DK181610B1

DK181610B1 - Conversion of carbon oxides to sustainable aviation fuel (SAF)

Info

Publication number: DK181610B1
Application number: DKPA202201127A
Authority: DK
Inventors: De Sarkar Sudip; Aasberg-Petersen Kim
Original assignee: Topsoe As
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2024-06-26
Also published as: DK202201127A1; WO2024126060A1

Abstract

A hydrocarbon synthesis plant and process comprising an alcohol synthesis unit and an alcohol-to-hydrocarbons section; the plant and process incorporating a reforming system for treating a by-product stream rich in C1-C4 paraffins and/or olefins being produced in the plant and process, thereby providing a reformer-based syngas stream which is fed to inlet the alcohol synthesis unit.

Description

DK 181610 B1 1

CONVERSION OF CARBON OXIDES TO SUSTAINABLE AVIATION FUEL (SAF)

The present invention relates to a more efficient system (plant) and process for producing hydrocarbons, including olefins as well as transportation fuels, such as synthetic kerosene e.g. jet fuel or sustainable aviation fuel (SAF), optionally also diesel, from a carbon oxide containing feed, such as from a carbon dioxide rich feed or a carbon monoxide rich feed. The plant or process comprises conversion of said feed to a C2-C4 alcohol, such as C2 alcohol (ethanol) in an alcohol synthesis unit and further synthesis of the C2-C4 alcohol in an alcohol-to-hydrocarbons (ATH) section to a first product rich in olefins. Embodiments of the invention include further synthesis of the first product rich in olefins to hydrocarbons boiling in the jet fuel range. Embodiments of the invention include the provision of steam reforming in a dedicated reformer to improve overall carbon and hydrogen efficiency by feeding the reformer with a by-product stream rich in paraffins and/or olefins, optionally also an off-gas stream, which are produced in the hydrocarbon synthesis plant, such as in the ATH section, and in which the thus produced reformer-based syngas is fed to the inlet of the alcohol synthesis unit.

Processes for the conversion of sustainable feeds, such as CO», biomass etc. to gasoline or jet fuel via methanol are known. Biomass can first be converted to syngas via gasification followed by conversion of said syngas to methanol, for instance in a methanol synthesis loop — hereinafter also referred to as “methanol loop” -, and finally methanol conversion to olefins. The olefins are then oligomerized and hydrogenated into jet fuel, which are hydrocarbons in the range C8-C19, such as C8-C16. A CO, feed, together with H> feed, can be converted to methanol followed by conversion of said methanol to jet fuel. Irrespective of the main feed, there are some by-products along with jet fuel. One of the by-products from such processes is a fraction containing lighter hydrocarbons than the above range corresponding to jet fuel (C8-19), in particular a by- product stream rich in paraffins and/or olefins, such as light paraffins in the range C3-

C7, including propane and/or butane (C3 and/or C4), as well as olefins. The C3 and/or

C4 fraction is known as liquified petroleum gas, LPG. Off-gas streams comprising CO»,

Hz, CH, higher hydrocarbons etc. are also typically produced and withdrawn as waste gas streams.

DK 181610 B1 2

The lighter hydrocarbons, e.g. the light paraffins, may often itself have little commercial value. Moreover, the off-gas streams often have no efficient use, apart from using them in fired equipment, which causes CO, emissions. It would, therefore, be of interest to be able to recycle these streams as part of the hydrocarbon synthesis process itself, in order to at least improve overall carbon efficiency (C-efficiency) of this process. Furthermore, reusing the by-product stream comprising lighter hydrocarbons, this being a stream rich in paraffins and/or olefins, hereinafter also referred to as “by-product stream rich in paraffins and/or olefins”, and/or reusing å waste stream generated in the plant or process, hereinafter also referred to as “off-gas stream” via a dedicated steam reforming into a synthesis gas stream, in e.g. a CO, and H; feed based alcohol synthesis plant, enhances alcohols synthesis, e.g. ethanol synthesis performance, as it will become apparent from one or more of the below embodiments of the invention.

EP 3730473 A1 discloses the use of renewable energy in a methanol synthesis plant.

Steam reforming of a number of hydrocarbon feedstocks including LPG is provided in a syngas generation section upstream methanol synthesis to provide for the methanol synthesis gas, and which is further configured such that more of the net energy required by i.a. the methanol synthesis plant, is provided by a non-carbon-based energy source, a renewable energy source, and/or electricity.

WO 2010143980 discloses a system for integrating methanol production and hydroprocessing of oil feedstock to produce a hydrocarbon product. A steam reformer processes a first feedstock and C1 to C4 hydrocarbons may be separated from the hydrocarbon product and recycled to the first feedstock. Hence, the steam reformer is provided upstream methanol synthesis to provide for the main methanol synthesis gas feed, and the hydroprocessing plant, having its own feed oil feedstock, is integrated by benefiting from the hydrogen produced in the methanol synthesis.

Applicant's co-pending European patent application No. 22166260.4 discloses the conversion of carbon dioxide to gasoline using e.g. electrical steam methane reforming (e-SMR) of a recycled liquified petroleum gas (LPG) stream.

A need therefore exists for an effective process and system for utilising a by-product stream rich in paraffins and/or olefins, optionally also off-gas streams, as well as

DK 181610 B1 3 hydrogen rich streams from a sustainable feed-to-hydrocarbon synthesis plant, such as a sustainable feed-to-jet fuel plant, to improve overall C-efficiency as well as hydrogen efficiency (H>-efficiency), but in which disadvantages can be avoided; in particular, in which additional CO, emissions are avoided, and in which there is improved alcohol synthesis performance, e.g. ethanol synthesis performance, including a smaller alcohol synthesis unit.

Applicant's co-pending European patent application No. 22179912.5 discloses a plant and process, in which a reforming system is provided for dedicated steam reforming of a stream rich in paraffins and/or olefins of a jet fuel synthesis plant incorporating the reforming system.

US 201213452073A discloses a process and system for producing high octane fuel from carbon dioxide and water. A reforming unit downstream of and in fluid communication with the liquid fuel generation unit is arranged to e.g. steam-reform any unaccepted portion of separated hydrocarbon product, such as LPG (C3-C4 hydrocarbons) and fuel gas (C1-C2 hydrocarbons), as LPG and fuel gas may amount to 15-40 wt% of the hydrocarbon product. The resulting synthesis gas (syngas) is fed to inlet of a methanol synthesis unit. This citation is at least silent on the provision of a C2-C4 alcohol synthesis unit in which the process or plant is dedicated to producing olefins and/or jet fuel as the hydrocarbon product, and for which the LPG and fuel gas may represent less than 15wt% of the hydrocarbon product, such as less than 10 wt%.. This citation is also at least silent on the syngas being fed to this C2-C4 alcohol synthesis unit instead of to the inlet of the methanol synthesis unit.

Unless otherwise specified, any given percentages content are % by volume. All feeds are preheated as required.

The term “synthesis gas” (abbreviated to “syngas”) is meant to denote a gas comprising hydrogen and a carbon oxide, and optionally small amounts of other gasses, such as argon, nitrogen, methane, etc.

The term “a carbon oxide” means CO and/or CO».

The term “first syngas feed” means a syngas rich in Hz and CO» resulting from the combination of the first Hy rich stream and the first CO, stream. For instance, the first syngas feed contains about 75 H2% and about 25% CO, with less than 1% CO.

DK 181610 B1 4

The term “second syngas feed” means a separate syngas feed produced upstream the alcohol synthesis unit of the hydrocarbon synthesis plant. For instance, the second syngas feed comprises Hz and the carbon oxide(s) in a molar ratio of at least 3:1. For instance, the second syngas feed as a module M=(H>-CO2)/(CO+CO») of 1.90-2.20.

A “sustainable feed” may be a CO; feed, a H feed, or combination thereof; or a biomass feed, or a syngas feed produced at least partly from electrolysis.

The term “first, second or third or fourth syngas stream”, are also referred to as a "reformer-based syngas stream” and means a syngas stream withdrawn from a dedicated reforming system comprising the reforming unit (reformer) for treating a by- product stream rich in C1-C4 paraffins and/or olefins. For instance, where the reformer is an e-SMR (electrically heated steam methane reformer, interchangeably referred to as electrical steam methane reforming), the reformer-based syngas stream is an e-SMR based syngas stream.

The term “reforming” and “steam reforming” are used interchangeably.

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

The term alcohol synthesis unit means a unit producing alcohol, in which the alcohol is any of a C2-C4 alcohol or combinations thereof. For instance, C2-alcohol (ethanol, also referred to as EtOH). The alcohol synthesis unit may comprise a methanol synthesis unit arranged upstream the C2-C4 alcohol synthesis unit. The alcohol synthesis unit may comprise only a C2-C4 alcohol synthesis unit, i.e. the alcohol synthesis unit is absent of an upstream methanol synthesis unit. The C2-C4 alcohol synthesis unit may for instance be a catalytic or bio-catalytic unit for producing EtOH.

The term “ATO” means alcohol to olefin conversion.

The term "OLI” means oligomerization of olefins.

The term “HYDRO” means hydrogenation of oligomerized olefins.

The term “ATH section” means the alcohol to hydrocarbons section of the hydrocarbon synthesis plant. The hydrocarbon may be an olefin stream, herein a first product rich in olefins. The hydrocarbon may be a jet fuel stream, such as a raw product stream containing hydrocarbons boiling in the jet fuel boiling range. The ATH section comprises an ATO reactor and may further comprise an OLI reactor and HYRO reactor.

The terms “system”, “plant” i.e. process plant, are used interchangeably. Throughout this specification, the term system is used for the reforming, hence the term “reforming system”.

DK 181610 B1

The terms “section” and “unit” refers normally in this specification to a subset of a plant or system.

The term “suitably” may be given the same meaning as “optionally”, i.e. an optional embodiment. 5 The term “comprising” include “comprising only” i.e. consisting of.

The terms “comprising” and “containing” are used interchangeably.

The term “invention” or “present invention” is used interchangeably with the term “application” or “present application”.

Other definitions are provided throughout the patent application in connection with the recital of one or more embodiments of the invention.

In a first general embodiment, there is provided a hydrocarbon synthesis plant (200), comprising: - a first CO, rich feed (201) comprising CO,» to said plant, a first H> rich feed (202) comprising H» to said plant, or a first syngas feed (209) combining the first CO; rich feed (201) and the first H, rich feed (202); or a second syngas feed (205) comprising a carbon oxide and hydrogen to said plant; - an alcohol synthesis unit (220), arranged to receive the first CO, rich feed (201) and the first Ha rich feed (202), or arranged to receive the first syngas feed (209), or arranged to receive the second syngas feed (205), and provide an effluent stream (221) comprising a C2-C4 alcohol, - an alcohol-to-hydrocarbons (ATH) synthesis section (230), arranged to receive at least a portion of the effluent stream (221) comprising a C2-C4 alcohol, the ATH synthesis section (230) comprising an alcohol-to-olefin reactor (ATO reactor) to provide a first product (231) rich in olefins; said ATH synthesis section (230) further being arranged to provide a by-product stream (242) rich in C1-C4 paraffins and/or olefins; - a reforming system (100) for reforming said by-product stream (1, 242) rich in C1-C4 paraffins and/or olefins, said reforming system (100) comprising: a first reforming feed stream (1) as said by-product stream (242) rich in C1-C4 paraffins and/or olefins; a reforming unit (reformer, 40) arranged to receive the by-product stream (1, 242) rich in

C1-C4 paraffins and/or olefins, carry out a steam reforming step, and provide a reformer- based syngas stream (41, 51, 53, 62); and wherein said reforming system (100) is further arranged for said first reforming feed (1, 242) being less than 15 wt% of said first product (231) rich in olefins;

DK 181610 B1 6 - said hydrocarbon synthesis plant (200) further being arranged to feed at least a portion of said reformer-based syngas stream (41, 51, 53, 62), to an inlet of the alcohol synthesis unit (220).

A much simpler plant with significantly lower carbon footprint is thereby provided, since the reforming is only conducted for a minor internal reforming feed stream, namely the by-product stream rich in paraffins, optionally also an off-gas stream, as it will also become apparent from one or more of below embodiments. In the present application, the by-product formation and off-gas formation of light hydrocarbons streams in a hydrocarbon synthesis plant in which the hydrocarbon is an olefin and/or jet fuel, represent less than 15 wt%, such as 10 wt% or less, for instance 5 wt% of the hydrocarbon product. Despite the by-product and off-gas only representing less than 15 wt% or less, e.g. about 10 wt%, or 5 wt%, of the hydrocarbon product, it is reused in the plant or process to increase its overall efficiency: carbon (C-efficiency) and hydrogen efficiency (H-efficiency). Despite the low percentage of e.g. by-product, a dedicated reforming unit for reforming such by-product and off-gas into a syngas, is advantageously provided. The syngas is suitably fed to inlet of a C2-C4 alcohol synthesis unit, such as a

C2 alcohol (ethanol) synthesis unit, which thereby provides an advantageous feeding point of the reformed-based syngas. The overall efficiency: carbon (C-efficiency) and hydrogen efficiency (H-efficiency) of the plant and process is increased, while at the same time enabling improving the performance of the alcohol synthesis unit, in particular the C2-C4 alcohol synthesis unit therein. A simpler and smaller alcohol synthesis unit is achieved.

In an embodiment, said hydrocarbon synthesis plant is further arranged for the reformer- based syngas stream (41, 51, 53, 62) being up to 50% by volume basis, such as 5-45%, e.g. 10-40% of the inlet of the alcohol synthesis unit (220).

In an embodiment, said hydrocarbon synthesis plant (200) does not comprise a reforming unit arranged upstream the alcohol synthesis unit (220) for providing said first (209) or second (205) syngas feed.

DK 181610 B1 7

Hence, the first or second syngas feed are for instance provided via electrolysis, such as electrolysis of water and/or steam for producing hydrogen, without resorting to upstream reforming of a hydrocarbon feed such as natural gas for providing the syngas feed. A more sustainable solution is thereby achieved.

In an embodiment, the C2-C4 alcohol is any of a C2-C4 alcohol or combinations thereof.

In an embodiment, the first product (231) rich in olefins contains at least 50 wt% C2-C9 olefins.

In an embodiment, the first product (231) rich in olefins contains at least 30 wt% olefins as hydrocarbons boiling in the jet fuel range such as C8-C19 hydrocarbons, e.g. C8-C17 hydrocarbons.

In an embodiment, said by-product stream (242) rich in C1-C4 paraffins and/or olefins is any of: methane, ethane, ethene (ethylene), propane, propene (propylene), butane, butene (butylene), and combinations thereof.

In an embodiment, the alcohol synthesis unit (220) comprises: - a methanol synthesis unit (220°) arranged to receive the first CO, rich feed (201) and the first Ha rich feed (202), or arranged to receive the first syngas feed (209), or arranged to receive the second syngas feed (205), and provide an effluent stream (211) comprising methanol; - a C2-C4 alcohol synthesis unit (220) arranged to receive the effluent stream (211) comprising methanol; optionally wherein the C2-C4 alcohol synthesis unit (220) is arranged to receive a portion of any of: the first CO» rich feed (201), the first Hz rich feed (202), and the first syngas feed (209); and provide said effluent stream (221) comprising a C2-C4 alcohol; and wherein said hydrocarbon synthesis plant (200) is arranged to feed said at least a portion of said reformer-based syngas stream (41, 51, 53, 62) to the inlet of the C2-C4 alcohol synthesis unit (220”).

DK 181610 B1 8

In an embodiment, the plant (200) is further arranged to feed a portion representing 50 vol% or less of said reformer-based syngas stream (41, 51, 53, 62) to the inlet of the methanol synthesis unit (220°).

Hence, there is a split of for instance 50:50 vol.% of the reformer-based syngas to the methanol synthesis unit and the C2-C4 alcohol synthesis unit.

In an embodiment, the plant (200) is further arranged to feed a minor portion representing 20 vol% or less of said reformer-based syngas stream (41, 51, 53, 62) to the inlet of the methanol synthesis unit (220°).

It has been found that by feeding the reformed-based syngas to the C2-C4 alcohol synthesis unit of the alcohol synthesis unit, optionally also feeding reformed-based syngas to a methanol synthesis unit therein, significant synergies are obtained. For instance, 99, 90, 80 vol.% of the reformed-based syngas stream, i.e. a major portion, is fed to the C2-C4 alcohol synthesis unit, while 1, 10, 20 vol.%, i.e. a minor portion, is fed to the methanol synthesis unit. Hence, the minor portion of said reformer-based syngas stream (41, 51, 53, 62) fed to the inlet of the methanol synthesis unit (220’) is 20 vol.% or less.

Where the alcohol synthesis unit comprises a methanol synthesis unit (e.g. MeOH loop) and a minor portion of the reformed-based syngas is fed thereto, a CO/CO, molar ratio needed for lower catalyst volume is obtained and thereby a smaller methanol synthesis unit, e.g. smaller MeOH loop.

Suitably, the C2-C4 alcohol synthesis unit (220) is further arranged to receive a portion of any of: the first CO, rich feed (201), the first H» rich feed (202), and the first syngas feed (209).

Suitably, the at least a portion of said reformer-based syngas stream is fed in admixture with said CO» rich feed (201) and/or said Ha rich feed (202), or in admixture with said first syngas feed (209), or in admixture with said second (205) syngas feed. The same may apply for the portion of the reformer-based syngas stream fed to the inlet of the methanol synthesis unit.

DK 181610 B1 9

In an embodiment, the reformer-based syngas stream is a first, second or third reformer- based syngas stream (41, 51, 53).

The reformed-based syngas contains not only hydrogen, but a significant amount of carbon oxides (CO), in particular CO. The presence of CO in the syngas enables conducting the conversion into C2-C4 alcohols with significantly lower generation of water. Water is suitably removed from the produced C2-C4 alcohol prior to any subsequent conversion into olefins in the alcohol-to-olefins (ATO) reactor, as the presence of water may be detrimental for the catalyst of the ATO reactor, suitably arranged therein as a fixed bed, as well as conveying increase size of units and associated equipment, as water needs to be carried over in the plant or process.

When producing methanol, if one were to produce methanol from CO, and Hy, this comes at a much higher cost compared to traditional methanol feed gas (via upstream syngas generation) comprising Hz, CO and CO», because the reaction from CO, forms water compared to the reaction from CO; as a result of the reaction: CO; + 3H, = CH3OH +

H>0, compared to CO + 2H, = CH3OH. The resulting water has a negative effect on the performance of the methanol conversion catalyst and the catalyst volume increases with more than 100% if the CO» concentration is too high, e.g. 90%. Much more energy is also required.

The negative effect of the presence of water is even higher when producing EtOH involving the use of CO2 and H2 as feed. While for methanol (CH30OH) conversion from

CO2 and H2, the molar ratio of the product is CH30H/H20 of 1, i.e. for each vol. part of ethanol, 1 vol. part of water is produced, for ethanol (CH3CH2OH) conversion from CO2 and H2, the molar ratio of CH3HC20H/H20 is 1/3, i.e. for each vol. part of ethanol, 3 vol. parts of water are produced: 2 CO2 + 6 H2 = CH3CH2OH + 3 H20. Hence, three times more water is produced compared to methanol synthesis alone.

The provision of the reformed-based syngas to the inlet of the C2-C4 alcohol synthesis unit, such as C2-alcohol synthesis unit (EtOH synthesis unit), together with methanol from an upstream methanol synthesis unit, enables a feed for e.g. EtOH synthesis that produces less water, thereby also thermodynamically favouring the formation of EtOH,

DK 181610 B1 10 and further simplifies the plant and process by limiting the need of removing the water.

The challenges associated with the water removal, requiring costly and energy intensive distillation in the alcohol synthesis unit, are thereby significantly reduced.

Methanol and water are highly miscible and therefore water removal from a methanol stream comprising water is highly inexpedient, not only in terms of capital expenditures (and thereby plot size due to need of providing a large distillation unit), but also operating expenditures, i.a. due to high energy requirements for distillation. Thus, the straightforward approach would have been to provide a major portion of reformer-based syngas stream to the inlet of the methanol synthesis unit, so as to minimize as much as possible the water production therein. In contrast thereto, the present application synergistically provides 50 vol% or more, hence suitably the major portion or all of the reformer-based syngas to the C2-C4 alcohol synthesis unit, despite the C2-C4 alcohol, e.g. EtOH, being less miscible in water. For instance, upon producing the C2-alcohol (EtOH), the higher C3-C4 alcohols (propanol and butanol) are also formed, these being even less miscible in water than EtOH.

The methanol is for instance carbonylated to acetic acid and then hydrogenated to EtOH:

Hz + CO, to MeOH: MeO H>+CO» to EtOH (e.g. catalytic process). In a bio-catalytic process H2 and CO2 may be converted directly to EtOH.

The invention is also applicable to other syngas to C2-C4 alcohol processes, e.g. EtOH process, including where there is no upstream production of methanol in the C2-C4 alcohol synthesis unit.

Accordingly, in an embodiment, the alcohol synthesis unit (220) is a C2-C4 alcohol synthesis unit (220”) arranged to directly receive the first CO; rich feed (201) and the first Hx rich feed (202), or arranged to directly receive the first syngas feed (209), or arranged to directly receive the second syngas feed (205), and provide said effluent stream (221) comprising a C2-C4 alcohol; i.e. the alcohol synthesis unit (220) is absent of a methanol synthesis unit (220°) upstream the C2-C4 alcohol synthesis unit (220”).

The term “directly” means that there are no intermediate steps or units changing the composition of the stream.

DK 181610 B1 11

For instance, as recited above, EtOH may be produced by feeding, without a prior or upstream alcohol synthesis unit, H2+CO, to EtOH in a catalytic process, or by H2+CO> to EtOH in a bio-catalytic process. Hence, the C2-C4 alcohol synthesis unit (2207) is also suitably a catalytic or bio-catalytic synthesis unt. Suitably also, in the bio-catalytic synthesis unit the molar ratio of H>:CO at the inlet including said reformer-based syngas stream (41, 51, 53, 62) is 1:1 to 5:1. At these molar ratios the yield of C2-C4 alcohol, such as C2 alcohol (ethanol), is the highest.

In an embodiment, the ATH synthesis section (230) comprises a first separation section arranged to receive at least a portion of said first product (231) rich in olefins and provide said by-product stream (242) rich in C1-C4 paraffins and/or olefins.

The first separation section comprises for instance a first separation unit such as a 3- phase separator arranged to receive the first product (231) rich in olefins, containing for instance at least 50 wt% C2-C9 olefins, and provide: a water stream; a gaseous fraction as said by-product stream rich in C1-C4 paraffins and/or olefins, such as any of: methane, ethane, ethene (ethylene), propane, propene (propylene), butane, butene (butylene), and combinations thereof, for instance containing C2-C3 olefins optionally also carbon monoxide, carbon dioxide and hydrogen; and a liquid hydrocarbon fraction optionally comprising a major portion of the C3-olefins contained in first product stream (231) rich in olefins. The by-product stream rich in C1-C4 paraffins and/or olefins or a portion thereof is recycled to the inlet of the alcohol synthesis unit. The first separation section may also comprise a fractionation unit arranged to receive the liquid hydrocarbon fraction and provide a C3-olefin product of high purity, e.g. at least 93 vol.%, i.e. a propylene-rich stream having a high commercial value, as described in applicant's co-pending European patent application No 22152691.6. From the fractionation unit an olefin product is produced as said first product rich in olefins.

Accordingly, in an embodiment, in the hydrocarbon synthesis plant (200), said first separation section is also arranged to provide a propylene-rich stream.

The ATH section may thus be regarded as alcohol-to-olefins (ATO) section, and the by- product stream (242) rich in C1-C4 paraffins and/or olefins may be at least a portion of

DK 181610 B1 12 the gaseous fraction as said by-product stream rich in C1-C4 paraffins and/or olefins, and which is withdrawn in the first separation section, as described above.

In an embodiment, the plant is arranged to recycle a portion of said by-product stream rich in C1-C4 paraffins and/or olefins to the inlet of the alcohol-to-olefin (ATO) reactor.

This recycle stream dilutes the inlet stream to the ATO reactor, i.e. it dilutes the effluent stream (221) comprising a C2-C4 alcohol, and thereby prevents undesired adiabatic temperature rise in the ATO reactor, as this is suitably provided as an adiabatic fixed bed catalyst reactor (fixed bed reactor).

This recycle is advantageously a major portion of said by-product stream rich in C1-C4 paraffins and/or olefins, for instance 60, 70, 80, 90%. Thereby, the by-product stream rich in C1-C4 paraffins and/or olefins which is fed to the reforming system is a minor stream thereof, for instance 40, 30, 20, 10%. A reforming system with significantly reduced plot size than the prior art is achieved, while at the same time providing significant synergy in plant or process operation by reducing the exothermicity of the

ATO reactor in the ATH synthesis section of the plant.

In an embodiment, the ATH synthesis section (230) further comprises an oligomerisation reactor (OLI reactor) arranged to receive at least a portion of said first product (231) rich in olefins, for instance after withdrawing said propylene-rich stream, to provide an oligomerised raw product stream, and a hydrogenation reactor (HYDRO reactor) to provide a raw product (231%) containing hydrocarbons boiling in the jet fuel range; and wherein the ATH synthesis section (230) further comprises: - a separator between the OLI reactor and HYDRO reactor, which is arranged to receive at least a portion of the oligomerised raw product stream and separate therefrom at least a portion of said by-product stream (242) rich in paraffins and/or olefins; and/or a separator downstream the HYDRO reactor which is arranged to receive at least a portion of the raw product (231°) containing hydrocarbons boiling in the jet fuel range, and separate therefrom at least a portion of said by-product stream (242) rich in paraffins and/or olefins.

DK 181610 B1 13

Hence, the ATH section is here specifically an alcohol-to-jet fuel (ATJ) section comprising the ATO reactor, OLI reactor and HYDRO reactor, in which the by-product stream (242) rich in C1-C4 paraffins and/or olefins may be any of the above-mentioned by-product streams or combinations thereof.

The term “hydrocarbons boiling in the jet fuel range” may be used interchangeably with the term “jet fuel hydrocarbons” or “jet fuel range hydrocarbons”, or respectively, “jet fuel” or “jet fuel range”. The term means C8-C19 hydrocarbons, such as C8-C17 or C8-C16 hydrocarbons, boiling in the range 175-300°C. For instance, the jet fuel is sustainable aviation fuel (SAF) in compliance with ASTM D7566 and ASTM D4054.

In an embodiment, the hydrocarbon synthesis plant (200) further comprises: - an upgrading section (240), arranged to receive at least a portion of the first product (231) rich in olefins or at least a portion of the raw product (231°) containing hydrocarbons boiling in the boiling in the jet fuel range, and provide a jet fuel product stream (241); - said upgrading section (240) being arranged to provide a by-product stream (242°) rich in paraffins and/or olefins, i.e. another by-product stream (242°) rich in paraffins and/or olefins.

Traditionally, steam reforming of a major hydrocarbon feed gas, such as natural gas, is required upstream a methanol synthesis unit for providing methanol synthesis gas as the syngas feed. The steam reforming unit is typically highly costly in terms of capital and operating expenses, and not least also with a significant carbon footprint. The present application obviates this and instead integrates a reforming system including a reformer which is only dedicated to steam reform a minor hydrocarbon stream, namely the by- product stream rich in paraffins and/or olefins from the ATH synthesis section or upgrading section of the plant, as well as optional off-gas stream(s). The sum of these streams still represents a minor stream being fed to the reforming system. Apart from the benefits associated with enabling a smaller alcohol synthesis unit e.g. methanol loop and/or C2-C4 alcohol synthesis unit as described farther above, a much smaller reformer in the reforming system is required, thereby reducing plant plot size and associated capital and operating expenses. Further, by for instance utilizing electrical steam methane reforming (e-SMR), the unit can be made even more compact and importantly, carbon emission is drastically reduced, as the electrical heating therein may be powered

DK 181610 B1 14 by renewable sources, such as wind, solar or hydropower. Other power sources, such as thermonuclear are also envisaged.

A by-product stream rich in paraffins and/or olefins may thus also be provided by the upgrading section of the plant, e.g. by a hydrocracking reactor (HCR reactor) and/or fractionation unit arranged therein. For instance, such by-product stream rich in paraffins and/or olefins may be a stream rich in propane and/or butane, such as a liquified petroleum gas (LPG) stream. The term “rich in propane and/or butane” means that at least 50%, such as at least 60%, preferably at least 75% of this by-product stream is propane and/or butane. Typically, LPG contains 70-80 vol% butane, 20-30 vol% propane and some other hydrocarbons. Hence, the by-product stream rich in paraffins and/or olefins may be an LPG stream (LPG feed). LPG is typically a mix of lighter hydrocarbons, such as propane and butane. Propylene, butylenes and various other hydrocarbons are usually also present in LPG in small concentrations such as C>He, CH4 etc. An LPG stream may also comprise olefins.

In an embodiment, the hydrocarbon synthesis plant is further arranged to provide any of: one or more off-gas streams, i.e. an off-gas stream, a naphtha stream, or a combination thereof; said one or more off-gas streams (253, 253’) being one or more waste-gas streams rich in CO,, H,, CH4, wherein: - said reforming system is arranged to receive at least a portion of said any of: said one or more off-gas streams, naphtha stream, or a combination thereof; and/or - the C2-C4 alcohol synthesis unit (2207) of the alcohol synthesis unit (220) comprises a bio-catalytic reactor which is arranged to receive at least a portion of said one or more off-gas stream(s).

For the purposes of the present application, an off-gas stream is regarded separately from a by-product stream rich in paraffins and/or olefins. The latter is regarded as a by- product stream, the former as a waste gas stream.

It would be understood that the by-product stream rich in paraffins and/or olefins may be produced in one or more sections of the plant downstream the alcohol synthesis unit, e.g.in the ATH section and/or the upgrading section of the plant.

DK 181610 B1 15

The invention enables also the production of a naphtha stream. For instance, said upgrading section is arranged to provide the naphtha stream.

The term “naphtha stream” or simply “naphtha” may be used interchangeably. The term refers to hydrocarbons boiling in the naphtha boiling range, and means C5-C12 hydrocarbons boiling in the range 30-160°C. For instance, C5-C9 hydrocarbons, such

C5-C8 hydrocarbons, e.g. C5-C8 olefins.

It would be understood that the off-gas stream(s) may also be produced in one or more sections of the plant, including the ATH section and/or the upgrading section of the plant and/or the alcohol synthesis unit of the plant.

Hence, for the purposes of the present application, the off-gas stream(s) is a waste-gas streams comprising CO>, H>, CH4, and optionally higher hydrocarbons etc. which are also produced in the hydrocarbon synthesis plant. For instance, an off-gas stream may come from the methanol synthesis unit (e.g. methanol loop); e.g. the off-gas stream is from a separation unit, such as low pressure separation unit, arranged in the methanol synthesis unit of the alcohol synthesis unit. Other off-gas streams may come from the upgrading section of the hydrocarbon synthesis plant. Other off-gas streams may come from the ATH section of the hydrocarbon synthesis plant producing the raw product containing hydrocarbons boiling in the jet fuel range, for instance from the ATO reactor therein. Other off-gas streams may come from the upgrading section. As already mentioned, the off-gas streams often have no efficient use, apart from using them in fired equipment, such as in fired heaters, which causes CO, emissions. These off-gas streams are now recycled as part of the hydrocarbon synthesis process or plant itself, in order to i.a. improve overall C-efficiency of the plant and process.

The one or more additional off-streams in the plant are arranged to be fed to the reforming system and/or the bio-catalytic reactor of the C2-C4 alcohol synthesis plant, optionally in combination with said by-product stream rich in paraffins and/or olefins.

Further synergetic integration is thereby achieved. Off-gas stream(s) are fed to the reforming system and/or the C2-C4 alcohol synthesis comprising the bio-catalytic reactor i.e. bioreactor. The bioreactor suitably incorporates a bacteria culture which tolerates

DK 181610 B1 16 and even thrives in the presence of off-gas, thereby increasing the yield of C2-C4 alcohol, e.g. EtOH, while at the same time keeping the reforming system small, as the latter does not need to handle such off-gas produced in the hydrocarbon synthesis plant, or only a minor portion thereof.

In an embodiment, the reformer (40) in the reforming system (100) is any of a: steam methane reformer (SMR) i.e. tubular reformer, electrical steam methane reformer (e-

SMR), autothermal reformer (ATR), convection heated reformer such as a heat exchange reformer (HER), and combinations thereof.

Suitably, steam is added to the reforming system upstream the reformer, as for instance shown by process steam 22 in appended Fig. 5.

Hence, in the reforming system receiving the by-product stream rich in paraffins and/or olefins, a primary reformer such as an SMR may be arranged together with e.g. an ATR; or a convection heated reformer (convection reformer) such as a heat exchange reformer (HER) may be arranged together with an ATR. For instance also, an ATR and e-SMR may be arranged together. The arrangement may be in series or in parallel.

The convection reformer may for instance comprise 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 a steam methane reformer (SMR) i.e. a tubular reformer, the heat for reforming is transferred chiefly by radiation in a radiant furnace. In an autothermal reformer (ATR), there is 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.

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”, Ib Dybkjær, Fuel

Processing Technology 42 (1995) 85-107; and EP 0535505 for a description of HTCR.

DK 181610 B1 17

For a description of ATR, see farther below. For a description of e-SMR which is a more recent technology, reference is given to in particular WO 2019/228797 A1.

In an embodiment, the catalyst in the steam reforming unit is a reforming catalyst, e.g. a nickel based catalyst. In an embodiment, the is active for water gas shift reactions.

Examples of reforming catalysts are Ni/MgAl>O4, Ni/AI2O3, Ni/CaAl,04, RU/MgAl2O4,

Rh/MgAl2O4, Ir/MgAlz2O4, Mo>C, Wo,C, CeO», Ni/ZrO,, Ni/MgAlzO:, Ni/CaAl>Os,

Ru/MgAl,Os, or Rh/MgAI>O3, a noble metal on an AL Os carrier, but other catalysts suitable for reforming are also conceivable. The catalytically active material may be Ni,

Ru, Rh, Ir, or a combination thereof, while the ceramic coating may be AlzO3, ZrO»,

MgAl.Os, CaAl>Os, or a combination therefore and potentially mixed with oxides of Y,

Ti, La, or Ce. The maximum temperature of the reactor may be between 850-1300°C.

The pressure of the feed gas may be 15-180 bar, preferably about 25 bar. Steam reforming catalyst is also denoted steam methane reforming catalyst or methane reforming catalyst.

In another embodiment, the reformer (40) in the reforming system (100) is: - an electrical steam methane reformer (e-SMR), which is arranged alone or together with an upstream pre-reformer; or - an autothermal reformer (ATR), which is arranged alone or together with an upstream pre-reformer.

Hence, there is for instance no primary reformer arranged together with the e-SMR in the reforming system), such as a steam methane reformer (SMR) arranged upstream the e-SMR, or a convection heated reformer such as a heat exchange reformer arranged in series or in parallel with the e-SMR. Yet, a pre-reformer (pre-reforming unit) is suitably arranged upstream the e-SMR. Thus, the e-SMR is arranged alone or together with an upstream pre-reformer. Such an arrangement is also referred to stand-alone e-SMR.

Likewise, there is for instance no primary reformer arranged together with the ATR in the reforming system), such as a steam methane reformer (SMR) arranged upstream the e-

ATR, or a convection heated reformer such as a heat exchange reformer arranged in series or in parallel with the ATR. Yet, a pre-reformer (pre-reforming unit) is suitably

DK 181610 B1 18 arranged upstream the ATR. Thus, the ATR is arranged alone or together with an upstream pre-reformer. Such an arrangement is also referred to stand-alone ATR.

An even simpler plant with only a single reformer, optionally including a pre-reformer, is thereby obtained, as so is an even lower carbon footprint particularly where the reformer is an e-SMR, as this can be powered by electricity from renewable sources such as wind, solar, hydro, geothermal, or for instance also, thermonuclear. For the purposes of the present application, the latter source is regarded as renewable.

It has been determined that the by-product stream rich in paraffins and/or olefins, optionally an off-gas stream which is recycled via the reforming system, can be enabled to provide higher efficiency of sustainable feed to jet fuel conversion. With the proposed plant layout, this can be achieved with no or significantly lower CO, emission compared to traditional processes for a similar purpose. Furthermore, the proposed layout also has provided a possibility of reducing the consumption of hydrogen feedstock, thereby increasing hydrogen-efficiency. The production of hydrogen is power consuming and capital cost intensive, e.g. when using an electrolysis unit for producing the hydrogen.

Thus, where electrolysis for producing hydrogen is omitted, the reduction of power consumption in the electrolysis unit more than outweighs the power consumption in the e-SMR resulting in a reduction of power consumption for the overall system. Further, with the provision of the reformer as an e-SMR, arranged alone or together with an upstream pre-reformer, enables no combustion of internal or external hydrocarbons, such as natural gas, thereby avoiding producing carbon dioxide which cannot be captured in the plant.

Further details on e-SMR and ATR are presented below:

In the reforming system, the reforming unit is, in an embodiment, an electrical steam methane reformer (e-SMR). The e-SMR is thus arranged to receive the first reforming feed stream and carry out an electrical steam methane reforming (e-SMR) step, to provide an e-SMR based syngas stream.

DK 181610 B1 19

Use of an e-SMR in this manner allows recycling of the by-product stream rich in paraffins and/or olefins, optionally the off-gas streams, such that additional CO; emissions can be avoided, or significantly minimised.

The e-SMR requires a feed of steam. The e-SMR receives the first reforming feed stream and carries out an electrical steam methane reforming (e-SMR) step, and thereby provides a first syngas stream. e-SMRs use electrical resistance heating to provide sufficient heating of the reactant stream and catalyst for effective reforming reaction to be carried out. The e-SMR preferably comprises a pressure shell housing a structured catalyst, wherein the structured catalyst comprises a macroscopic structure of an electrically conductive material. The macroscopic structure supports a ceramic coating, where said ceramic coating supports a catalytically active material. The reforming step comprises the step of supplying electrical power via electrical conductors connecting an electrical power supply placed outside said pressure shell to said structured catalyst, allowing an electrical current to run through said macroscopic structure material, thereby heating at least part of the structured catalyst to a temperature of at least 500°C.

Suitably, the electrical power supplied to the e-SMR is generated by means of a renewable energy source. Suitable e-SMR for use in reforming system of the present invention are as disclosed in co-pending applications WO2019228797 and

WO/2019/228798.

In a steam reforming process, a stream of hydrocarbons and steam is catalytically reformed to a product stream of hydrogen and carbon oxides; typified by the following reactions:

CH4 + H20 > CO + 3H: AH?298 = -49.3 kcal/mole

CH4 + 2H20 — CO» + 4H> AH?298 = -39.4 kcal/mole

The water gas shift (WGS) reaction may also take place:

CO + H20 & CO, + Hz AH?298 = 41 kJ/mole

DK 181610 B1 20

The reactions are in equilibrium at reactor outlet conditions.

In the reforming system, the reforming unit is, in another embodiment, an ATR. The ATR is thus arranged to receive the first reforming feed stream along with the oxidant stream which includes oxygen from an electrolysis unit, and carry out an autothermal reforming step, to provide e.g. said first ATR-based syngas stream.

Also use of an ATR in this manner allows recycling of e.g. the by-product stream rich in paraffins and/or olefins, optionally off-gas streams, such that additional CO; emissions can be avoided, or significantly minimised.

The main elements of an ATR reactor are a burner, a combustion chamber, and a catalyst bed contained within a refractory lined pressure shell. In an ATR reactor, partial oxidation or combustion of a hydrocarbon feed by sub-stoichiometric amounts of oxygen is followed by steam reforming of the partially combusted hydrocarbon feed stream in a fixed bed of steam reforming catalyst. Steam reforming also takes place to some extent in the combustion chamber due to the high temperature. The steam reforming reaction is accompanied by the water gas shift reaction. Typically, the gas is at or close to equilibrium at the outlet of the ATR reactor with respect to steam reforming and water gas shift reactions. The temperature of the exit gas is typically in the range between 850 and 1100° C. More details of ATR and a full description can be found in the art such as “Studies in Surface Science and Catalysis, Vol. 152,” Synthesis gas production for FT synthesis”; Chapter 4, p.258-352, 2004”.

Suitable process conditions (temperatures, pressures, flow rates etc.) and suitable catalysts for such steam reforming processes are known in the art.

In an embodiment of the invention, as already recited, the hydrocarbon synthesis plant does not comprise steam reforming for preparing the first or second syngas feed.

Optionally, however, the hydrocarbon synthesis plant may be provided with a reverse water gas shift unit (r'WGS unit) arranged upstream the alcohol synthesis unit for preparing said second syngas feed, as it also will become apparent from a below embodiment.

DK 181610 B1 21

Traditionally, steam reforming of a major hydrocarbon feed gas, such as natural gas, is required upstream the methanol synthesis unit for providing a methanol synthesis gas as the syngas feed. The steam reforming unit is typically highly costly in terms of capital and operating expenses, and not least also with a significant carbon footprint. The present application obviates this and instead integrates a reforming system including a reformer which is only dedicated to steam reform a minor hydrocarbon stream, namely the by-product stream rich in paraffins and/or olefins from the ATH synthesis section or upgrading section of the plant, as well as optional off-gas streams. The sum of these streams still represents a minor stream being fed to the reforming system, as at least a portion of the by-product stream rich in C1-C4 paraffins and/or olefins, is advantageously recycled to the ATO reactor, and off-gases are advantageously fed to the C2-C4 alcohol synthesis unit, as explained above.

The first CO» rich feed is provided to the alcohol synthesis unit, such as methanol synthesis unit therein (as mentioned before, this suitably being a methanol synthesis loop, or simply methanol loop, i.e. MeOH loop); and/or to the C2-C4 alcohol synthesis unit therein. For instance, the first CO; rich feed comprises more than 75% CO, such as more than 90% CO, for instance more than 95% CO, or more than 99% CO. The first

CO, rich feed may in addition to CO> comprise minor amounts of, for example, steam, oxygen, nitrogen, oxygenates, amines, ammonia, carbon monoxide, and/or hydrocarbons. The first CO, rich feed suitably comprises only low amounts of hydrocarbon, such as for example less than 5% hydrocarbons or less than 3% hydrocarbons or less than 1% hydrocarbons.

The first Hz rich feed is provided to the to the alcohol synthesis unit, such as methanol synthesis unit therein; and/or to the C2-C4 alcohol synthesis unit therein. Suitably, the first H» rich feed consists essentially of hydrogen. The first H, rich feed of hydrogen is suitably "hydrogen rich” meaning that the major portion of this feed is hydrogen; i.e. over 75%, such as over 85%, preferably over 90%, more preferably over 95%, even more preferably over 99% of this feed is hydrogen.

One source of the first H» rich feed of hydrogen can be one or more electrolyser units.

Accordingly, in an embodiment, the hydrocarbon synthesis plant further comprises:

DK 181610 B1 22 - an electrolysis section comprising: an electrolysis unit (260) arranged to receive a water feedstock (203), i.e. steam and/or water, and provide a second, i.e. another, H» rich feed (202) comprising Hz; optionally as said first Hz rich feed (202) comprising Ha, or a portion thereof as said first

H2 rich feed (202); and/or, an electrolysis unit (250) arranged to receive a second, i.e. another, first CO, rich feed (201°), or said first CO, rich feed (201) comprising CO», or a portion thereof, and provide a CO-enriched feed (204); means such as a mixing unit or junction to combine the first or second H, rich feed (202) comprising Hz with the CO-enriched feed (204), and provide said second syngas feed (205).

In an embodiment, the reformer (40) in the reforming system (100) comprises an ATR, such as a stand-alone ATR, the electrolysis unit (260) arranged to receive a water feedstock (203) provides a first oxygen stream (206), and the hydrocarbon synthesis plant (200) further comprises: means such as a mixing unit or junction to combine a steam stream (207) with the first oxygen stream (206) to provide an oxidant stream (208); and the ATR is arranged to receive said oxidant stream (208).

Suitably also, the electrolysis unit arranged to receive a second CO, rich feed (201), or said first CO, rich feed (201) comprising CO,, or a portion thereof, provides a second oxygen stream, and the hydrocarbon synthesis plant further comprises: means such as mixing unit or junction to combine the first and/or second oxygen streams, with said steam stream, to provide the oxidant stream.

Thereby, there is provided a high integration of process streams in the plant, while at the same time eliminating the need of providing a large and expensive air separation unit (ASU), typically required for the generation of the oxygen needed when the reformer is an ATR.

Suitably also, a portion of the second CO, rich feed, or a portion of the first CO rich feed, may bypass the electrolysis unit and combine with the CO-enriched feed stream. Some

CO, is required in the syngas feed, here the second syngas feed, so the by-pass enables adjusting the syngas feed module M=(H>-CO2)/(CO+CO») and CO» content for optimum

DK 181610 B1 23 performance of a methanol synthesis unit arranged downstream in the alcohol synthesis unit. In a particular embodiment, up to 10% of the first or second CO>-rich feed bypasses the electrolysis unit.

In addition to hydrogen, the first or second H>-rich feed may for example comprise steam, nitrogen, argon, carbon monoxide, carbon dioxide, and/or hydrocarbons. In some cases, a minor content of oxygen may be present in this first or second H, rich feed, typically less than 100 ppm. The first or second H, rich feed suitably comprises only low amounts of hydrocarbon, such as for example less than 5% hydrocarbons or less than 3% hydrocarbons or less than 1% hydrocarbons.

Suitably, there is also provided a purification section to remove impurities such as oxygen and hydrocarbons from the first or second H» rich feed. Suitably also, there is a purification section to remove impurities such as sulfur containing compounds e.g. COS, from e.g. the first CO, rich feed.

The first CO, rich feed and the first H» rich feed are — in one aspect— combined into said first syngas feed prior to being fed to the alcohol synthesis unit.

For instance, the alcohol synthesis plant comprises an methanol synthesis unit, being arranged to receive the first CO, rich feed and first H» rich feed, or the first syngas feed which combines the first CO; rich feed and first H» rich feed, as well as the reformer- based syngas from the reforming system, suitably the second reformer-based syngas therefrom. An effluent stream comprising methanol is obtained. The process of converting the first CO» rich and first Hy rich streams can occur, for example by compressing them in a first syngas feed compressor and sending the compressed, combined gas as first syngas feed through e.g. a boiling water methanol reactor as one embodiment of a methanol reactor in the methanol synthesis unit, and where at least a portion of the CO, CO» and H, is converted to methanol followed by a condensation section separating the purge gas stream from the methanol in a liquid phase.

The raw methanol stream, i.e., the effluent stream comprising methanol 211, comprises a major portion of methanol; i.e. over 50 wt%, such as over 75 wt%, preferably over 85 wt%, more preferably over 90 wt% of this feed is methanol. Other minor components of

DK 181610 B1 24 this stream include but not limited to, higher alcohols, ketones, aldehydes, DME, organic acids and dissolved gases. The raw methanol comprises also water, which normally requires removal e.g. by distillation in order to purify the stream into a stream comprising more than 90% wt methanol. For instance, raw methanol from pure H> and CO; would comprise about 50 wt% water. Hence, a water separation section is suitably located between the methanol synthesis unit (220) and the C2-C4 alcohol synthesis unit (2207), and being arranged to remove water from the effluent stream (211) comprising methanol.

A water separation section is suitably also located between the C2-C4 alcohol synthesis unit (220”), e.g. an EtOH synthesis unit, and the ATH synthesis section (230), and being arranged to remove water from the effluent stream (221) comprising a C2-C4 alcohol, e.g. EtOH.

The invention enables reducing the production of such water and thereby significantly reduce the requirements for water removal, which are normally high in terms of operation and capital costs due to the high miscibility of water in methanol and EtOH. Further, as also explained previously, the presence of water in the downstream ATO reactor in the

ATH section of the plant is undesirable. The invention enables therefore also in a simple manner to protect the ATO reactor downstream.

As recited, a second syngas feed comprising a carbon oxide and hydrogen may also be provided to the methanol synthesis unit. This second syngas feed is suitably provided by combining the second H» rich feed and the CO-enriched feed generated in the electrolysis section.

This also ensures a higher molar ratio CO/CO, to the alcohol synthesis unit, suitably to the methanol synthesis unit therein, and/or the C2-C4 alcohol synthesis unit therein, which is superior than e.g. simply providing a CO»-rich feed by enabling a lower catalyst volume, less water formation and thus less need for purification downstream to remove it, and thereby also a smaller alcohol synthesis unit, e.g. smaller MeOH loop.

In an embodiment, the hydrocarbon synthesis plant further comprises: - a thermal decomposition unit, such as a gasification unit, arranged to receive a biomass feedstock to provide a crude syngas feed, and a crude syngas purification section arranged to receive the crude syngas feed and to provide said second syngas feed.

DK 181610 B1 25

Suitably, at least a portion of the first and/or second oxygen streams from the electrolysis section, is provided to the thermal gasification unit, such as gasification unit.

The thermal decomposition unit is not a primary reforming unit. It would be understood that the latter, e.g. SMR (tubular reformer), or a convection heated reformer such as a heat exchange reformer, comprises a catalyst arranged as a fixed bed for converting a hydrocarbon feed gas into syngas.

Typically, where there is a gasification for producing a syngas feed for downstream methanol production, the syngas feed is subjected to a shifting step i.e. water gas shift step (WGS step) in a WGS section for changing the composition of the syngas according to the reaction CO+H20 = CO>+H>. The WGS may either be sweet (without sulfur in the syngas) our sour (including sulfur in the syngas). Finally, some of the CO, is removed in a CO; removal section, which is a highly large unit with concomitant high capital and operating expenses. Further, this results in venting CO» from the process. For adjusting of the module M=(H>-CO2)/(CO+CO») of the syngas feed to the desired level of about 2.0 for e.g. the downstream methanol synthesis, typically part of the syngas bypasses the WGS step and the CO, removal.

By the present invention, the second syngas feed may be combined with reformer-based syngas stream, e.g. the first, second or third reformer-based syngas stream of the reforming system, to adjust the feed to the methanol synthesis unit. The need of a WGS section and CO>-removal section on the second syngas feed may thus be eliminated.

The term “thermal decomposition” means any decomposition process, in which a material is partially decomposed at elevated temperature, typically 250°C to 800°C or perhaps 1000°C, in the presence of sub-stoichiometric amount of oxygen (including no oxygen). The product will typically be a combined liquid and gaseous stream, as well as an amount of solid char. The term shall be construed to include processes known as gasification, pyrolysis, partial combustion, or hydrothermal liquefaction.

In a particular embodiment, the thermal decomposition is gasification. Thus, the thermal decomposition unit is a gasification unit. The gasification is suitably conducted under the

DK 181610 B1 26 presence of a gasification agent such as oxygen, steam, carbon dioxide, or a combination thereof. Suitably also, the gasification agent is produced in the process; for instance, oxygen is provided by electrolysis and steam from the methanol conversion step in the methanol synthesis unit.

In the crude syngas purification section, under the addition of e.g. water, impurities such as heavy metals, silica, sulfur, which may be detrimental for downstream units and corresponding process steps are removed.

The term “biomass feedstock” means renewable feed, in particular a solid renewable feed. The solid renewable feed is: - a lignocellulosic biomass including: wood products, forestry waste, and agricultural residue; and/or - refused derived fuel (RDF) including municipal waste, i.e. municipal solid waste, in particular the organic portion thereof.

The term “lignocellulosic biomass” means a biomass containing, cellulose, hemicellulose and optionally also lignin. The lignin or a significant portion thereof may have been removed, for instance by a prior bleaching step. The lignocellulosic biomass is forestry waste and/or agricultural residue and comprises biomass originating from plants including grass such as nature grass (grass originating from natural landscape), wheat e.g. wheat straw, oats, rye, reed grass, bamboo, sugar cane or sugar cane derivatives such as bagasse, maize and other cereals.

The term “refused derived fuel (RDF)” means a fuel produced from various types of waste, such as municipal solid waste (MSW), industrial waste or commercial waste. In accordance with the definition provided by Wikipedia.org as of 25 April 2022, RDF consists largely of combustible components of such waste, as non-recyclable plastics (not including PVC), paper cardboard, labels, and other corrugated materials. These fractions are separated by different processing steps, such as screening, air classification, ballistic separation, separation of ferrous and non-ferrous materials, glass, stones and other foreign materials and shredding into a uniform grain size, or also pelletized in order to produce a homogeneous material which can be used as

DK 181610 B1 27 substitute for fossil fuels in e.g. cement plants, lime plants, coal fired power plants or as reduction agent in steel furnaces.

The term “municipal solid waste (MSW)” means trash or garbage thrown away as everyday items from homes, school, hospitals and business. Municipal solid waste includes packaging, newspapers, clothing, appliances, and food rests.

The second syngas feed is rich in CO, for instance (by mole or volume, dry basis): 40- 70 % such as 60% CO, 1-10 % CO, such as 5%, 20-40% H: such as 30% H,, the balance being inerts: N>+Ar, and H»S. The high molar ratio of CO/CO, in the second syngas feed thus provides the same benefits of having a high CO/CO» molar ratio recited above.

The reformer-based syngas generated by reforming the stream rich in paraffins and/or olefins contains CO, CO, and H», has a composition which also ensures a CO/CO, molar ratio, needed for lower methanol catalyst volume and thereby, smaller methanol synthesis unit, e.g. smaller MeOH loop. For instance, the composition of a first e-SMR syngas stream, which is the syngas withdrawn from an e-SMR in the reforming system, is (by volume, dry basis): 40-70% H», 10-30% CO, 2-20% CO», 0.5-5% CHa.

To obtain an optimized yield in the methanol production, the stoichiometry of H., CO and

CO» needs to be considered. Hence, in an embodiment, the first or second syngas feed has a molar ratio CO/CO, greater than 1, such as greater than 2, e.g. 10 or higher.

Suitably also, the first or second syngas feed has module M=(H>-CO2)/(CO+CO») defined in terms of molar content, in the range 1.80-2.20, such as 1.95-2.10. Similarly, the reformed-based syngas, e.g. the first and second reformer-based syngas streams, may have a molar ratio CO/CO; greater than 2, such as 10 or higher. Suitably also, the reformer-based syngas has a module M=(H>-CO>)/(CO+CO») in the range 1.80-2.40, such as 1.95-2.10.

In an embodiment, the hydrocarbon synthesis plant (200) comprises: - a reverse water gas shift ((WGS) unit, preferably an electrical r'wWGS unit (e-rWGS) unit, arranged to receive a portion of said first CO, rich feed (201) comprising CO, and a portion of said first H rich feed (202) comprising Hz, to provide a rWGS syngas feed; and means such as a mixing unit or junction to combine the rWGS syngas feed with the

DK 181610 B1 28 remaining portion of: said first CO, rich feed (201) comprising CO» and said first H rich feed (202) comprising H>, and provide said second syngas feed. In a particular embodiment, the rWGS is also arranged to receive a portion of said by-product stream (242, 242’) rich in paraffins.

The rWGS reaction CO; + H, = CO + HO is endothermic, requiring a significant heat input. The r'WGS unit is thus preferably electrically heated (e-rWGS unit). In that case, optionally a portion of the by-product stream rich in paraffins and/or olefins, optionally also a portion of the off-gas stream is sent to the e-rWWGS unit, since the e-r'WGS unit may also enable some steam reforming of these streams.

For details on e-rWGS, reference is given to e.g. applicant's WO 2022079098 (e-RWGS section therein).

The first or second syngas feed as well as the reformer-based syngas may be combined and fed to the alcohol synthesis unit.

Accordingly, in an embodiment, the at least a portion of said reformer-based syngas stream (41, 51, 53, 62), such said first, second or third syngas stream (51, 53, 62), is arranged to be fed to the inlet of the alcohol synthesis unit, suitably to the inlet of the C2-

C4 alcohol synthesis unit, in admixture with said CO, rich feed and/or said H, rich feed, or in admixture with said first syngas feed, or in admixture with said second syngas feed.

In an embodiment, the alcohol synthesis unit (220) is arranged for the reformer-based syngas stream (41, 51, 53, 62) being up to up to 25% by volume basis, such as 5, 10, 15, 20% of the inlet of the alcohol synthesis unit (220).:

In an embodiment, the alcohol synthesis unit, such as the methanol synthesis unit (220) therein, is arranged to provide an excess hydrogen stream, i.e. excess hydrogen stream from the methanol synthesis unit (220); the plant (200) further comprises in said reforming system (100) a hydrogenation section (11), and said hydrogenation section is arranged to receive excess hydrogen stream from the methanol synthesis unit.

DK 181610 B1 29

In the hydrogenation section 10, e.g. in a hydrogenator, while hydrogen or a hydrogen- rich stream such as said excess hydrogen stream from the methanol synthesis unit may be added to the hydrogenation section, there is suitably no addition of a diluting stream, e.g. a dilution gas, to this section e.g. to the hydrogenator, or to the reforming feed to the hydrogenator.

The provision of the excess hydrogen stream from e.g. the methanol synthesis unit enables a simpler layout in the reforming system by eliminating the need e.g. a hydrogen recovery section in the reforming system of the plant to provide a hydrogen rich stream and thereby also a hydrogen compressor to send the hydrogen rich stream to the hydrogenation section of the reforming system.

In an embodiment, the reforming system of the plant further comprises a separation section arranged to receive at least a portion of said first reformer-based syngas stream and separate it into at least said second reformer-based syngas stream and a process condensate. This separation section advantageously removes water from the first syngas stream, which is detrimental for its use in methanol synthesis.

The reforming system may comprise said hydrogenation section, which is arranged to receive the first reforming feed stream, i.e. the by-product stream rich in paraffins and/or olefins, optionally also an off-gas stream, and provide a hydrogenated first reforming feed stream. In the hydrogenation section, the first reforming feed stream is mixed with a hydrogen feed, suitably an excess hydrogen stream from the methanol synthesis unit of the plant, as earlier recited, and passed over a catalyst active in hydrogenation. Again, the provision of excess hydrogen stream from the methanol synthesis unit enables a simpler layout without the need of a hydrogen recovery section in the reformer-based syngas to provide a hydrogen rich stream and thereby a hydrogen compressor to send the hydrogen rich stream to the hydrogenation section, as e.g. illustrated in appended

Fig. 5. The hydrogenation section may comprise one or more hydrogenation reactors in series. Hydrogenation converts unsaturated hydrocarbon components, such as olefins, e.g. as propylene or butylene, to the corresponding saturated hydrocarbons, which can reduce or avoid carbon formation (in a reforming step) by converting olefins into alkanes.

Hydrogenation catalysts and reactors suitable for such processes are commercially available and known to the skilled person.

DK 181610 B1 30

The reforming system may also comprise a desulfurisation section arranged to receive the hydrogenated first reforming feed stream, and provide a desulfurised first and/or second reforming feed stream. Typically, the desulfurisation section comprises one or more hydrodesulfurization (HDS) reactors. Desulfurisation converts sulfur-containing compounds in the first stream to hydrocarbons (typically saturated hydrocarbons) and sulfur-containing compounds (e.g., H>S) as by-product. This can reduce catalyst poisoning in subsequent conversion steps. Desulfurisation catalysts and reactors suitable for such processes are commercially available and known to the skilled person.

Substances other than sulfur that might need to be removed in such a purification step include chlorine, dust and heavy metals.

A pre-reforming section, i.e. a pre-reformer (or interchangeably, a pre-reforming unit), may be arranged to receive the first reforming feed stream and carry out a pre-reforming step. A pre-reformed stream is provided. Pre-reforming is an additional reforming step, which allows a syngas with a desired composition to ultimately be obtained, i.e. in which higher hydrocarbons are converted to methane. Pre-reforming suitably takes place at ca. 350-700°C to convert higher hydrocarbons as an initial step. Pre-reforming catalysts and reactors suitable for such processes are commercially available and known to the skilled person. Pre-reformer units used in the present invention are catalyst-containing reactor vessels, and are typically adiabatic. In the pre-reforming units, heavier hydrocarbon components in the hydrocarbon feedstock are steam reformed and the products of the heavier hydrocarbon reforming are methanated. The skilled person can construct and operate suitable pre-reformer units as required. Pre-reformer units suitable for use in the present system/process are provided in applicant's co-pending applications

EP20201822 and EP21153815. The pre-reformed stream comprises methane, hydrogen, carbon monoxide and also carbon dioxide. The pre-reformed stream at the outlet of the prereformer may be in the temperature range: 400°C-500°C.

As the first reformer-based syngas stream is at an elevated temperature (e.g. 900- 1100°C) at the outlet of the reformer, it can advantageously be heat-exchanged with upstream components in the system, for effective energy use in the reforming system.

The reforming system may therefore comprise one or more heat exchangers, being arranged to provide heat exchange between the first syngas stream and one or more of:

DK 181610 B1 31 the first reforming feed stream, the desulfurised first reforming feed stream and boiler feed water stream. Suitably, the first reformer-based syngas stream is heat exchanged with the desulfurised first reforming feed stream first, then a boiler feed water stream, and then with the first reforming feed stream. Alternatively, or additionally, one or more electrical heaters may be used to raise the temperature of one or more of: the first reforming feed stream, the hydrogenated first reforming feed stream, the desulfurised first reforming feed stream and boiler feed water stream.

As explained above, the reforming system may further comprise a second reforming feed stream being an off-gas stream comprising CO», H> and CHa, said second stream suitably being arranged to be mixed with the first reforming feed stream, upstream the inlet of the reformer, for instance upstream the inlet of an e-SMR or an ATR

In an embodiment, the reforming system comprises a hydrogen recovery section, said hydrogen recovery section being arranged to receive at least a portion of the second reformer-based based syngas stream and provide at least a hydrogen-rich stream and a fourth reformer-based syngas stream; and at least a portion of the second reformer- based syngas stream and at least a portion of the fourth reformer-based syngas stream are arranged to be combined to a combined syngas stream as said third reformer-based syngas stream. The hydrogen recovery section may comprise a membrane hydrogen separation unit or a PSA (pressure swing adsorption) unit or both.

At least a portion of the hydrogen-rich stream obtained from the hydrogen recovery section and/or a portion of the second syngas stream from the separation section may be used in the hydrogenation section of the reforming system. Therefore, at least a portion of the hydrogen-rich stream may be combined with e.g. the first reforming feed stream upstream the hydrogenation section. Alternatively, or additionally, recovered H» can also be used in the hydrogenation reactor (HYDRO reactor) of the ATH synthesis section.

Further integration and improved hydrogen-efficiency - by internal sourcing of hydrogen -, of the hydrocarbon synthesis plant is thereby also achieved.

DK 181610 B1 32

As recited, the jet fuel product stream is suitably in accordance with the requirements to qualify as a sustainable aviation fuel (SAF), in compliance with ASTM D7566 and

ASTM D4054.

The invention provides also a process for hydrocarbon synthesis of a first CO; rich feed (201) comprising CO», and a first H» rich feed (202) comprising H., or of a first syngas feed (209) which combines said first CO; rich feed (201) and said first Hz rich feed (202); or of a second syngas feed (205) comprising a carbon oxide and hydrogen, said process comprising the steps of: - providing a hydrocarbon synthesis plant (200), according to any one of the above plant embodiments; - supplying CO, rich feed (201) and H, rich feed (202), or said first syngas feed; or said second syngas feed (205), to the alcohol synthesis unit (220), and providing an effluent stream (221) comprising a C2-C4 alcohol, such as any of a C2-C4 alcohol or combinations thereof; - supplying at least a portion of the effluent stream (221) comprising a C2-C4 alcohol from the alcohol synthesis unit (220) to the alcohol-to-hydrocarbons (ATH) synthesis section (230), the ATH synthesis section (230) comprising an alcohol-to-olefin reactor (ATO reactor), and providing first product (231) rich in olefins (as said hydrocarbon), suitably the first product (231) containing at least 50 wt% C2-C9 olefins; and further withdrawing from said ATH synthesis section (230) a by-product stream (242) rich in C1-

C4 paraffins and/or olefins, such as any of: methane, ethane, ethene (ethylene), propane, propene (propylene), butane, butene (butylene, and combinations thereof; - supplying at least a portion of a first reforming feed stream (1) as said by-product stream (242) rich in C1-C4 paraffins and/or olefins, to reforming system (100), performing a reforming step in reforming unit (reformer, 40), and providing a reformer-based syngas stream (41, 51, 53, 62), such as a first, second or third reformer-based syngas stream (41, 51, 53); said first reforming feed (1, 242) being less than 15 wt% of said first product (231) rich in olefins; - supplying at least a portion of said reformer-based syngas stream (41, 51, 53, 62) to the inlet of the alcohol synthesis unit (220);

DK 181610 B1 33

In an embodiment, the reformer-based syngas stream (41, 51, 53, 62) is up to up to 50% by volume basis, such as 15-45%, e.g. 20-40% of the inlet of the alcohol synthesis unit (220).

In an embodiment, the process does not comprise steam reforming of a hydrocarbon feed gas for proving said first (209) or said second syngas feed (205).

In an embodiment, the alcohol synthesis unit (220) comprises a methanol synthesis unit (220) and a C2-C4 alcohol synthesis unit (2207), and the process further comprises: - supplying to the methanol synthesis unit (220°): the first CO, rich feed (201) and the first H rich feed (202); or the first syngas feed (209), or the second syngas feed (205); and providing effluent stream (211) comprising methanol; - supplying to the C2-C4 alcohol synthesis unit (2207) the effluent stream (211) comprising methanol and providing the effluent stream (221) comprising a C2-C4 alcohol; and - supplying, i.e. feeding, the at least a portion of said reformer-based syngas stream (41, 51, 53, 62) to the inlet of the C2-C4 alcohol synthesis unit (220”).

In an embodiment, a portion representing 50 vol% or less of said reformer-based syngas stream (41, 51, 53, 62) is arranged to be fed to the inlet of the methanol synthesis unit (220).

In an embodiment, the process further comprises supplying any of: one or more off-gas streams, a naphtha stream, or a combination thereof; said one or more off-gas streams being one or more waste-gas streams rich in CO,, H,, CH,; to said reforming system.

Accordingly, the first reforming feed stream also comprises any of: one or more off-gas streams (253, 253’), a naphtha stream, or a combination thereof.

It would be understood, that any of the embodiments and associated benefits in connection with the hydrocarbon synthesis plant, are applicable to the process, and thus may be used in connection with the corresponding embodiments of the process; or viceversa.

DK 181610 B1 34

The technology is illustrated by means of the following schematic illustrations, in which:

Fig. 1 shows an embodiment of a hydrocarbon synthesis plant according to the invention, in which the hydrocarbon product is a first product rich in olefins.

Fig. 2 shows an embodiment of a hydrocarbon synthesis plant according to the invention, in which the hydrocarbon product is a jet fuel product stream.

Fig. 3 shows another embodiment of a hydrocarbon synthesis plant according to the invention, in which the hydrocarbon product is a jet fuel product stream and the alcohol synthesis unit is a C2-C4 synthesis unit.

Fig. 4 shows another embodiment of a hydrocarbon synthesis plant according to the invention, in which the hydrocarbon product is a jet fuel product stream, and a second syngas feed comprising a carbon oxide and hydrogen is fed to the plant.

Figure 5 shows an embodiment of the reforming system of the invention.

Fig. 1 shows a jet fuel synthesis plant 200 according to the invention. A reforming system 100, as per Fig. 5 is provided to make advantageous recycling of the first reforming feed stream 1 possible. It would be understood, that in the plant 200, stream 242, 242’ (see also Fig. 2) correspond to the first reforming feed stream 1 in Fig. 5. It would also be understood that a reforming feed stream may also be provided as one or more off-gas streams 253, 253’. A first CO; rich feed 201 comprising CO, and a first H, rich feed 202 comprising Ha, suitably after combining them into a first syngas feed 209, are sent to alcohol synthesis unit 220 comprising methanol synthesis unit 220 (e.g. methanol loop 220’) and C2-C4 alcohol synthesis unit 220”, from which an effluent stream 221 comprising a C2-C4 alcohol, such as any of a C2-C4 alcohol or combinations thereof, for instance ethanol (EtOH) is provided. The effluent stream 221 is supplied to alcohol- to-hydrocarbons (ATH) synthesis section 230 comprising an alcohol-to-olefin reactor (ATO reactor, not shown) to provide first product (231) rich in olefins. The ATH synthesis section (230) is further arranged to provide a by-product stream (242) rich in C1-C4

DK 181610 B1 35 paraffins and/or olefins, such as any of: methane, ethane, ethene (ethylene), propane, propene (propylene), butane, butene (butylene), and combinations thereof, and which is fed to reforming system 100, whereby a reformer-based stream such as third e-SMR based syngas stream 53 (see also Fig. 5) is provided. This stream is then fed to inlet of the alcohol synthesis unit (220), suitably to the inlet of the C2-C4 alcohol synthesis unit 220”. From the reforming system 100, the first or second reformer-based stream, such as first or second e-SMR based syngas stream 41, 51 of Fig. 5 (not shown here), may also be recycled to the alcohol synthesis unit 220. Further, the hydrocarbon synthesis plant (200) does not comprise a reforming unit arranged upstream the alcohol synthesis unit (220) for providing said first (209). The reformer-based, syngas, such as here illustrated as stream 53, is a minor syngas stream compared with the major syngas stream thereto, namely the first syngas feed (resulting from combining the first CO, rich feed 201 and the first H,» rich feed 202; or compared with a second syngas feed 205 resulting from combining electrolysis of CO2 and water/steam, as illustrated in Fig. 4, or for instance also by the thermal decomposition of a biomass feedstock, i.e. a solid renewable feed.

Fig. 2 shows a hydrocarbon synthesis plant 200 according to another embodiment of the invention. A reforming system 100, as per Fig. 5 is provided to make advantageous recycling of the first reforming feed stream 1 possible. It would be understood, that in the plant 200 of Fig. 2, stream 242, 242’ corresponds to the first reforming feed stream 1 in

Fig. 5. It would also be understood that a reforming feed stream may also be provided as one or more off-gas streams 253, 253’. A first CO, rich feed 201 comprising CO, and a first Hz rich feed 202 comprising Ha, suitably after combining them into a first syngas feed 209 (not shown), are sent to alcohol synthesis unit 220 comprising methanol synthesis unit 220’ (e.g. methanol loop 220’) and C2-C4 alcohol synthesis unit 220”, from which an effluent stream 221 comprising a C2-C4 alcohol, such as any of a C2-C4 alcohol or combinations thereof, for instance ethanol (EtOH) is provided. A portion of the first CO» rich feed 201, and/or a portion of the first H, rich feed 202 comprising H> may be fed to the C2-C4 alcohol synthesis unit 220”, as shown in the figure. From the alcohol synthesis unit 220 an off-gas stream 253 is generated and fed to the reforming system 100, as so is another off-gas stream 253’ from downstream upgrading section 240. The effluent stream 221 comprising a C2-C4 alcohol 221 is supplied to ATH synthesis section 230, which apart from the ATO reactor (not shown), also may comprise an olefin reactor

DK 181610 B1 36 (OLI reactor, not shown) and a hydrogenation reactor (HYDRO reactor, not shown), thereby providing raw product 231’ containing hydrocarbons boiling in the jet fuel range, namely C8-C19, e.g. C8-C16. From ATH section 230 (here an alcohol to jet fuel section, i.e. ATJ section), suitably between the OLI and HYDRO reactor therein, and/or downstream a HYDRO reactor, a by-product stream rich in paraffins and/or olefins 1, 242 is fed to the reforming system 100. Downstream upgrading section 240 may also provide a by-product stream 242’ rich in paraffins and/or olefins. The raw product 231° containing hydrocarbons in the jet fuel range is fed to the upgrading section 240, where it is upgraded to a jet fuel product stream 241 under optional generation of an off-gas stream 253’. The by-product stream rich in paraffins and/or olefins 242, 242’ is fed to a system 100 as described above, and a reformer-based stream such as third e-SMR based syngas stream 53 is provided, which is then fed to the inlet of the C2-C4 alcohol synthesis unit 220” of the alcohol synthesis unit 220. A portion (not shown) of said reformer-based syngas stream 53 may also be fed to the inlet of the methanol synthesis unit 220’. From the reforming system 100, the first or second reformer-based stream, such as first or second e-SMR based syngas stream (41, 51), may also be fed to the C2-

C4 alcohol synthesis unit 220” (not shown).

Fig. 3 illustrates a hydrocarbon synthesis plant 200 according to another embodiment of the invention, in which a jet fuel product stream 241 is produced, and in which the alcohol synthesis unit 220 is a C2-C4 alcohol synthesis unit 220” arranged to receive the first

CO, rich feed 201 and the first H rich feed 202, or arranged to receive the first syngas feed 209 (not shown here, see Fig. 1), or arranged to receive the second syngas feed 205 (see Fig. 4), and provide said effluent stream 221 comprising a C2-C4 alcohol. The alcohol synthesis unit 220 is absent of a methanol synthesis unit upstream the C2-C4 alcohol synthesis unit 220”. Accordingly, the C2-C4 alcohol synthesis unit 220” arranged to directly receive the first CO» rich feed 201 and the first H, rich feed 202, or arranged to directly receive the first syngas feed 209, or arranged to directly receive the second syngas feed 205, and provide said effluent stream 221 comprising a C2-C4 alcohol. The

C2-C4 alcohol synthesis unit 220” is suitably a catalytic or bio-catalytic synthesis unt. An

ATH section 230 and upgrading section 240 are provided as in Fig. 2 for producing the raw product 231’ containing hydrocarbons boiling in the jet fuel range and then the jet fuel product stream 241, as so is the reforming system 100 as also explained in

DK 181610 B1 37 connection with Fig. 2 and for which additional details are presented in connection with

Fig. 5.

Fig. 4 illustrates a hydrocarbon synthesis plant 200 as in Fig. 2 or 3, in which the alcohol synthesis unit 220 is now fed with second syngas feed 205. The plant 200 comprises an electrolysis unit 260 arranged to receive a water feedstock 203, i.e. steam and/or water, and provide a second H- rich feed 202’ comprising Ha; optionally as said first H, rich feed 202, as well as first oxygen stream 206. The plant 200 further comprises an electrolysis unit 250 arranged to receive a second CO, rich feed 201’, or the first CO, rich feed 201 of Fig. 2 comprising CO,, or a portion thereof, and provide a CO-enriched feed stream 204, as well as second oxygen stream 206’. Suitably also, a portion of the second CO rich feed 201° may bypass the electrolysis unit 250 and combine with the CO-enriched feed stream 204 (not shown). A mixing unit or junction (not shown), serves to combine streams 202’ and 204 into second syngas feed 205, having a molar ratio of CO/CO: higher than 1, for instance 10 or higher, thus also enabling a more reactive syngas for alcohol synthesis unit 220. A mixing unit or junction (not shown) combine a steam stream 207 with first oxygen stream 206 and/or second oxygen stream 206’, to provide an oxidant stream 208, which may be fed to reforming system 100, suitably where the reformer 40 is an autothermal reformer (ATR). The third reformer-based syngas 53 is suitably admixed to the second syngas feed 205 (not shown) to provide a more reactive feed gas to the inlet to alcohol synthesis unit 220, or to the inlet of C2-C4 alcohol synthesis unit 220” therein (not shown).

Fig. 5 shows a layout of the reforming system 100. A first reforming feed stream 1, corresponding to by-product stream 242, 242’ rich in paraffins and/or olefins in Fig. 2, is compressed in first pump 69. It would also be understood that the reforming feed may also be provided as one or more off-gas streams 253, 253’. The compressed first reforming feed stream is — in this layout — mixed with hydrogen rich stream 61 at mixer 68 before being passed through heat exchangers 64, 63 to heat exchange with the first syngas stream 41. The heated first reforming feed stream 1 is hydrogenated in hydrogenation section 10 to provide a hydrogenated first reforming feed stream 11 which is subsequently desulfurised in desulfurisation section 20, to provide a desulfurised first reforming feed stream 21. As shown in Fig. 5, In the hydrogenation section 10, e.g. in a hydrogenator, while hydrogen or a hydrogen-rich stream such as stream 61 may be

DK 181610 B1 38 added to the hydrogenation section 10, there is suitably no addition of a diluting stream, e.g. a dilution gas, to this section e.g. to the hydrogenator or to the reforming feed to the hydrogenator. The desulfurised first reforming feed stream 21 may be mixed with process steam 22, and the mixed stream is again heat exchanged with the first syngas stream 41. The desulfurised first reforming feed stream 21 is pre-reformed in pre- reforming section 30, to provide a pre-reformed stream 31. Electrical steam methane reforming (e-SMR) is performed on the pre-reformed stream 31 in electrical steam methane reformer (e-SMR, 40), for which electrical power is illustrated by the “lightning” symbol, to provide an e-SMR based syngas stream, such as a first syngas stream 41.

First syngas stream 41 is then heat exchanged with boiler feed water 90 in waste heat boiler 62, providing export steam 91. The export steam 91 may suitably be used as feed for an electrolysis unit of the plant. Subsequently, first syngas stream 41 is passed through heat exchangers 64, 63 (as noted above), and then heat-exchanged once more with boiler feed water 90 in heat exchanger 65. Additional cooling takes place in cooling unit 66. The first e-SMR based syngas stream 41 is passed to a separation section 50 where it is separated into at least a second e-SMR based syngas stream 51 and a process condensate 52.

A portion of the second syngas stream 51 is optionally passed to hydrogen recovery section 60, where a hydrogen-rich stream 61 is separated and a fourth e-SMR based syngas stream 62 is provided. A portion of the second e-SMR based syngas stream 51 and a portion of the fourth e-SMR based syngas stream 62 are combined to a combined e-SMR based syngas stream, namely third e-SMR based syngas stream 53. The hydrogen-rich stream 61 is compressed at compressor 67, and then combined with the first reforming feed stream 1 upstream the hydrogenation section 10 (as noted above).

Overall, in the illustrated system of Fig. 5, first feed rich in paraffins, optionally also an off-gas stream, to the reforming plant are hydrogenated, desulfurized and pre-reformed before sending it to e-SMR. The effluent stream from the e-SMR (first e-SMR based syngas stream) gets cooled in series of heat exchangers by pre-reformer feed preheat, steam generation in waste heat boiler, feed preheater, first feed vaporizer, preheating of boiler feed water etc. The water in the effluent stream gets condensed and then separated, thereby providing a second e-SMR based syngas stream. A part of e-SMR based syngas is then used for H2 recovery for internal use for hydrogenation and pre-

DK 181610 B1 39 reforming, or for the HYDRO reactor in the ATH synthesis section of the plant (Fig. 1-4).

The rest of the e-SMR based syngas is sent as a third e-SMR based syngas stream to e.g. the alcohol synthesis unit of the plant.

The present invention has been described with reference to a number of embodiments and figures. However, the skilled person is able to select and combine various embodiments within the scope of the invention, which is defined by the appended claims.

All documents referenced herein are incorporated by reference.

Claims

DK 181610 B1 40 PATENT CLAIM

1. Hydrocarbon synthesis plant (200), which comprises: - a first CO»-rich supply (201), which comprises CO», to said plant, a first H>-rich supply (202), which comprises Ho, to said plant, or a first synthesis gas feed (209) combining the first CO»-rich feed (201) and the first H>-rich feed (202), or a second synthesis gas feed (205) comprising a carbon monoxide and hydrogen, to said plant , - an alcohol synthesis unit (220) arranged to receive the first CO»-rich feed (201) and the first H»-rich feed (202), or arranged to receive the first synthesis gas feed (209), or — adapted to receive the second synthesis gas feed (205) and provide an effluent stream (221) comprising a C>-C4 alcohol, - an alcohol-to-hydrocarbon (ATH) synthesis section (230) adapted to receive at least a portion of the effluent stream (221) comprising a C>-C4 alcohol, which ATH synthesis section (230) comprises an alcohol-to-olefin reactor (ATO reactor) to provide a first product (231 ), which is rich in olefins, said ATH synthesis section (230) being further arranged to provide a by-product stream (242) which is rich in C+-Cs paraffins and/or -olefins, - a reforming system (100) for reforming said by-product stream (242) rich in C1-Cs paraffins and/or olefins, said reforming system (100) comprising: a first reforming feed stream (1) as said by-product stream (242) rich in C1-C4 - paraffins and/or olefins, a reforming unit (40) arranged to receive the by-product stream (1, 242) rich in C+-C4 paraffins and/or olefins, perform a steam reforming step and provide a reformer-based synthesis gas stream (41, 51, 53, 62), and where said reforming system (100) is further arranged so that said first reforming feed (1, 242) is less than 15% by weight of said first product (231), which is rich in olefins, - in that said hydrocarbon synthesis plant (200) is also arranged to supply at least part of said reformer-based synthesis gas stream (41, 51, 53, 62) to an inlet of the alcohol synthesis unit (220).

2. Hydrocarbon synthesis plant (200) according to claim 1, which hydrocarbon synthesis plant (200) is further arranged so that the reformer-based

DK 181610 B1 41 synthesis gas flow (41, 51, 53, 62) is up to 50% by volume, such as 5-45%, e.g. 10-40% of the inlet of the alcohol synthesis unit (220).

3. Hydrocarbon synthesis plant (200) according to any one of claims 1-2, which hydrocarbon synthesis plant (200) does not comprise a reforming unit placed upstream of the alcohol synthesis unit (220) in order to provide said first (209) or second (205) synthesis gas supply.

4. Hydrocarbon synthesis plant (200) according to any one of claims 1-3, where: the alcohol synthesis unit (220) comprises: - a methanol synthesis unit (220°) which is arranged to receive the first CO»-rich feed (201) and the first H»-rich feed (202), or adapted to receive the first synthesis gas feed (209), or — adapted to receive the second synthesis gas feed (205) and provide an effluent stream (211) comprising methanol, - a KC »>-C4 alcohol synthesis unit (2207) adapted to receive the effluent stream (211) comprising methanol, optionally wherein the C2-C4 alcohol synthesis unit (220”) is adapted to receive a portion of any of: the first CO»-rich feed (201), the first H>-rich feed (202) and the first synthesis gas feed (209) and providing said effluent stream (221) comprising a C>-C4 alcohol, and - wherein said hydrocarbon synthesis plant (200) is arranged to supply at least part of said reformer-based synthesis gas stream (41, 51, 53, 62) to the inlet of the C>-C4 alcohol synthesis unit (220').

5. Hydrocarbon synthesis plant (200) according to claim 4, which plant (200) is further arranged to supply a portion that constitutes 50 percent by volume or less of said reformer-based synthesis gas stream (41, 51, 53, 62) to the methanol synthesis unit's (220') inlet.

6. Hydrocarbon synthesis plant (200)) according to claim 1, wherein the alcohol synthesis unit (220) is a C>-C4 alcohol synthesis unit (220"), which is arranged to receive the first CO»>-rich feed (201) and the first H »-rich feed (202) directly, or arranged to receive the first synthesis gas feed (209) directly, or arranged to receive the second

DK 181610 B1 42 synthesis gas feed (205) directly and providing said effluent stream (221) which comprises a C>-C4 alcohol.

7. Hydrocarbon synthesis plant (200) according to any one of claims 1-6, wherein the ATH synthesis section (230) comprises a first separation section adapted to receive at least a part of said first product (231) which is rich in olefins, and providing said by-product stream (242) rich in C 1 -C paraffins and/or olefins.

8. Hydrocarbon synthesis plant (200) according to claim 7, which plant is arranged to recycle a part of said by-product stream, which is rich in C:-C4 paraffins and/or - olefins, to the alcohol-to-olefin (ATO) reactor inlet.

9. Hydrocarbon synthesis plant (200) according to any one of claims 1-8, wherein the ATH synthesis section (230) further comprises an oligomerization reactor (OLI reactor) arranged to receive at least part of said first product ( 231) rich in olefins to provide an oligomerized crude product stream and a hydrogenation reactor (HYDRO reactor) to provide a crude product (231°) containing hydrocarbons boiling in the jet fuel range and where The ATH synthesis section (230) further comprises: - a separator between the OLI reactor and the HYDRO reactor, which is arranged to receive at least a part of the oligomerized raw product stream and separate therefrom at least a part of said by-product stream (242) , rich in paraffins and/or olefins, and/or a separator downstream of the HYDRO reactor adapted to receive at least part of the crude product (231°) containing hydrocarbons boiling in the jet fuel range, and separating therefrom at least a portion of said by-product stream (242) rich in paraffins and/or olefins.

10. Hydrocarbon synthesis plant (200) according to any one of claims 1-9, further comprising: - an upgrading section (240) arranged to receive at least part of the first product (231) which is rich on olefins, or at least a portion of the crude product (231°) containing hydrocarbons which boil in the jet fuel region, and provide a jet fuel product stream (241),

DK 181610 B1 43 - in that said upgrading section (240) is arranged to provide a by-product stream (242) that is rich in paraffins and/or olefins.

11. Hydrocarbon synthesis plant (200) according to any one of claims 1-10, which plant (200) is further arranged to provide any one of: one or more off-gas streams (253, 253'), a naphtha stream or a combination thereof, said one or more off-gas streams being one or more waste gas streams rich in CO,, H,, CH, where: - said reforming system is arranged to receive at least part of any of said one or more off-gas streams (253, 253'), naphtha stream or a combination thereof, and/or - the C»-Cs alcohol synthesis unit (220) of the alcohol synthesis unit (220) comprises a biocatalytic reactor arranged in order to receiving at least a portion of said one or more off-gas streams (253, 253).

12. Hydrocarbon synthesis plant (200) according to any one of claims 1-11, wherein the reformer (40) in the reforming system (100) is any one of: steam methane reformer (SMR), i.e. tubular reformer, electric steam methane reformer (e-SMR), autothermal reformer (ATR), convection heated reformer and combinations thereof, or where the reformer (40) in the reforming system (100) is: - an electric steam methane reformer (e-SMR) placed alone or together with an upstream pre-reformer, or where the reformer (40) in the reforming system (100) is: - an autothermal reformer (ATR) placed alone or together with an upstream pre-reformer.

13. Hydrocarbon synthesis plant (200) according to any one of claims 1-12, which further comprises: - an electrolysis section which comprises: - an electrolysis unit (260) which is arranged to receive a water raw material (203), i.e. steam and/or water, and provide another H»-rich

DK 181610 B1 44 feed (2027) comprising H, optionally as said first H»-rich feed (202) comprising Hy, or part thereof as said first H,-rich feed (202), and/or - an electrolysis unit (250) arranged to receive a second first CO>-rich supply (201°), or said first CO»-rich supply (201) comprising CO,, or a part thereof, and providing a CO-enriched feed (204), - means such as a mixing unit or assembly for combining the first or second H»-rich feed (202) comprising Hz with the CO-enriched feed (204) and providing said second synthesis gas feed (205), or - a thermal decomposition unit adapted to receive a biomass feedstock to provide a raw synthesis gas feed, and a raw synthesis gas purification section adapted to receive the raw synthesis gas feed and to provide said second synthesis gas feed (205), or - a reverse water gas process (rWGS) unit, preferably an electric rWGS unit (e-rWGS), which is arranged to receive a part of said first CO»-rich feed (201) comprising CO,, and a part of said first H,-rich feed (202) comprising H,, for providing a TWGS synthesis gas feed, and means such as a mixing unit or assembly for combining (the WGS synthesis gas feed with the remainder of: said first CO»-rich feed ( 201) comprising CO» and said first H»-rich feed (202) comprising H» and providing said second synthesis gas feed (205).

14. Hydrocarbon synthesis plant (200) according to claim 13, where the rWGS is also arranged to receive part of said by-product stream (242, 242') which is rich in paraffins.

15. Process for hydrocarbon synthesis of a first CO»-rich feed (201) comprising CO» and a first H»-rich feed (202) comprising Hy, or of a first synthesis gas feed (209) combining said first CO»-rich feed (201) and said first H»>-rich feed (202), or of a second synthesis gas feed (205) comprising a carbon oxide and hydrogen, which method comprises the following steps:

DK 181610 B1 45 - provision of a hydrocarbon synthesis plant (200) according to any one of claims 1-14, - supply of CO»-rich feed (201) and H»>-rich feed (202), or said first synthesis gas feed, or said other synthesis gas feed (205), to the alcohol synthesis unit (220), and providing an effluent stream (221) comprising a C>-C4 alcohol, such as any of a C>-C4 alcohol or combinations thereof, - feeding at least part of the effluent stream (221) comprising a C>-C4 alcohol from the alcohol synthesis unit (220) to the alcohol-to-hydrocarbon (ATH) synthesis section (230), which ATH synthesis section (230 ) comprises an alcohol-to-olefin reactor (ATO reactor), and providing a first product (231) rich in olefins (such as said hydrocarbon), wherein the first product (231) rich in olefins , suitably containing at least 50% by weight of C 1 -C 5 olefins, and further withdrawing from said ATH synthesis section (230) a by-product stream (242) rich in C 1 -C 4 paraffins and/or olefins, such as which any of: methane, ethane, ethene (ethylene), propane, propene (propylene), butane, butene (butylene), and combinations thereof, - feeding at least part of a first reforming feed stream (1) as said by-product stream ( 242) rich in C:-Ca paraffins and/or olefins to the reforming system (100), performing a reforming step in the reforming unit (reformer, 40), and providing a reformer-based synthesis gas stream (41, 51, 53, 62), such as a first, second or third reformer-based synthesis gas stream (41, 51, 53), said first reforming feed (1, 242) being less than 15% by weight of said first product (231) rich in olefins, - feed of at least a portion of said reformer-based synthesis gas stream (41, 51, 53, 62) to the inlet of the alcohol synthesis unit (220).