FI20246015A1 - A process for manufacturing a jet fuel component - Google Patents

Abstract

A process for producing a jet fuel component is provided. The process comprises the steps of providing carbon dioxide gas and hydrogen gas; reacting the carbon dioxide gas and the hydrogen gas into methanol and water, and subsequently recovering the formed methanol; reacting the recovered methanol into acetic acid through alkylation, and subsequently recovering the formed acetic acid; subjecting the formed acetic acid to thermochemical conversion for the formation of isobutene, water and carbon dioxide in the presence of a catalyst; separating and recovering the formed isobutene and carbon dioxide; recycling at least part of the recovered carbon dioxide, and directing at least part of the recovered isobutene to oligomerization, and to subsequent hydrogenation.

Description

A PROCESS FOR MANUFACTURING A JET FUEL COMPONENT

TECHNICAL FIELD

The present disclosure relates to production of a jet fuel component. More particularly, the disclosure relates, though not exclusively, to a process for producing a jet fuel component, and to a use of a jet fuel component.

BACKGROUND

This section illustrates useful background information without admission of any technique — described herein representative of the state of the art.

Presently, there is a growing need to reduce greenhouse gas (GHG) emissions and/or carbon footprint in transportation, especially in aviation. Accordingly, the need for renewable jet fuels and jet fuel components complying with international standards is, and has been, growing.

There is an increasing demand for scalable and sustainable feedstock materials and industrially viable conversion routes to produce sustainable jet fuel. One option may be starting from carbon monoxide and renewable electricity used for hydrogen production, which can be generated via multiple alternative routes. For example, the carbon may originate from biomass reforming, municipal solid waste gasification, or via captured COs.

Renewable electricity may be produced e.g. by wind, solar or tidal energy and converted into hydrogen by e.g. electrolysis.

Several different technologies and unit operations may be combined to form an overall conversion pathway that leads to suitable hydrocarbons of the jet fuel range. Different s production technologies such as Fischer-Tropsch and Methanol-to-Jet based technologies

S 25 — are still under development. As multiple steps are needed in the overall process route the 3 challenge will be to maintain compatibility, high selectivities and high yields for the > subprocesses to enable a technically reasonable and economically viable whole process

I route outcome. The Fischer-Tropsch conversion inherently produces an extremely wide - range of carbon number distribution. A carbon chain too long for jet fuel applications needs

LO

S 30 to be cracked, leading to another product distribution. A too short carbon chain will either

O

3 lead to formation of by-products or need to be recycled and converted back to syngas to be

O

N fed to the Fischer-Tropsch reactor anew. The Fischer-Tropsch synthesis products are highly paraffinic and therefore reguire an isomerization step to fulfill the cold flow property reguirement of the jet fuel. Whereas, the methanol route has a Methanol to Olefin (MtO)

step that produces a range of olefins, from C2 to C6 at least, making the oligomerization step complicated as the different olefins have different reactivities and may require different catalysts. Some by-products will inevitably form and e.g. more than 10% of the product may be fuel gas, which is undesirable because it is hard to valorize as sustainable fuel in a meaningful application.

And yet, a further concern for the producers will be the size, throughput and location match for the subprocesses of an overall process route to set up a technically and economically feasible refinery.

SUMMARY

The present application concerns an invention defined in the appended independent claims, and embodiments disclosed herein. The appended claims define the present invention. Any example and/or technical description of an apparatus, system, product and/or process in the description and/or drawing which is not covered by the claims, is presented herein not as an embodiment of the invention but as background art or as an example useful for understanding the invention.

It is an object of the present disclosure to provide a process for producing a jet fuel component, which can be used as such or as a jet fuel component. Another object is to provide a use of a jet fuel component which meets the requirements set out for jet fuels.

It is a further object of the present disclosure to provide use of the jet fuel component manufactured by the method of claim 1 in jet fuel compositions according to the requirements set out in ASTM D7566-22.

According to a first aspect, there is provided a process for producing a jet fuel component, comprising the steps of < i. providing carbon dioxide gas and hydrogen gas;

N

& 25 ii. reacting the carbon dioxide gas and the hydrogen gas into methanol and water, and 3 subsequently recovering the formed methanol; <t iii. reacting the recovered methanol into acetic acid through alkylation, preferably by = carbonylation with carbon monoxide, and subseguently recovering the formed acetic

O acid; 3 a 30 iv. subjecting the formed acetic acid to thermochemical conversion for the formation

N of isobutene, water and carbon dioxide, in the presence of a catalyst; v. separating and recovering the formed isobutene and carbon dioxide; vi. recycling at least part of the recovered carbon dioxide from step v by a. directing the recovered carbon dioxide to step ii, and/or b. subjecting the recovered carbon dioxide to a reverse water gas shift reaction to form carbon monoxide and directing the formed carbon monoxide to step iii, and vii. directing at least part of the recovered isobutene from step v to oligomerization, and to subsequent hydrogenation for producing a jet fuel component.

The inventors have surprisingly found that in the present process the production of isobutene has a high conversion and a high selectivity, and less other hydrocarbons are formed as side products compared to producing isobutene from e.g. directly from syngas.

This makes product separation after the isobutene synthesis less complicated as there is no need to e.g. remove water, capture CO2, separate unconverted gas from products, and separate C4=+ from the rest of the hydrocarbon products which leads to a very high recycling ratio increasing parasitic consumptions and capital expenses. In addition, as the present route proceeds via methanol, it is possible to decentralize methanol production and centralize the methanol to jet via isobutene facility.

BRIEF DESCRIPTION OF THE FIGURES

An exemplary embodiment will be described with reference to the accompanying figure, in which:

Fig. 1 schematically shows as an exemplary embodiment of the whole process route of the present disclosure configured to carry out the present process.

DETAILED DESCRIPTION

N As used herein, the term “comprising” includes the broader meanings of “including”,

N 25 —”containing”, and "comprehending", as well as the narrower expressions “consisting of? and © <Q “consisting only of”. <t

I As used herein the term “jet fuel” or “jet fuel component” refers to a component complying

T with required properties of the standard ASTM D7566-22. Moreover, in an embodiment any

O feature characterizing the present process or analytical method has the meaning specified

O

O 30 in ASTM D7566-22. The jet fuel component can be partly, or entirely renewable jet fuel

N

2 component. In an embodiment, the jet fuel component according to the present disclosure comprises branched C8-C16 hydrocarbons.

As used herein, the term “renewable CO?” or “renewable carbon dioxide” refers to CO,,

which is obtained from, but not limited to, fermentation processes, traditional power plants, oxy-combustion power plants, ambient air CO. capture systems, secondary oil recovery processes, seawater, pulp mill recovery boilers, and other CO: sources. The term renewable CO; can also refer to renewable CO, which is recycled CO. from other process steps of the current process, and/or other processes, such as production of renewable fuel.

As used herein, the term “recycled CO?” or “recycled carbon dioxide” refers to recycled CO; which is recycled carbon dioxide from other process steps of the current process, and/or recycled CO. from other processes, which CO: is then recycled and utilized in the current process. Recycled CO: can be renewable CO. and/or CO; originating at least partly from fossil sources.

As used herein, the term “renewable CO” or “renewable carbon monoxide” refers to CO, which is obtained from, but not limited to, renewable CO,. The term renewable carbon monoxide can also refer to renewable carbon monoxide which is recycled carbon monoxide from other process steps of the current process, and/or other processes.

The present disclosure provides a multistep process for producing a jet fuel component and uses thereof.

In an embodiment the present process is an industrial scale process. In another embodiment the industrial scale process may exclude small scale methods such as laboratory scale methods or pilot size testing that are not scaled up to volumes used in — industry.

The present disclosure provides a process for producing a jet fuel component, comprising at least the following the steps: i. providing carbon dioxide gas and hydrogen gas; < ii. reacting the carbon dioxide gas and the hydrogen gas into methanol and water,

N 25 and subseguently recovering the formed methanol;

N

3 lii. reacting the recovered methanol into acetic acid through alkylation, preferably by s carbonylation with carbon monoxide, and subseguently recovering the formed acetic

E acid;

LO iv. subjecting the formed acetic acid to thermochemical conversion for the formation 3 30 of isobutene, water and carbon dioxide in the presence of a catalyst,

S v. separating and recovering the formed isobutene and carbon dioxide;

O

N vi. recycling at least part of the recovered carbon dioxide from step v by c. directing the recovered carbon dioxide to step ii, and/or d. subjecting the recovered carbon dioxide to a reverse water gas shift reaction to form carbon monoxide and directing the formed carbon monoxide to step iii, and vii. directing at least part of the recovered isobutene from step v to oligomerization, and to subsequent hydrogenation for producing a jet fuel component. 5 Developing an industrial scale chemical process is typically more complicated than merely connecting unit operations together. This applies also to a direct conversion of CO; to methanol, and concomitant production of green hydrogen. However, this type of a process has economical and environmental advantages.

In an embodiment, the carbon dioxide gas used as feed is pure CO, gas. Contrary to the use of gas mixtures, such as a mixture of CO, CO», and H); as is the case with syngas, the use of pure CO, gas simplifies the further processing, as the outcome of the reactions are more predictable, and less purification is needed for the reaction products. Essentially, the reaction impurities are limited to only water and dissolved CO2, when methanol is produced.

In an embodiment the carbon dioxide gas is obtained from captured carbon dioxide.

The captured carbon dioxide may be produced from a process of fossil origin, or it may be of biogenic or renewable origin, or a mixture. Preferably, the captured carbon dioxide is of renewable origin. Some CO, may be removed and recovered from a methanol synthesis intermediate product stream by e.g. stripping an overhead stream of a distillation column.

The renewable character of carbon-containing compound, such as CO>, may be determined — by comparing the 1*C-isotope content of the feedstock to the 'C-isotope content in the air in 1950. The '“C-isotope content can be used as evidence of the renewable origin of the material. Carbon atoms of renewable material comprise a higher number of unstable radiocarbon (14C) atoms compared to carbon atoms of fossil origin. Therefore, it is possible to distinguish between carbon compounds derived from biological sources, and carbon

N 25 compounds derived from fossil sources by analysing the ratio of 12C and 14C isotopes.

N Thus, a particular ratio of said isotopes can be used to identify and guantify renewable = carbon compounds and differentiate those from non-renewable i.e. fossil carbon

A compounds. The isotope ratio does not change in the course of chemical reactions. An = example of a suitable method for analysing the content of carbon from biological sources is

O 30 disclosed in ASTM D6866 (2020). An example of how to apply ASTM D6866 to determine

O the renewable content in e.g. fuels is provided in the article of Dijs et al., Radiocarbon, 48(3),

O 2006, pp 315-323. For the purpose of the present invention, a carbon-containing material, such as CO: is considered to be of renewable origin if it contains 90% or more modern carbon, such as 100% modern carbon, as measured using ASTM D6866.

Similarly, the needed hydrogen may be e.g. grey, blue or green hydrogen. Grey hydrogen is being generated from fossil sources, such as natural gas or methane, through steam methane reforming without capturing the greenhouse gases made in the process. Blue hydrogen involves reforming hydrocarbons, such as methane, to obtain hydrogen and carbon dioxide. So, grey hydrogen is essentially the same as blue hydrogen, but without the use of carbon capture and storage. Whereas green hydrogen is obtained by separating hydrogen from oxygen through the electrolysis of water. This electrolysis can be carried out with energy from renewable sources, which makes the process more sustainable and provides a clean energy source. The hydrogen obtained in this way can be stored or used in industrial or heavy mobility processes, while the resulting oxygen is released into the atmosphere or can be used as a by-product. In the same way, the electrolyzer generates heat that can be harnessed through the use of heat pump technologies for e.g. district heating. Green hydrogen is therefore a pollutant-free carbon neutral process.

In an embodiment, the hydrogen is green hydrogen, preferably produced by the electrolysis of water using SOEC (Solid Oxide Electrolysis Cell). SOEC may run in regenerative mode to achieve the electrolysis of water by using a solid oxide, or ceramic, electrolyte to produce hydrogen gas and oxygen. The renewable energy for the production of hydrogen may be generated from, but not limited to, renewable and/or low-carbon sources such as wind, solar, geothermal, hydro, ocean currents, biomass, flare-gas, nuclear and others. In an embodiment, the hydrogen gas is generated by sustainable electricity sources, such as water electrolysis using wind, solar, geothermal, wave, tidal or nuclear power. Other possible sources include low-cost (off-peak) power from traditional fossil fuel power plants or efficient power produced from oxy-combustion plants. The renewable hydrogen can also refer to hydrogen which is recycled hydrogen from other process steps of the current process, and/or other processes.

S A climate-neutral solution for vehicle operation is provided by using e-fuels (electricity- & based fuels). The climate neutrality of e-fuels is derived from the fact that electricity from 3 renewable energy sources is used in the production and only as much CO: is emitted during s use as was previously bound during production. Jet fuel may be produced starting from

E 30 electrolytically produced hydrogen by splitting of water using renewable electricity.

LO Combining thus produced hydrogen with renewable CO2, such as CO2 extracted from air, a 3 conversion into liquid energy in the form of e-fuel is achieved. This e-fuel may be produced

S matching the jet fuel reguirements, thus obtaining e-jet fuel or components thereto. In an

N embodiment, the jet fuel component is an e-jet fuel component.

Methanol may be produced directly from carbon dioxide gas and hydrogen gas. There are both environmental and economical advantages for this type of process. Using pure starting materials simplifies the chemistry by reducing the by-product formation and the need for downstream purification of the reaction product.

In an embodiment, carbon dioxide gas, preferably in pure form, and hydrogen gas, preferably in pure form, are reacted into methanol and water, and subsequently the formed methanol is recovered.

Even when using pure reactants from separate sources, the resulting methanol product, crude methanol, contains some water and some dissolved CO,. The CO, may be removed from the crude methanol by stripping and distillation, whereas the separation of water from the crude methanol is straightforward and well known in the art. In one embodiment, CO, and H.are added in separate pure or purified feed streams, and the flow rates are regulated by mass flow meters independently of each other, resulting in stoichiometric ratio (CO, +3H> = CH3OH +H,0). In an embodiment, a catalyst is used for the reaction, such as a copper containing catalyst, for example CuO. The copper containing catalyst may further contain

Ga, Pd, Zn, Al and/or Si, such as Ga.0s, PdO, ZnO, Al.O; and/or ZrO. In an embodiment, the reaction temperature is in the range of 150-300 °C, such as 200-300 °C, or even 230- 270 °C. In an embodiment, the reaction pressure is in the range of 1-10 MPa, such as 4-6

MPa, or even 4.5-5.5 MPa. Methanol conversion may be at least 70 mol-% based CO,, preferably at least 75 mol-%, such as at least 80 mol-%, or even at least 85 mol-%.

Depending on the processing conditions, methane may be formed as a by-product, which may be separated from the methanol by known means.

In an embodiment, the reaction between the hydrogen gas and the carbon dioxide gas with each other takes place at a temperature from 150 to 300 °C, and at a pressure from 1 to 10

MPa, in the presence of a catalyst comprising Cu, Zn and Al, to produce a reaction mixture comprising methanol, such as methanol and methane. <

S 25 The formed methanol from step iii is directed to alkylation for formation of acetic acid. There are

Od several processes available from this conversion reaction. A well-known process is the <+ Monsanto process utilizing a rhodium-based catalyst, operating at a pressure of 30-60 atm and = at a temperature of 150-200 °C, reacting methanol and carbon monoxide in liquid phase. The o selectivity of this process can be very high, over 99 %, for methanol. There are several 2 30 modifications from this process available in the art. The alkylation of methanol with carbon

O monoxide with several different catalysts is discussed e.g. in Kalck, Coordination Chemistry

O Reviews, 2020, 402, pp.213078. 10.1016/j.ccr.2019.213078.

The alkylation of the present process comprises a reaction of methanol with carbon monoxide in the presence of a rhodium or iridium catalyst, and is performed at a pressure from 3000 to 60000 kPa, and at a temperature from 150 to 200°C.

The recovered acetic acid may be converted into isobutene using a thermochemical conversion reaction in the presence of a catalyst suitable thereto. In an embodiment, the catalyst is a mixed oxide catalyst of the formula Zr.Zn,O,. The performance of the catalyst depends on the ratio of the mixed oxides. In isolation, ZnO and ZrO, are incapable of producing isobutene from acetic acid. However, under optimal conditions, the mixed binary oxide catalyst, Zr,Zn,Oz, is able to generate at least 50 % isobutane.

The reaction is anticipated to proceed via sequential ketonization, aldol condensation and

C-C hydrolytic bond cleavage. First, two acetic acid molecules ketonize to form acetone, — water and CO? over the oxide surface through an acetoacetic acid intermediate. Secondly, acetone undergoes self-condensation through an aldol pathway to generate an enone, mesityl oxide, as the main product, with a minor amount of mesitylene and isophorone as byproducts. Thirdly, the enone undergoes a C-C bond cleavage step producing the isobutene and some acetic acid.

ZnO (wurtzite) may be considered to be a weak base, whereas ZrO, (tetragonal) is considered to be an acid. The functionalities of both metal oxides are needed for the reactions, dependent on the reaction conditions. The ratio of the metal oxides influences on the yield and selectivity towards the isobutene formation, and to the formed by-products. In an embodiment, subjecting to thermochemical conversion of step iv comprises, in addition to formation of isobutene, water and carbon dioxide also formation of acetic acid, acetone, and methane.

In an embodiment, the thermochemical conversion in step iv comprises use of a Zr,Zn,Oz mixed oxide catalyst with x:y ratio from 0.03-1.00, such as 0.08-0.42, even about 0.20-0.30, is used in the thermochemical conversion.

N 25 The acetic acid stream from step iii may contain water, and preferably aqueous acetic acid

N is directed into the thermochemical conversion reaction. In an embodiment, the amount of = water in the acetic acid infeed is less than 50 wt-%, such as less than 25 wt-%, such as less = than 10 wt-%. Preferably, the reaction is conducted in a gaseous phase. In an embodiment, : the thermochemical conversion in step iv takes place in a gaseous phase by vaporizing an

O 30 aqueous acetic acid solution and bringing the vapour into contact with the Zr;ZnyO; catalyst.

O v The catalytic thermochemical conversion reaction of acetic acid to isobutane takes place & under reaction conditions which are effective for the conversion. In an embodiment, the temperature is from 400 °C to 500 °C, preferably from 420 °C to 480 °C. In an embodiment, the reaction is conducted at a pressure ranging from 70 kPa to 150 kPa, preferably from 90 kPa to 110 kPa, such as at atmospheric pressure (ca 101 kPa).

Acetic acid infeed may be complemented by additionally feeding e.g. acetone into the thermochemical reaction.

The isobutene i.e. isobutene monomers formed in step iv may be recovered as a stream comprising isobutene monomers in step v. The stream comprising isobutene monomers is preferably a liquid stream. Recovering isobutene monomers as a separate intermediate product from step v is beneficial, as it can be delivered further for oligomerization, whereas the other intermediate products, such as carbon dioxide can also be further utilized in the present process. Additional components may further be recovered as separate intermediate — products at step v, and either used in the present process, taken elsewhere for upgrading, or recovered as a further intermediate product.

Isobutene monomers can react seguentially with itself and form longer olefinic products, such as olefin dimers, olefin trimers and/or olefin tetramers. Isobutene monomer can also react with other olefins, such as olefin dimers, olefin trimers and olefin tetramers, although — the reaction rate may be slower.

The oligomerization reaction of the step vii comprises subjecting a stream of recovered isobutene, comprising at least isobutene monomers, to oligomerization in the presence of an oligomerization catalyst.

In an embodiment, step vii of the process comprises at least partially oligomerizing the isobutene monomers into an oligomerized product containing at least trimers of isobutene and tetramers of isobutene. In an embodiment, at least partially oligomerizing the isobutene monomers into an oligomerized product means, that varying lengths of oligomers of isobutene and varying intermediate products from monomers are obtained with the reaction.

In an embodiment, the process conditions of the oligomerization can be adjusted

N 25 independently of the other process conditions.

N In an embodiment, the oligomerization of the step vii is carried out at a temperature of 30 - = 140 °C, such as 40 - 120 °C, such as 45 - 120 °C, or 50 - 120 °C, or even 90 - 110 °C. In

T an embodiment, the oligomerization reaction of the step vii is carried out at a temperature

E of 45 - 110 °C, or 50 - 110 °C, or 60 - 110 °C. A temperature of about 90 - 110 °C, or 95 -

O 30 105 °C favors formation of isobutylene (isobutene) dimers. A temperature of about 30 - 50

O *C favors formation of isobutylene trimers. A temperature of 90 - 110 *C favors formation of

O isobutylene tetramers.

In an embodiment, if the oligomerization reaction of the step vii is carried out in two separate reactor units, the reaction in said two separate reactor units can be carried out at different temperatures selected from the range 30 to 140 °C, and at different pressures selected from the range 150 kPa to 5000 kPa.

In an embodiment, the oligomerization of the step vii is carried out at a pressure of 150 - 5000 kPa, such as 800 - 5000 kPa. In an embodiment, the oligomerization reaction of the — step vii is carried out at a pressure of 1500 - 3500 kPa, 2400 - 3000 kPa, 1900 - 2300 kPa or 1500 — 2300 kPa. The oligomerization reaction of the step vii is an exothermic reaction, therefore keeping the isobutene monomer feedstock and the reaction products in liquid phase with a high enough pressure is beneficial for absorbing the excess heat produced during the oligomerization reaction.

In an embodiment, wherein the oligomerization of the step vii is carried out in two separate reactor units, the pressure in the first reactor unit is higher than the pressure in the second reactor unit.

In an embodiment, the oligomerization catalyst of the step vii comprises an acidic oligomerization catalyst, preferably a strongly acidic ion exchange resin catalyst, more preferably a macroreticular acid ion exchange resin catalyst.

In an embodiment, the oligomerization catalyst is a heterogenous acidic catalyst. In an embodiment, the oligomerization catalyst is a heterogeneous acidic ion exchange resin catalyst. In an embodiment, the oligomerization of the step vii is carried out by using a heterogenous acidic catalyst, selected from the group consisting of macroreticular acidic ion exchange resin catalyst. In an embodiment, the oligomerization catalyst is a solid catalyst. In one embodiment, the acidic catalyst for oligomerizing is a commercial catalyst selected from, e.g., 1042, Amberlyst-36, and Amberlyst-35. In the embodiment, wherein more than one reaction unit for oligomerization is used, each of the reaction units contains a catalyst, preferably an acidic ion exchange resin catalyst. In a preferred embodiment, the + 25 same catalyst is used in each reactor unit, and the amount of catalyst is kept low in the first

S reactor unit, and the amount is increased in the subseguent reactor vessels in the

Od downstream direction of the process.

J In a preferred embodiment, the oligomerization in step vii is carried out in the presence of = an oligomerization catalyst, and at a temperature from 30 to 140 °C, preferably from 45 to > 30 110 °C; and at a pressure from 150 to 5000 kPa, preferably from 800 to 5000 kPa, using an 3 acidic oligomerization catalyst, preferably a strongly acidic ion exchange resin catalyst,

N more preferably a macroreticular acid ion exchange resin catalyst.

N In an embodiment, the oligomerization comprises providing a feed of at least isobutene monomers and an oxygenate i.e., at least one oxygen-containing moderator, and subjecting the feed stream to oligomerization in the presence of an oligomerization catalyst. In an embodiment, the at least one oxygen-containing moderator affects the performance of the oligomerization catalyst. In an embodiment, the at least one oxygen-containing moderator used in the oligomerization of the step vii is selected from water, demiwater, alcohol, tert- butyl alcohol, and combinations thereof. In an embodiment, the preferred oxygen-containing moderator is water together with tert-butyl alcohol formed in a reaction between water and isobutene present in the oligomerization feed stream. In an embodiment, the amount of the oxygen containing moderator in the oligomerization of the step vii is selected from the range 5-15000 mol-ppm, or 1000-15000 mol-ppm, or 10-10000 mol-ppm, or 10-2500 mol-ppm. If the oligomerization of the step vii is carried out in two separate reactor units, said two reactor — units may comprise different amounts of the at least one oxygen-containing moderator. An amount of about 1000-15000 mol-ppm of the at least one oxygen-containing moderator is advantageous when producing olefin dimers. An amount of 5-20 mol-ppm of the at least one oxygen-containing moderator is advantageous when producing olefin trimers. An amount of 500-2500 mol-ppm of the at least one oxygen-containing moderator is advantageous when producing olefin tetramers. Hence, the isobutene monomer conversion into isobutene dimers can be adjusted by adjusting an amount of oxygen-containing moderator.

In an embodiment, the isobutene monomer conversion into isobutene dimers can be adjusted by adjusting an amount of diluent, which is any inert agent, or an agent which is less reactive than the olefins present in the oligomerization reaction.

In an embodiment, any water present in the isobutene monomers fed into the oligomerization of the step vii is removed (e.g., by passing over a desiccant, condensing, etc.) to prevent excessive alcohol/ether formation during the oligomerization, which may increase isobutene dimer (C8) formation.

In an embodiment, the amount of C12 and C16 oligomers of isobutene can be optimized in

N the oligomerized product to produce a jet fuel component with desired properties. In an

N embodiment, the optimization is done by appropriate selection of catalyst, reaction time, = temperature, and/or pressure, during the oligomerization reaction step. = In an embodiment, the oligomerization of the step vii is carried out at an operating weight o 30 hour space velocity (WHSV) of 0.2-10 1/h. = In an embodiment, in the oligomerization of the step vii, the feed stream comprising

S isobutene monomers is passed to a catalytic oligomerization where a single pass

N conversion of isobutene monomers may be suitably controlled. With the term single pass conversion is meant here the conversion of isobutene monomers to give another compound over single pass through the oligomerization step. Single pass conversion of isobutene monomers in this respect is defined as a single pass conversion of isobutene monomers (%) = 100 x (number of moles of isobutene monomers in the feed prior to the oligomerization reaction step - number of moles of isobutene monomers in the product after the oligomerization reaction step) / number of moles of isobutene monomers in the feed stream — prior to the oligomerization step. With the term total oligomerization conversion is meant here the conversion of isobutene monomers to give another compound during the oligomerization reactions of the entire process. The oligomerization conversion of the oligomerization is an adjustable process parameter which can be adjusted by modifying one or more of the operating conditions of the process step in question, selected from temperature, pressure, oligomerization catalyst, the amount of the oligomerization catalyst, weight hourly space velocity (WHSV), or combination thereof.

In an embodiment, the oligomerization of the step vii is carried out in more than one step, for example, in two steps. The two (sub)steps of the oligomerization of the step vii may comprise: - at least partially oligomerizing the isobutene monomers into an oligomerized product, which is then distilled into a distillate comprising at least unreacted isobutene monomers and a distillate comprising isobutene oligomers; and - at least partially oligomerizing the distillate comprising isobutene oligomers.

In an embodiment, the oligomerization conditions result in total isobutene dimer selectivity of less than 5 %, isobutene trimer selectivity of at least 70 %, and isobutene tetramer selectivity of at least 10 %.

In an embodiment, recycling the distillate comprising dimers of isobutene back to the oligomerization of the step vii increases the amount of isobutene trimers and/or tetramers in the oligomerized product at least 90 wt-%. In an embodiment, at least 0.1 — 99 wt-% of the dimers of isobutene comprising the second oligomerization product, are recycled back

N to the oligomerization of the step vii after distillation. In an embodiment, dimers of isobutene

N are recycled back to the oligomerization of the step vii, to obtain a ratio of trimers to = tetramers of 25 - 0.05 (wt-%/wt-%) in the oligomerized product. = Recycling the isobutene monomers, and/or the isobutene dimers back to the s 30 oligomerization reaction is beneficial as the recycled stream acts as a diluent to absorb heat = from the oligomerization reaction. Thermal control of adiabatic temperature rise is also

O easier when utilizing recycled streams and when a plurality of reactor vessels is used.

O Moreover, the recycled isobutene monomers, and/or the isobutene dimers can react with itself (or with each other) to form further oligomers. The presence of recycled isobutene monomer proportionally increases the amount of C12 isobutene oligomer in the first oligomerized product stream compared to single pass (i.e., no recycle of monomer) first oligomerized product stream. The presence of recycled isobutene dimer proportionally increases the amount of C16 isobutene oligomer in the second oligomerized product stream compared to single pass (i.e., no recycle of dimer) second oligomerized product.

In an embodiment, in the oligomerization of the step vii, a feed stream comprising compounds having from 1-20 or more carbon atoms may be formed. Such compounds may be, for example, linear or branched, and can contain one or more unsaturated carbon- carbon bonds (e.g., double or triple bond). However, the oligomerization of the step vii typically produces mostly branched C8-C16 oligomers of isobutene, preferably mostly branched C12-C16 oligomers of isobutene. In an embodiment, the C8 - C16 oligomers of isobutene include C8, C9, C10, C11, C12, C13, C14, C15 and C16 oligomers of isobutene, which are mainly strongly branched and can contain one or more unsaturated carbon- carbon bonds. In an embodiment, the oligomerization of the step vii produces only branched

C8-C16 oligomers of isobutene, more preferably only branched C12-C16 oligomers of — isobutene, whereas linear oligomers of isobutene are not comprised in the end product. In an embodiment, the oligomerization comprises providing a composition having at least C8,

C12 and C16 oligomers of isobutene, more preferably having at least C12 and C16 oligomers of isobutene.

In an embodiment, wherein the isobutene recovered in step v is subjected at least partly to oligomerization, whereby the obtained isobutene product contains at least trimers of isobutene and/or tetramers of isobutene, and wherein the hydrocarbons of the oligomerized product have a carbon number in the range of C8 — C16.

In the present process, jet fuel component is produced via isobutene oligomerization using processing conditions leading to dimerized, trimerized or tetramerized oligomers, thus + 25 — providing predominantly hydrocarbons of carbon numbers up to 16 or below to the final

S product. In an embodiment, the jet fuel component obtained by the present process has

Od carbon numbers ranging from C8 to C16, preferably from C12 to C16. + Hydrogenating is performed to saturate any double bonds present in the oligomerized = product. In an embodiment, the hydrogenating comprises removal of double bonds and > 30 impurities through hydrotreatment, such impurities being selected from halogens, metals,

O phosphorus, aromatics, or any combination thereof. In an embodiment, the process v conditions of the hydrogenation reaction can be adjusted independently of the other process

N conditions of the present process.

In an embodiment, the hydrogenating of the step vii. is done in the presence of a hydrogenation catalyst containing at least one supported Pt, Pd, and/or Ni catalyst, the support being zeolite, silica, alumina and/or amorphous SiO2—-Al203 (ASA), or combinations thereof. In an embodiment, the hydrogenation catalyst is a Pt or Pd supported on ASA and/or alumina.

In an embodiment, the hydrogenation of the step vii. is carried out at a Ha feed ratio of 1-2 mol Ha2/ mol of feed, preferably 1.05 - 1.15 mol H2/ mol of feed, more preferably 1.07-1.12 mol H2/ mol of feed.

In an embodiment, the hydrogenation of the step v. is carried out at a temperature of 120 - 200 °C, and/or at a pressure of 1000 - 20000 kPa, preferably the pressure is 2000 - 10000 kPa.

In a preferred embodiment, the hydrogenation in step vii is carried out at a H? feed ratio of 1-2 mol H2/ mol of feed, at a temperature of 120 - 200 °C and at a pressure of 1000 - 20000 kPa, using at least one supported Pt, Pd, and/or Ni catalyst on a support selected from zeolite, silica, alumina and ASA.

In a more preferred embodiment, the hydrogenation in step vii is carried out in the presence of an alumina supported Pt catalyst, under hydrogen pressure from 3000 to 4000 kPa, and at a temperature from 130 °C to 260 °C.

In an embodiment, the hydrogenation reaction conditions result in saturated oligomerized product total selectivity of at least 80 %, preferably at least 90 %. In an embodiment, the reaction conditions of the hydrogenation of the step vii are selected to avoid hydrocracking (HC), as this would unnecessarily reduce the final yield of the jet fuel component.

In an embodiment, at least 95 wt-%, preferably at least 98 wt-%, more preferably at least 99 wt-%, of the hydrocarbons in the oligomerized product entering the hydrogenation of the step vii have a carbon number of at least C8. In an embodiment, at least 99 wt-%, preferably at least 99.5 wt-% of the hydrocarbons in the oligomerized product have a carbon number

S 25 — within the range C8 — C16, which is why the carbon number distribution of the hydrocarbons

N present in the oligomerized product is already suitable for a jet fuel component. 00 = In an embodiment, the oligomerized isobutene trimers and/or tetramers in step vii having a = carbon number between C8 — C16, are hydrogenated under hydrogenation conditions to z obtain the jet fuel component. = 30 In an embodiment, at least 95 wt-%, preferably at least 98 wt-%, more preferably at least v 99 wt-%, of the hydrocarbons in the jet fuel component have a carbon number of at least

R C8. In an embodiment, at least 99 wt-%, preferably at least 99.5 wt-%, of the hydrocarbons in the jet fuel component have a carbon number of C8 — C16, which is why the carbon number distribution of the hydrocarbons present in the jet fuel component complies with the requirements set out for jet fuel boiling point range by the ASTM D7566-22 standard.

In an embodiment, the jet fuel component obtained by the present process is used for manufacturing a jet fuel composition complying with the requirements as set out in ASTM

D7566-22.

The obtained jet fuel component may be blended with any hydrocarbon based renewable or fossil jet fuel.

In an embodiment, the jet fuel component obtained by the present process is used for increasing the renewable content of a jet fuel composition.

The term "greenhouse gas" or "GHG" refers here to an atmospheric gas that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the atmosphere include carbon dioxide (CO>) in addition to water vapor, methane, nitrogen oxides, ozone and halide containing gases.

The jet fuel component manufactured by the present process complies with the requirements as set out in ASTM D7566-22 standard and has modern carbon content (pMC) of about 100 percent (ASTM D6866). Increasing the bio content of jet fuel i.e. decreasing the use of fossil- based jet fuel will reduce the greenhouse gas emissions (GHG). Replacing a fossil jet fuel totally with the jet fuel component of the present invention results in at least 50 percent reduction, such as at least 70 percent reduction, or even such as 90 percent reduction, in GHG emissions (gC02eqg/MJ), when emissions over the life cycles of fuels are taken into account using a calculation method complying with the EU Renewable Energy Directive 2009/28/EC.

If blended with fossil jet fuel it increases the renewable content of the final product. In aviation, combustion of jet fuel consumption produces 3.16 kilograms of CO, per 1 kilogram x of fuel consumed, thus increasing the amount of greenhouse gas by an egual amount.

O

N 25 In an embodiment, the jet fuel component obtained by the present process is used for © > decreasing the GHG emissions of a jet fuel composition. <t - In an embodiment, jet fuel component obtained from the present process is used in a jet a a fuel composition for reducing the GHG emissions at least 50 percent, such as at least 70 = percent, or even such as at least 90 percent, by gC02eg/MJ calculated according to the EU v 30 Renewable Energy Directive 2009/28/EC.

O

N Certain parts of the present jet fuel manufacturing process produce carbon dioxide, whereas certain parts of the process consume it. In view of the process carbon efficiency, it is preferred that carbon dioxide is recycled within the one processing scheme.

Carbon dioxide may be recovered, for example, from step v. It may be at least partly, or even totally, recycled the upstream processing steps requiring CO: or e.g. CO infeed. CO; may be converted into CO e.g. through RWGS (reverse water gas shift) reaction. The term “reverse water gas shift reaction” or “RWGS reaction” describes the catalyzed reaction of carbon dioxide and hydrogen to form carbon monoxide and water vapor: CO, + H? = CO +

H2O.

The use of an RWGS reaction as a source of carbon monoxide is advantageous in the present process, because recycling CO2 from downstream process steps into the RWGS reaction increases the carbon efficiency of the process, and hence, the yield of the final jet fuel component. Utilizing RWGS reaction and recycling as a source of carbon monoxide feed is especially advantageous when the upstream reactions have advantageously a low single pass conversion rate e.g. due to a need to inhibit by-product formation. Obtaining

CO, as a separate intermediate product is beneficial, as it can be circulated upstream producing a mixture of CO and hydrogen gas.

In an embodiment, the RWGS reaction is carried out at a temperature from 300 to 1050 °C, preferably from 700 to 900 *C; and at a pressure from 50 to 1500 kPa, preferably from 80 kPa to 1000 kPa. In an embodiment, the RWGS reaction is carried out at a temperature of 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C, 600 °C, 650 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, 950 °C, 1000 °C or 1050 °C.

In an embodiment, the RWGS reaction is carried out at a pressure of 5000 kPa or less, 2500 kPa or less, 1500 kPa or less, 1200 kPa or less, 1000 kPa or less, 800 kPa or less, 500 kPa or less, or 300 kPa or less. In an embodiment, the RWGS reaction is carried out at a pressure of 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, 100 kPa, 110 kPa or 120 kPa. In an embodiment, the RWGS reaction is carried out at a pressure of 100 kPa, 200 kPa, 300 kPa, 400 kPa, 500 kPa, 600 kPa, 700 kPa or 1500 kPa. In an embodiment, the RWGS

N reaction is preferably carried out at a pressure of 1500 kPa. 3 In an embodiment, the RWGS reaction is carried out catalytically, preferably with a solid + RWGS metal or metal oxide catalyst comprising nickel (Ni), magnesium (Mg), copper (Cu), = or combinations thereof. In one embodiment the catalyst is nickel based, especially for high & 30 temperature RWGS. In an embodiment, the RWGS catalyst is a high-surface area Ni and = Mg solid-solution catalyst, preferably the RWGS catalyst comprises Ni2Mg. In an v embodiment, the RWGS catalyst further comprises at least one support, preferably the

I support is a silica support. In an embodiment, the catalyst comprises Cu impregnated on a support, wherein the support is selected from Al>O3-ZrO> and Al2O3-CeO>.

In an embodiment, the RWGS catalyst is an impregnated, metal-coated spinel comprising about 2 - 25 wt-% of magnesium. In an embodiment, the RWGS catalyst comprises about 2 - 20 wt-% nickel from the total weight of a silica support. In an embodiment, the RWGS catalyst further comprises 0.1 - 5 wt-% of cerium, ruthenium, lanthanum, platinum or rhenium, from the total weight of the impregnated, metal-coated spinel.

In an embodiment, nickel and magnesium as RWGS reaction catalysts are beneficial as these are specific RWGS catalysts, thereby suppressing CO. methanation. In an embodiment, nickel and magnesium as RWGS reaction catalysts are also beneficial as they are low-cost catalyst.

In an embodiment, the RWGS is performed at a low temperature, from 300 °C to 600 °C, at a pressure range of 100-5000 kPa, using a catalyst comprising Cu impregnated on a support, wherein the support is selected from mixed phases oxides, Al>O3-ZrO> or Al,O3-

CeO,.

In an embodiment, in the RWGS reaction, the feed comprising CO2 and Ha is passed into a catalytic reaction where a single pass conversion of CO, may be suitably controlled. With — the term “single pass conversion” is here meant the conversion of CO; to give another compound during the RWGS reactions in a single pass through a RWGS reaction zone.

The RWGS conversion of the RWGS reaction is an adjustable process parameter which can be adjusted by modifying one or more of the operating conditions of the process step in question, selected from availability of H> and CO, temperature, pressure, and combinations thereof.

In an embodiment, it is preferred to recycle the unconverted CO, from the RWGS reaction step. In an embodiment, the total conversion and selectivity are improved by efficient recycling of the CO.. In an embodiment, the efficient recycling of the CO. requires the adjustment of the RWGS reaction conditions to values preventing undesired side reactions < 25 and thereby avoiding most unspecific by-products such as methane and carbon. In an

S embodiment, it is preferred to remove water from the RWGS reaction product prior to

Od providing the RWGS reaction product to e.g. the isosynthesis reaction. s In an embodiment, the carbon dioxide recovered from step v is, at least partly, recycled to

E step ii, or to step iii through a reverse water gas shift reaction to form carbon monoxide from

LO 30 — the carbon dioxide.

O In an embodiment, the reverse water gas shift reaction is performed at a temperature from

O 500 to 1050 *C, at a pressure of 1500 kPa or less, using a solid RWGS metal or metal oxide catalyst comprising nickel (Ni), magnesium (Mg), copper (Cu), or combinations thereof.

In an exemplary embodiment of the process of the present disclosure, as depicted in figure 1, carbon dioxide gas 1 and hydrogen gas 2 are directed to a reaction chamber 100 and reacted into a mixture of methanol and water. Subsequently, the formed methanol 3 is recovered from this mixture, and the formed water 4 is directed into further use elsewhere.

The recovered methanol 3 is directed into an alkylation unit 200, wherein it is reacted into acetic acid by carbonylation with carbon monoxide 5. The formed acetic acid 6 is recovered and directed from the alkylation unit 200 into a thermochemical conversion unit 300, wherein the acetic acid is catalytically converted, preferably using a Zn,Zr,O, catalyst in a fixed bed reactor, directly into isobutene 7, preferably with 50 wt.-% yield, and the conversion reaction — further producing water 8 and carbon dioxide 9, and possibly some intermediate product acetone and unreacted acetic acid, as well. The recovered isobutene 7 is directed to oligomerization in an oligomerization unit 400 for production of oligomers 10, such as dimers, trimers and/or tetramers. The oligomerized product 10 is subseguently hydrogenated in a hydrogenation unit 500 to form paraffinic hydrocarbons 11 suitable for — use as jet fuel components. The carbon dioxide formed in the thermochemical conversion unit 300 may be recycled upstream either to methanol formation in the reaction chamber 100, or to alkylation unit 200 via a reverse water gas shift reaction in a unit 600 to form a recycled carbon monoxide stream 5', to enhance the carbon efficiency of the processing schema. <t

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Claims (19)

1.A process for producing a jet fuel component, comprising the steps of i. providing carbon dioxide gas and hydrogen gas;

ii. reacting the carbon dioxide gas and the hydrogen gas into methanol and water, and subsequently recovering the formed methanol;

lii. reacting the recovered methanol into acetic acid through alkylation, preferably by carbonylation with carbon monoxide, and subsequently recovering the formed acetic acid;

iv. subjecting the formed acetic acid to thermochemical conversion for the formation of isobutene, water and carbon dioxide in the presence of a catalyst;

v. separating and recovering the formed isobutene and carbon dioxide;

vi. recycling at least part of the recovered carbon dioxide from step v by e. directing the recovered carbon dioxide to step ii, and/or f. subjecting the recovered carbon dioxide to a reverse water gas shift reaction to form carbon monoxide and directing the formed carbon monoxide to step iii, and vii. directing at least part of the recovered isobutene from step v to oligomerization, and to subsequent hydrogenation for producing a jet fuel component.

N

2.The process of claim 1, wherein the jet fuel component is an e-jet fuel component. N 25

3.The process of claim 1 or 2, wherein the jet fuel component has carbon numbers 2 ranging from C8 to C16. <t

—

4.The process of any one of claims 1-3, wherein the carbon dioxide gas is obtained E from captured carbon dioxide. LO

5.The process of any one of claims 1-4, wherein the hydrogen gas is generated by 2 30 sustainable electricity sources, such as water electrolysis using wind, solar, wave, + O tidal or nuclear power.

6. The process of any one of claims 1-5, wherein the reacting of the hydrogen gas and the carbon dioxide gas with each other takes place at a temperature from 150 to 300° C, and at a pressure from 1 to 10 MPa, in the presence of a catalyst comprising

Cu, Zn and Al, providing a reaction mixture comprising methanol, such as methanol and methane.

7.The process of any one of claims 1-6, wherein the alkylation comprises a reaction of methanol with carbon monoxide in the presence of a rhodium or iridium catalyst, and is performed at a pressure from 3000 to 6000 kPa, and at a temperature from 150 to 200°C.

8. The process of any one of claims 1-7, wherein the thermochemical conversion in step iv comprises the use of a Zr,Zn,O, mixed oxide catalyst with x:y ratio from 0.03-1.00, such as 0.08-0.42, even about 0.20-0.30, is used in the thermochemical conversion.

9. The process of any one of the claims 1-8, wherein the thermochemical conversion in step iv takes place in a gaseous phase by vaporizing an aqueous acetic acid solution and bringing the vapour into contact with the Zr,ZnyO; catalyst.

10. The process of any one of claims 1-9, wherein the formation of isobutene in step iv further comprises formation of acetic acid, acetone, methane and CO..

11. The process of any one of claims 1-10, wherein the reverse water gas shift reaction is performed at a temperature from 300 to 1050 °C, at a pressure of 5000 kPa or less, using a solid RWGS metal or metal oxide catalyst comprising nickel (Ni), magnesium (Mg), copper (Cu), or combinations thereof.

12. The process of any one of claims 1-11, wherein the oligomerization in step vii is carried out in the presence of an oligomerization catalyst, and at a temperature from 30 to 140 °C, preferably from 45 to 110 °C; and at a pressure from 15 to 5000 kPa, preferably from 800 to 5000 kPa, using an acidic oligomerization catalyst, preferably a strongly acidic ion exchange resin catalyst, more preferably a macroreticular acid ion exchange resin catalyst.

13. The process of any one of claims 1-12, wherein the hydrogenation in step vii is carried out at a Ha feed ratio of 1-2 mol H2/ mol of feed, at a temperature of 120 - N 200 *C and at a pressure of 1000 - 20000 kPa, using at least one supported Pt, Pd, N and/or Ni catalyst on a support selected from zeolite, silica, alumina and ASA. =

14. The process of any one of claims 1-13, wherein the isobutene recovered in step v is A 30 subjected at least partly to oligomerization, whereby the obtained isobutene product E contains at least trimers of isobutene and/or tetramers of isobutene, and wherein O the hydrocarbons of the oligomerized product have a carbon number in the range of O C8 -C16. O

15. The process of claim 14, wherein the trimers and/or tetramers having carbon numbers in the range of C8 — C16 are hydrogenated under hydrogenation conditions to obtain the jet fuel component.

16. Use of the jet fuel component manufactured by the process of any one of the claims

1-15, for manufacturing a jet fuel composition according to the requirements as set out in ASTM D7566-22.

17. Use of the jet fuel component manufactured by the process of any one of the claims 1-15 for increasing the renewable content of a jet fuel composition.

18. Use of the jet fuel component manufactured by the process of any one of the claims 1-15 for decreasing the GHG emissions of a jet fuel composition.

19. Use of the jet fuel component manufactured by the process of any one of the claims 1-15 in a jet fuel composition for reducing the GHG emissions at least 50 percent, such as at least 70 percent, or even such as at least 90 percent, by gC02eg/MJ calculated according to the EU Renewable Energy Directive 2009/28/EC. i N O N © ? <t I [an a LO O O + N O N