rich gas (41 E), in which a conduit is arranged to supply the combined raw H2-rich gas (41 E) to said second hydrogen purification unit off-gas and provide said second H2-rich gas (41”); a conduit is arranged to divert and supply another portion of said H2-rich gas (41), as the portion (41A) of said raw H2-rich gas (41).

An example of this embodiment is shown in Fig. 5.

As recited above, the provision of such an arrangement enables in particular the provision of a gas stream 41 C which carries the inerts along with a separated H2-rich gas 41 of which a portion 41 D may be combined with said gas 41 C to produce the second H2- rich gas 41” which is sent to fired heater(s). Yet again, the inerts are thereby withdrawn as part of the second H2-rich gas 41” instead of being withdrawn with the off-gas 9 from the first hydrogen purification unit 24’A, or with the first H2-rich gas 4T of the second hydrogen purification unit 24’B. Preferably, the first 24’A hydrogen purification unit of the first hydrogen purification section (24’) is a PSA unit.

Preferably, the first 24’A hydrogen purification unit of the first hydrogen purification section (24’) is a PSA unit, and the second 24’B hydrogen purification unit of the first hydrogen purification section 24’ is a PSA unit or a membrane unit; preferably a PSA unit.

For the purposes of the present application, the term “arranged in series” means that at least a portion of the outlet from the first unit, suitably a major portion thereof, is in direct fluid communication with the inlet of the second unit. Accordingly, a gas stream or a portion thereof withdrawn from the first unit is directly supplied to the second unit.

For the purposes of the present application, the term “direct fluid communication” means that there are no intermediate units changing the composition of the associated process stream. The associated process gas stream is directly supplied to the unit. Conversely, the term “indirect fluid communication” means that there are intermediate units changing the composition of the associated process stream. The associated process gas stream is indirectly supplied to the unit.

In connection with the present embodiment, as exemplified in appended Fig. 3, most of the carbon containing molecules such as CF are carried in the first hydrogen purification section off-gas 9 and advantageously integrated in the plant by supplying at least a portion thereof to the gaseous hydrocarbon feed 1 ,7 of the synthesis gas section 8, 10, 12, as exemplified in appended Fig. 1. The first hydrogen purification unit 24’A produces a raw H2-rich gas 41 of less purity, i.e. lower content of H2, than the second hydrogen purification unit H2-rich gas i.e. the first H2-rich gas 4T, and a major part of the inerts is passed on to the second hydrogen purification unit off-gas corresponding to said second H2-rich gas 41”. Most of the inerts are withdrawn from the plant via fired heater(s) receiving at least a portion of this second H2-rich gas 41”.

In an optional embodiment, as recited above, the first hydrogen purification section 24’ further comprises: a conduit arranged to divert and supply a portion 41 B of said raw H2- rich gas 41 to said second hydrogen purification unit off-gas and provide said second H2-rich gas 41”. Inerts are thereby also passed on directly, from the raw H2-rich gas 41 withdrawn from the first hydrogen purification unit 24’A, as also exemplified in appended Fig. 3, to the second hydrogen purification unit off-gas corresponding to said second H2-rich gas 41”, while at the same time also enabling a reduction in size of the second hydrogen purification unit 24’B, as a reduced flow is supplied thereto.

Suitably, the portion 41 B to said second hydrogen purification unit off-gas is a minor portion of said raw H2-rich gas 41 . Accordingly, the least a portion 41 A of said raw H2- rich gas 41 to the second hydrogen purification unit 24’B is a major portion of said raw H2-rich gas 41.

For the purposes of the present application, the term “major portion” means more than 50%, such as 60%, 70%, 80%, or 90%, or greater e.g. 95%; the term “minor portion” means less than 50%, such as 40%, 30%, 20%, or 10%, or lower e.g. 5%.

In an embodiment, the at least two hydrogen purification units 24’A, 24’B arranged in series are any of: at least two PSA units arranged in series; at least two membrane units arranged in series; a single membrane unit and a single PSA unit arranged in series in either order, i.e. a single membrane unit and a single PSA unit arranged in series, or a single PSA unit and a single membrane unit arranged in series.

Preferably, as recited, the first hydrogen purification unit is a PSA unit; and the second hydrogen purification unit is a PSA unit or a membrane unit, preferably a PSA unit.

In an embodiment, the plant comprises a second hydrogen purification section 24” arranged to receive at least a portion of the first purge gas 33 upstream the WGS section 20 and provide: a third H2-rich gas 4T” and a second hydrogen purification section offgas as a second purge gas 33’ to the WGS section 20.

It is understood that in connection with this embodiment, as shown in appended Fig. 2, the first hydrogen purification section 24’ is arranged to provide a single H2-rich gas as said first H2-rich gas 41’, along with said first hydrogen purification section off-gas 9; and the plant comprises: one or more fired heaters arranged to receive: at least a portion of said first H2-rich gas 4T.

The present embodiment further provides the benefit of reducing the size of the associated WGS section, CCh-removal section and first hydrogen purification section; however, at the cost of extra equipment for another hydrogen purification unit, i.e. the second hydrogen purification unit.

In an embodiment,

- the first hydrogen purification section 24’ is a single PSA unit or a single membrane unit;

- the second hydrogen purification section 24” is: a PSA unit and/or membrane unit.

By the first hydrogen purification section 24’ being a single PSA unit or a single membrane unit, only the first H2-rich gas 4T is withdrawn therefrom as a hydrogen-rich gas, thereby carrying a significant portion of inerts. The first H2-rich gas 4T is then advantageously supplied to the fired heater(s).

Suitably, in any of the above embodiments, the membrane unit is a Pd-membrane unit.

PSA units and membrane units are well-known in the art.

Suitably, any of the first and/or second hydrogen purification section further comprises, respectively, a first and/or second hydrogen purification section off-gas recycle compressor and a first and/or second hydrogen purification section H2-rich gas compressor, i.e. a hydrogen compressor.

For instance, in the first hydrogen purification section, as exemplified in appended Fig. 1 and 3, the hydrogen purification section off-gas 9 is suitably supplied to the synthesis gas section via an off-gas compressor 26. The first H2-rich gas 4T is suitably supplied via hydrogen compressor 28 to the methanol synthesis section 14, in particular to the syngas 13 to the methanol synthesis section 14 and/or to e.g. downstream HDI and/or HCR reactors of e.g. a downstream upgrading section 18, 18’ of a gasoline or jet fuel synthesis section 16.

In an embodiment, the WGS section 20 is further arranged to receive a portion 15 of the synthesis gas; optionally, wherein the WGS section 20 is a medium shift temperature (MTS) unit; optionally, wherein the MTS unit is in direct fluid communication with a low temperature shift (LTS) unit.

This provides flexibility and reduction of capacity of the methanol synthesis section, as less synthesis gas is suppled thereto. Preferably a major portion of the synthesis gas, i.e. more than 50 vol.%, such as more than 60 vol.% or more than 70 vol%, of the synthesis gas is supplied to the methanol synthesis section. Preferably a minor portion of the synthesis gas, i.e. less than 50 vol.%, such as less than 40 vol.% or less than 30 vol%, of the synthesis gas is supplied to the WGS section.

As recited, the plant comprises a conduit arranged to supply at least a portion of the first H2-rich gas (4T) to the methanol synthesis section (14); optionally, in combination with the at least a portion (13) of the synthesis gas. It is understood that according to this embodiment, the plant does not comprise the second hydrogen purification section.

Hence, as already explained, high purity H2-product having a low content of inerts, i.e. the first H2-rich gas, is sent to the methanol synthesis section, preferably to the inlet thereto, e.g. to the inlet of the methanol reactor, to meet module requirement of the syngas, i.e. module “M” of about 2, as explained above; and at the same time, since at least the first H2-rich gas is very low in inert components, the build-up of inert components, herein also referred to as “inerts”, e.g. in the overhead recycle gas of the methanol synthesis loop recycle and in different sections of the plant is reduced. It is thereby understood that the second hydrogen-rich gas is not sent to the methanol synthesis section, as this stream contains most if not all of the inerts, which then accumulate in the plant, e.g. in the methanol synthesis loop.

In an embodiment, the plant comprises a conduit arranged to supply at least a portion of the third H2-rich gas 4T” to the methanol synthesis section 14; optionally, in combination with the at least a portion 13 of the synthesis gas. It is understood that according to this embodiment, the plant comprises the second hydrogen purification section 24”. Preferably, the first hydrogen purification section 24’ is a single PSA unit or a single membrane unit.

Where the second hydrogen purification section is provided, the third H2-rich gas is also advantageously incorporated into the synthesis gas, i.e. methanol synthesis gas, to the methanol synthesis section, thereby further adjusting the synthesis gas to ensure the module “M” being about 2. This provides increase integration and flexibility as any divergence in the syngas to the methanol synthesis section may be adjusted by the provision of the hydrogen of any of the first and third H2-rich gas. The first H2-rich gas now withdrawn from the single PSA unit or single membrane unit carries the majority of inerts and is thus suitably supplied to the fired heater(s).

It will be understood that the term “first H2-rich gas” or “second H2-rich gas” or “third H2- rich gas” means a gas stream comprising at least 80 vol.% H2, such as at least 90 vol.% H2, or such as at least 95 vol.% H2.

Suitably, the first H2-rich gas comprises at least 95 vol.% H2, and the second H2-rich gas comprises less hydrogen than the first H2-rich gas, such as less than 95 vol.% H2, for instance 80-90 vol.% H2 or 80-97 vol.% H2 such 90-96 vol.% H2. For instance, the first H2-rich gas comprises 95, 96, 97, 98, 99 vol.% H2. For instance, the second H2-rich gas comprises 80, 81 , 82, 83, 84, 85, 86, 87,88, 89, 90, 91 , 92, 93, 94 vol.% H2. For instance, the first H2-rich gas comprises at least 99 vol.% H2, and the second H2-rich gas comprises 96 vol.%. The corresponding content of inert components is about 1 vol. % in the first H2-rich gas and about 4 vol.% in the second H2-rich gas. For instance, the third H2-rich gas comprises 80, 81 , 82, 83, 84, 85, 86, 87,88, 89, 90, 91 , 92, 93, 94 vol.% H₂.

In an embodiment, the plant comprises:

- a conduit arranged to supply at least a portion of the first hydrogen purification section off-gas 9 to the gaseous hydrocarbon feed 1 , 7; and/or

- a conduit arranged to supply a portion of said first purge gas 33 to the gaseous hydrocarbon feed 1 , 7. In an embodiment, the plant comprises:

- a conduit arranged to supply a portion of said second purge gas 33’ to the gaseous hydrocarbon feed 1 , 7.

This first and/or second hydrogen purification section off-gas, for instance the second hydrogen purification section off-gas being the second purge gas, comprising methane and light hydrocarbons, is thereby advantageously combined with the process gas of the syngas synthesis section, the process gas being here the gaseous hydrocarbon feed at any point upstream a reforming unit such as upstream an autothermal reforming unit (ATR unit) of the syngas synthesis section, preferably between a pre-reforming unit and the ATR unit.

Accordingly, in an embodiment, the synthesis gas section 8, 10, 12 comprises a prereforming unit 10 arranged upstream an autothermal reforming (ATR) unit 12; and:

- said conduit arranged to supply the least a portion of the first hydrogen purification section off-gas 9 to the gaseous hydrocarbon feed 1 , 7 is a conduit arranged to supply the first hydrogen purification section off-gas 9 to a pre-reformed hydrocarbon feed 7, thereby to a mixing point, such as a mixing unit or a juncture, between the pre-reforming unit 10 and the ATR unit 12; optionally, at inlet 11 of the ATR unit 12; and/or

- said conduit arranged to supply a portion of said first purge gas 33 to the gaseous hydrocarbon feed 1 , 7 is a conduit arranged to supply the portion of said first 33 to a prereformed hydrocarbon feed 7, 11 , thereby to a mixing point, such as a mixing unit or a juncture, between the pre-reforming unit 10 and the ATR unit 12; optionally, at inlet 11 of the ATR unit 12.

In an embodiment, the synthesis gas section 8, 10, 12 comprises a pre-reforming unit 10 arranged upstream an autothermal reforming (ATR) unit 12; and:

- said conduit arranged to supply a portion of said second purge gas 33’ to the gaseous hydrocarbon feed 1 , 7 is a conduit arranged to supply the portion of said second purge gas 33’ to a pre-reformed hydrocarbon feed 7, 11 , thereby to a mixing point, such as a mixing unit or a juncture, between the pre-reforming unit 10 and the ATR unit 12; optionally, at inlet 11 of the ATR unit 12.

Hence, for instance, a portion of the first purge gas is routed to inlet of the ATR to compensate an increase in the syngas flow (process line/process stream 15 in appended Fig. 1-2) to the WGS section, i.e. said portion of the synthesis gas being supplied to the WGS section. This embodiment provides also the advantage of reduced off-gas production from the first hydrogen purification unit, e.g. first PSA unit or first membrane unit, leading to less power requirement for the associated off-gas compressor, despite a penalty cost in terms of overall increase in the size of the ATR unit.

In an embodiment, the gaseous hydrocarbon feed is preferably natural gas. In a particular embodiment, the natural gas is renewable natural gas (RNG). In a particular embodiment, the natural gas is substitute natural gas (SNG).

For the purposes of the present application, RNG means biomethane or biogas, and means natural gas produced from organic waste materials which are renewable, and which are selected from at least one of: agricultural waste, food waste, sewage, landfill gas.

For the purposes of the present application, SNG means natural gas prepared by methanation of a syngas at least partly prepared by electrolysis of water/steam, and by electrolysis of carbon dioxide.

The gaseous hydrocarbon feed is preferably natural gas, and/or natural gas to which one or more by-product streams rich in paraffins and/or one or more waste off-gas streams produced in the plant, have been added. The one or more waste off-gas streams are for instance any of: the waste off-gas streams produced in the methanol section, herein referred to as said first set of one or more waste off-gas streams, waste off-gas streams produced in the optional transportation range fuel synthesis section, or a combination thereof. The one or more by-product streams rich in paraffins are also produced in the optional transportation range fuel synthesis section, i.e. a gasoline or jet fuel synthesis section.

It is understood, as earlier recited, that the gaseous hydrocarbon feed may be a process gas at any point upstream the reforming unit of the synthesis gas section, such as upstream the ATR. For instance, the gaseous hydrocarbon feed may be a pre-reformed hydrocarbon feed.

In an embodiment,

- the reforming section comprises a reforming unit, which is any of: an autothermal reformer (ATR), a steam methane reformer (SMR), an electrically heated steam methane reformer (e-SMR), a convection heated reactor, and combinations thereof;

- the WGS section comprises at least one of: a high temperature shift (HTS) reactor; a medium shift temperature (MTS) reactor, and a low temperature shift (LTS) reactor;

- the CC>2-removal section is any of: an amine wash unit, a CO2 membrane separation unit, and a cryogenic separation unit, preferably an amine wash unit.

- the first hydrogen purification section is at least one of: a pressure swing adsorption (PSA) unit; a membrane unit;

- the second hydrogen purification section is at least one of: a pressure swing adsorption (PSA) unit; a membrane unit.

It is understood that a given section provides an associated process step.

For instance, there is reforming in the reforming section; there is water gas shifting (shift) in the WGS section; there is 002-removal in the 002-removal section; there is hydrogen purification in the first or second hydrogen purification section.

As already recited, the term “section” may be used interchangeably with the term “unit” and means a physical section comprising one or more units. For instance, the term “reforming section” may comprise a hydrogenator, sulfur absorber, pre-reforming unit, and ATR. In an embodiment, the reforming section comprises an ATR unit and optionally also a pre-reforming unit, yet there is no steam methane reforming (SMR) unit, i.e. the use of a conventional SMR, also referred to in the art as “radiant furnace” or “tubular reformer”, is omitted.

The ATR, SMR, e-SMR and convection heated reactor (convection reformer), are well- known in the art. In a convection reformer, preferably comprising one or more bayonet reforming tubes such as an HTCR reformer i.e. Topsoe bayonet reformer, where the heat for reforming is transferred by convection along with radiation. In an SMR, the heat for reforming is transferred chiefly by radiation in a radiant furnace; in an autothermal reformer (ATR), there is a partial oxidation of the hydrocarbon feed with oxygen and steam followed by catalytic reforming; in an electrically heated steam methane reformer (e-SMR), electrical resistance is used for generating the heat for catalytic reforming. Combinations of these reactors are also envisaged. In particular, when using e-SMR, electricity from green resources may be utilized, such as from electricity produced by wind power, hydropower, and solar sources, thereby further minimizing the carbon dioxide footprint.

For more information on these reformers, details are herein provided by direct reference to Applicant’s patents and/or literature. For instance, for tubular and autothermal reforming an overview is presented in “Tubular reforming and autothermal reforming of natural gas - an overview of available processes”, lb Dybkjaer, Fuel Processing Technology 42 (1995) 85-107; and EP 0535505 for a description of HTCR. For a description of ATR and/or SMR for large scale hydrogen production, see e.g. the article “Large- scale Hydrogen Production”, Jens R. Rostrup-Nielsen and Thomas Rostrup-Nielsen”: https://www.topsoe.com/sites/default/files/topsoe_large_scale_hydrogen_produc.pdf For a description of e-SMR which is a more recent technology, reference is given to in particular applicant’s WO 2019/228797 A1.

The WGS section comprises at least one of: a high temperature shift (HTS) reactor; a medium shift temperature (MTS) reactor, and a low temperature shift (LTS) reactor. In an embodiment the WGS section is a medium shift temperature (MTS) unit in direct fluid communication with a low temperature shift (LTS) unit. These shift reactors are well- known in the art. The CCh-removal section is any of: an amine wash unit, a CO2 membrane i.e. CO2 membrane separation unit, and a cryogenic separation unit, preferably an amine wash unit. These units are also well-known in the art.

In an embodiment, the reforming section further comprises a pre-reforming unit, such as an adiabatic pre-reforming unit. In an embodiment, the associated pre-reforming is conducted in one or more adiabatic pre-reforming stages with interstage preheating, i.e. with heating in between pre-reforming stages. In another embodiment, a single prereforming unit, such as a single adiabatic pre-reforming unit is provided. In another embodiment, two pre-reforming units, are provided.

Suitably, a pre-reforming unit is provided upstream the reforming unit, e.g. upstream the ATR unit. In the pre-reforming unit all higher hydrocarbons can be converted to carbon oxides and methane, but the pre-reforming unit is also advantageous for light hydrocarbons. Providing the pre-reforming unit, hence pre-reforming step, may have several advantages including reducing the required O2 consumption in the ATR and allowing higher inlet temperatures to the ATR since cracking risk by preheating is minimized. Furthermore, the pre-reforming unit may provide an efficient sulfur guard resulting in a practically sulfur free feed gas entering the ATR and the downstream system. The prereforming step may be carried out at temperatures between 300-650°C, preferably 390-480°C. Preferably, the pre-reforming is conducted in one or more adiabatic pre-re- forming stages with interstage preheating, i.e. with heating in between pre-reforiming stages.

In an embodiment,

- the reforming section comprises a pre-reforming unit, preferably a single pre-reforming unit, such as a single adiabatic pre-reforming unit, together with an ATR unit, i.e. a stand-alone ATR;

- the WGS section is a HTS reactor together with a downstream LTS reactor; or a MTS reactor;

- the CCh-removal unit is an amine wash unit;

- the first hydrogen purification section comprises a single PSA unit or single membrane unit, such as a Pd-membrane unit; or the first hydrogen purification section comprises at least two hydrogen purification units arranged in series are any of: at least two PSA units arranged in series; at least two membrane units arranged in series; a single membrane unit and a single PSA unit arranged in series.

For the purposes of the present application, the provision of a pre-reforming unit, in particular a single pre-reforming unit, together with an ATR unit, may also be referred to as “stand-alone ATR”. It will be understood that this term means that no other reformers are included, such as a primary reformer e.g. an SMR.

In an embodiment, the synthesis gas section 8, 10, 12 comprises a hydrogenator and a sulfur absorber 8, suitably arranged upstream pre-reforming unit 10; the plant comprises a conduit arranged to divert another portion of the overhead recycle gas of the methanol synthesis loop as a first H2-rich off-gas 5 and to supply at least a portion thereof to the gaseous hydrocarbon feed 1 upstream the hydrogenator and sulfur absorber 8; and/or wherein the plant comprises a conduit arranged to supply a portion of the first 4T H2-rich gas to the gaseous hydrocarbon feed 1 upstream the hydrogenator and sulfur absorber 8.

In an embodiment, the synthesis gas section 8, 10, 12 comprises a hydrogenator and a sulfur absorber 8, suitably arranged upstream pre-reforming unit 10; the plant comprises a conduit arranged to divert another portion of the overhead recycle gas of the methanol synthesis loop as a first H2-rich off-gas 5 and to supply at least a portion thereof to the gaseous hydrocarbon feed 1 upstream the hydrogenator and sulfur absorber 8; and/or wherein the plant comprises a conduit arranged to supply a portion of the third 4T” H2-rich gas to the gaseous hydrocarbon feed 1 upstream the hydrogenator and sulfur absorber 8.

Preferably, as already recited, the gaseous hydrocarbon feed is natural gas. Any sulfur compounds contained therein and which act as poison for downstream catalysts are removed via the hydrogenator and sulfur absorber. At least a portion of the hydrogen required for these units and associated process is provided by combining the e.g. natural gas with the first H2-rich off-gas diverted from the methanol synthesis loop, or a portion of the first and/or third H2-rich gas from the second hydrogen purification section, e.g. a second PSA-unit or membrane unit. Further integration is thereby achieved, with full utilization of hydrogen-containing gas streams produced in the plant. The need for externally sourcing hydrogen is thus minimized.

In an embodiment, the plant comprises:

- a methanol tank arranged to receive and store the raw methanol product 17; and/or

- a fractionation section arranged to receive the raw methanol product 17 and provide a methanol product 17’.

The raw methanol product may be stored in a methanol tank thereby serving as a buffer tank for stable supply of the raw methanol via a methanol pump to downstream sections.

The raw methanol product contains water and may then be subjected to a water removal step in a fractionation section, such is a distillation column, thereby providing the methanol product. The methanol product is understood as a purified methanol stream of the required grade, such as >95%, >98% or >99% methanol.

In an embodiment, the plant is further arranged to convert the gaseous hydrocarbon feed 1 to a transportation range fuel product 25 selected from at least one of: a gasoline product, a jet fuel product, and a diesel product; optionally, a heavy hydrocarbon fraction e.g. maritime fuel or fuel oil; wherein the plant further comprises:

- a transportation range fuel synthesis section 16, 18, 18’ arranged to receive at least a portion of the raw methanol product 17 or at least a portion of the methanol product 17’ and provide: said transportation range fuel product 25, as well as: a second set 31” of one or more waste off-gas streams; one or more by-product streams rich in paraffins 29; and a third set 3T” of one or more waste off-gas streams;

- a conduit arranged to supply at least a portion of at least one of the first 3T, second 31” and third 3T” set of one or more waste off-gas streams to the gaseous hydrocarbon feed; optionally, upstream the hydrogenator and sulfur absorber 8.

The second set 31” of one or more waste off-gas streams is for instance a portion of the overhead recycle gas of a gasoline synthesis loop of a methanol-to-gasoline (MTG) section or the synthesis loop of a methanol-to-olefins (MTO) section. This waste off-gas stream is hydrocarbon-rich, for instance by containing light hydrocarbons such as methane, and therefore advantageously incorporated into the gaseous hydrocarbon feed, e.g. upstream the hydrogenator and sulfur absorber. Further integration in the plant is thereby achieved, as waste off-gas is advantageously reutilized in the plant instead of being withdrawn as a waste fuel gas. Thereby also, the invention provides a transportation range fuel product, such as gasoline, or jet fuel, or diesel, having a significantly lower carbon intensity (Cl) than prior art plant/process layouts.

For the purposes of the present application, the term carbon intensity (Cl) is directly linked to the associated CCh-emissions to the atmosphere via flue gas of the one or more fired heaters of the plant. CO2 removed as the CCh-rich gas is as such recovered, and thus not part of CCh-emissions.

In an embodiment,

- the one or more by-product streams rich in paraffins 29 is at least one of LPG (liquified petroleum gas) and naphtha, and the plant comprises a conduit arranged to supply at least a portion thereof to the gaseous hydrocarbon feed 1 ; optionally, upstream the hydrogenator and sulfur absorber 8.

Thereby there is a further increase in carbon and hydrogen efficiency in the plant, as carbon not ending in the transportation range fuel product, but withdrawn as LPG and/or naphtha, and/or as waste off-gas, is advantageously re-utilized by becoming part of the gaseous hydrocarbon feed. The associated hydrogen of e.g. LPG is thereby also recovered.

Suitably, the LPG is recycled as a liquid stream.

In an embodiment, the plant comprises a separate reforming system, i.e. a dedicated reforming system, arranged to receive: any of the first 3T, second 31” and third 3T” set of one or more waste off-gas streams; and/or the one or more by-product streams rich in paraffins 29 is at least one of LPG (liquified petroleum gas) and naphtha; and provide a side synthesis gas. The plant may further comprise a conduit for supplying at least a portion the side synthesis gas to said synthesis gas, i.e. methanol synthesis gas, to the methanol synthesis section. The dedicated reforming system may comprise a pre-reforming unit along with any of an ATR or e-SMR. The dedicated reforming system provides said side synthesis gas as a minor side synthesis gas stream which is advantageously combined with said methanol synthesis gas, this being the major i.e. main synthesis gas. For details, reference is given to earlier mentioned Applicant’s citations: WO 2023187147, WO 2023247316 and WO 2023247315.

The one or more of the by-products stream rich in paraffins is preferably a stream rich in propane and/or butane (C3 and/or 04). A propane and/or butane stream is known as liquified petroleum gas, LPG.

LPG, herein also referred to as “LPG stream” is for instance withdrawn from the LPG- splitter of the distillation section of a gasoline synthesis section. LPG is for instance withdrawn from the fractionation section of a jet fuel synthesis section.

The one or more of the by-product streams rich in paraffins is preferably a naphtha stream. Naphtha is for instance withdrawn from the fractionation section of a jet fuel synthesis section.

The term “naphtha” means C5-C9 hydrocarbons boiling in the range 30-160°C, such C5-C8 hydrocarbons, e.g. C5-C8 olefins. The term “naphtha” may be used interchangeably with the term “naphtha stream”. The naphtha stream is advantageously incorporated into the gaseous hydrocarbon feed.

The LPG and naphtha are suitably provided as separate streams, thus via separate conduits, to the gaseous hydrocarbon feed, e.g. to the natural gas feed.

As recited, the LPG may be suitably recycled as a liquid stream.

Any of the first, second and third waste off-gas stream comprises CO2, H2, CH4, optionally also higher hydrocarbons such 02 hydrocarbons. Traditionally, waste off-gas streams produced in the plant are withdrawn as low pressure (LP) off-gas streams and utilized as fuel gas in fired heater(s)s, which also causes high CO2 emissions. While traditionally the fired heater(s)s utilize such waste off-gases as fuel gas thereto, along with natural gas, and which associated burning (combustion) entails said significant CO2- emissions in the produced flue gas, the present invention, in contrast, significantly reduces the consumption of natural gas and waste off-gas, as any of the first and/or second H2-rich gas is provided as the main fuel gas to the fired heater(s) instead; for instance representing up 99% of the required fuel gas i.e. of the fired duty requirement. Natural gas and waste off-gases thus become a minor part of the fuel gas required. The associated CC>2-emissions are thereby significantly reduced, while at the same time increasing carbon efficiency in the plant. Yet again, most of the carbon goes into either the methanol, or transportation range fuel product, or CO2 capture, and thereby a low carbon intensity methanol as well as a low carbon intensity transportation range fuel product, such as low carbon intensity gasoline product or low carbon intensity jet fuel, are produced.

The term “transportation range fuel product” may be used interchangeably with the term “transportation range hydrocarbon fuel product” or simply “transportation range fuel” and means at least one of: a gasoline product, a jet fuel product, and a diesel product. The transportation range fuel may also be a heavy hydrocarbon fraction e.g. maritime fuel or fuel oil.

The term “gasoline product” means C5-C12 hydrocarbons boiling in the range 30- 210°C.

The term “jet fuel product” means C8-C19 hydrocarbons, such as C8-C17 or C8-C16 hydrocarbons, boiling in the range 130-300°C. For instance, the jet fuel is sustainable aviation fuel (SAF) in compliance with ASTM D7566 and ASTM D4054. For instance, the jet fuel is in compliance with ASTM D7566.

The term “diesel” means C8-C25 hydrocarbons boiling in the range 120-360°C, for instance 160-360°C.

The term boiling in a given range, shall be understood as a hydrocarbon mixture of which at least 80 wt% boils in the stated range.

The term: “first hydrogen purification section off-gas”, “second hydrogen purification section off-gas”, or “waste off-gas stream”, means a low-pressure (LP) off-gas comprising CO2, H2, CH4, optionally also higher hydrocarbons such C2 hydrocarbons. Low pressure (LP) means 1-15 barg, such as 1-10 barg. The “first hydrogen purification section off-gas” is off-gas withdrawn at low pressure from the first hydrogen purification section. The “second hydrogen purification section off-gas” is off-gas withdrawn at low pressure from the second hydrogen purification section. The term: “first H2-rich off-gas” means a H2-rich purge gas, for instance a gas having 70 vol.% or more H2, which is suitably diverted from the overhead recycle gas of a synthesis loop. The “first H2-rich off-gas” is suitably diverted from the methanol synthesis loop of the methanol synthesis section.

In an embodiment, the transportation range fuel synthesis section 16, 18, 18’ is a gasoline synthesis section which comprises: a methanol-to-gasoline section (MTG section, 16); a first upgrading section 18 comprising a distillation section, the distillation section comprising a deethanizer and a LPG-splitter; a second upgrading section (18’) comprising a hydroisomerisation (HDI) reactor, and/or a hydrocracking (HCR) reactor, thereby providing a gasoline product as said transportation range fuel product 25; or the transportation range fuel synthesis section 16, 18, 18’ is a jet fuel synthesis section which comprises: a methanol-to-olefins section and oligomerization section (MTO and OLI section, 16); a fractionation section 18 and a hydroprocessing section 18’ such as a hydrogenation section, thereby providing a jet fuel product as said transportation range fuel product 25.

It will be understood that the distillation section of the gasoline synthesis section may further comprise separation units, such as a gasoline splitter, optionally heavy gasoline stripper, optionally 05 side column.

For details of the gasoline synthesis section and associated units, reference is for instance given to above-mentioned applicant’s WO 2023247315. For details of the jet fuel synthesis section and associated units, reference is for instance given to above-mentioned applicant’s WO 2023247316.

In an embodiment, the plant comprises a conduit arranged to supply a portion any of the first 4T and second 41” H2-rich gas to: the HDI reactor and/or HCR reactor of the second upgrading section 18’ of the gasoline synthesis section; or to the hydroprocessing section 18’, such as a hydrogenation section, of the jet fuel synthesis section, e.g. a hydrogenation reactor for saturation of olefins in the jet fuel synthesis section. In an embodiment, the plant comprises a conduit arranged to supply a portion of any of the first 41’, second 41” and third 41”’ H2-rich gas to: the HDI reactor and/or HCR reactor of the second upgrading section 18’ of the gasoline synthesis section; or to the hydroprocessing section 18’, such as a hydrogenation section, of the jet fuel synthesis section, e.g. a hydrogenation reactor for saturation of olefins in the jet fuel synthesis section.

For instance, as exemplified in connection with appended Fig. 1 and 3, 5, where the first hydrogen purification section is further arranged to provide a second H2-rich gas with a lower content of H2 and a higher content of an inert component than the first H2-rich gas, the inert component being at least one of nitrogen (N2) and argon (Ar), the first H2-rich gas is supplied to e.g. said HDI and/or HCR reactor.

Further integration and high hydrogen efficiency is thereby achieved, as a hydrogen-rich gas produced in the methanol synthesis section is advantageously utilized in units downstream requiring hydrogen such as HDI or HCR reactors in connection with gasoline upgrading, or for instance in a hydrogenation reactor for saturation of olefins in connection with jet fuel production. The need for externally sourcing hydrogen is thereby further reduced or eliminated. The high purity of e.g. the first H2-rich gas, this suitably being at least 99 vol.% H2, and suitably further comprising less than 10 ppmv CO_X, i.e. free of COx, makes it highly advantageous for use in said units downstream the methanol synthesis section,

In an embodiment,

- the synthesis gas section 8, 10, 12 comprises a pre-reforming unit 10 in fluid communication with ATR unit 12; preferably, via inlet 11 of the ATR, i.e. via conduit 11 , in direct fluid communication downstream said mixing point of the first hydrogen purification section off-gas 9 to the pre-reformed hydrocarbon feed 7;

- the at least a portion 13 of the synthesis gas is in indirect fluid communication with the methanol synthesis section 14, by the plant further comprising a process condensation unit (PC-unit) arranged between the ATR unit 12 and the methanol synthesis section 14; optionally, the plant further comprising a gas cleaning reactor arranged between the ATR unit 12 and the PC-unit. Thereby, the syngas is cleaned from any impurities, particularly sulfur impurities, which may still be present in the syngas and damage the performance of downstream catalysts, particularly methanol synthesis catalyst in the methanol reactor.

The term “in fluid communication” means “indirect or direct fluid communication”.

For instance, by the synthesis gas section 8,10, 12 comprising a pre-reforming unit 10 in fluid communication with and ATR unit 12, it is meant that the pre-reforming unit 10 is in: direct fluid communication with the ATR unit 12, or indirect fluid communication with the ATR unit.

For instance, in connection with appended Fig. 1 and 2, the pre-reforming unit 10 and ATR 12 are in indirect fluid communication, as first hydrogen purification section off-gas 9 is supplied to pre-reformed gas 7, thereby changing its composition. The pre-reforming unit 10 is in direct fluid communication with and ATR unit 12 via inlet 11 of the ATR, i.e. via conduit 11 , as conduit 11 is arranged downstream said mixing point of the first hydrogen purification section off-gas 9 to the pre-reformed hydrocarbon feed 7.

Again, the term “direct fluid communication” means that there are no intermediate units changing the composition of the associated process stream. The associated process gas stream is directly supplied to the unit.

For instance, in connection with the present embodiment, there are no units changing the composition of the process gas in between the pre-reforming unit and the ATR-unit after said mixing point of the first hydrogen purification section off-gas to the pre-re- formed hydrocarbon feed. The pre-reformed gas and/or the inlet of the ATR, may be preheated via a fired heater prior to entering the ATR unit.

Again, the term “indirect fluid communication” means that there are intermediate units changing the composition of the associated process stream. The associated process gas stream is indirectly supplied to the unit.

For instance, in connection with the present embodiment, the syngas from the ATR unit passes through a PC-condensation unit, such as a syngas wash column, under the production of a process condensate. Accordingly, the synthesis gas is indirectly supplied to the methanol synthesis section, in particular to the methanol reactor therein.

An optional cleaning reactor is advantageously arranged between the ATR and the PC- unit for removing impurities in the syngas, such as HCN, which otherwise may convert into component such as TMA (Tri Methhyl Amine) in the methanol synthesis section and subsequently poison the transportation range fuel synthesis section catalyst, such as gasoline synthesis catalyst or methanol-to-olefins synthesis catalyst.

As already recited, in an embodiment, the first hydrogen purification unit or second hydrogen purification unit is any of a PSA unit, a membrane unit such as Pd-membrane unit, and combinations thereof. These units are well-known in the art.

In an embodiment, the one or more fired heaters is at least one of:

- a fired heater associated with the synthesis gas section 8, 10, 12 for preheating the gaseous hydrocarbon feed gas 1 , 7;

- a fired steam superheater for producing a superheated steam;

- a fired heater associated with a HDI reactor, i.e. a HDI heater, for preheating the feed to the HDI reactor;

- a fired heater associated with a HCR reactor, i.e. a HCR heater, for preheating the feed to the HCR reactor;

- a fired heater reboiler of a fractionation section, such as said a fractionation section arranged to receive the raw methanol product 17, or said fractionation section 18 of the jet fuel synthesis section, or said first upgrading section 18 of the gasoline synthesis section.

For the purposes of the present application, the term “associated with” means “arranged to cooperate with”. For instance, a fired heater being supplied with a hydrogen-rich gas according to the invention and comprising inerts, as the main fuel gas source, is arranged to cooperate with the synthesis gas section, whereby the fired heater pre-heats the gaseous hydrocarbon feed gas, for instance prior to pre-reforming and/or prior to the autothermal reforming. Thereby, instead of utilizing an external hydrocarbon fuel source such as natural gas, as well as waste off-gas, as the main fuel gas source for the burners of the one or more fired heaters, the first and/or second H2-rich gas serves as the major fuel gas source for the fired heater(s), thus leading to much lower CO2 emissions, as already explained. The one or more waste off-gas streams from the methanol synthesis section, the transportation range fuel synthesis section, or from both, are withdrawn as low pressure (LP) offgas and thus may still advantageously be utilized, albeit in lower amounts than in traditional plants, as fuel gas for the fired heater(s).

In another (second) general embodiment of the first aspect (plant) of the invention, there is provided a plant 100 for converting a gaseous hydrocarbon feed 1 such as natural gas to methanol; wherein the plant comprises:

- a synthesis gas section 8, 10, 12 arranged to receive the gaseous hydrocarbon feed 1 and provide a synthesis gas 13, 15;

- a methanol synthesis section 14 arranged to receive at least a portion 13 of the synthesis gas and provide: a raw methanol product 17, a first purge gas 33, and a first set 3T of one or more waste off-gas streams;

- a first hydrogen purification section 24’ arranged to receive said CCh-depleted shifted gas 39 and provide: a first H2-rich gas 4T and a first hydrogen purification section offgas 9; wherein:

- the first hydrogen purification section 24’ is arranged to provide a single H2-rich gas as said first H2-rich gas 4T, along with said first hydrogen purification section off-gas 9; and wherein the plant further comprises:

- one or more fired heaters arranged to receive: at least a portion of said first H2-rich gas 4T;

- a second hydrogen purification section 24” arranged to receive at least a portion of the first purge gas 33 upstream the WGS section 20 and provide: a third H2-rich gas 4T” and a second hydrogen purification section off-gas as a second purge gas 33’ to the WGS section 20 and/or as a second purge gas 33’ to the first hydrogen purification off-gas 9; optionally, wherein:

- the second hydrogen purification section 24” is: a PSA unit and/or membrane unit;

- the plant comprises a conduit arranged to supply at least a portion of the third H2-rich gas 4T” to the methanol synthesis section 14; optionally, in combination with the at least a portion 13 of the synthesis gas.

This second general embodiment is depicted in appended Fig. 2, Fig. 4.

Any of the relevant embodiments and associated benefits recited in connection with the first general embodiment of the first aspect (plant) of the invention may be used in connection with this another general embodiment, or vice versa.

In a first general embodiment of a second aspect (process) of the invention, there is provided a process for converting a gaseous hydrocarbon feed 1 to methanol, wherein the process comprises:

- providing a plant according to any of the above plant embodiments according to the first general embodiment of the first aspect (plant) of the invention;

- supplying a gaseous hydrocarbon feed 1 to a synthesis gas section 8, 10, 12 and withdrawing therefrom a synthesis gas 13, 15;

- supplying at least a portion 13 of the synthesis gas to a methanol synthesis section 14 and withdrawing therefrom: a raw methanol product 17, a first purge gas 33, and a first set of one or more waste off-gas streams 3T;

- optionally, the methanol synthesis section 14 being arranged as a methanol synthesis loop comprising: a methanol reactor, a first separator, and a recycle compressor; supplying the at least a portion 13 of the synthesis gas to the methanol reactor and withdrawing therefrom a raw methanol effluent stream; supplying the raw methanol effluent stream to the first separator and withdrawing therefrom an overhead recycle gas and a bottom stream as said raw methanol product 17; supplying the overhead recycle gas via the recycle compressor to the methanol reactor; and diverting a portion of the overhead recycle gas as said first purge gas 33;

- supplying said first purge gas 33 to a water gas shift (WGS) section 20 and withdrawing therefrom a shifted gas; - supplying said shifted gas to a CCh-removal section 22 and withdrawing therefrom: a CC>2-rich gas 37 and a CCh-depleted shifted gas 39;

- supplying said CCh-depleted shifted gas 39 to a first hydrogen purification section 24’ and withdrawing therefrom: a first H2-rich gas 4T; a second H2-rich gas 41” comprising a lower content of H2 and a higher content of an inert component than the first H2-rich gas 4T, the inert component being at least one of N2 and Ar; and a first hydrogen purification section off-gas 9; providing one or more fired heaters and supplying thereto at least a portion of the second H2-rich gas 41”;

- supplying at least a portion of the first H2-rich gas 41’ to the methanol synthesis section 14;

- optionally, wherein the first H2-rich gas 4T comprises at least 95 vol.% H2, such as at least 99 vol.% H2, and the inert content of the first H2-rich gas 4T in terms of N2 and Ar is: less than 0.10 vol. % N2 and less than 0.6 vol.% Ar; and/or the second H2-rich gas 41” comprises at least 80 vol.% H2, such as up to 97 or 96 vol.% H2, and the inert content of the second H2-rich gas 41” in terms of N2 and Ar is: 0.5 vol.% N2 or higher, such as 0.6-10 vol.% N2, and 0.6 vol. % Ar or higher, such as 0.6-1.0 vol.% Ar.

In a second general embodiment of a second aspect (process) of the invention, there is provided a process for converting a gaseous hydrocarbon feed 1 to methanol, wherein the process comprises:

- supplying at least a portion 13 of the synthesis gas to a methanol synthesis section 14 and withdrawing therefrom: a raw methanol product 17, a first purge gas 33, and a first set 3T of one or more waste off-gas streams;

- supplying at least a portion of said first purge gas 33 to a water gas shift (WGS) section 20 and withdrawing therefrom a shifted gas;

- supplying said shifted gas to a CCh-removal section 22 and withdrawing therefrom: a CC>2-rich gas 37 and a CCh-depleted shifted gas 39;

- supplying said CCh-depleted shifted gas 39 to a first hydrogen purification section 24’ and withdrawing therefrom: a first H2-rich gas 4T; optionally: a second H2-rich gas 41” comprising a lower content of H2 and a higher content of an inert component than the first H2-rich gas 41’, the inert component being at least one of N2 and Ar; and a first hydrogen purification section off-gas 9;

- supplying at least a portion of said first H2-rich gas 4T to one or more fired heaters;

- providing a second hydrogen purification section 24” upstream the WGS section 20; supplying at least a portion of the first purge gas 33 to the second hydrogen purification unit 24” and withdrawing therefrom: a third H2-rich gas 4T” and a second hydrogen purification section off-gas as a second purge gas 33’ to the WGS section 20 and/or as a second purge gas 33’ to the first hydrogen purification off-gas 9; optionally:

- providing the first hydrogen purification section 24’ as a single PSA unit or a single membrane unit;

- providing the second hydrogen purification section 24” as: a PSA unit and/or membrane unit;

- supplying at least a portion of the third H2-rich gas 41’” to the methanol synthesis section 14; optionally, in combination with the at least a portion 13 of the synthesis gas.

This second general embodiment is depicted in appended Fig. 2, Fig. 4.

Any of the embodiments and associated benefits in connection with the first aspect (plant) of the invention may be used in connection with the second aspect (process) of the invention, or vice versa.

For instance, embodiments related to compositions of process streams and associated benefits may be used in connection with the second aspect (process) of the invention. BRIEF DESCRIPTIONS OF FIGURES

Fig. 1 shows a block flow diagram of a plant/process according to an embodiment of the present invention, in which a gaseous hydrocarbon feed is converted to methanol and the methanol is optionally converted to transportation range fuels.

Fig. 2 shows a block flow diagram of a plant/process according to another embodiment of the present invention, in which a gaseous hydrocarbon feed is converted to methanol and the methanol is optionally converted to transportation range fuels.

Fig. 3 shows a more detailed representation of the first hydrogen purification section 24’ of Fig. 1.

Fig. 4 shows another embodiment which is similar to Fig. 2, in which associated streams are directed to other positions in the plant.

Fig. 5 shows another embodiment of the first hydrogen purification section 24’ of Fig. 3.

DETAILED DESCRIPTION OF FIGURES

With reference to Fig. 1 , plant/process 100 converts a gaseous hydrocarbon feed 1 such as natural gas to a raw methanol product 17 or methanol product 17’, which is further converted to a transportation range fuel product 25 selected from at least one of: a gasoline product, a jet fuel product, and a diesel product. Optionally also, a heavy hydrocarbon fraction 27 e.g. maritime fuel or fuel oil is also produced. A synthesis gas section, shown here simply as block units 8, 10, 12 is arranged to receive the gaseous hydrocarbon feed 1 and provide a synthesis gas 13, 15. The block unit 8, 10 comprises a prereforming unit 10, and upstream the pre-reforming unit 10, a hydrogenator and sulfur absorber (herein denoted as 8) are also arranged. Steam 3 is added as so is a first H2- rich off-gas 5 from downstream methanol synthesis section 14. The pre-reformed hydrocarbon feed 7 is combined in a mixing point with first hydrogen purification section offgas 9 resulting in pre-reformed hydrocarbon feed 11 (conduit 11) as the inlet to e.g. an autothermal reforming (ATR) unit. The pre-reforming unit 10 and ATR unit 12 are in direct fluid communication via conduit 11 , thus downstream the mixing point, as there are no units changing the composition of the pre-reformed hydrocarbon feed 11. Block 12 of the synthesis gas section preferably comprises an ATR unit 12 as the sole reforming unit. The first hydrogen purification section off-gas 9 is thus added to said mixing point in between the pre-reforming unit 10 and the ATR unit 12. A methanol synthesis section 14 is arranged to receive at least a portion 13 of the synthesis gas and provide: a raw methanol product 17, a first purge gas 33, and a first set of one or more waste off-gas streams 3T. A methanol tank (not shown) may be arranged to receive and store the raw methanol product 17; and/or a fractionation section (not shown) may be arranged to receive the raw methanol product 17 and provide a methanol product 17’. The methanol synthesis section 14 is suitably arranged as a methanol synthesis loop (not shown); the methanol synthesis loop comprises: a methanol reactor arranged to receive the at least a portion 13 of the synthesis gas and provide a raw methanol effluent stream; a first separator which is arranged to receive the raw methanol effluent stream and provide: an overhead recycle gas, and a bottom stream as said raw methanol product 17; a recycle compressor which is arranged to supply the overhead recycle gas to the methanol reactor; a conduit is also arranged to divert a portion of the overhead recycle gas as said first purge gas 33.

The plant/process further comprises: a water gas shift (WGS) section 20 arranged to receive said first purge gas 33, optionally steam 3’, and provide a shifted gas; a CO2- removal section 22 arranged to receive said shifted gas and provide: a CCh-rich gas 37 and a CCh-depleted shifted gas 39. The WGS section 20 is suitably further arranged to receive a portion 15 of the synthesis gas. The CO2-rich gas 37 is advantageously subjected to carbon capture and storage (CCS), or carbon capture and utilization (CCU). For simplicity, the WGS section 20 and the CO2-removal section 22 are shown in a common block unit. A first hydrogen purification section 24’ is arranged to receive the CO2- depleted shifted gas 39 and provide: first hydrogen purification section off-gas 9, a first H2-rich gas 4T and optionally a second H2-rich gas 41”. Suitably, the optional second H2-rich gas 41” has a lower content of H2 and a higher content of an inert component, than the first H2-rich gas 4T, the inert component being at least one of nitrogen (N2) and argon (Ar). Suitably also, one or more fired heaters (not shown) are arranged to receive at least a portion of the first 4T and/or second H2-rich gas 41” thus enabling not only the firing in the fired heater being provided mainly with hydrogen produced in the plant/process, thus drastically reducing the CCh-emissions in the flue gas, but suitably mainly with second H2-rich gas 41” thereby also carrying the inert components away with the flue gas instead of being accumulated in the plant/process, for instance in the methanol synthesis loop. Suitably, at least a portion of the first H2-rich gas 4T is supplied to the methanol synthesis section 14 (not shown), preferably to the synthesis gas 13 thereto, thereby enabling to adjust the module “M” of the synthesis gas 13 (methanol synthesis gas) to about 2. A portion of the first H2-rich gas 4T and/or second H2-rich gas 41” is suitably also utilized as hydrogen for optional downstream hydroprocessing units of the transportation range fuel synthesis section, such as for HDI and/or HCR reactors therein, or a hydrogenation reactor for saturation of olefins.

The plant may further comprise a transportation range fuel synthesis section 16, 18, 18’ arranged to receive at least a portion of the raw methanol product 17 or the methanol product 17’ and provide: said transportation range fuel product 25, as well as: a second set 31” of one or more waste off-gas streams; one or more by-product streams rich in paraffins (29), such as LPG; and a third 3T” set of one or more waste off-gas streams. In an embodiment, the transportation range fuel synthesis section 16, 18, 18’ is a gasoline synthesis section which comprises: a methanol-to-gasoline section (MTG section, 16) to provide a raw gasoline 21 ; a first upgrading section 18 arranged to receive the raw gasoline 21 and comprising a distillation section, the distillation section comprising a deethanizer and a LPG-splitter; a second upgrading section 18’ comprising a hydroisomerisation (HDI) reactor and/or a hydrocracking (HCR) reactor, thereby providing a gasoline product as said transportation range fuel product 25. In an embodiment, the transportation range fuel synthesis section 16, 18, 18’ is a jet fuel synthesis section which comprises: a methanol-to-olefins section and oligomerization section (MTO and OLI section, 16) to provide a raw hydrocarbon stream 21 comprising jet fuel hydrocarbons; a fractionation section 18 and a hydroprocessing section 18’ comprising e.g. a hydrogenation section, thereby providing a jet fuel product as said transportation range fuel product 25. For the purposes of the present application, the oligomerization section is comprised in block unit 16. The olefins produced in the MTO section are further oligomerized to jet fuel hydrocarbons in the OLI section.

With reference to Fig. 2, another embodiment according to the invention is provided. All the units and associated conduits or process streams are as in Fig. 1 , with the addition that the plant 100 includes a first hydrogen purification section with a single hydrogenrich gas 41’, as well as a second hydrogen purification section 24”. The latter is arranged to receive at least a portion of the first purge gas 33 upstream the WGS section 20 and provide: a third H2-rich gas 4T” and a second hydrogen purification section off-gas as a second purge gas 33’ to the WGS section 20. Suitably, as for the first H2-rich gas 4T, at least a portion of the third H2-rich gas 4T” is supplied to the methanol synthesis section 14, preferably to the synthesis gas 13 thereto.

With reference to Fig. 3, a more detailed representation of the first hydrogen purification section 24’ of Fig. 1 is shown. The first hydrogen purification section 24’ comprises at least two hydrogen purification units 24’A, 24’B arranged in series. The first 24’A hydrogen purification unit is arranged to receive the CO2-depleted shifted gas 39 and provide: a raw H2-rich gas 41 and a first hydrogen purification unit off-gas as the first hydrogen purification section off-gas 9, which is suitably supplied to the ATR 12 of the synthesis gas section via off-gas compressor 26. The second 24’B hydrogen purification unit is arranged to receive at least a portion 41 A of the raw H2-rich gas 41 and provide: the first H2-rich gas 4T and a second hydrogen purification unit off-gas as the second H2-rich gas (41”). A conduit is suitably arranged to divert and supply a portion 41 B of said raw H2-rich gas 41 to the second hydrogen purification unit off-gas and provide the second H2-rich gas 41”. This second H2-rich gas 41”, albeit being hydrogenrich, has a lower hydrogen purity and higher content of inerts than the first H2-rich gas 4T, and is then supplied as fuel gas to fired heater(s) (not shown). A portion of the first H2-rich gas 4T is suitably supplied via hydrogen compressor 28 to the syngas to methanol synthesis section 14 for adjustment of the syngas module “M”, while another portion is suitably supplied to e.g. downstream HDI and/or HCR reactors (not shown).

With reference to Fig. 4, the plant 100 includes, as in connection with Fig. 2, a first hydrogen purification section with a single hydrogen-rich gas 4T, as well as a second hydrogen purification section 24”. The latter is here arranged to receive a portion of the first purge gas 33 upstream the WGS section 20 and provide: a third Fh-rich gas 4T” and a second hydrogen purification section off-gas as a second purge gas 33’ which is directed, e.g. combined, with the first hydrogen purification section off-gas 9. A portion of the second purge gas 33’ may also be directed (not shown) to the WGS section 20. The WGS section 20 is arranged to receive another portion of the first purge gas 33. The third H2- rich gas 41”’ is supplied to: the methanol synthesis section 14, preferably to the synthesis gas 13 thereto; and/or downstream HDI and/or HCR reactors (not shown).

With reference to Fig. 5, an alternative to Fig. 3 is shown. The first hydrogen purification section 24’ further provides: a separate inert-containing gas 41 C having a higher inert content than the raw H2-rich gas 41. Hence, 24’A, here a PSA unit, provides three outlets: the off-gas stream 9, the raw H2-rich gas 41 and the separate inert-containing gas 41 C. In a particular embodiment, a conduit is arranged to divert and supply a portion 41 D of said raw H2-rich gas 41 to said separate inert-containing gas 41 C into a combined raw H2-rich gas 41 E. The separate inert-containing gas 41 C is supplied directly to the second hydrogen purification unit off-gas outlet i.e. exiting 24’B thus providing the second H2-rich gas 41” carrying the inerts (not shown); and/or the combined raw H2-rich gas 41 E is supplied to the second hydrogen purification unit off-gas outlet i.e. exiting 24’B thus providing the second H2-rich gas 41” carrying the inerts. A conduit is arranged to divert and supply portion 41A of said raw H2-rich gas 41 to the second hydrogen purification unit, here a PSA unit or a membrane unit. As in Fig. 3, the first H2-rich gas 4T exiting 24’B is suitably supplied via hydrogen compressor 28 to the syngas to methanol synthesis section 14 for adjustment of the syngas module “M”. Another portion of the first H2-rich gas 4T is suitably supplied to e.g. downstream HDI and/or HCR reactors (not shown) in connection with the production of transportation range fuels, such as gasoline, diesel, or jet fuel.

EXAMPLES

The following examples are provided:

Cases C1 and C2 are according to present invention; C3 and C4 are prior art representing WO 2022248434; C5 is prior art representing a very simple version of blue gasoline production; C6 is prior art representing grey methanol and gasoline production.

C1 : According to present invention Relevant figures are Fig. 1 and Fig. 5 of present application. HRU 24’ is made of two PSA units (24’A and 24’B) in series. For a methanol production plant with no gasoline production, the second PSA (24’B) is not needed. The first PSA unit (24’A) has three outlet streams: H2-rich gas (with as little inerts as possible, 41), off-gas (9), and “inerts” stream (41 C). This “inerts” stream is technically also a H2-rich gas (H2 is the major component), but this represents the inerts removal mechanism according to the present application. Since H2 is used as fuel for fired heaters, this H2-rich inerts stream is added to the fuel to fired heater(s). The H2-rich gas with minimal inerts (41) from the first PSA unit (24’A) is split with one portion (41 D) going to the fuel, as necessary, and the rest (41 A) going to the second PSA unit (24’B) for further purification. The second PSA unit has two outlet streams: a high purity H2 gas (first H2-rich gas 4T) and a less pure H2 gas containing very small amounts of inerts and impurities (N2, Ar, COx, etc.). The less pure H2 gas (second H2-rich gas 41”) is sent to fired heater(s), while the high purity H2 gas (first H2-rich gas 4T) is split with a significant portion going to the methanol synthesis section (14) to adjust the module “M” of the synthesis gas and another portion, preferably a small portion, going to e.g. the isomerization unit (HDI) in the gasoline upgrading section (18’).

C2: According to present invention

Relevant figures are Fig 4 and Fig 5 in the present application. This has two HRUs. The first HRU (24’) has one PSA, which is functionally the same as 24’A in Fig 5. The H2-rich gas (41) with minimal inerts from this PSA unit (24’A) is split with one portion (41 D) going to the fuel (as necessary) and the rest (41 A) going to the methanol synthesis section to adjust the module. The second HRU 24” receives a tiny portion of the purge gas (33) from the methanol synthesis section and provides two outlet streams: a high purity H2 gas (4T”) (for isomerization in gasoline upgrading or other uses) and an off-gas (33’) that is combined with the off-gas from 24’ and returned as stream 9 to the reforming section.

C3: According to prior art - WO 2022248434 - Fig 5

Relevant figure is WO 2022248434 - Fig 5 yet with no off-gas 17 going to fuel system, so no explicit inerts reduction included. H2-rich streams 14 and 16 have the same composition. They are basically the withdrawn H2-rich gas split into two streams. Since WO 2022248434 is made only for blue methanol, there was no need for a very high purity H2 stream for e.g. isomerization (HDI) downstream. Since here a comparison is made including downstream gasoline production, unit HRU 24” is added (as Fig 4 of present application) and as it is used in C2 above).

C4: According to prior art -WO 2022248434 - Fig 5

Relevant figure is WO 2022248434 - Fig 5 as drawn with the “second” off-gas stream 17 going to fuel system to reduce inerts to similar levels to C1/C2 according to present invention. As in C3, HRU 24” is added to meet hydrogen purity need for isomerization. The off-gas 17 carries the inerts as well as significant carbon containing compounds - the mechanism for removal of inerts in WO 2022248434 - Fig 5 is via off-gas 17. This offgas 17 contains for instance 25-30 vol.% CH4, 4-5 vol.% CO, 50-55 vol.% H2, along with 15-20 vol.% N₂ and 1-5 vol.% Ar.

C5: According to prior art

This case is made to compare the results when the hydrogen purification needed for both methanol and gasoline synthesis are met by a single PSA and therefore where methanol is used for gasoline synthesis. This layout has only HRU 24’ which consists of one PSA unit (like Fig 3 of present application with only 24’A). This PSA unit has two outlet streams: a high purity H2 gas (41 but equivalent in purity to 4T) and an off-gas (9). This off-gas is different from stream 9 in C1 and C2 because it still contains a lot of hydrogen, almost all the carbon from PSA feed, and almost all the inerts from PSA feed. A small portion of the high-purity H2 is used for isomerization, while the rest is used for module adjustment in the methanol synthesis section. A portion of the off-gas (like off-gas stream 17 in WO 2022248434 - Fig 5) is sent to fuel, as necessary, and the remaining is recycled to the reforming section, or could also be sent a bit earlier to feed purification section.

C6: According to prior art

This represents grey methanol and gasoline production. The only carbon-rich stream recycled to the frontend (feed purification + reforming) is the LPG stream from gasoline upgrading section. The rest of the recycle streams, all carbon-rich waste off-gases, are used as fuel, and any excess fuel is exported. The HRU (same location as 24” in Fig 4 of present application) in this layout has two PSA units. The first PSA unit takes a portion of the purge gas from the methanol synthesis section and provides an H2-rich gas and a first off-gas. A tiny portion of the H2-rich gas is sent to the second PSA unit, while the rest of it is used for module adjustment. The second PSA unit provides two outlet streams: a high-purity H2 gas and a second off-gas. The high-purity H2 gas is sent to the isomerization unit in the gasoline upgrading section. The off-gases from both the PSA units (first and second off-gases) are sent to the fuel system. Table 1 below shows carbon intensity metrics for an approx. 2020 MTPD methanol and approx.6000 BPSD gasoline production where the natural gas feed contains 0.4% N2. The metrics are shown in relative terms using the maximum value in each row as the basis.

TABLE 1

C1 and C2 are according to present invention; C3 and C4 are prior art representing WO 2022248434-Fig. 5; C5 is prior art representing a very simple version of blue gasoline production;

C6 is prior art representing grey methanol and gasoline production.

Table 2 below shows a more detailed comparison of C1-4 using C1 as the basis. This shows that C4 (modified WO 2022248434-Fig. 5) would have 3 times higher CO2 emission in the flue gas if inert levels are reduced to the level of C2. TABLE 2

C1 and C2 are according to present invention; C3 and C4 are prior art representing WO 2022248434-Fig. 5 Table 3 below shows the same comparison as in Table 2 but when the natural gas feed contains 3% N2. This is done to show how increased inerts levels are handled by the present claims compared to prior art (C4: modified WO 2022248434-Fig. 5). This shows that WO 2022248434- Fig. 5 would have 4 times higher CO2 emission in the flue gas if inert levels are reduced to the level of C2.

TABLE 3

C1 and C2 are according to present invention; C3 and C4 are prior art representing WO 2022248434-Fig. 5 Table 2 and Table 3 show that the present invention enables to have low CO2 emissions while reducing the size of equipment (by reducing inerts), whereas the prior art (WO 2022248434-Fig. 5) in comparison can either get similarly low CO2 emissions, or similarly reduced equipment sizes via removal of inerts, but not both at the same time. In other words, by the closest prior art (C3, C4):

C4: where inerts are removed there is a high penalty in terms of CO2-emissions thus high Cl; or

C3: where there is possible to achieve low Cl, there is no removal of inerts (C3) - with associated disadvantages as shown in Table 2, 3 e.g. higher ATR inlet flow, higher re- cycle gas compressor work, higher methanol synthesis reactor (MeOH reactor) inlet flow. By the present application/invention, there is low Cl while at the same time removing inerts.

Claims

1. Plant (100) for converting a gaseous hydrocarbon feed (1) such as natural gas to methanol; wherein the plant comprises:

- a synthesis gas section (8, 10, 12) arranged to receive the gaseous hydrocarbon feed (1) and provide a synthesis gas (13, 15);

- a methanol synthesis section (14) arranged to receive at least a portion (13) of the synthesis gas and provide: a raw methanol product (17), a first purge gas (33), and a first set (3T) of one or more waste off-gas streams;

- a water gas shift (WGS) section (20) arranged to receive at least a portion of said first purge gas (33) and provide a shifted gas;

- a CC>2-removal section (22) arranged to receive said shifted gas and provide: a CO2- rich gas (37) and a CCh-depleted shifted gas (39);

- a first hydrogen purification section (24’) arranged to receive said CCh-depleted shifted gas (39) and provide: a first H2-rich gas (41’) and a first hydrogen purification section off-gas (9); wherein said first hydrogen purification section (24’) is further arranged to provide a second H2-rich gas (41”) with a lower content of H2 and a higher content of an inert component than the first H2-rich gas (4T), the inert component being at least one of nitrogen (N2) and argon (Ar); wherein the plant comprises:

- one or more fired heaters arranged to receive at least a portion of the second H2-rich gas (41”);

- a conduit arranged to supply at least a portion of the first H2-rich gas (41’) to the methanol synthesis section (14).

2. Plant according to claim 1 , wherein: the supply of at least a portion of the first H2-rich gas (41’) to the methanol synthesis section (14) is arranged in combination with the at least a portion (13) of the synthesis gas.

3. Plant according to any of claims 1-2, wherein the first hydrogen purification section (24’) is arranged to provide only three outlets, the first outlet being the first H2-rich gas (4T), the second outlet being the first hydrogen purification section off-gas (9), and the third outlet being the second H2-rich gas (41”) or a gas stream 41 C forming part of the second H2-rich gas (41”).

4. Plant according to any of claims 1-3, wherein:

- the first H2-rich gas (4T) comprises at least 95 vol.% H2, such as at least 99 vol.% H2, and the inert content of the first H2-rich gas (4T) in terms of N2 and Ar is: less than 0.10 vol. % N2 and less than 0.6 vol.% Ar; and/or

- the second H2-rich gas (41”) comprises at least 80 vol.% H2, such as up to 97 or 96 vol.% H2, and the inert content of the second H2-rich gas (41”) in terms of N2 and Ar is: 0.5 vol.% N2 or higher, such as 0.6-10 vol.% N2, and 0.6 vol. % Ar or higher, such as 0.6-1.0 vol.% Ar.

5. Plant according to any of claims 1-4, wherein the one or more fired heaters are arranged so that:

- there is no supply thereto of said first hydrogen purification section off-gas (9); and/or

- there is no supply thereto of a second hydrogen purification section off-gas.

6. Plant according to any of claims 1-5, wherein the methanol synthesis section (14) is arranged as a methanol synthesis loop; the methanol synthesis loop comprising: a methanol reactor arranged to receive the at least a portion (13) of the synthesis gas and provide a raw methanol effluent stream; a first separator arranged to receive the raw methanol effluent stream and provide: an overhead recycle gas, and a bottom stream as said raw methanol product (17); a recycle compressor arranged to supply the overhead recycle gas to the methanol reactor; a conduit arranged to divert a portion of the overhead recycle gas as said first purge gas (33).

7. Plant according to any of claims 1-6, wherein:

- the first hydrogen purification section (24’) comprises at least two hydrogen purification units (24’A, 24’B) arranged in series;

- the first (24’A) hydrogen purification unit is arranged to receive said CCh-depleted shifted gas (39) and provide: a raw H2-rich gas (41) and a first hydrogen purification unit off-gas as said first hydrogen purification section off-gas (9); - the second (24’B) hydrogen purification unit is arranged to receive at least a portion (41 A) of said raw H2-rich gas (41) and provide: said first H2-rich gas (41’) and a second hydrogen purification unit off-gas as said second H2-rich gas (41”);

8. Plant according to claim 7, wherein:

- the first hydrogen purification section (24’) further comprises: a conduit arranged to divert and supply a portion (41 B) of said raw H2-rich gas (41) to said second hydrogen purification unit off-gas and provide said second H2-rich gas (41”); or

9. Plant according to claim 7, wherein the at least two hydrogen purification units (24’A, 24’B) arranged in series are any of: at least two PSA units arranged in series; at least two membrane units arranged in series; a single membrane unit and a single PSA unit arranged in series in either order.

10. Plant according to any of claims 1-9, wherein the WGS section (20) is further arranged to receive a portion (15) of the synthesis gas; optionally, wherein the WGS section (20) is a medium shift temperature (MTS) unit; optionally, wherein the MTS unit is in direct fluid communication with a low temperature shift (LTS) unit.

11 . Plant according to any of claims 1-10, wherein the plant comprises:

- a conduit arranged to supply at least a portion of the first hydrogen purification section off-gas (9) to the gaseous hydrocarbon feed (1 , 7); and/or

- a conduit arranged to supply a portion of said first purge gas (33) to the gaseous hydrocarbon feed (1 , 7).

12. Plant according to claim 11 , wherein the synthesis gas section (8, 10, 12) comprises a pre-reforming unit (10) arranged upstream an autothermal reforming (ATR) unit (12); and wherein:

- said conduit arranged to supply the least a portion of the first hydrogen purification section off-gas (9) to the gaseous hydrocarbon feed (1 , 7) is a conduit arranged to supply the first hydrogen purification section off-gas (9) to a pre-reformed hydrocarbon feed (7), thereby to a mixing point, such as a mixing unit or a juncture, between the pre-reforming unit (10) and the ATR unit (12); optionally, at inlet (11) of the ATR unit (12); and/or

- said conduit arranged to supply a portion of said first purge gas (33) to the gaseous hydrocarbon feed (1 , 7) is a conduit arranged to supply the portion of said first (33) to a pre-reformed hydrocarbon feed (7, 11), thereby to a mixing point, such as a mixing unit or a juncture, between the pre-reforming unit (10) and the ATR unit (12); optionally, at inlet (11) of the ATR unit (12).

13. Plant according to any of claims 6-12, wherein the synthesis gas section (8, 10, 12) comprises a hydrogenator and a sulfur absorber (8), suitably arranged upstream prereforming unit (10); wherein the plant comprises a conduit arranged to divert another portion of the overhead recycle gas of the methanol synthesis loop as a first H2-rich offgas (5) and to supply at least a portion thereof to the gaseous hydrocarbon feed (1) upstream the hydrogenator and sulfur absorber (8); and/or wherein the plant comprises a conduit arranged to supply a portion of the first (4T) H2-rich gas to the gaseous hydrocarbon feed (1) upstream the hydrogenator and sulfur absorber (8).

14. Plant according to any of claims 1-13, wherein the plant comprises:

- a methanol tank arranged to receive and store the raw methanol product (17); and/or - a fractionation section arranged to receive the raw methanol product (17) and provide a methanol product (17’).

15. Plant according to any of claims 1-14, wherein the plant is further arranged to convert the gaseous hydrocarbon feed (1) to a transportation range fuel product (25) selected from at least one of: a gasoline product, a jet fuel product, and a diesel product; wherein the plant further comprises:

- a transportation range fuel synthesis section (16, 18, 18’) arranged to receive at least a portion of the raw methanol product (17) or at least a portion of the methanol product (17’) and provide: said transportation range fuel product (25), as well as: a second set (31”) of one or more waste off-gas streams; one or more by-product streams rich in paraffins (29); and a third set (3T”) of one or more waste off-gas streams;

- a conduit arranged to supply at least a portion of at least one of the first (3T), second (31”) and third (31’”) set of one or more waste off-gas streams to the gaseous hydrocarbon feed; optionally, upstream the hydrogenator and sulfur absorber (8).

16. Plant according to claim 15, wherein:

- the one or more by-product streams rich in paraffins (29) is at least one of LPG (liquified petroleum gas) and naphtha, and the plant comprises a conduit arranged to supply at least a portion thereof, to the gaseous hydrocarbon feed (1); optionally, upstream the hydrogenator and sulfur absorber (8).

17. Plant according to any of claims 15-16, wherein: the transportation range fuel synthesis section (16, 18, 18’) is a gasoline synthesis section which comprises: a methanol-to-gasoline section (MTG section, 16); a first upgrading section (18) comprising a distillation section, the distillation section comprising a deethanizer and a LPG-splitter; a second upgrading section (18’) comprising a hydroisomerisation (HDI) reactor and/or a hydrocracking (HCR) reactor, thereby providing a gasoline product as said transportation range fuel product (25); or the transportation range fuel synthesis section (16, 18, 18’) is a jet fuel synthesis section which comprises: a methanol-to-olefins section and oligomerization section (MTO and OLI section, 16); a fractionation section (18) and a hydroprocessing section (18’) such as a hydrogenation section, thereby providing a jet fuel product as said transportation range fuel product (25).

18. Plant according to claim 17, wherein the plant comprises a conduit arranged to supply a portion of any of the first (4T) and second (41”) H2-rich gas to: the HDI reactor and/or HCR reactor of the second upgrading section (18’) of the gasoline synthesis section; or to the hydroprocessing section (18’), such as a hydrogenation section, of the jet fuel synthesis section.

19. Plant according to any of claims 12-18, wherein:

- the synthesis gas section (8, 10, 12) comprises a pre-reforming unit (10) in fluid communication with ATR unit (12); preferably, via inlet 11 of the ATR, in direct fluid communication downstream said mixing point of the first hydrogen purification section off-gas 9 to the pre-reformed hydrocarbon feed 7;

- the at least a portion (13) of the synthesis gas is in indirect fluid communication with the methanol synthesis section (14), by the plant further comprising a process condensation unit (PC-unit) arranged between the ATR unit (12) and the methanol synthesis section (14); optionally, the plant further comprising a gas cleaning reactor arranged between the ATR unit (12) and the PC-unit.

20. Plant according to any of claims 1-19, wherein the one or more fired heaters is at least one of:

- a fired heater associated with the synthesis gas section (8, 10, 12) for preheating the gaseous hydrocarbon feed gas (1 , 7);

- a fired steam superheater for producing a superheated steam;

- a fired heater reboiler of a fractionation section, such as: said fractionation section arranged to receive the raw methanol product (17), or said fractionation section (18) of the as jet fuel synthesis section, or said first upgrading section (18) of the gasoline synthesis section.

21. Plant (100) for converting a gaseous hydrocarbon feed (1) such as natural gas to methanol; wherein the plant comprises:

- a first hydrogen purification section (24’) arranged to receive said CCh-depleted shifted gas (39) and provide: a first H2-rich gas (41’) and a first hydrogen purification section off-gas (9); wherein:

- the first hydrogen purification section (24’) is arranged to provide a single H2-rich gas as said first H2-rich gas (4T), along with said first hydrogen purification section off-gas (9); and wherein the plant further comprises:

- one or more fired heaters arranged to receive: at least a portion of said first H2-rich gas (4T);

- a second hydrogen purification section (24”) arranged to receive at least a portion of the first purge gas (33) upstream the WGS section (20) and provide: a third H2-rich gas (41’”) and a second hydrogen purification section off-gas as a second purge gas (33’) to the WGS section (20) and/or as a second purge gas (33’) to the first hydrogen purification off-gas (9); optionally, wherein:

- the first hydrogen purification section (24’) is a single PSA unit or a single membrane unit;

- the second hydrogen purification section (24”) is: a PSA unit and/or membrane unit;

- the plant comprises a conduit arranged to supply at least a portion of the third H2-rich gas (4T”) to the methanol synthesis section (14); optionally, in combination with the at least a portion (13) of the synthesis gas.

22. Process (100) for converting a gaseous hydrocarbon feed (1) to methanol, wherein the process comprises:

- providing a plant according to any of claims 1-20;

- supplying a gaseous hydrocarbon feed (1) to a synthesis gas section (8, 10, 12) and withdrawing therefrom a synthesis gas (13, 15);

- supplying at least a portion (13) of the synthesis gas to a methanol synthesis section (14) and withdrawing therefrom: a raw methanol product (17), a first purge gas (33), and a first set of one or more waste off-gas streams (3T);

- optionally, the methanol synthesis section (14) being arranged as a methanol synthesis loop comprising: a methanol reactor, a first separator, and a recycle compressor; supplying the at least a portion (13) of the synthesis gas to the methanol reactor and withdrawing therefrom a raw methanol effluent stream; supplying the raw methanol effluent stream to the first separator and withdrawing therefrom an overhead recycle gas and a bottom stream as said raw methanol product (17); supplying the overhead recycle gas via the recycle compressor to the methanol reactor; and diverting a portion of the overhead recycle gas as said first purge gas (33);

- supplying said first purge gas (33) to a water gas shift (WGS) section (20) and withdrawing therefrom a shifted gas;

- supplying said shifted gas to a CCh-removal section (22) and withdrawing therefrom: a CC>2-rich gas (37) and a CCh-depleted shifted gas (39);

- supplying said CCh-depleted shifted gas (39) to a first hydrogen purification section (24’) and withdrawing therefrom: a first H2-rich gas (4T); a second H2-rich gas (41”) comprising a lower content of H2 and a higher content of an inert component than the first H2-rich gas (41’), the inert component being at least one of N2 and Ar; and a first hydrogen purification section off-gas (9); providing one or more fired heaters and supplying thereto at least a portion of the second H2-rich gas (41”);

- supplying at least a portion of the first H2-rich gas (4T) to the methanol synthesis section (14);

- optionally, wherein the first H2-rich gas (4T) comprises at least 95 vol.% H2, such as at least 99 vol.% H2, and the inert content of the first H2-rich gas 4T in terms of N2 and Ar is: less than 0.10 vol. % N2 and less than 0.6 vol.% Ar; and/or the second H2-rich gas (41”) comprises at least 80 vol.% H2, such as up to 97 or 96 vol.% H2, and the inert content of the second H2-rich gas 41” in terms of N2 and Ar is: 0.5 vol.% N2 or higher, such as 0.6-10 vol.% N2, and 0.6 vol. % Ar or higher, such as 0.6-1.0 vol.% Ar.